WorldWideScience

Sample records for intermediate mass nuclei

  1. X-Ray Emission from Active Galactic Nuclei with Intermediate-Mass Black Holes

    Science.gov (United States)

    Dewangan, G. C.; Mathur, S.; Griffiths, R. E.; Rao, A. R.

    2008-12-01

    We present a systematic X-ray study of eight active galactic nuclei (AGNs) with intermediate-mass black holes (MBH ~ 8-95 × 104 M⊙) based on 12 XMM-Newton observations. The sample includes the two prototype AGNs in this class—NGC 4395 and POX 52 and six other AGNs discovered with the Sloan Digitized Sky Survey. These AGNs show some of the strongest X-ray variability, with the normalized excess variances being the largest and the power density break timescales being the shortest observed among radio-quiet AGNs. The excess-variance-luminosity correlation appears to depend on both the BH mass and the Eddington luminosity ratio. The break timescale-black hole mass relations for AGN with IMBHs are consistent with that observed for massive AGNs. We find that the FWHM of the Hβ/Hα line is uncorrelated with the BH mass, but shows strong anticorrelation with the Eddington luminosity ratio. Four AGNs show clear evidence for soft X-ray excess emission (kTin ~ 150-200 eV). X-ray spectra of three other AGNs are consistent with the presence of the soft excess emission. NGC 4395 with lowest L/LEdd lacks the soft excess emission. Evidently small black mass is not the primary driver of strong soft X-ray excess emission from AGNs. The X-ray spectral properties and optical-to-X-ray spectral energy distributions of these AGNs are similar to those of Seyfert 1 galaxies. The observed X-ray/UV properties of AGNs with IMBHs are consistent with these AGNs being low-mass extensions of more massive AGNs, those with high Eddington luminosity ratio looking more like narrow-line Seyfert 1 s and those with low L/LEdd looking more like broad-line Seyfert 1 galaxies.

  2. Ab initio results for intermediate-mass, open-shell nuclei

    Science.gov (United States)

    Baker, Robert B.; Dytrych, Tomas; Launey, Kristina D.; Draayer, Jerry P.

    2017-01-01

    A theoretical understanding of nuclei in the intermediate-mass region is vital to astrophysical models, especially for nucleosynthesis. Here, we employ the ab initio symmetry-adapted no-core shell model (SA-NCSM) in an effort to push first-principle calculations across the sd-shell region. The ab initio SA-NCSM's advantages come from its ability to control the growth of model spaces by including only physically relevant subspaces, which allows us to explore ultra-large model spaces beyond the reach of other methods. We report on calculations for 19Ne and 20Ne up through 13 harmonic oscillator shells using realistic interactions and discuss the underlying structure as well as implications for various astrophysical reactions. This work was supported by the U.S. NSF (OCI-0904874 and ACI -1516338) and the U.S. DOE (DE-SC0005248), and also benefitted from the Blue Waters sustained-petascale computing project and high performance computing resources provided by LSU.

  3. Regional regularities for the even-even nuclei in intermediate mass region

    International Nuclear Information System (INIS)

    Varshney, Mani; Singh, M.; Gupta, D.K.; Singh, Yuvraj; Gupta, K.K.; Bihari, Chhail; Sharma, Aparna; Varshney, A.K.

    2011-01-01

    With the development of experimental techniques more and more nuclear data are accumulated and compiled for over five decades. The proton neutron interaction has been considered the key ingredient in the development of collectivity and ultimately the deformation in atomic nuclei. The purpose of the present study is to analyze the growth of R4/2 in different mass regions. The rate of growth regions in regions having proton number Z = 38, 54, 60 and 76 with changing neutron number where the interaction between particle - particle, particle - hole and hole - hole

  4. Fission of intermediate mass nuclei by bremsstrahlung photons in the energy range 0.8-1.8 GeV

    International Nuclear Information System (INIS)

    Lima, D.A. de.

    1983-01-01

    The fission of intermediate mass nuclei in the Al-Ta internal induced by bremsstrahlung photons of maximum energies between 0,8 to 1,8 GeV is studied. Thin targets of Nd and Sm and dense targets of Al,Ti,Co,Zr,Nb,Ag,In and Ta are utilized, and all the aspects related with the fission fragment absorption by the targets themselves are considered. The samples are exposed in th 2,5 GeV Electron Synchrotron at Bonn University. Muscovite mica, CR-39 and makrofol are used as fission fragments detectors. Fission cross sections and nuclear fissionabilities of the studied elements are estimated. (L.C.) [pt

  5. Modified viscosity in accretion disks. Application to Galactic black hole binaries, intermediate mass black holes, and active galactic nuclei

    Science.gov (United States)

    Grzędzielski, Mikołaj; Janiuk, Agnieszka; Czerny, Bożena; Wu, Qingwen

    2017-07-01

    Aims: Black holes (BHs) surrounded by accretion disks are present in the Universe at different scales of masses, from microquasars up to the active galactic nuclei (AGNs). Since the work of Shakura & Sunyaev (1973, A&A, 24, 337) and their α-disk model, various prescriptions for the heat-production rate are used to describe the accretion process. The current picture remains ad hoc due the complexity of the magnetic field action. In addition, accretion disks at high Eddington rates can be radiation-pressure dominated and, according to some of the heating prescriptions, thermally unstable. The observational verification of their resulting variability patterns may shed light on both the role of radiation pressure and magnetic fields in the accretion process. Methods: We compute the structure and time evolution of an accretion disk, using the code GLADIS (which models the global accretion disk instability). We supplement this model with a modified viscosity prescription, which can to some extent describe the magnetisation of the disk. We study the results for a large grid of models, to cover the whole parameter space, and we derive conclusions separately for different scales of black hole masses, which are characteristic for various types of cosmic sources. We show the dependencies between the flare or outburst duration, its amplitude, and period, on the accretion rate and viscosity scaling. Results: We present the results for the three grids of models, designed for different black hole systems (X-ray binaries, intermediate mass black holes, and galaxy centres). We show that if the heating rate in the accretion disk grows more rapidly with the total pressure and temperature, the instability results in longer and sharper flares. In general, we confirm that the disks around the supermassive black holes are more radiation-pressure dominated and present relatively brighter bursts. Our method can also be used as an independent tool for the black hole mass determination

  6. CHARACTERIZATION OF A SAMPLE OF INTERMEDIATE-TYPE ACTIVE GALACTIC NUCLEI. II. HOST BULGE PROPERTIES AND BLACK HOLE MASS ESTIMATES

    Energy Technology Data Exchange (ETDEWEB)

    Benitez, Erika; Cruz-Gonzalez, Irene; Martinez, Benoni; Jimenez-Bailon, Elena [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apdo. Postal 70-264, Mexico D.F. 04510 (Mexico); Mendez-Abreu, Jairo; Lopez-Martin, Luis [Instituto de Astrofisica de Canarias, E-38200 La Laguna, Tenerife (Spain); Fuentes-Carrera, Isaura [Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional (ESFM-IPN), U.P. Adolfo Lopez Mateos, Mexico D.F. 07730 (Mexico); Chavushyan, Vahram [Instituto Nacional de Astrofisica, Optica y Electronica, Apdo. Postal 51-216, 72000 Puebla (Mexico); Leon-Tavares, Jonathan, E-mail: erika@astro.unam.mx [Aalto University Metsaehovi Radio Observatory, Metsaehovintie 114, 02540 Kylmaelae (Finland)

    2013-02-15

    We present a study of the host bulge properties and their relations with the black hole mass for a sample of 10 intermediate-type active galactic nuclei (AGNs). Our sample consists mainly of early-type spirals, four of them hosting a bar. For 70{sup +10} {sub -17}% of the galaxies, we have been able to determine the type of the bulge, and find that these objects probably harbor a pseudobulge or a combination of classical bulge/pseudobulge, suggesting that pseudobulges might be frequent in intermediate-type AGNs. In our sample, 50% {+-} 14% of the objects show double-peaked emission lines. Therefore, narrow double-peaked emission lines seem to be frequent in galaxies harboring a pseudobulge or a combination of classical bulge/pseudobulge. Depending on the bulge type, we estimated the black hole mass using the corresponding M {sub BH}-{sigma}* relation and found them within a range of 5.69 {+-} 0.21 < log M {sup {sigma}}*{sub BH} < 8.09 {+-} 0.24. Comparing these M {sup {sigma}}*{sub BH} values with masses derived from the FWHM of H{beta} and the continuum luminosity at 5100 A from their SDSS-DR7 spectra (M {sub BH}), we find that 8 out of 10 (80{sup +7} {sub -17}%) galaxies have black hole masses that are compatible within a factor of 3. This result would support that M {sub BH} and M {sup {sigma}}*{sub BH} are the same for intermediate-type AGNs, as has been found for type 1 AGNs. However, when the type of the bulge is taken into account, only three out of the seven (43{sup +18} {sub -15}%) objects of the sample have their M {sup {sigma}}*{sub BH} and M {sub BH} compatible within 3{sigma} errors. We also find that estimations based on the M {sub BH}-{sigma}* relation for pseudobulges are not compatible in 50% {+-} 20% of the objects.

  7. Proton drip-line nuclei studied at intermediate energies

    International Nuclear Information System (INIS)

    Blank, B.

    2001-01-01

    In experiments at the SISSI/LISE3 facility of GANIL, the doubly-magic nucleus 48 Ni has been observed for the first time and decay information was gained for very proton-rich nuclei like 42 Cr, 45 Fe, and 49 Ni, as 48 Ni possible candidates for two-proton radioactivity. In the lighter-mass region, detailed studies of 21 Mg and 25 Si were performed and complete decay schemes for allowed decays were established

  8. Intermediate structures in alpha scattering on 28Si nuclei

    International Nuclear Information System (INIS)

    Kamys, B.; Bobrovska, A.; Budzanovski, A. et al.

    1975-01-01

    Excitation functions and angular distributions of α-particles scattering on 28 Si nuclei, measured by various authors, are analyzed. Theoretical processing of results is divided into two stages: statistical analysis and analysis in terms of the Regge pole model (RPM). The aim of the statistical analysis is to demonstrate that the structure of excitation curves contains resonance effects. RMP with non-resonance background, described by the optical model (OM), is used to obtain data on properties of intermediate resonances. Autocorrelation functions for one elastic and two inelastic scattering channels are calculated. The mean width of compound states is about 100keV, which is in a good agreement with results of other authores. An analysis of correlation coefficients calculated for all pairs of excitation curves for elastic and two inelastic channels points to the existence of intermediate resonances in each of investigated reaction channels. In the case of large-angle scattering the contribution of potential interaction into the total cross-section is 20-30%, and that of resonance scattering is 50-60%. Energy dependence of Regge pole parameters has also been studied to obtain data on the existence and properties of intermediate resonances

  9. Mechanism for the Suppression of Intermediate-Mass Black Holes

    OpenAIRE

    Dokuchaev, V. I.; Eroshenko, Yu. N.; Rubin, S. G.; Samarchenko, D. A.

    2010-01-01

    A model for the formation of supermassive primordial black holes in galactic nuclei with the simultaneous suppression of the formation of intermediate-mass black holes is presented. A bimodal mass function for black holes formed through phase transitions in a model with a "Mexican hat" potential has been found. The classical motion of the phase of a complex scalar field during inflation has been taken into account. Possible observational manifestations of primordial black holes in galaxies an...

  10. Compound nuclei, binary decay, and multifragmentation in intermediate-energy heavy-ion reactions

    International Nuclear Information System (INIS)

    Moretto, L.G.; Wozniak, G.J.

    1988-07-01

    Hot compound nuclei, frequently produced in intermediate-energy reactions through a variety of processes, are shown to be an important and at times dominant source of complex fragments. 13 refs., 12 figs

  11. Role of compound nuclei in intermediate-energy heavy-ion reactions

    International Nuclear Information System (INIS)

    Moretto, L.G.; Wozniak, G.J.

    1988-05-01

    Hot compound nuclei are frequently produced in intermediate-energy reactions through a variety of processes. Their decay is shown to be an important and at times dominant source of complex fragments, high energy-gamma rays, and even pions

  12. Mass Measurements of Proton-rich Nuclei with JYFLTRAP

    OpenAIRE

    Eronen, Tommi

    2011-01-01

    The Penning trap setup JYFLTRAP, connected to the IGISOL facility, has been extensively used for atomic mass measurements of exotic nuclei. On the proton rich side of the chart of nuclei mass measurements have mostly contributed to fundamental physics and nuclear astrophysics studies with about 100 atomic masses measured.

  13. Researchers Resolve Intermediate Mass Black Hole Mystery

    Science.gov (United States)

    2004-04-01

    New research, funded by the Royal Netherlands Academy of Sciences, the Institute of Advanced Physical and Chemical Research, NASA and the University of Tokyo, solved the mystery of how a black hole, with the mass more than several hundreds times larger than that of our Sun, could be formed in the nearby starburst galaxy, M82. Recent observations of the Chandra X-ray observatory (Matsumoto et al., 2001 ApJ 547, L25) indicate the presence of an unusually bright source in the star cluster MGG11 in the starburst galaxy M82. The properties of the X-ray source are best explained by a black hole with a mass of about a thousand times the mass of the Sun, placing it intermediate between the relatively small (stellar mass) black holes in the Milky way Galaxy and the supermassive black holes found in the nuclei of galaxies. For comparison, stellar-mass black holes are only a few times more massive than the Sun, whereas the black hole in the center of the Milky-way Galaxy is more than a few million times more massive than the Sun. An international team of researchers, using the world's fastest computer, the GRAPE-6 system in Japan, were engaged in a series of simulations of star clusters that resembled MGG11. They used the GRAPE-6 to perform simulations with two independently developed computer programs (Starlab and NBODY4 developed by Sverre Aarseth in Cambridge), both of which give the same qualitative result. The simulations ware initiated by high resolution observations of the star cluster MGG11 by McCrady et al (2003, ApJ 596, 240) using the Hubble Space Telescope and Keck, and by Harashima et al (2001) using the giant Subaru telescope. M82 Chandra X-ray image of the central region of the starburst galaxy M82. The GRAPE's detailed, star-by-star simulations represent the state of the art in cluster modeling. For the first time using the GRAPE, researchers perform simulations of the evolution of young and dense star clusters with up to 600000 stars; they calculate the

  14. MCNP6 Simulation of Light and Medium Nuclei Fragmentation at Intermediate Energies

    Energy Technology Data Exchange (ETDEWEB)

    Mashnik, Stepan Georgievich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kerby, Leslie Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Idaho, Moscow, ID (United States)

    2015-08-24

    Fragmentation reactions induced on light and medium nuclei by protons and light nuclei of energies around 1 GeV/nucleon and below are studied with the Los Alamos transport code MCNP6 and with its CEM03.03 and LAQGSM03.03 event generators. CEM and LAQGSM assume that intermediate-energy fragmentation reactions on light nuclei occur generally in two stages. The first stage is the intranuclear cascade (INC), followed by the second, Fermi breakup disintegration of light excited residual nuclei produced after the INC. CEM and LAQGSM account also for coalescence of light fragments (complex particles) up to sup>4He from energetic nucleons emitted during INC. We investigate the validity and performance of MCNP6, CEM, and LAQGSM in simulating fragmentation reactions at intermediate energies and discuss possible ways of further improving these codes.

  15. Study of halo nuclei breakup on light targets at intermediate and high energies

    CERN Document Server

    Parfenova, Ioulia

    2002-01-01

    The study of exotic nuclei is one of the most important topics in modern nuclear physics. It allows general understanding of the structure and nature of light nuclear systems in the vicinity of the driplines. Most of the leading facilities in the world, CERN, GANIL, GSI in Europe, RIKEN in Japan, and NSCL(MSU) in USA, are involved in these investigations. Recently, new experimental data on the properties of light halo nuclei such as extremely large interaction cross sections, huge electromagnetic dissociation cross sections, narrow momentum distribution of fragments from breakup reactions, unusual modes of the beta-decay of these nuclei on the borders of the stability, were obtained. This Thesis is based on a series of articles devoted to theoretical investigations of nuclear breakup reactions with light halo nuclei at intermediate energies impinging on light target nuclei. Special attention is paid to the question of sensitivity of the calculated breakup cross sections and longitudinal momentum distributions...

  16. 4th International Conference on Exotic Nuclei and Atomic Masses

    CERN Document Server

    Gross, Carl J; Rykaczewski, Krzysztof P; The European Physical Journal A : Volume 25, Supplement 1, 2005

    2005-01-01

    The International Conference on Exotic Nuclei and Atomic Masses (ENAM) has gained the status of the premier meeting for the physics of nuclei far from stability. The selected and refereed papers presenting the main results constitute valuable proceedings that offer everyone working in this field an authoritative and comprehensive source of reference.

  17. Deformation and shape coexistence in medium mass nuclei

    International Nuclear Information System (INIS)

    Meyer, R.A.

    1985-01-01

    Emerging evidence for deformed structures in medium mass nuclei is reviewed. Included in this review are both nuclei that are ground state symmetric rotors and vibrational nuclei where there are deformed structures at excited energies (shape coexistence). For the first time, Nilsson configurations in odd-odd nuclei within the region of deformation are identified. Shape coexistence in nuclei that abut the medium mass region of deformation is also examined. Recent establishment of a four-particle, four-hole intruder band in the double subshell closure nucleus 96 Zr 56 is presented and its relation to the nuclear vibron model is discussed. Special attention is given to the N=59 nuclei where new data have led to the reanalysis of 97 Sr and 99 Zr and the presence of the [404 9/2] hole intruder state as isomers in these nuclei. The low energy levels of the N=59 nuclei from Z=38 to 50 are compared with recent quadrupole-phonon model calculations that can describe their transition from near-rotational to single closed shell nuclei. The odd-odd N=59 nuclei are discussed in the context of coexisting shape isomers based on the (p[303 5/2]n[404 9/2])2 - configuration. Ongoing in-beam (t,p conversion-electron) multiparameter measurements that have led to the determination of monopole matrix elements for even-even 42 Mo nuclei are presented, and these are compared with initial estimates using IBA-2 calculations that allow mixing of normal and cross subshell excitations. Lastly, evidence for the neutron-proton 3 S 1 force's influence on the level structure of these nuclei is discussed within the context of recent quadrupole-phonon model calculations. (Auth.)

  18. Precision measurement of the mass difference between light nuclei and anti-nuclei

    CERN Document Server

    Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahmed, Ijaz; Ahn, Sang Un; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Alam, Sk Noor; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Ball, Markus; Baltasar Dos Santos Pedrosa, Fernando; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Bartke, Jerzy Gustaw; Bartsch, Esther; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batista Camejo, Arianna; Batyunya, Boris; Batzing, Paul Christoph; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bello Martinez, Hector; Bellwied, Rene; Belmont Iii, Ronald John; Belmont Moreno, Ernesto; Belyaev, Vladimir; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhat, Inayat Rasool; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Biswas, Saikat; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Borri, Marcello; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boettger, Stefan; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Brucken, Erik Jens; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Buxton, Jesse Thomas; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calero Diaz, Liliet; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Carena, Francesco; Carena, Wisla; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Chartier, Marielle; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chelnokov, Volodymyr; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Chochula, Peter; Choi, Kyungeon; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortes Maldonado, Ismael; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; Deisting, Alexander; Deloff, Andrzej; Denes, Ervin Sandor; D'Erasmo, Ginevra; Di Bari, Domenico; Di Mauro, Antonio; Di Nezza, Pasquale; Diaz Corchero, Miguel Angel; Dietel, Thomas; Dillenseger, Pascal; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dupieux, Pascal; Ehlers Iii, Raymond James; Elia, Domenico; Engel, Heiko; Erazmus, Barbara Ewa; Erhardt, Filip; Eschweiler, Dominic; Espagnon, Bruno; Estienne, Magali Danielle; Esumi, Shinichi; Evans, David; Evdokimov, Sergey; Eyyubova, Gyulnara; Fabbietti, Laura; Fabris, Daniela; Faivre, Julien; Fantoni, Alessandra; Fasel, Markus; Feldkamp, Linus; Felea, Daniel; Feliciello, Alessandro; Feofilov, Grigorii; Ferencei, Jozef; Fernandez Tellez, Arturo; Gonzalez Ferreiro, Elena; Ferretti, Alessandro; Festanti, Andrea; Figiel, Jan; Araujo Silva Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Fleck, Martin Gabriel; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Furs, Artur; Fusco Girard, Mario; Gaardhoeje, Jens Joergen; Gagliardi, Martino; Gago Medina, Alberto Martin; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Gao, Chaosong; Garabatos Cuadrado, Jose; Garcia-Solis, Edmundo Javier; Gargiulo, Corrado; Gasik, Piotr Jan; Germain, Marie; Gheata, Andrei George; Gheata, Mihaela; Ghosh, Premomoy; Ghosh, Sanjay Kumar; Gianotti, Paola; Giubellino, Paolo; Giubilato, Piero; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez Ramirez, Andres; Gonzalez Zamora, Pedro; Gorbunov, Sergey; Gorlich, Lidia Maria; Gotovac, Sven; Grabski, Varlen; Graczykowski, Lukasz Kamil; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoryev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grynyov, Borys; Grion, Nevio; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerzoni, Barbara; Gulbrandsen, Kristjan Herlache; Gulkanyan, Hrant; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Haake, Rudiger; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Hanratty, Luke David; Hansen, Alexander; Harris, John William; Hartmann, Helvi; Harton, Austin Vincent; Hatzifotiadou, Despina; Hayashi, Shinichi; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hilden, Timo Eero; Hillemanns, Hartmut; Hippolyte, Boris; Hristov, Peter Zahariev; Huang, Meidana; Humanic, Thomas; Hussain, Nur; Hussain, Tahir; Hutter, Dirk; Hwang, Dae Sung; Ilkaev, Radiy; Ilkiv, Iryna; Inaba, Motoi; Ionita, Costin; Ippolitov, Mikhail; Irfan, Muhammad; Ivanov, Marian; Ivanov, Vladimir; Izucheev, Vladimir; Jacobs, Peter Martin; Jahnke, Cristiane; Jang, Haeng Jin; Janik, Malgorzata Anna; Pahula Hewage, Sandun; Jena, Chitrasen; Jena, Satyajit; Jimenez Bustamante, Raul Tonatiuh; Jones, Peter Graham; Jung, Hyungtaik; Jusko, Anton; Kalinak, Peter; Kalweit, Alexander Philipp; Kamin, Jason Adrian; Kang, Ju Hwan; Kaplin, Vladimir; Kar, Somnath; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karpechev, Evgeny; Kebschull, Udo Wolfgang; Keidel, Ralf; Keijdener, Darius Laurens; Keil, Markus; Khan, Kamal; Khan, Mohammed Mohisin; Khan, Palash; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Beomkyu; Kim, Do Won; Kim, Dong Jo; Kim, Hyeonjoong; Kim, Jinsook; Kim, Mimae; Kim, Minwoo; Kim, Se Yong; Kim, Taesoo; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Kiss, Gabor; Klay, Jennifer Lynn; Klein, Carsten; Klein, Jochen; Klein-Boesing, Christian; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Kobayashi, Taiyo; Kobdaj, Chinorat; Kofarago, Monika; Kohler, Markus Konrad; Kollegger, Thorsten; Kolozhvari, Anatoly; Kondratev, Valerii; Kondratyeva, Natalia; Kondratyuk, Evgeny; Konevskikh, Artem; Kouzinopoulos, Charalampos; Kovalenko, Vladimir; Kowalski, Marek; Kox, Serge; Koyithatta Meethaleveedu, Greeshma; Kral, Jiri; Kralik, Ivan; Kravcakova, Adela; Krelina, Michal; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Kryshen, Evgeny; Krzewicki, Mikolaj; Kubera, Andrew Michael; Kucera, Vit; Kucheryaev, Yury; Kugathasan, Thanushan; Kuhn, Christian Claude; Kuijer, Paulus Gerardus; Kulakov, Igor; Kumar, Jitendra; Lokesh, Kumar; Kurashvili, Podist; Kurepin, Alexander; Kurepin, Alexey; Kuryakin, Alexey; Kushpil, Svetlana; Kweon, Min Jung; Kwon, Youngil; La Pointe, Sarah Louise; La Rocca, Paola; Lagana Fernandes, Caio; Lakomov, Igor; Langoy, Rune; Lara Martinez, Camilo Ernesto; Lardeux, Antoine Xavier; Lattuca, Alessandra; Laudi, Elisa; Lea, Ramona; Leardini, Lucia; Lee, Graham Richard; Lee, Seongjoo; Legrand, Iosif; Lehnert, Joerg Walter; Lemmon, Roy Crawford; Lenti, Vito; Leogrande, Emilia; Leon Monzon, Ildefonso; Leoncino, Marco; Levai, Peter; Li, Shuang; Li, Xiaomei; Lien, Jorgen Andre; Lietava, Roman; Lindal, Svein; Lindenstruth, Volker; Lippmann, Christian; Lisa, Michael Annan; Ljunggren, Hans Martin; Lodato, Davide Francesco; Lonne, Per-Ivar; Loggins, Vera Renee; Loginov, Vitaly; Loizides, Constantinos; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lowe, Andrew John; Lu, Xianguo; Luettig, Philipp Johannes; Lunardon, Marcello; Luparello, Grazia; Maevskaya, Alla; Mager, Magnus; Mahajan, Sanjay; Mahmood, Sohail Musa; Maire, Antonin; Majka, Richard Daniel; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Liudmila; Mal'Kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Manceau, Loic Henri Antoine; Manko, Vladislav; Manso, Franck; Manzari, Vito; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Margutti, Jacopo; Marin, Ana Maria; Markert, Christina; Marquard, Marco; Martashvili, Irakli; Martin, Nicole Alice; Martin Blanco, Javier; Martinengo, Paolo; Martinez Hernandez, Mario Ivan; Martinez-Garcia, Gines; Martinez Pedreira, Miguel; Martynov, Yevgen; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Massacrier, Laure Marie; Mastroserio, Annalisa; Matyja, Adam Tomasz; Mayer, Christoph; Mazer, Joel Anthony; Mazzoni, Alessandra Maria; Mcdonald, Daniel; Meddi, Franco; Menchaca-Rocha, Arturo Alejandro; Meninno, Elisa; Mercado-Perez, Jorge; Meres, Michal; Miake, Yasuo; Mieskolainen, Matti Mikael; Mikhaylov, Konstantin; Milano, Leonardo; Milosevic, Jovan; Minervini, Lazzaro Manlio; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz Czeslaw; Mitra, Jubin; Mitu, Ciprian Mihai; Mohammadi, Naghmeh; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Montes Prado, Esther; Morando, Maurizio; Moreira De Godoy, Denise Aparecida; Moretto, Sandra; Morreale, Astrid; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhlheim, Daniel Michael; Muhuri, Sanjib; Mukherjee, Maitreyee; Muller, Hans; Mulligan, James Declan; Gameiro Munhoz, Marcelo; Murray, Sean; Musa, Luciano; Musinsky, Jan; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Naru, Muhammad Umair; Nattrass, Christine; Nayak, Kishora; Nayak, Tapan Kumar; Nazarenko, Sergey; Nedosekin, Alexander; Nellen, Lukas; Ng, Fabian; Nicassio, Maria; Niculescu, Mihai; Niedziela, Jeremi; Nielsen, Borge Svane; Nikolaev, Sergey; Nikulin, Sergey; Nikulin, Vladimir; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Norman, Jaime; Nyanin, Alexander; Nystrand, Joakim Ingemar; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Ohlson, Alice Elisabeth; Okatan, Ali; Okubo, Tsubasa; Olah, Laszlo; Oleniacz, Janusz; Oliveira Da Silva, Antonio Carlos; Oliver, Michael Henry; Onderwaater, Jacobus; Oppedisano, Chiara; Ortiz Velasquez, Antonio; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Ozdemir, Mahmut; Pachmayer, Yvonne Chiara; Pagano, Paola; Paic, Guy; Pajares Vales, Carlos; Pal, Susanta Kumar; Pan, Jinjin; Pandey, Ashutosh Kumar; Pant, Divyash; Papikyan, Vardanush; Pappalardo, Giuseppe; Pareek, Pooja; Park, Woojin; Parmar, Sonia; Passfeld, Annika; Paticchio, Vincenzo; Paul, Biswarup; Pawlak, Tomasz Jan; Peitzmann, Thomas; Pereira Da Costa, Hugo Denis Antonio; Pereira De Oliveira Filho, Elienos; Peresunko, Dmitry Yurevich; Perez Lara, Carlos Eugenio; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petrov, Viacheslav; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Pikna, Miroslav; Pillot, Philippe; Pinazza, Ombretta; Pinsky, Lawrence; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Planinic, Mirko; Pluta, Jan Marian; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polishchuk, Boris; Poljak, Nikola; Poonsawat, Wanchaloem; Pop, Amalia; Porteboeuf, Sarah Julie; Porter, R Jefferson; Pospisil, Jan; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puccio, Maximiliano; Puddu, Giovanna; Pujahari, Prabhat Ranjan; Punin, Valery; Putschke, Jorn Henning; Qvigstad, Henrik; Rachevski, Alexandre; Raha, Sibaji; Rajput, Sonia; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Razazi, Vahedeh; Read, Kenneth Francis; Real, Jean-Sebastien; Redlich, Krzysztof; Reed, Rosi Jan; Rehman, Attiq Ur; Reichelt, Patrick Simon; Reicher, Martijn; Reidt, Felix; Ren, Xiaowen; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Rettig, Felix Vincenz; Revol, Jean-Pierre; Reygers, Klaus Johannes; Riabov, Viktor; Ricci, Renato Angelo; Richert, Tuva Ora Herenui; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Ristea, Catalin-Lucian; Rivetti, Angelo; Rocco, Elena; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roeed, Ketil; Rogochaya, Elena; Rohr, David Michael; Roehrich, Dieter; Romita, Rosa; Ronchetti, Federico; Ronflette, Lucile; Rosnet, Philippe; Rossi, Andrea; Roukoutakis, Filimon; Roy, Ankhi; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Russo, Riccardo; Ryabinkin, Evgeny; Ryabov, Yury; Rybicki, Andrzej; Sadovskiy, Sergey; Safarik, Karel; Sahlmuller, Baldo; Sahoo, Pragati; Sahoo, Raghunath; Sahoo, Sarita; Sahu, Pradip Kumar; Saini, Jogender; Sakai, Shingo; Saleh, Mohammad Ahmad; Salgado Lopez, Carlos Alberto; Salzwedel, Jai Samuel Nielsen; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sanchez Castro, Xitzel; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Santagati, Gianluca; Sarkar, Debojit; Scapparone, Eugenio; Scarlassara, Fernando; Scharenberg, Rolf Paul; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schuchmann, Simone; Schukraft, Jurgen; Schulc, Martin; Schuster, Tim Robin; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Rebecca Michelle; Seeder, Karin Soraya; Seger, Janet Elizabeth; Sekiguchi, Yuko; Selyuzhenkov, Ilya; Senosi, Kgotlaesele; Seo, Jeewon; Serradilla Rodriguez, Eulogio; Sevcenco, Adrian; Shabanov, Arseniy; Shabetai, Alexandre; Shadura, Oksana; Shahoyan, Ruben; Shangaraev, Artem; Sharma, Ankita; Sharma, Natasha; Shigaki, Kenta; Shtejer Diaz, Katherin; Sibiryak, Yury; Siddhanta, Sabyasachi; Sielewicz, Krzysztof Marek; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, Catherine Micaela; Simatovic, Goran; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singha, Subhash; Singhal, Vikas; Sinha, Bikash; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Slupecki, Maciej; Smirnov, Nikolai; Snellings, Raimond; Snellman, Tomas Wilhelm; Soegaard, Carsten; Soltz, Ron Ariel; Song, Jihye; Song, Myunggeun; Song, Zixuan; Soramel, Francesca; Sorensen, Soren Pontoppidan; Spacek, Michal; Spiriti, Eleuterio; Sputowska, Iwona Anna; Spyropoulou-Stassinaki, Martha; Srivastava, Brijesh Kumar; Stachel, Johanna; Stan, Ionel; Stefanek, Grzegorz; Steinpreis, Matthew Donald; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Strmen, Peter; Alarcon Do Passo Suaide, Alexandre; Sugitate, Toru; Suire, Christophe Pierre; Suleymanov, Mais Kazim Oglu; Sultanov, Rishat; Sumbera, Michal; Symons, Timothy; Szabo, Alexander; Szanto De Toledo, Alejandro; Szarka, Imrich; Szczepankiewicz, Adam; Szymanski, Maciej Pawel; Takahashi, Jun; Tanaka, Naoto; Tangaro, Marco-Antonio; Tapia Takaki, Daniel Jesus; Tarantola Peloni, Attilio; Tariq, Mohammad; Tarzila, Madalina-Gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terasaki, Kohei; Terrevoli, Cristina; Teyssier, Boris; Thaeder, Jochen Mathias; Thomas, Deepa; Tieulent, Raphael Noel; Timmins, Anthony Robert; Toia, Alberica; Trogolo, Stefano; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vajzer, Michal; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Van Leeuwen, Marco; Vanat, Tomas; Vande Vyvre, Pierre; Varga, Dezso; Diozcora Vargas Trevino, Aurora; Vargyas, Marton; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vauthier, Astrid; Vechernin, Vladimir; Veen, Annelies Marianne; Veldhoen, Misha; Velure, Arild; Venaruzzo, Massimo; Vercellin, Ermanno; Vergara Limon, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viesti, Giuseppe; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Vinogradov, Alexander; Vinogradov, Leonid; Vinogradov, Yury; Virgili, Tiziano; Vislavicius, Vytautas; Viyogi, Yogendra; Vodopyanov, Alexander; Volkl, Martin Andreas; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; Von Haller, Barthelemy; Vorobyev, Ivan; Vranic, Danilo; Vrlakova, Janka; Vulpescu, Bogdan; Vyushin, Alexey; Wagner, Boris; Wagner, Jan; Wang, Hongkai; Wang, Mengliang; Wang, Yifei; Watanabe, Daisuke; Weber, Michael; Weber, Steffen Georg; Wessels, Johannes Peter; Westerhoff, Uwe; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Williams, Crispin; Windelband, Bernd Stefan; Winn, Michael Andreas; Yaldo, Chris G; Yamaguchi, Yorito; Yang, Hongyan; Yang, Ping; Yano, Satoshi; Yasnopolskiy, Stanislav; Yin, Zhongbao; Yokoyama, Hiroki; Yoo, In-Kwon; Yurchenko, Volodymyr; Yushmanov, Igor; Zaborowska, Anna; Zaccolo, Valentina; Zaman, Ali; Zampolli, Chiara; Correia Zanoli, Henrique Jose; Zaporozhets, Sergey; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhang, Yonghong; Zhao, Chengxin; Zhigareva, Natalia; Zhou, Daicui; Zhou, You; Zhou, Zhuo; Zhu, Hongsheng; Zhu, Jianhui; Zhu, Xiangrong; Zichichi, Antonino; Zimmermann, Alice; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zyzak, Maksym

    2015-08-17

    The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. This force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons (d) and anti-deuterons ($\\bar{d}$), and $^{3}{\\rm He}$ and $^3\\overline{\\rm He}$ nuclei carried out with the ALICE (A Large Ion Collider Experiment) detector in Pb-Pb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Our direct measurement of the mass-over-charge differences confirm CPT invariance to an unprecedented precision in the sector of light nuclei. This funda...

  19. Structure of light mass (exotic) nuclei as evidenced by scattering from hydrogen

    International Nuclear Information System (INIS)

    Amos, K.; Dortmans, P.J.

    1998-01-01

    Microscopic optical model potentials generated by full folding of realistic two-nucleon (n/N) interactions with nuclear structure specified by large basis shell model calculations have been constructed. With those (nonlocal) optical potentials, predictions of light mass nuclei-hydrogen scattering were obtained at intermediate energies (65 to 800 MeV) that agree well with observations of cross sections and analyzing powers

  20. Neutrino mass as the probe of intermediate mass scales

    Energy Technology Data Exchange (ETDEWEB)

    Senjanovic, G.

    1980-01-01

    A discussion of the calculability of neutrino mass is presented. The possibility of neutrinos being either Dirac or Majorana particles is analyzed in detail. Arguments are offered in favor of the Majorana case: the smallness of neutrino mass is linked to the maximality of parity violation in weak interactions. It is shown how the measured value of neutrino mass would probe the existence of an intermediate mass scale, presumably in the TeV region, at which parity is supposed to become a good symmetry. Experimental consequences of the proposed scheme are discussed, in particular the neutrino-less double ..beta.. decay, where observation would provide a crucial test of the model, and rare muon decays such as ..mu.. ..-->.. e..gamma.. and ..mu.. ..-->.. ee anti e. Finally, the embedding of this model in an O(10) grand unified theory is analyzed, with the emphasis on the implications for intermediate mass scales that it offers. It is concluded that the proposed scheme provides a distinct and testable alternative for understanding the smallness of neutrino mass. 4 figures.

  1. Precise mass measurements of exotic nuclei--the SHIPTRAP Penning trap mass spectrometer

    International Nuclear Information System (INIS)

    Herfurth, F.; Ackermann, D.; Block, M.; Dworschak, M.; Eliseev, S.; Hessberger, F.; Hofmann, S.; Kluge, H.-J.; Maero, G.; Martin, A.; Mazzocco, M.; Rauth, C.; Vorobjev, G.; Blaum, K.; Ferrer, R.; Neidherr, D.; Chaudhuri, A.; Marx, G.; Schweikhard, L.; Neumayr, J.

    2007-01-01

    The SHIPTRAP Penning trap mass spectrometer has been designed and constructed to measure the mass of short-lived, radioactive nuclei. The radioactive nuclei are produced in fusion-evaporation reactions and separated in flight with the velocity filter SHIP at GSI in Darmstadt. They are captured in a gas cell and transfered to a double Penning trap mass spectrometer. There, the cyclotron frequencies of the radioactive ions are determined and yield mass values with uncertainties ≥4.5·10 -8 . More than 50 nuclei have been investigated so far with the present overall efficiency of about 0.5 to 2%

  2. Initial mass function of intermediate-mass black hole seeds

    Science.gov (United States)

    Ferrara, A.; Salvadori, S.; Yue, B.; Schleicher, D.

    2014-09-01

    We study the initial mass function (IMF) and hosting halo properties of intermediate-mass black holes (IMBHs, 104-6 M⊙) formed inside metal-free, UV-illuminated atomic-cooling haloes (virial temperature Tvir ≥ 104 K) either via the direct collapse of the gas or via an intermediate supermassive star (SMS) stage. These IMBHs have been recently advocated as the seeds of the supermassive black holes observed at z ≈ 6. We achieve this goal in three steps: (a) we derive the gas accretion rate for a proto-SMS to undergo General Relativity instability and produce a direct collapse black hole (DCBH) or to enter the zero-age main sequence and later collapse into an IMBH; (b) we use merger-tree simulations to select atomic-cooling haloes in which either a DCBH or SMS can form and grow, accounting for metal enrichment and major mergers that halt the growth of the proto-SMS by gas fragmentation. We derive the properties of the hosting haloes and the mass distribution of black holes at this stage, and dub it the `birth mass function'; (c) we follow the further growth of the DCBH by accreting the leftover gas in the parent halo and compute the final IMBH mass. We consider two extreme cases in which minihaloes (Tvir populate haloes (a) of mass 7.5 < log (Mh/ M⊙) < 8, (b) in the redshift range 8 < z < 17, (c) with IMBH in the mass range 4.75 < (log M•/ M⊙) < 6.25.

  3. Production of nuclei far from the beta stability line using intermediate-energy heavy ions

    International Nuclear Information System (INIS)

    Guerreau, D.

    1986-05-01

    The production of far unstable nuclei using heavy ion accelerators in the intermediate energy domain is reviewed. The various mechanisms responsible for the production of exotic species, mainly the projectile fragmentation and transfer reactions, are discussed, and the first experimental results presented. Results can be summarized as follows: existence of 4 new isotopes 22 C, 23 N, 29 Ne, 30 Ne; indication of bound character of 71 Ni, 72 Ni; clear evidence for bound character of 23 Si, 27 S, 31 Ar, 35 Ca; indications of bound character of 43 V, 46 Mn, 47 Mn, 48 Fe, 50 Co, 52 Co, 52 Ni, 55 Cu, 56 Cu

  4. Decay properties of heavier nuclei and mass formula

    Energy Technology Data Exchange (ETDEWEB)

    Uno, Masahiro [Ministry of Education, Science and Culture, Tokyo (Japan)

    2000-03-01

    The stabilities of heavy nuclei, including super-heavy elements, are governed by alpha decay and fission. Some exotic types of decay, such as heavy cluster decay, which does not occur so frequently as to govern stability, have been also reported. The half-time estimations of various types of decay are reviewed. And the possibility of decay, mainly in case of heavy cluster decay, is discussed with Q-value obtained from mass formulae as well. Some topics concerning other types of exotic decay are presented. Recent trends in the research on mass formula are reviewed from the historical point of view, to get perspectives of future development. (Yamamoto, A.)

  5. Decay properties of heavier nuclei and mass formula

    International Nuclear Information System (INIS)

    Uno, Masahiro

    2000-01-01

    The stabilities of heavy nuclei, including super-heavy elements, are governed by alpha decay and fission. Some exotic types of decay, such as heavy cluster decay, which does not occur so frequently as to govern stability, have been also reported. The half-time estimations of various types of decay are reviewed. And the possibility of decay, mainly in case of heavy cluster decay, is discussed with Q-value obtained from mass formulae as well. Some topics concerning other types of exotic decay are presented. Recent trends in the research on mass formula are reviewed from the historical point of view, to get perspectives of future development. (Yamamoto, A.)

  6. Intermediate mass fragments emission in binary fragmentation model

    International Nuclear Information System (INIS)

    Bhattacharya, C.; Bhattacharya, S.

    1991-01-01

    Intermediate mass fragments emission in intermediate-energy nucleus-nucleus collisions has been studied in the framework of a generalized model where the fragments are assumed to be emitted from binary fissionlike decay of the fully equilibrated compound nucleus. The present formulation, with a schematic exit channel shape configuration and simple rotating liquid-drop nuclear potential, has been found to explain most of the intermediate mass fragments emission cross sections reasonably well without incorporating any free parameters in the calculation

  7. Mass Measurement of Very Short Half-Lived Nuclei

    CERN Multimedia

    Duma, M; Iacob, V E; Thibault, C

    2002-01-01

    The MISTRAL (Mass measurements at ISolde with a Transmission RAdiofrequency spectrometer on-Line) experiment exploits a rapid measurement technique to make accurate mass determinations of very short-lived nuclei. The physics goals are to elucidate new nuclear structure effects and constrain nuclear mass models in regions of interest to nuclear astrophysics.\\\\ \\\\The spectrometer, installed in May 97, performed as promised in the proposal with mass resolution exceeding 100,000. In its first experiment in July 1998, neutron-rich Na isotopes having half-lives as short as 31 ms were measured. A second experiment in November 1998 enabled us to improve the measurement precision of the isotopes $^{26-30}$Na to about 20 keV. The measurement program continues as experiment IS 373.

  8. Beyond mean-field calculations for odd-mass nuclei.

    Science.gov (United States)

    Bally, B; Avez, B; Bender, M; Heenen, P-H

    2014-10-17

    Beyond mean-field methods are very successful tools for the description of large-amplitude collective motion for even-even atomic nuclei. The state-of-the-art framework of these methods consists in a generator coordinate method based on angular-momentum and particle-number projected triaxially deformed Hartree-Fock-Bogoliubov (HFB) states. The extension of this scheme to odd-mass nuclei is a long-standing challenge. We present for the first time such an extension, where the generator coordinate space is built from self-consistently blocked one-quasiparticle HFB states. One of the key points for this success is that the same Skyrme interaction is used for the mean-field and the pairing channels, thus avoiding problems related to the violation of the Pauli principle. An application to ^{25}Mg illustrates the power of our method, as agreement with experiment is obtained for the spectrum, electromagnetic moments, and transition strengths, for both positive and negative parity states and without the necessity for effective charges or effective moments. Although the effective interaction still requires improvement, our study opens the way to systematically describe odd-A nuclei throughout the nuclear chart.

  9. Mechanism of intermediate mass fragment emission at low energy

    International Nuclear Information System (INIS)

    Dhara, A.K.; Bhattacharya, C.; Bhattacharya, S.; Krishan, K.

    1993-01-01

    The study of the dynamics of intermediate mass fragment emission in fusion-fission processes has been carried out. The average kinetic energies and relative yield ratio of different fragments are calculated and compared with experimental values

  10. A multistep evaporation model for intermediate mass fragment emission

    International Nuclear Information System (INIS)

    Cole, A.J.; Grotowski, K.; Kozik, T.; Rebel, H.

    1988-11-01

    A multistep evaporation model for intermediate mass fragment emission in heavy ion reactions is described. It applies the canonical transition-state method for the determination of the probability for disintegration of a fused system. The energy and angular momentum relations at the saddle and scission points are calculated on the basis of the finite range liquid drop model. The derivation of the total kinetic energy release uses the concept of amplifying modes which is equivalent to that of shape fluctuations at the ridge point. The model reproduces fairly well the mass and angular distributions and the energy spectra of intermediate mass fragments yields from inclusive and coincidence experiments. (orig.) [de

  11. Precision measurement of the mass difference between light nuclei and anti-nuclei with ALICE at the LHC

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    is produced in the central pseudorapidity region allowing for a precise investigation of their properties. Mass and binding energy are expected to be the same in nuclei and anti-nuclei as long as the CPT invariance holds for the nuclear force, a remnant of the underlying strong interaction between quarks and gluons. The measurements of the difference in mass-to-charge ratio between deuteron and anti-deuteron, and 3He and 3\\bar{He} nuclei performed with the ALICE detector at the LHC is presented. The ALICE measurements improve by one to two orders of magnitude previous analogous direct measurements. Given the equivalence between mass and energy, the results improve by a factor two the constraints on CPT invariance inferred from measurements in the (anti-)deuteron system. The binding energy difference has been determined for the first time in the case of (anti-)3He, with a precision comparable to the one obtained in the...

  12. Signatures of shape phase transitions in odd-mass nuclei

    Science.gov (United States)

    Nomura, K.; Nikšić, T.; Vretenar, D.

    2016-12-01

    Quantum phase transitions between competing ground-state shapes of atomic nuclei with an odd number of protons or neutrons are investigated in a microscopic framework based on nuclear energy density functional theory and the particle-plus-boson-core coupling scheme. The boson-core Hamiltonian, as well as the single-particle energies and occupation probabilities of the unpaired nucleon, are completely determined by constrained self-consistent mean-field calculations for a specific choice of the energy density functional and paring interaction, and only the strength parameters of the particle-core coupling are adjusted to reproduce selected spectroscopic properties of the odd-mass system. We apply this method to odd-A Eu and Sm isotopes with neutron number N ≈90 , and explore the influence of the single unpaired fermion on the occurrence of a shape phase transition. Collective wave functions of low-energy states are used to compute quantities that can be related to quantum order parameters: deformations, excitation energies, E 2 transition rates, and separation energies, and their evolution with the control parameter (neutron number) is analyzed.

  13. Search for Gravitational Waves from Intermediate Mass Binary Black Holes

    Science.gov (United States)

    Blackburn, L.; Camp, J. B.; Cannizzo, J.; Stroeer, A. S.

    2012-01-01

    We present the results of a weakly modeled burst search for gravitational waves from mergers of non-spinning intermediate mass black holes (IMBH) in the total mass range 100-450 solar Mass and with the component mass ratios between 1:1 and 4:1. The search was conducted on data collected by the LIGO and Virgo detectors between November of 2005 and October of 2007. No plausible signals were observed by the search which constrains the astrophysical rates of the IMBH mergers as a function of the component masses. In the most efficiently detected bin centered on 88 + 88 solar Mass , for non-spinning sources, the rate density upper limit is 0.13 per Mpc(exp 3) per Myr at the 90% confidence level.

  14. Mass-measurements far from stability of neutron rich light nuclei

    International Nuclear Information System (INIS)

    Mittig, W.; Gregoire, C.; Schutz, Y.

    1987-07-01

    The study of nuclei far from stability is a verification of nuclear models that generally have been established using the properties of stable nuclei. The direct measurement of the mass has considerable advantages for nuclei very far from stability. This implies a high resolution measurement device, reasonable production rates of the nuclei of interest, and very low systematic errors. This is discussed here. Some of the results have been published recently. They are compared to different classes of models. Region presented is Z=9-15 region

  15. Magnetic Dipole Sum Rules for Odd-Mass Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ginocchio, J.N.; Leviatan, A. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Ginocchio, J.N.; Leviatan, A. [European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT), I-38050 Villazano, Trento (Italy)

    1997-08-01

    Sum rules for the total- and scissors-mode M1 strength in odd-A nuclei are derived within the single-j interacting boson-fermion model. We discuss the physical content and geometric interpretation of these sum rules and apply them to {sup 167}Er and {sup 161}Dy. We find consistency with the former measurements but not with the latter. {copyright} {ital 1997 } {ital The American Physical Society}

  16. Magnetic Dipole Sum Rules for Odd-Mass Nuclei

    International Nuclear Information System (INIS)

    Ginocchio, J.N.; Leviatan, A.; Leviatan, A.; Ginocchio, J.N.; Leviatan, A.

    1997-01-01

    Sum rules for the total- and scissors-mode M1 strength in odd-A nuclei are derived within the single-j interacting boson-fermion model. We discuss the physical content and geometric interpretation of these sum rules and apply them to 167 Er and 161 Dy. We find consistency with the former measurements but not with the latter. copyright 1997 The American Physical Society

  17. Intermediate Mass Black Holes: Their Motion and Associated Energetics

    Directory of Open Access Journals (Sweden)

    C. Sivaram

    2014-01-01

    Full Text Available There is a lot of current astrophysical evidence and interest in intermediate mass black holes (IMBH, ranging from a few hundred to several thousand solar masses. The active galaxy M82 and the globular cluster G1 in M31, for example, are known to host such objects. Here, we discuss several aspects of IMBH such as their expected luminosity, spectral nature of radiation, and associated jets. We also discuss possible scenarios for their formation including the effects of dynamical friction, and gravitational radiation. We also consider their formation in the early universe and also discuss the possibility of supermassive black holes forming from mergers of several IMBH and compare the relevant time scales involved with other scenarios.

  18. The decay of hot nuclei formed in La-induced reactions at intermediate energies

    International Nuclear Information System (INIS)

    Libby, B.; Mignerey, A.C.; Madani, H.; Marchetti, A.A.; Colonna, M.; DiToro, M.

    1992-01-01

    The decay of hot nuclei formed in lanthanum-induced reactions utilizing inverse kinematics has been studied from E/A = 35 to 55 MeV. At each bombarding energy studied, the probability for the multiple emission of complex fragments has been found to be independent of target. Global features (total charge, source velocity) of the reaction La + Al at E/A = 45 MeV have been reproduced by coupling a dynamical model to study the collision stage of the reaction to a statistical model of nuclear decay

  19. Tidal disruption of white dwarfs by intermediate mass black holes

    Directory of Open Access Journals (Sweden)

    Bode T.

    2012-12-01

    Full Text Available Modeling ultra-close encounters between a white dwarf and a spinning, intermediate mass black hole requires a full general relativistic treatment of gravity. This paper summarizes results from such a study. Our results show that the disruption process and prompt accretion of the debris strongly depend on the magnitude and orientation of the black hole spin. On the other hand, the late-time accretion onto the black hole follows the same decay, Ṁ ∝  t−5/3, estimated from Newtonian gravity disruption studies. The spectrum of the fallback material peaks in the soft X-rays and sustains Eddington luminosity for 1–3 yrs after the disruption. The orientation of the black hole spin has also a profound effect on how the outflowing debris obscures the central region. The disruption produces a burst of gravitational radiation with characteristic frequencies of ∼3.2 Hz and strain amplitudes of ∼10−18 for galactic intermediate mass black holes.

  20. nfluence of the nuclear part of the nuclei interaction potential to the mass yields of fragments from fission of highly-excited nuclei

    Directory of Open Access Journals (Sweden)

    V. Yu. Denisov

    2017-11-01

    Full Text Available The influence for various parameterizations of the nuclear part of the interaction potential to the mass yields of fission fragments of highly excited nuclei for the reaction α+197Au → fission was studied. It is shown that using of various nuclear potentials leads to small changes in the yields of fission fragments of the nuclei.

  1. The decay of proton-rich nuclei in the mass A=36-56 region

    International Nuclear Information System (INIS)

    Dossat, C.; Adimi, N.; Aksouh, F.

    2007-01-01

    In a series of experiments at the SISSI/LISE3 facility of GANIL conducted between 1999 and 2004, we have collected decay information for proton-rich nuclei between 36 Ca and 56 Zn. The data allowed us to study the decay properties of 26 nuclei. The main experimental information obtained for all nuclei is their β-decay half-life and their total β-delayed proton emission branching ratio. For many nuclei, individual proton groups and γ rays were identified and allowed us to establish first partial decay schemes for some of the nuclei studied. In addition, mass-excess values have been determined for some of the nuclei by means of the isobaric multiplet mass equation. For 50 Ni, the decay via β-delayed two-proton emission could be tentatively identified. The decay of 49 Ni allowed for the first time to identify the first 2 + state in 48 Fe. The experimental data are confronted to model predictions for the half-life and the mass-excess values

  2. Mass coefficient systematics in triaxially deformed Xe and Ba nuclei

    International Nuclear Information System (INIS)

    Singh, Yuvraj; Bihari, Chhail; Singh, M.; Varshney, A.K.; Gupta, K.K.; Gupta, D.K.

    2009-01-01

    In A ∼ 120-140 region where transition occurs from vibrator like stretching around the neutron closed shell (N = 82) to a region with more rotational character (N = 66) energies and B(E2) values of the low lying states change slowly and smoothly with N and Z indicating the collective nature of the levels. The systematic investigation of such nuclei within an isotopic chain undergoing shape or phase transitions is of particular current interest in nuclear structure physics. Rotation is one of the specific collective motions in finite body systems. When the angular momentum increase, one can observe how the energies of the quantum state change due to the effect of the coriolis and centrifugal forces. Thus in the transition to excited states the axial symmetry of the nucleus is violated even if it existed in the ground state

  3. Elastic scattering of intermediate energy kaons from nuclei and its Coulomb effects

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhenqiu; Kong Lingjiang; Liu Xianhui

    1986-04-01

    In the frame of the eikonal multiple scattering theory, using the basic parameters which are given by the different authors, the elastic scattering of the intermediate energy kaon mesons on /sup 12/C and /sup 40/Ca is studied. The Coulomb effect is calculated too. The results are in agreement with the experimental data. The Coulomb effect not only enhances the small angle differential cross section, but also fills up the dip of the differential cross section.

  4. Strong nuclear enhancement in intermediate mass Drell-Yan production

    CERN Document Server

    Jian Wei Qiu

    2002-01-01

    We calculate nuclear effect in Drell-Yan massive lepton-pair production in terms of parton multiple scattering in Quantum Chromodynamics (QCD). We present the nuclear modification to inclusive Drell-Yan cross sections d sigma /dQ/sup 2/ in terms of multiparton correlation functions. By extracting the size of the correlation functions from measured Drell-Yan transverse momentum broadening in nuclear media, we determine the nuclear modification at O( alpha /sub s//Q/sup 2/). We find that the nuclear modification strongly enhances the inclusive Drell-Yan cross section in the intermediate mass region (IMR): 1.5

  5. Microscopic core-quasiparticle coupling model for spectroscopy of odd-mass nuclei

    Science.gov (United States)

    Quan, S.; Liu, W. P.; Li, Z. P.; Smith, M. S.

    2017-11-01

    Background: Predictions of the spectroscopic properties of low-lying states are critical for nuclear structure studies but are problematic for nuclei with an odd nucleon due to the interplay of the unpaired single particle with nuclear collective degrees of freedom. Purpose: To predict the spectroscopic properties of odd-mass medium-heavy and heavy nuclei with a model that treats single-particle and collective degrees of freedom within the same microscopic framework. Method: A microscopic core-quasiparticle coupling (CQC) model based on the covariant density functional theory is developed that contains the collective excitations of even-mass cores and spherical single-particle states of the odd nucleon as calculated from a quadrupole collective Hamiltonian combined with a constrained triaxial relativistic Hartree-Bogoliubov model. Results: Predictions of the new model for excitation energies, kinematic and dynamic moments of inertia, and transition rates are shown to be in good agreement with results of low-lying spectroscopy measurements of the axially deformed odd-proton nucleus 159Tb and the odd-neutron nucleus 157Gd. Conclusions: A microscopic CQC model based on covariant density functional theory is developed for odd-mass nuclei and shown to give predictions that agree with measurements of two medium-heavy nuclei. Future studies with additional nuclei are planned.

  6. Bulgeless galaxies at intermediate redshift: Sample selection, color properties, and the existence of powerful active galactic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bizzocchi, Luca; Leonardo, Elvira; Grossi, Marco; Afonso, José; Fernandes, Cristina; Retrê, João [Centro de Astronomia e Astrofísica da Universidade de Lisboa, Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisbon (Portugal); Filho, Mercedes E.; Lobo, Catarina [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Griffith, Roger L. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Anton, Sonia [Centro de Investigação em Ciências Geo-Espaciais, Faculdade de Ciências da Universidade do Porto, Porto (Portugal); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Brinchmann, Jarle [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Henriques, Bruno [Max-Planck-Institut für Astrophysik, Karl Schwarzschild Straße 1, D-85748 Garching bei München (Germany); Messias, Hugo [Departamento de astronomía, Av. Esteban Iturra 6to piso, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción (Chile)

    2014-02-10

    We present a catalog of bulgeless galaxies, which includes 19,225 objects selected in four of the deepest, largest multi-wavelength data sets available—COSMOS, AEGIS, GEMS, and GOODS—at intermediate redshift (0.4 ≤ z ≤ 1.0). The morphological classification was provided by the Advanced Camera for Surveys General Catalog (ACS-GC), which used publicly available data obtained with the ACS instrument on the Hubble Space Telescope. Rest-frame photometric quantities were derived using kcorrect. We analyze the properties of the sample and the evolution of pure-disk systems with redshift. Very massive [log (M {sub *}/M {sub ☉}) > 10.5] bulgeless galaxies contribute to ∼30% of the total galaxy population number density at z ≥ 0.7, but their number density drops substantially with decreasing redshift. We show that only a negligible fraction of pure disks appear to be quiescent systems, and red sequence bulgeless galaxies show indications of dust-obscured star formation. X-ray catalogs were used to search for X-ray emission within our sample. After visual inspection and detailed parametric morphological fitting we identify 30 active galactic nuclei (AGNs) that reside in galaxies without a classical bulge. The finding of such peculiar objects at intermediate redshift shows that while AGN growth in merger-free systems is a rare event (0.2% AGN hosts in this sample of bulgeless galaxies), it can indeed happen relatively early in the history of the universe.

  7. Photon and proton induced fission on heavy nuclei at intermediate energies

    Directory of Open Access Journals (Sweden)

    Andrade-II E.

    2014-04-01

    Full Text Available We present an analysis of fission induced by intermediate energy protons or photons on actinides. The 660 MeV proton induced reactions are on 241Am, 238U, and 237Np targets and the Bremmstrahlung-photons with end-point energies at 50 MeV and 3500 MeV are on 232Th and 238U targets. The study was performed by means of the Monte Carlo simulation code CRISP. A multimodal fission extension was added to the code within an approach which accounts for the contribution of symmetric and asymmetric fission. This procedure allowed the investigation of fission cross sections, fissility, number of evaporated nucleons and fission-fragment charge distributions. The comparison with experimental data show a good agreement between calculations and experiments.

  8. Nuclear structure studies of medium-mass nuclei using large Ge arrays

    International Nuclear Information System (INIS)

    Baktash, C.

    1996-01-01

    The advent of large Ge arrays and their ancillary detectors has greatly advanced spectroscopic studies of the medium-mass nuclei. These nuclei undergo rapid shape changes as a function of spin, excitation energy and particle number and, thus, provide a unique laboratory to test and refine a variety of theoretical models. Following a brief review of the physics motivation, some of the highlights of the experimental results obtained with the help of these powerful detector systems will be discussed. Among results presented here are the newly-discovered island of superdeformation in the A∼80 mass region, and the high-spin band structures in the N∼Z nuclei. These band structures may be understood in the framework of the conventional cranking models, without the introduction of additional T=0 neutron-proton pairing correlations

  9. Dynamical and luminosity evolution of active galactic nuclei - Models with a mass spectrum

    International Nuclear Information System (INIS)

    Murphy, B.W.; Cohn, H.N.; Durisen, R.H.

    1991-01-01

    A multimass energy-space Fokker-Planck code is used to follow the dynamical and luminosity evolution of an AGN model that consists of a dense stellar system surrounding a massive black hole. It is found that stellar evolution and tidal disruption are the predominant mass-loss mechanisms for low-density nuclei, whereas physical collisions dominate in high-density nuclei. For initial central densities greater than 10 million solar masses/cu pc the core of the stellar system contacts due to the removal of kinetic energy by collisions, whereas for densities less than this the core of the stellar system expands due to heating that results from the settling of a small population of stars into orbits tightly bound to the black hole. These mechanisms produce differing power-law slopes in the resulting stellar density cusp surrounding the black hole, -7/4 and -1/2 for low- and high-density nuclei, respectively. 60 refs

  10. Direct mass measurements of light neutron-rich nuclei using fast recoil spectrometers

    International Nuclear Information System (INIS)

    Vieira, D.J.; Wouters, J.M.

    1987-01-01

    Extensive new mass measurement capabilities have evolved with the development of recoil spectrometers. In the Z = 3 to 9 neutron-rich region alone, 12 neutron-rich nuclei have been determined for the first time by the fast-recoil direct mass measurement method. A recent experiment using the TOFI spectrometer illustrates this technique. A systematic investigation of nuclei that lie along or near the neutron-drip line has provided a valuable first glimpse into the nuclear structure of such nuclei. No evidence for a large single-particle energy gap at N = 14 is observed; however, a change in the two-neutron separation model calculations, and is interpreted in terms of the smaller 1s/sub 1/2/ - 1s/sub 1/2/ interaction compared to that of the 0d/sub 5/2/ - 0d/sub 5/2/ neutron-neutron interaction. 18 refs., 7 figs., 1 tab

  11. ENAM'04 Fourth International Conference on Exotic Nuclei and Atomic Masses

    International Nuclear Information System (INIS)

    Gross, C. J.; Nazarewicz, W.; Rykaczewski, K. P.

    2005-01-01

    The conference can trace its origins to the 1950s and 1960s with the Atomic Mass and Fundamental Constants (AMCO) and the Nuclei Far From Stability (NFFS) series of conferences. Held jointly in 1992, the conferences officially merged in 1995 and the fourth conference was held at Callaway Gardens in Pine Mountain, GA and was organized by the Physics Division at Oak Ridge National Laboratory. The conference covered a broad list of topics consisting of a series of invited and contributed presentation highlighting recent research in the following fields: Atomic masses, nuclear moments, and nuclear radii; Forms of radioactivity; Nuclear structure, nuclei at the drip lines, cluster phenomena; Reactions with radioactive ion beams; Nuclear astrophysics; Fundamental symmetries and interactions; Heaviest elements and fission; Radioactive ion beam production and experimental developments; Applications of exotic nuclei

  12. ENAM'04 Fourth International Conference on Exotic Nuclei and Atomic Masses

    Energy Technology Data Exchange (ETDEWEB)

    Gross, C. J.; Nazarewicz, W.; Rykaczewski, K. P.

    2005-01-01

    The conference can trace its origins to the 1950s and 1960s with the Atomic Mass and Fundamental Constants (AMCO) and the Nuclei Far From Stability (NFFS) series of conferences. Held jointly in 1992, the conferences officially merged in 1995 and the fourth conference was held at Callaway Gardens in Pine Mountain, GA and was organized by the Physics Division at Oak Ridge National Laboratory. The conference covered a broad list of topics consisting of a series of invited and contributed presentation highlighting recent research in the following fields: Atomic masses, nuclear moments, and nuclear radii; Forms of radioactivity; Nuclear structure, nuclei at the drip lines, cluster phenomena; Reactions with radioactive ion beams; Nuclear astrophysics; Fundamental symmetries and interactions; Heaviest elements and fission; Radioactive ion beam production and experimental developments; Applications of exotic nuclei

  13. Partial dynamical symmetry in odd-mass nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.

    2015-01-01

    Spectral features of the odd-mass nucleus 195 Pt are analyzed by means of an interacting boson-fermion Hamiltonian with SO(6) partial dynamical symmetry. For the latter, selected eigenstates are solvable and preserve the symmetry exactly, while other states are mixed. The analysis constitutes a first example of this novel symmetry construction in a mixed Bose-Fermi system

  14. Infinite nuclear matter model and mass formulae for nuclei

    International Nuclear Information System (INIS)

    Satpathy, L.

    2016-01-01

    The matter composed of the nucleus is a quantum-mechanical interacting many-fermionic system. However, the shell and classical liquid drop have been taken as the two main features of nuclear dynamics, which have guided the evolution of nuclear physics. These two features can be considered as the macroscopic manifestation of the microscopic dynamics of the nucleons at fundamental level. Various mass formulae have been developed based on either of these features over the years, resulting in many ambiguities and uncertainties posing many challenges in this field. Keeping this in view, Infinite Nuclear Matter (INM) model has been developed during last couple of decades with a many-body theoretical foundation employing the celebrated Hugenholtz-Van Hove theorem, quite appropriate for the interacting quantum-mechanical nuclear system. A mass formula called INM mass formula based on this model yields rms deviation of 342 keV being the lowest in literature. Some of the highlights of its result includes its determination of INM density in agreement with the electron scattering data leading to the resolution of the long standing 'r 0 -paradox' it predicts new magic numbers giving rise to new island of stability in the drip-line regions. This is the manifestation of a new phenomenon where shell-effect over comes the repulsive component of nucleon-nucleon force resulting in the broadening of the stability peninsula. Shell quenching in N= 82,and N= 126 shells, and several islands of inversion have been predicted. The model determines the empirical value of the nuclear compression modulus, using high precission 4500 data comprising nuclear masses, neutron and proton separation energies. The talk will give a critical review of the field of mass formula and our understanding of nuclear dynamics as a whole

  15. Phases, quantum interferences and effective vector meson masses in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Soyeur, M.

    1996-12-31

    We discuss the prospects for observing the mass of {rho}- and {omega}-mesons around nuclear matter density by studying their coherent photoproduction in nuclear targets and subsequent in-medium decay into e{sup +}e{sup -}pairs. The quantum interference of {rho} and {omega}-mesons in the e{sup +}e{sup -}channel and the interference between Bethe-Heitler pairs and dielectrons from vector meson decays are of particular interest. (author). 21 refs.

  16. Study of GDR properties in hot nuclei of mass A≅125

    International Nuclear Information System (INIS)

    Fan Hongmei; Bellia, G.; Migneco, E.; Blumenfeld, Y.; Delaunay, F.; Frascaria, N.; Lima, V.

    2004-01-01

    The experiment was carried out at the National Laboratory of South in Italy using 116 Sn beam of 17 and 23 MeV/u delivered from the Superconducting Cyclotron impinging on 12 C and 24 Mg targets. The hot nuclei have been formed by complete and incomplete fusion reactions. The characteristics of the giant dipole resonance (GDR) in hot nuclei of mass A≅125 at lower excitation energies between 160 and 300 MeV have been measured with the multi element detector array (MEDEA) detector. A comparison of GDR yield for three reactions is presented. (authors)

  17. Study of interactions between hadrons and light nuclei at intermediate energies

    International Nuclear Information System (INIS)

    Levy, Dominique.

    1977-01-01

    A theoretical study of the following reactions: πN→πN, πd→πd and Nd→Nπd, at incident energies of a few hundreds MeV is presented. The amplitudes of the πN→πN reaction are studied when at least one of the external particles is off-mass-shell. This study leads to the selection of a model used subsequently. For the πd→πd reaction, the simple scattering model is analyzed in detail then the Glauber and Brueckner double scattering models are compared. In the simple scattering model, the effect of the Fermi motion is examined in detail: a calculation of this effect, taking into account both the deuteron D wave and the nucleon spins is completed. Several approximations to the Fermi integral are also presented and the deficiencies of the models are discussed. In the inelastic Nd→Nπd reaction, the peak observed around 1150 MeV in the invariant mass spectrum of the Nπ final system is studied. This Nπ(1150) effect is explained using a Deck-type model. Other mechanisms that might contribute to the Nd→Nπd reaction, in particular at high transfers, are analyzed [fr

  18. A versatile triple radiofrequency quadrupole system for cooling, mass separation and bunching of exotic nuclei

    Science.gov (United States)

    Haettner, Emma; Plaß, Wolfgang R.; Czok, Ulrich; Dickel, Timo; Geissel, Hans; Kinsel, Wadim; Petrick, Martin; Schäfer, Thorsten; Scheidenberger, Christoph

    2018-02-01

    The combination of in-flight separation with a gas-filled stopping cell has opened a new field for experiments with exotic nuclei. For instance, at the SHIP/SHIPTRAP facility at GSI in Darmstadt high-precision mass measurements of rare nuclei have been successfully performed. In order to extend the reach of SHIPTRAP to exotic nuclei that are produced together with high rates of unwanted reaction products, a novel compact radio frequency quadrupole (RFQ) system has been developed. It implements ion cooling, identification and separation according to mass numbers and bunching capabilities. The system has a total length of one meter only and consists of an RFQ cooler, an RFQ mass filter and an RFQ buncher. A mass resolving power (FWHM) of 240 at a transmission efficiency of 90% has been achieved. The suppression of contaminants from neighboring masses by more than four orders of magnitude has been demonstrated at rates exceeding 106 ions/s. A longitudinal emittance of 0.45 eV μs has been achieved with the RFQ buncher, which will enable improved time-of-flight mass spectrometry downstream of the device. With this triple RFQ system the measurement of e.g. N= Z nuclides in the region up to tin will become possible at SHIPTRAP. The technology is also well suited for other rare-isotope facilities with experimental setups behind a stopping cell, such as the fragment separator FRS with the FRS Ion Catcher at GSI.

  19. Description of odd-mass nuclei by multi-reference energy density functional methods

    International Nuclear Information System (INIS)

    Bally, B.

    2014-01-01

    In this work, we are interested in the treatment of odd-mass atomic nuclei in energy density functional (EDF) models. More precisely, the goal of this thesis is to develop and to apply to odd-mass nuclei, the theoretical extensions of the EDF method that are: first, the projection technique, and secondly the configuration mixing by the generator coordinate method (GCM). These two extensions are part of the so-called multi-reference energy density functional (MR-EDF) formalism and allow one to take into account, within an EDF context, the 'beyond-mean-field' correlations between the nucleons forming the nucleus. Until now, the MR-EDF formalism has been applied, in its fully-fledged version, only to the calculation of even-even nuclei. In this thesis, we want to demonstrate the applicability of such a model also for the description of odd-mass nuclei. In the first part of this thesis, we describe the theoretical formalism of the EDF models, giving particular attention to the treatment of symmetries within our approach. In the second part of the manuscript, we apply our model to the nucleus 25 Mg and investigate different aspects of the method (e.g. numerical accuracy, convergence of the configuration mixing, comparison to known experimental data). The results obtained in this work are encouraging and demonstrate the potential of our approach for theoretical nuclear structure calculations. (author)

  20. Direct mass measurements of 100Sn and magic nuclei near the N=Z line

    International Nuclear Information System (INIS)

    Chartier, M.

    1996-01-01

    The masses of nuclei far from stability are of particular interest in nuclear structure studies, and many methods of varying precision have been developed to undertake their measurement. A direct time of flight technique in conjunction with the SPEG spectrometer at GANIL has been extended to the mass measurement of proton-rich nuclei near N = Z line in the mass region A ≅ 60-80 known to provide input for astrophysical modelling of the rp-process and information relevant to the nuclear structure in a region of high deformation. The radioactive beams were produced via the fragmentation of a 78 Kr beam on a nat Ni target, using the new SISSI device. A purification method based on the stripping of the secondary ions was successfully used for the first time, and the masses of 70 Se and 71 Se were measured. In order to improve the mass resolution for heavier nuclei, another method using the second cyclotron of GANIL (CSS2) as a high resolution spectrometer has been developed. An experiment aimed at measuring the masses of A 100 isobars in the vicinity of the doubly magic nucleus 100 Sn was successfully performed, using this original technique. Secondary ions of 100 Ag, 100 Cd, 100 In and 100 Sn produced via fusion-evaporation reaction 50 Cr + 58 Ni and simultaneously accelerated in the CSS2 cyclotron. The mass of 100 Cd and, for the first time, the masses of 100 Sn were determined directly with respect to the reference mass of 100 Ag. These results have been compared to various theoretical predictions and open the discussion on considerations of spin-isospin symmetry. (author)

  1. Virgo Redux: The Masses and Stellar Content of Nuclei in Early-type Galaxies from Multiband Photometry and Spectroscopy

    Science.gov (United States)

    Spengler, Chelsea; Côté, Patrick; Roediger, Joel; Ferrarese, Laura; Sánchez-Janssen, Rubén; Toloba, Elisa; Liu, Yiqing; Guhathakurta, Puragra; Cuillandre, Jean-Charles; Gwyn, Stephen; Zirm, Andrew; Muñoz, Roberto; Puzia, Thomas; Lançon, Ariane; Peng, Eric W.; Mei, Simona; Powalka, Mathieu

    2017-11-01

    We present an analysis of 39 nuclei and their early-type hosts in the Virgo Cluster using 10 broadband filters: F300W, F475W, F850LP, F160W, {u}* {\\text{}}{griz}, and K s . We describe the Virgo Redux program, which provides high-resolution UV and NIR imaging. Combining this data with optical and NIR imaging from the ACS Virgo Cluster Survey and the Next Generation Virgo Cluster Survey, we estimate masses, metallicities, and ages using simple stellar population (SSP) models. For 19 nuclei, we compare to SSP parameters derived from Keck and Gemini spectra and find reasonable agreement between the photometric and spectroscopic metallicity: the rms scatter is 0.3 dex. We reproduce the nucleus-galaxy mass fraction of {0.33}-0.07+0.09% for galaxy stellar masses {10}8.4{--}{10}10.3 {M}⊙ with a typical precision of ˜35% for the nuclei masses. Based on available model predictions, there is no single preferred formation scenario for nuclei, suggesting that nuclei are formed stochastically through a mix of processes. Nuclei metallicities are statistically identical to those of their hosts, appearing 0.07 ± 0.3 dex more metal-rich on average; however, omitting galaxies with unusual origins, nuclei are 0.20 ± 0.28 dex more metal-rich. Nuclei appear to be 0.56 ± 0.12 dex more metal-rich than ultracompact dwarf galaxies (UCDs) at fixed mass. We find no clear age difference between nuclei and their galaxies, with nuclei displaying a broad range of ages. Interestingly, we find that the most massive nuclei may be flatter and more closely aligned with the semimajor axes of their hosts, suggesting that they formed through predominantly dissipative processes.

  2. Coupled channel alpha decay theory for even- and odd-mass light and heavy nuclei

    International Nuclear Information System (INIS)

    Rauscher, E.A.

    1978-02-01

    Four major approaches to the theoretical calculation of alpha decay widths were examined for light and heavy, even- and odd-mass nuclei. Application of the microscopic shell model rate theory as well as macroscopic models utilizing the coupled-channel formalism were studied. Use of the R-matrix and S-matrix theories have been applied in order to overcome problems involving dependency on the connection radius and nuclear potential parameters of the relative and absolute alpha decay widths. 105 references

  3. Shell-model method for Gamow-Teller transitions in heavy deformed odd-mass nuclei

    Science.gov (United States)

    Wang, Long-Jun; Sun, Yang; Ghorui, Surja K.

    2018-04-01

    A shell-model method for calculating Gamow-Teller (GT) transition rates in heavy deformed odd-mass nuclei is presented. The method is developed within the framework of the projected shell model. To implement the computation requirement when many multi-quasiparticle configurations are included in the basis, a numerical advancement based on the Pfaffian formula is introduced. With this new many-body technique, it becomes feasible to perform state-by-state calculations for the GT nuclear matrix elements of β -decay and electron-capture processes, including those at high excitation energies in heavy nuclei which are usually deformed. The first results, β- decays of the well-deformed A =153 neutron-rich nuclei, are shown as the example. The known log(f t ) data corresponding to the B (GT- ) decay rates of the ground state of 153Nd to the low-lying states of 153Pm are well described. It is further shown that the B (GT) distributions can have a strong dependence on the detailed microscopic structure of relevant states of both the parent and daughter nuclei.

  4. Mass fragmentographic determination of gamma-aminobutyric acid and glutamic acid in discrete amygdaloid nuclei of rat brain.

    Science.gov (United States)

    Nakamura, K; Matsumoto, T; Hirano, M; Kagoshima, H; Kuroki, T; Yao, H; Uchimura, H; Nakahara, T

    1987-06-01

    A mass fragmentographic method for the simultaneous quantification of gamma-aminobutyric acid (GABA) and glutamic acid is described. In a convenient one-step reaction, the two amino acids were derivatized with pentafluoropropionic anhydride and pentafluoropropanol. The derivatization products were stable for several days. The technique has been applied to the assay of GABA and Glu in five amygdaloid nuclei of the rat brain. The GABA level was high in the central and medial nuclei, whereas the Glu level was high in the lateral and basal nuclei. The regional distribution of GABA was different from that of Glu within the amygdaloid nuclei.

  5. Meson exchange second class currents and the neutrino mass in the muon capture by light nuclei

    International Nuclear Information System (INIS)

    Katkhat, Ch.L.

    1988-01-01

    Influence of the Kubodera-Delorme-Rho model parameters (ζ and ξ), the scalar form factor (F s ) and the muonic neutrino rest mass (m νμ ) on the asymmetry coefficient (α μν ) of neutrino emission with respect to the muon spin orientation in the muon capture by light nuclei is analyzed. It is shown, that the mass m νμ , the parameters of ζ and ξ, and the form factor F s may be estimated by studying the coefficient α μν in O -> O, Gamov-Teller, and mixed transitions, respectively

  6. Intermediate coupling vibrational descriptions of odd mass gold isotopes

    CERN Document Server

    Vieu, C; Paar, V

    1976-01-01

    The theoretical analysis of /sup 193-195/Au levels is semi qualitatively performed in the frame of the intermediate coupling vibrational models of Kisslinger-Sorensen and Alaga. From the comparison between the experimental data and the corresponding predictions of the two models, conclusions are drawn on the influence of the clusters and broken pairs.

  7. Jetted tidal disruptions of stars as a flag of intermediate mass black holes at high redshifts

    Science.gov (United States)

    Fialkov, Anastasia; Loeb, Abraham

    2017-11-01

    Tidal disruption events (TDEs) of stars by single or binary supermassive black holes (SMBHs) brighten galactic nuclei and reveal a population of otherwise dormant black holes. Adopting event rates from the literature, we aim to establish general trends in the redshift evolution of the TDE number counts and their observable signals. We pay particular attention to (I) jetted TDEs whose luminosity is boosted by relativistic beaming and (II) TDEs around binary black holes. We show that the brightest (jetted) TDEs are expected to be produced by massive black hole binaries if the occupancy of intermediate mass black holes (IMBHs) in low-mass galaxies is high. The same binary population will also provide gravitational wave sources for the evolved Laser Interferometer Space Antenna. In addition, we find that the shape of the X-ray luminosity function of TDEs strongly depends on the occupancy of IMBHs and could be used to constrain scenarios of SMBH formation. Finally, we make predictions for the expected number of TDEs observed by future X-ray telescopes finding that a 50 times more sensitive instrument than the Burst Alert Telescope (BAT) on board the Swift satellite is expected to trigger ˜10 times more events than BAT, while 6-20 TDEs are expected in each deep field observed by a telescope 50 times more sensitive than the Chandra X-ray Observatory if the occupation fraction of IMBHs is high. Because of their long decay times, high-redshift TDEs can be mistaken for fixed point sources in deep field surveys and targeted observations of the same deep field with year-long intervals could reveal TDEs.

  8. Semimicroscopic description of basic properties of isoscalar monopole and dipole excitations in medium-mass spherical nuclei

    NARCIS (Netherlands)

    Gorelik, ML; Urin, MH

    2003-01-01

    A description of basic properties (strength function, transition density, probabilities of direct nucleonic decays) of isoscalar giant monopole (including an overtone) and dipole resonances in medium-mass spherical nuclei is proposed within a semimicroscopic approach. The approach relies on

  9. The time-of-flight isochronous (TOFI) spectrometer for direct mass measurements of exotic light nuclei

    International Nuclear Information System (INIS)

    Wouters, J.M.; Vieira, D.J.; Butler, G.W.; Wollnik, H.; Kraus, R.H. Jr.; Vaziri, K.

    1987-01-01

    A new type of time-of-flight recoil spectrometer designed to measure the masses of neutron-rich light nuclei has recently been completed at LAMPF. The spectrometer relies on an isochronous design that directly correlates an ion's time-of-flight through the spectrometer with its mass-to-charge ratio. Additional measurements of the ion's velocity and energy enable the charge state of the recoil to be uniquely defined and thus permit precision mass measurements given sufficient statistics. The performance of the spectrometer has been investigated in both-off line (using alpha sources) and on-line tests. The design resolution of ΔM/M=1/2000 (fwhm) has been achieved. Initial performance results of the spectrometer are described with emphasis placed on the techniques used to achieve the overall high mass resolution and large solid angle/momentum acceptance. (orig.)

  10. Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the Black Hole Mass-Velocity Dispersion Relationship for Active Galactic Nuclei

    DEFF Research Database (Denmark)

    Onken, Christopher A.; Ferrarese, Laura; Merritt, David

    2004-01-01

    We calibrate reverberation-based black hole masses in active galactic nuclei (AGNs) by using the correlation between black hole mass, M, and bulge/spheroid stellar velocity dispersion, sigma. We use new measurements of sigma for 6 AGNs and published velocity dispersions for 10 others......, in conjunction with improved reverberation mapping results, to determine the scaling factor required to bring reverberation-based black hole masses into agreement with the quiescent galaxy M-sigma relationship. The scatter in the AGN black hole masses is found to be less than a factor of 3. The current...

  11. Mass models of NGC 6624 without an intermediate-mass black hole

    Science.gov (United States)

    Gieles, Mark; Balbinot, Eduardo; Yaaqib, Rashid I. S. M.; Hénault-Brunet, Vincent; Zocchi, Alice; Peuten, Miklos; Jonker, Peter G.

    2018-02-01

    An intermediate-mass black hole (IMBH) was recently reported to reside in the centre of the Galactic globular cluster (GC) NGC 6624, based on timing observations of a millisecond pulsar (MSP) located near the cluster centre in projection. We present dynamical models with multiple mass components of NGC 6624 - without an IMBH - which successfully describe the surface brightness profile and proper motion kinematics from the Hubble Space Telescope (HST) and the stellar-mass function at different distances from the cluster centre. The maximum line-of-sight acceleration at the position of the MSP accommodates the inferred acceleration of the MSP, as derived from its first period derivative. With discrete realizations of the models we show that the higher-order period derivatives - which were previously used to derive the IMBH mass - are due to passing stars and stellar remnants, as previously shown analytically in literature. We conclude that there is no need for an IMBH to explain the timing observations of this MSP.

  12. Universal charge-mass relation: From black holes to atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hod, Shahar, E-mail: shaharhod@gmail.co [The Ruppin Academic Center, Emeq Hefer 40250 (Israel); The Hadassah Institute, Jerusalem 91010 (Israel)

    2010-10-04

    The cosmic censorship hypothesis, introduced by Penrose forty years ago, is one of the corner stones of general relativity. This conjecture asserts that spacetime singularities that arise in gravitational collapse are always hidden inside of black holes. The elimination of a black-hole horizon is ruled out by this principle because that would expose naked singularities to distant observers. We test the consistency of this prediction in a gedanken experiment in which a charged object is swallowed by a charged black hole. We find that the validity of the cosmic censorship conjecture requires the existence of a charge-mass bound of the form q{<=}{mu}{sup 2/3}E{sub c}{sup -1/3}, where q and {mu} are the charge and mass of the physical system respectively, and E{sub c} is the critical electric field for pair-production. Applying this bound to charged atomic nuclei, one finds an upper limit on the number Z of protons in a nucleus of given mass number A: Z{<=}Z{sup *}={alpha}{sup -1/3}A{sup 2/3}, where {alpha}=e{sup 2}/h is the fine structure constant. We test the validity of this novel bound against the (Z,A)-relation of atomic nuclei as deduced from the Weizsaecker semi-empirical mass formula.

  13. Study of nuclear reactions involving heavy nuclei and intermediate- and high-energy protons and an application in nuclear reactor physics (ADS)

    International Nuclear Information System (INIS)

    Matuoka, Paula Fernanda Toledo

    2016-01-01

    In the present work, intermediate- and high-energy nuclear reactions involving heavy nuclei and protons were studied with the Monte Carlo CRISP (Rio - Ilheus - Sao Paulo Collaboration) model. The most relevant nuclear processes studied were intranuclear cascade and fission-evaporation competition. Preliminary studies showed fair agreement between CRISP model calculation and experimental data of multiplicity of evaporated neutrons (E < 20 MeV) from the p(1200 MeV) + 208 Pb reaction and of spallation residues from the p(1000 MeV) + 208 Pb reaction. The investigation of neutron multiplicity from proton-induced fission of 232 Th up to 85 MeV showed that it was being overestimated by CRISP model; on the other hand, fission cross section were being underestimated. This behavior is due to limitations of the intranuclear cascade model for low-energies (around 50 MeV). The p(1200 MeV) + 208 Pb reaction was selected for the study of a spallation neutron source. High-energy neutrons (E > 20 MeV) were emitted mostly in the intranuclear cascade stage, while evaporation presented larger neutron multiplicity. Fission cross section of 209 mb and spallation cross section of 1788 mb were calculated { both in agreement with experimental data. The fission process resulted in a symmetric mass distribution. Another Monte Carlo code, MCNP, was used for radiation transport in order to understand the role of a spallation neutron source in a ADS (Accelerator Driven System) nuclear reactor. Initially, a PWR reactor was simulated to study the isotopic compositions in spent nuclear fuel. As a rst attempt, a spallation neutron source was adapted to an industrial size nuclear reactor. The results showed no evidence of incineration of transuranic elements and modifications were suggested. (author)

  14. Landscape of α preformation probability for even–even nuclei in medium mass region

    Science.gov (United States)

    Qian, Yibin; Ren, Zhongzhou

    2018-03-01

    The behavior of α cluster preformation probability, in α decay, is a rich source of the structural information, such as the clustering, pairing, and shell evolution in heavy nuclei. Meanwhile, the experimental α decay data have been very recently compiled in the newest table NUBASE2016. Through a least square fit to the available experimental data of nuclear charge radii plus the neutron skin thickness, we obtain a new set of parameters for the two-parameter Fermi nucleon density distributions in target nuclei. Subsequently, we make use of these refreshed inputs, involved in the density-dependent cluster model, to extract α preformation factor ({P}α ) for a large range of medium α emitters with N pattern of P α in the open-shell region, the special attention has been paid to those exotic α-decaying nuclei around the Z = 50 and N = 82 shell closures. Moreover, the correlation between the α preformation factor and the microscopic correction of nuclear mass, corresponding to the effect of shell and pairing plus deformation, is in particular investigated, to pursue the valuable knowledge of the P α pattern over the nuclide chart. The feature of α preformation factor along with the neutron–proton asymmetry is then detected and discussed to some extent.

  15. A multi-reflection time-of-flight mass spectrograph for short-lived and super-heavy nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Schury, P., E-mail: schury@riken.jp [University of Tsukuba, Institute of Physics, Tsukuba City, Ibaraki (Japan); RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); New Mexico State University, Dept. of Chem. and BioChem., Las Cruces, NM (United States); Wada, M. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Ito, Y. [University of Tsukuba, Institute of Physics, Tsukuba City, Ibaraki (Japan); RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Naimi, S.; Sonoda, T. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Mita, H. [University of Tsukuba, Institute of Physics, Tsukuba City, Ibaraki (Japan); RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Takamine, A. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Aoyama Gakuin University, Sagamihara, Kanagawa (Japan); Okada, K. [Sophia University, Chiyoda-ku, Tokyo (Japan); Wollnik, H. [New Mexico State University, Dept. of Chem. and BioChem., Las Cruces, NM (United States); Chon, S. [KEK, Tsukuba, Ibaraki (Japan); Haba, H.; Kaji, D. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Koura, H. [Japan Atomic Energy Research Institute, Ibaraki (Japan); Miyatake, H. [KEK, Tsukuba, Ibaraki (Japan); Morimoto, K.; Morita, K. [RIKEN, Nishina Center for Accelerator Based Science, Wako City, Saitama (Japan); Ozawa, A. [University of Tsukuba, Institute of Physics, Tsukuba City, Ibaraki (Japan)

    2013-12-15

    Highlights: • Demonstrated very fast mass measurements with a multi-reflection time of flight mass spectrograph. • Mass resolving power of R{sub m}≈150,000 was achieved in 1.2-ms for A/q=39 ions. • Mass precision of (δm)/m =7.7×10{sup 8} was demonstrated for {sup 40}Ca{sub +}. • Effects of thermal and voltage instabilities are described. • Effects of thermal and voltage instabilities are described. -- Abstract: A multi-reflection time-of-flight (MRTOF) mass spectrograph has been implemented at RIKEN to provide high-precision mass measurements of very short-lived nuclei. Of particular interest are mass measurements of r-process nuclei and trans-uranium nuclei. In such nuclei, the MRTOF can perform on par with or better than traditional Penning trap systems. We demonstrate that the MRTOF-MS is capable of accurately attaining relative mass precision of δm/m<10{sup -7} and describe it’s utility with heavy, short-lived nuclei.

  16. Mass-spectrometer of knock-on nuclei for reactor 'Pik'

    International Nuclear Information System (INIS)

    Begzhanov, P.B.; Nazarov, A.G.; Petrov, G.A.; Pikul', V.P.

    1999-01-01

    For reactor 'Pik' (that is being built in St. Petersburg Institute of Nuclear Physics) there was designed a universal two shoulder mass-spectrometer for non-decelerated fission products (FP) of nuclei. The spectrometer helps to obtain different values of linear magnification, dispersion, aberration coefficients and transmission without making structural changes in the device. To separate FP for one shoulder of spectrometer we chose ion-optical scheme (IOS) consisting of three electrostatic analyzers and three-sectional magnet 'JOSEF' that had high dispersion by masses at small deflection radius. IOS calculations of mass-spectrometer were performed with the help of program TRANSVOL (transfer of phase volume) designed basing on TRIO program. The program allows calculating of complete IOS transmission with taking into account elements aperture and beam officering

  17. Relative mass distributions of neutron-rich thermally fissile nuclei within a statistical model

    Science.gov (United States)

    Kumar, Bharat; Kannan, M. T. Senthil; Balasubramaniam, M.; Agrawal, B. K.; Patra, S. K.

    2017-09-01

    We study the binary mass distribution for the recently predicted thermally fissile neutron-rich uranium and thorium nuclei using a statistical model. The level density parameters needed for the study are evaluated from the excitation energies of the temperature-dependent relativistic mean field formalism. The excitation energy and the level density parameter for a given temperature are employed in the convolution integral method to obtain the probability of the particular fragmentation. As representative cases, we present the results for the binary yields of 250U and 254Th. The relative yields are presented for three different temperatures: T =1 , 2, and 3 MeV.

  18. Isoscalar giant resonances for nuclei with mass between 56 and 60

    International Nuclear Information System (INIS)

    Lui, Y.-W.; Youngblood, D.H.; Clark, H.L.; Tokimoto, Y.; John, B.

    2006-01-01

    The giant resonance region from 10 MeV x 56 Fe, 58 Ni, and 60 Ni has been studied with inelastic scattering of 240 MeV α particles at small angles, including 0 deg. Most of the expected isoscalar E0 and E2 strength has been identified below E x =40 MeV. Between 56 and 72% of the isoscalar E1 strength has been located in these nuclei. The mass dependence of the giant monopole energy between A=40 and 90 is compared to relativistic and nonrelativistic calculations for interactions with compressibility of nuclear matter K NM ∼211-225 MeV

  19. Shell model calculations for the mass 18 nuclei in the sd-shell

    International Nuclear Information System (INIS)

    Hamoudi, A.

    1997-01-01

    A simple effective nucleon-nucleon interaction for shell model calculations in the sd-shell is derived from the Reid soft-core potential folded with two-body correlation functions which take account of the strong short-range repulsion and large tensor component in the Reid force. Calculations of binding energies and low-lying spectra are performed for the mass A=18 with T=0 and 1 nuclei using this interaction. The results of this shell model calculations show a reasonable agreement with experiment

  20. Radio Detections During Two State Transitions of the Intermediate-Mass Black Hole HLX-1

    Science.gov (United States)

    Webb, Natalie; Cseh, David; Lenc, Emil; Godet, Olivier; Barret, Didier; Corbel, Stephane; Farrell, Sean; Fender, Robert; Gehrels, Neil; Heywood, Ian

    2012-01-01

    Relativistic jets are streams of plasma moving at appreciable fractions of the speed of light. They have been observed from stellar-mass black holes (approx. 3 to 20 solar masses) as well as supermassive black holes (approx.. 10(exp 6) to 10(exp 9) Solar Mass) found in the centers of most galaxies. Jets should also be produced by intermediate-mass black holes (approx. 10(exp 2) to 10(exp 5) Solar Mass), although evidence for this third class of black hole has, until recently, been weak. We report the detection of transient radio emission at the location of the intermediate-mass black hole candidate ESO 243-49 HLX-1, which is consistent with a discrete jet ejection event. These observations also allow us to refine the mass estimate of the black hole to be between approx. 9 × 10(exp 3) Solar Mass and approx. 9 × 10(exp 4) Solar Mass.

  1. The Masses and Stellar Content of Nuclei in Early-Type Galaxies from Multi-Band Photometry and Spectroscopy

    Science.gov (United States)

    Spengler, Chelsea; Côté, Patrick; Roediger, Joel; Ferrarese, Laura; Sánchez-Janssen, Rubén; Toloba, Elisa; Liu, Yiqing; Guhathakurta, Puragra; Cuillandre, Jean-Charles; Gwyn, Stephen; Zirm, Andrew; Muñoz, Roberto; Puzia, Thomas; Lançon, Ariane; Peng, Eric; Mei, Simona; Powalka, Mathieu

    2018-01-01

    It is now established that most, if not all, massive galaxies host central supermassive black holes (SMBHs), and that these SMBHs are linked to the growth their host galaxies as shown by several scaling relations. Within the last couple of decades, it has become apparent that most lower-mass galaxies without obvious SMBHs nevertheless contain some sort of central massive object in the form of compact stellar nuclei that also follow identical (or similar) scaling relations. These nuclei are challenging to study given their small sizes and relatively faint magnitudes, but understanding their origins and relationship to their hosts is critical to gaining a more complete picture of galaxy evolution. To that end, we highlight selected results from an analysis of 39 nuclei and their early-type hosts in the Virgo Cluster using ten broadband filters: F300W, F475W, F850LP, F160W, u*griz, and Ks. We estimate masses, metallicities and ages using simple stellar population (SSP) models. For 19 nuclei, we compare to SSP parameters derived from Keck and Gemini spectra and find reasonable agreement between the photometric and spectroscopic metallicity: the RMS scatter is 0.3 dex. We reproduce the nucleus-galaxy mass fraction of 0.33 ± 0.08% for galaxy stellar masses 108.4-1010.3 M⊙ with a typical precision of ~35% for the nuclei masses. Based on available model predictions, there is no single preferred formation scenario for nuclei, suggesting that nuclei are formed stochastically through a mix of processes. Nuclei metallicities are statistically identical to those of their hosts, appearing 0.07 ± 0.3 dex more metal-rich on average — although, omitting galaxies with unusual origins (i.e., compact ellipticals), nuclei are 0.20 ± 0.28 dex more metal-rich. We find no clear age difference between nuclei and their galaxies, with nuclei displaying a broad range of ages. Interestingly, we find that the most massive nuclei may be flatter and more closely aligned with the semi

  2. Hot nuclei production and deexcitation in heavy ions induced reactions on medium mass targets in the 10-84 MeV/nucleon energy domain

    International Nuclear Information System (INIS)

    Lleres, A.

    1988-01-01

    Velocity, angular distributions and total cross sections for heavy residues produced in the reactions 12 C, 14 N, 20 Ne, 40 Ar + 124 Sn have been measured in the 10-84 MeV/nucleon incident energy range using catchers technique in association with off-line gamma-activity spectroscopy. The observed reaction products are interpreted as evaporation residues from equilibrated systems formed by complete or incomplete fusion of the projectile and target nuclei. From the velocities and residual masses measured at forward angles, the linear momentum transfers and excitation energies associated with the intermediate systems are estimated using simple fusion-evaporation models and are next compared to the predictions of the preequilibrium and Fermi jets models. Energy, angular, charge and charge correlation distributions for intermediate mass fragments emitted in the reaction 32 S + nat Ag at 30 MeV/nucleon were also measured using gaseous and silicon detectors. The energy and angular distributions indicate that both equilibrated and non-equilibrated emitting sources are present. The equilibrium emission is attributed to the deexcitation of systems produced by incomplete fusion of the projectile and target nuclei. The charge correlation distributions are consistent with an asymmetric fission decay process. The linear momentum transfer and excitation energy associated with the equilibrated source are estimated using a simple fusion-fission model [fr

  3. High-accuracy mass determination of unstable nuclei with a Penning trap mass spectrometer

    CERN Multimedia

    2002-01-01

    The mass of a nucleus is its most fundamental property. A systematic study of nuclear masses as a function of neutron and proton number allows the observation of collective and single-particle effects in nuclear structure. Accurate mass data are the most basic test of nuclear models and are essential for their improvement. This is especially important for the astrophysical study of nuclear synthesis. In order to achieve the required high accuracy, the mass of ions captured in a Penning trap is determined via their cyclotron frequency $ \

  4. Nuclear Data Evaluation for Mass Chain A=217:Odd-Proton Nuclei.

    Science.gov (United States)

    Nafee, Sherif S; Shaheen, Salem A; Al-Ramady, Amir M

    2016-01-01

    Thallium (81(217)Tl, Bismuth (83(217)Bi), Astatine (85(217)At), Francium (87(217)Fr), Actinium (89(217)Ac) and Protactinium (91(217)Pa) are of odd-proton numbers among the mass chain A = 217. In the present work, the half-lives and gamma transitions for the six nuclei have been studied and adopted based on the recently published interactions or unevaluated nuclear data sets XUNDL. The Q (α) has been updated based on the recent published work of the Atomic Mass Evaluation AME2012 as well. Moreover, the total conversion electrons as well as the K-Shell to L-Shell, L-Shell to M-Shell and L-Shell to N-Shell Conversion Electron Ratios have been calculated using BrIcc code v2.3. An updated skeleton decay scheme for each of the above nuclei has been presented here. The decay hindrance factors (HF) calculated using the ALPHAD program, which is available from Brookhaven National Laboratory's website, have been calculated for the α- decay data sets for (221)Fr-, (221)Ac- and (221)Pa-α-decays.

  5. X-ray induced stellar mass loss near active galactic nuclei

    International Nuclear Information System (INIS)

    Voit, G.M.; Shull, J.M.

    1988-01-01

    The effects of UV and X-ray radiation on stars in active galactic nuclei (AGN) are critically evaluated. Mass loss rates in X-ray-induced winds are evaluated for realistic red giant models, and the effects of the ablation of stellar envelopes by radiation pressure are considered. The importance of X-ray-induced mass loss in the standard quasar model is evaluated and whether it can provide a source of accretion fuel or emission-line clouds is discussed. It is concluded that thermal winds driven by X-ray heating are a minor total supply of mass to AGN, but that thermal plus line-driven winds and stellar ablation may increase the mass loss and improve the chances for supplying a fraction of the necessary mass supply to the central object. It is speculated that when steady winds are inefficient, complex time-dependent processes due to X-ray energy injection deep into a stellar atmosphere could still release significant mass from stars. 49 references

  6. Precision Mass Measurements of Neutron-Rich Rare-Earth Nuclei

    Science.gov (United States)

    Orford, Rodney; Buchinger, Fritz; Clark, Jason; Klimes, Jeffrey; Burkey, Mary; Savard, Guy; Gorelov, Dmitry; Sharma, Kumar

    2017-09-01

    One of the open problems in nuclear astrophysics is the identification of the astrophysical site of the rapid neutron capture process (r process). Due to the lack of experimental nuclear data of neutron-rich nuclei far from stability, it remains difficult to constrain or judge the accuracy of r-process models and calculations. The Canadian Penning Trap mass spectrometer (CPT) is located in the CARIBU facility at Argonne National Laboratory where intense beams of neutron-rich isotopes are created from the spontaneous fission of a 252Cf source. The implementation of a phase-imaging mass measurement technique (PI-ICR) at the CPT in conjunction with the MR-TOF mass separator at CARIBU has improved our experimental sensitivity by more than two orders of magnitude. Recently, PI-ICR was used to make the first direct mass measurements of a number of neutron-rich rare-earth isotopes near N = 100. The phase-imaging technique, and insights from these new masses into possible r-process sites will be discussed. This work was supported by the following: NSERC SAPPJ-2015-034, NSF Grants PHY-1419765 and PHY-14330152, and the U.S. Department of Energy, Office of Nuclear Physics. This research used resources of ANL's ATLAS facility.

  7. Mass measurement of the proton rich nuclei in the A = 60-80 region

    International Nuclear Information System (INIS)

    Angelique, J.C.; Orr, N.

    1998-01-01

    In the SPEG experiments performed in 1994 a 78 Kr beam of 73 MeV/u was used to bombard an Ni target placed in SISSI to which an alpha spectrometer was associated to select the nuclei of interest. The nuclear mass determination was based on the direct measurement time-of-flight procedures worked out by the collaboration. This was made possible due to the long (around 100 m) flight base separating the alpha spectrometer and the SPEG spectrograph. From the rigidity B ρ , flight base length L, flight time T vol of the studied ion and its charge Q one can obtain its mass m by means of the relation: B ρ = m.L/(Q.T vol ). The time-of-flight was measured with a microchannel plate detector placed at the exit of alpha spectrometer and with another one located in the focus plane of SPEG. The rigidity was measured by means of a microchannel position sensitive detector placed in the dispersive image plane of SPEG detector. The particle identification (A, Z, and Q) was achieved with silicon diodes (ΔE-E technique and time-of-flight measurement). The mass uncertainty depends on the statistical indeterminacy, the mass calibration indeterminacy and on the experimental precision of the system. The overall final precision depends mainly on the counting rate. A precision better than 250 keV, giving a mass resolution of about 3.10 -4 requires a minimal statistics of 1000 counts

  8. Rapid and Bright Stellar-mass Binary Black Hole Mergers in Active Galactic Nuclei

    Science.gov (United States)

    Bartos, Imre; Kocsis, Bence; Haiman, Zoltán; Márka, Szabolcs

    2017-02-01

    The Laser Interferometer Gravitational-wave Observatory (LIGO) found direct evidence for double black hole binaries emitting gravitational waves. Galactic nuclei are expected to harbor the densest population of stellar-mass black holes. A significant fraction (˜ 30 % ) of these black holes can reside in binaries. We examine the fate of the black hole binaries in active galactic nuclei, which get trapped in the inner region of the accretion disk around the central supermassive black hole. We show that binary black holes can migrate into and then rapidly merge within the disk well within a Salpeter time. The binaries may also accrete a significant amount of gas from the disk, well above the Eddington rate. This could lead to detectable X-ray or gamma-ray emission, but would require hyper-Eddington accretion with a few percent radiative efficiency, comparable to thin disks. We discuss implications for gravitational-wave observations and black hole population studies. We estimate that Advanced LIGO may detect ˜20 such gas-induced binary mergers per year.

  9. Investigation of the disappearance of collective motion in nuclei of mass A~120-130

    Science.gov (United States)

    Maiolino, C.; Santonocito, D.; Wang, D.; Blumenfeld, Y.; Agodi, C.; Alba, R.; Amorini, F.; Auditore, L.; Bellia, G.; Cardella, G.; Coniglione, R.; Delaunay, F.; De Filippo, E.; Del Zoppo, A.; Emanuele, U.; Finocchiaro, P.; Frascaria, N.; Hongmei, F.; Lima, V.; Monrozeau, C.; Migneco, E.; Papa, M.; Piattelli, P.; Pirrone, S.; Rizzo, F.; Sapienza, P.; Scarpaci, J. A.; Trifirò, A.; Trimarchi, M.

    2014-03-01

    A study of hot Giant Dipole Resonance (GDR) in nuclei of mass A=120~130 in an excitation energy range from 150 to 330 MeV, where the GDR quenching is expected to arise, has been undertaken using the MEDEA multi-detector system. Hot nuclei were populated using complete and incomplete fusion reactions. The characterization of hot system was performed through the study of residue time of flight combined with the analysis of light charged energy spectra detected in coincidence. Gamma-ray energy spectra show an evolution of the GDR main features both in terms of width and multiplicity. Evidences of a saturation of gamma multiplicity appear at high excitation energy at variance with predictions of statistical model calculations. Gamma-ray energy spectra can been reproduced in a phenomenological way introducing in the statistical model a sharp suppression of the gamma-ray emission above E* = 240 MeV. A comparison of experimental data to models describing the GDR disappearance will be presented.

  10. Investigation of the disappearance of collective motion in nuclei of mass A~120-130

    Directory of Open Access Journals (Sweden)

    Maiolino C.

    2014-03-01

    Full Text Available A study of hot Giant Dipole Resonance (GDR in nuclei of mass A=120~130 in an excitation energy range from 150 to 330 MeV, where the GDR quenching is expected to arise, has been undertaken using the MEDEA multi-detector system. Hot nuclei were populated using complete and incomplete fusion reactions. The characterization of hot system was performed through the study of residue time of flight combined with the analysis of light charged energy spectra detected in coincidence. Gamma-ray energy spectra show an evolution of the GDR main features both in terms of width and multiplicity. Evidences of a saturation of gamma multiplicity appear at high excitation energy at variance with predictions of statistical model calculations. Gamma-ray energy spectra can been reproduced in a phenomenological way introducing in the statistical model a sharp suppression of the gamma-ray emission above E* = 240 MeV. A comparison of experimental data to models describing the GDR disappearance will be presented.

  11. Semimicroscopic description of the ODD iodine nuclei in the mass region 123<=A<=133

    International Nuclear Information System (INIS)

    Toledo, A.S. de; Rao, M.N.; Sala, O.; Krmpotic, F.

    A systematic study of the low-energy properties of odd-mass I nuclei is performed in terms of the Alaga model. Previous theoretical works are made up-to-date, according to the present level of experimental information, and extended to lighter isotopes. The residual interaction among the valence protons is approximated by both the pairing force and the surface delta interaction. The refinements introduced by the last interaction are of little importance in the description of low energy states. Excitation energies, one-body reaction amplitudes, dipole and quadrupole moments and B(M1) and B(E2) values are calculated and compared with the corresponding experimental data. Also, a few allowed β-transitions are briefly discussed

  12. Study of some odd-mass nuclei with 51 neutrons or 51 protons

    International Nuclear Information System (INIS)

    Duffait, Roger.

    1976-01-01

    The level schemes of 93 Mo, 113 Sb, 115 Sb and 119 Sb nuclei were studied. The knowledge of the sup(93m+g)Tc decays was improved. The 2,0 min 113 Te isotope was produced and studied for the first time; two 115 Te isomers with neighbouring half-lives were found and ambiguities on the 115 Te nature cleared up. The sup(119m+g)Te decays were studied with the help of isotopically separated sources and the 119 Sb level scheme was revised. The 93 Mo and 119 Sb level lifetimes were studied using Doppler-shift attenuation method (DSAM) using (p,nγ) reactions at the Van de Graaff accelerator of the University of Lyon. On the whole 16 lifetimes were measured. The experimental results were interpreted in the unified model by intermediate coupling between particle states and the even-even vibrational core; attempts to improve the interpretation by using a semi-microscopical model with the delta surface interaction were made and the two calculations were compared [fr

  13. A SCALING RELATION BETWEEN MEGAMASER DISK RADIUS AND BLACK HOLE MASS IN ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Wardle, Mark; Yusef-Zadeh, Farhad

    2012-01-01

    Several thin, Keplerian, sub-parsec megamaser disks have been discovered in the nuclei of active galaxies and used to precisely determine the mass of their host black holes. We show that there is an empirical linear correlation between the disk radius and the black hole mass. We demonstrate that such disks are naturally formed by the partial capture of molecular clouds passing through the galactic nucleus and temporarily engulfing the central supermassive black hole. Imperfect cancellation of the angular momenta of the cloud material colliding after passing on opposite sides of the hole leads to the formation of a compact disk. The radial extent of the disk is determined by the efficiency of this process and the Bondi-Hoyle capture radius of the black hole, and naturally produces the empirical linear correlation of the radial extent of the maser distribution with black hole mass. The disk has sufficient column density to allow X-ray irradiation from the central source to generate physical and chemical conditions conducive to the formation of 22 GHz H 2 O masers. For initial cloud column densities ∼ 23.5 cm –2 the disk is non-self-gravitating, consistent with the ordered kinematics of the edge-on megamaser disks; for higher cloud columns the disk would fragment and produce a compact stellar disk similar to that observed around Sgr A* at the galactic center.

  14. Radio detections during two state transitions of the intermediate-mass black hole HLX-1.

    Science.gov (United States)

    Webb, Natalie; Cseh, David; Lenc, Emil; Godet, Olivier; Barret, Didier; Corbel, Stephane; Farrell, Sean; Fender, Robert; Gehrels, Neil; Heywood, Ian

    2012-08-03

    Relativistic jets are streams of plasma moving at appreciable fractions of the speed of light. They have been observed from stellar-mass black holes (~3 to 20 solar masses, M(⊙)) as well as supermassive black holes (~10(6) to 10(9) M(⊙)) found in the centers of most galaxies. Jets should also be produced by intermediate-mass black holes (~10(2) to 10(5) M(⊙)), although evidence for this third class of black hole has, until recently, been weak. We report the detection of transient radio emission at the location of the intermediate-mass black hole candidate ESO 243-49 HLX-1, which is consistent with a discrete jet ejection event. These observations also allow us to refine the mass estimate of the black hole to be between ~9 × 10(3) M(⊙) and ~9 × 10(4) M(⊙).

  15. Constraining the Population of Small Close-in Planets Around Evolved Intermediate Mass Stars

    Science.gov (United States)

    Medina, Amber; Johnson, John Asher

    2018-01-01

    Intermediate mass stars ( > 1.3 M_Sun) have high occurrence rates of Jupiter mass planets in predominately long period orbits (~1.0 AU). There is a prominent planet gap, known as the ‘Planet Desert’, for low mass planets (Super-Earth, Neptune) < 0.5 AU from subgiants, the evolved counterpart to intermediate mass stars. Thus far, using current radial velocity methods, we have not been able to detect short period planets around subgiants due to noise from p-mode oscillations perhaps mimicking radial velocity signals (~5 m/s) in this planetary regime. Here we present techniques and preliminary results with regards to finding low mass, short period planets around subgiants and its implications for the Planet Desert.

  16. Age and mass of the star cluster around the intermediate-mass black hole HLX-1

    Science.gov (United States)

    Soria, Roberto

    2017-08-01

    We propose to study the optical counterpart of the intermediate-mass black hole (IMBH) HLX-1, about 3 years after its last X-ray outburst. Previous HST observations taken at epochs closer to an outburst show a variable near-UV/blue component, plus a constant red/near-IR component. The redder component probably comes from an old stellar population around the black hole; the bluer component may be a combination of emission from an irradiated accretion disk, and from a young stellar population. Their relative contributions and the age of the stellar population(s) are still subject of debate. By re-observing the system when the irradiated component is minimal, we will determine whether the near-UV/blue optical emission has declined even further and whether the red/near-IR optical emission has stayed approximately constant. This will tell us whether the optical counterpart is a massive star cluster, and place a strong upper limit to the young stellar population around the IMBH. Having determined the constant contribution of the stellar emission, we will then insert it into broad-band models of the emission in outburst, and obtain a better estimate of the accretion disk parameters, constraining formation and evolution scenarios for the IMBH. We will use the same set of filters as in previous HST observations, for direct comparison of brightness and colors: F140LP (ACS SBC); F300X, F336W, F390W, F555W, F621M, F775W (WFC3 UVIS); F105W, F160W (WFC3 IR). We request a total of 7 orbits.

  17. The measurement of intermediate mass fragments in the fermi energy domain

    International Nuclear Information System (INIS)

    Rudolf, G.

    1987-01-01

    Intermediate mass fragments in the Fermi energy domain were studied at GANIL via the Kr84 + Au reaction at 44 MeV/u. The Erel* quantity is used to study correlations between fragments. Fast-fast coincidences; fast-slow coincidences; slow-slow coincidences; and light particles are considered. Reaction mechanisms are discussed. Only qualitative analysis results are available, but they suggest that the quantitative results will be very instructive: light particle spectra will deliver source parameters (velocity, total charge, excitation energy and temperature); the multiplicity of intermediate mass fragments will be deduced from the triple coincidences between modules of XYZt detector

  18. An intermediate-mass black hole in the centre of the globular cluster 47 Tucanae.

    Science.gov (United States)

    Kızıltan, Bülent; Baumgardt, Holger; Loeb, Abraham

    2017-02-08

    Intermediate-mass black holes should help us to understand the evolutionary connection between stellar-mass and super-massive black holes. However, the existence of intermediate-mass black holes is still uncertain, and their formation process is therefore unknown. It has long been suspected that black holes with masses 100 to 10,000 times that of the Sun should form and reside in dense stellar systems. Therefore, dedicated observational campaigns have targeted globular clusters for many decades, searching for signatures of these elusive objects. All candidate signatures appear radio-dim and do not have the X-ray to radio flux ratios required for accreting black holes. Based on the lack of an electromagnetic counterpart, upper limits of 2,060 and 470 solar masses have been placed on the mass of a putative black hole in 47 Tucanae (NGC 104) from radio and X-ray observations, respectively. Here we show there is evidence for a central black hole in 47 Tucanae with a mass of solar masses when the dynamical state of the globular cluster is probed with pulsars. The existence of an intermediate-mass black hole in the centre of one of the densest clusters with no detectable electromagnetic counterpart suggests that the black hole is not accreting at a sufficient rate to make it electromagnetically bright and therefore, contrary to expectations, is gas-starved. This intermediate-mass black hole might be a member of an electromagnetically invisible population of black holes that grow into supermassive black holes in galaxies.

  19. Collective properties of the odd-mass I nuclei: 123,125,127I

    Science.gov (United States)

    Shroy, R. E.; Gordon, D. M.; Gai, M.; Fossan, D. B.; Gaigalas, A. K.

    1982-09-01

    The high-spin states of 123,125,127I have been investigated via the ASn(6Li, 3n)A+3I reactions to study the collective properties of the odd-mass I isotopes. In-beam measurements of γ-ray excitations, γ-γ coincidences, γ-ray angular distributions, and pulsed beam-γ timing were performed with Ge detectors to determine level energies, decay schemes, γ-ray multipolarities, Jπ assignments, and lifetime information. A similar study of the 117,119,121I isotopes is reported in the following paper. Two collective features have been identified in these odd-mass I nuclei. Systematic ΔJ=1 bands built on low-lying 92+ proton-hole (4p-1h) states were observed. The 92+ bandheads, that involve the excitation of a 1g92 proton across the Z=50 shell, drop to very low energies near the middle of the neutron shell. The properties of the 92+ proton-hole states for all of the odd-mass I isotopes are presented and related to the systematic information for the proton-hole states in the entire Z>50 transition region. Systematic ΔJ=2 bands built on 112- (1h112 quasiproton) states, on 72+ (1g72 quasiproton) states, and on 52+ (2d52 quasiproton) states were also observed. The ΔJ=2 band spacings generally follow the spacings of the Te-core ground-state bands with the exception of the 112- ΔJ=2 bands, for which the spacings decrease significantly relative to those for the Te cores as A decreases. These systematic properties are discussed in terms of several theoretical approaches to the onset of collectivity in transitional nuclei. An isomer at 2660 keV in 123I was observed to have a mean lifetime τ=38+/-3 ns. NUCLEAR REACTIONS 120-124Sn(6Li, 3n)123-127I measured γ-γ coincidences, γ(E, θ, t) deduced level schemes in odd-mass 123-127I, γ multipolarities, Jπ, T12. Enriched targets, Ge(Li) detectors.

  20. Excitation of high frequency voices from intermediate-mass-ratio inspirals with large eccentricity

    Science.gov (United States)

    Han, Wen-Biao; Cao, Zhoujian; Hu, Yi-Ming

    2017-11-01

    The coalescence of a stellar-mass compact object together with an intermediate-mass black hole, also known as an intermediate-mass-ratio inspiral, is usually not expected to be a viable gravitational wave source for the current ground-based gravitational wave detectors, due to the generally lower frequency of such a source. In this paper, we adopt the effective-one-body formalism as the equation of motion, and obtain the accurately calculated gravitational waveforms by solving the Teukolsky equation using the frequency-domain method. We point out that high frequency modes of gravitational waves can be excited by large eccentricities of intermediate-mass-ratio inspirals. These high frequency modes can extend to more than 10 Hz, and enter the designed sensitive band of Advanced LIGO and Advanced Virgo. We propose that such kinds of highly eccentric intermediate-mass-ratio inspirals could be feasible sources and potentially observable by the ground-based gravitational wave detectors, like the Advanced LIGO and Advanced Virgo.

  1. Giant dipole resonance in very hot nuclei of mass A≅115

    International Nuclear Information System (INIS)

    Suomijaervi, T.; Blumenfeld, Y.; Piattelli, P.; Le Faou, J.H.; Agodi, C.; Alamanos, N.; Alba, R.; Auger, F.; Bellia, G.; Chomaz, P.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Gaardho/je, J.J.; Garron, J.P.; Gillibert, A.; Lamehi-Rachti, M.; Liguori-Neto, R.; Maiolino, C.; Migneco, E.; Russo, G.; Roynette, J.C.; Santonocito, D.; Sapienza, P.; Scarpaci, J.A.; Smerzi, A.

    1996-01-01

    Gamma rays, light charged particles, and evaporation residues emitted from hot nuclei formed in the 36 Ar+ 90 Zr reaction at 27 MeV/nucleon have been measured at the GANIL facility with the 4π barium fluoride multidetector MEDEA. The combination of the residue and particle measurements shows that nuclei with masses around 115 and excitation energies between 350 and 550 MeV are produced. The γ spectra measured in coincidence with the evaporation residues exhibit three components: a low-energy statistical component, a high-energy contribution due to nucleon-nucleon bremsstrahlung during the initial stages of the collision, and a contribution from the decay of the giant dipole resonance built on highly excited states. The characteristics of the bremsstrahlung component are in agreement with previously published systematics. The γ yield from the decay of the giant dipole resonance remains constant over the excitation energy range studied. A comparison with other experiments shows that the N/Z asymmetry in the entrance channel does not affect the γ yield. Statistical calculations performed using the code CASCADE and supposing a fixed width and full sum rule strength for the dipole resonance strongly overpredict the data. The hypothesis of a continuously increasing width of the resonance with temperature gives a better agreement with experiment near the centroid of the resonance but overpredicts the γ spectra at higher energies. The best account of the data is given by assuming a cutoff of γ emission from the resonance above an excitation energy of approximately 250 MeV. This cutoff is discussed in terms of the time necessary to equilibrate the dipole oscillations with the hot compound nucleus. Finally, some evidence is given for a possible new low-energy component of the dipole strength at very high temperatures. copyright 1996 The American Physical Society

  2. Giant dipole resonance in very hot nuclei of mass A~=115

    Science.gov (United States)

    Suomijärvi, T.; Blumenfeld, Y.; Piattelli, P.; Le Faou, J. H.; Agodi, C.; Alamanos, N.; Alba, R.; Auger, F.; Bellia, G.; Chomaz, Ph.; Coniglione, R.; del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Gaardhøje, J. J.; Garron, J. P.; Gillibert, A.; Lamehi-Rachti, M.; Liguori-Neto, R.; Maiolino, C.; Migneco, E.; Russo, G.; Roynette, J. C.; Santonocito, D.; Sapienza, P.; Scarpaci, J. A.; Smerzi, A.

    1996-05-01

    Gamma rays, light charged particles, and evaporation residues emitted from hot nuclei formed in the 36Ar+90Zr reaction at 27 MeV/nucleon have been measured at the GANIL facility with the 4π barium fluoride multidetector MEDEA. The combination of the residue and particle measurements shows that nuclei with masses around 115 and excitation energies between 350 and 550 MeV are produced. The γ spectra measured in coincidence with the evaporation residues exhibit three components: a low-energy statistical component, a high-energy contribution due to nucleon-nucleon bremsstrahlung during the initial stages of the collision, and a contribution from the decay of the giant dipole resonance built on highly excited states. The characteristics of the bremsstrahlung component are in agreement with previously published systematics. The γ yield from the decay of the giant dipole resonance remains constant over the excitation energy range studied. A comparison with other experiments shows that the N/Z asymmetry in the entrance channel does not affect the γ yield. Statistical calculations performed using the code CASCADE and supposing a fixed width and full sum rule strength for the dipole resonance strongly overpredict the data. The hypothesis of a continuously increasing width of the resonance with temperature gives a better agreement with experiment near the centroid of the resonance but overpredicts the γ spectra at higher energies. The best account of the data is given by assuming a cutoff of γ emission from the resonance above an excitation energy of approximately 250 MeV. This cutoff is discussed in terms of the time necessary to equilibrate the dipole oscillations with the hot compound nucleus. Finally, some evidence is given for a possible new low-energy component of the dipole strength at very high temperatures.

  3. Giant dipole resonance in very hot nuclei of mass {ital A}{approx_equal}115

    Energy Technology Data Exchange (ETDEWEB)

    Suomijaervi, T.; Blumenfeld, Y.; Piattelli, P.; Le Faou, J.H.; Agodi, C.; Alamanos, N.; Alba, R.; Auger, F.; Bellia, G.; Chomaz, P.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Gaardho/je, J.J.; Garron, J.P.; Gillibert, A.; Lamehi-Rachti, M.; Liguori-Neto, R.; Maiolino, C.; Migneco, E.; Russo, G.; Roynette, J.C.; Santonocito, D.; Sapienza, P.; Scarpaci, J.A.; Smerzi, A. [Institut de Physique Nucleaire, IN2P3-CNRS, 91406 Orsay, France INFN-Laboratorio Nazionale del Sud, Via S. Sofia 44, 95123, Catania, Italy SPhN, DAPNIA, CEN Saclay, 91191 Gif sur Yvette, France GANIL, BP 5027, 14021 Caen, France The Niels Bohr Institute, University of Copenhagen, DK-2100 O/ (Denmark)

    1996-05-01

    Gamma rays, light charged particles, and evaporation residues emitted from hot nuclei formed in the {sup 36}Ar+{sup 90}Zr reaction at 27 MeV/nucleon have been measured at the GANIL facility with the 4{pi} barium fluoride multidetector MEDEA. The combination of the residue and particle measurements shows that nuclei with masses around 115 and excitation energies between 350 and 550 MeV are produced. The {gamma} spectra measured in coincidence with the evaporation residues exhibit three components: a low-energy statistical component, a high-energy contribution due to nucleon-nucleon bremsstrahlung during the initial stages of the collision, and a contribution from the decay of the giant dipole resonance built on highly excited states. The characteristics of the bremsstrahlung component are in agreement with previously published systematics. The {gamma} yield from the decay of the giant dipole resonance remains constant over the excitation energy range studied. A comparison with other experiments shows that the {ital N}/{ital Z} asymmetry in the entrance channel does not affect the {gamma} yield. Statistical calculations performed using the code CASCADE and supposing a fixed width and full sum rule strength for the dipole resonance strongly overpredict the data. The hypothesis of a continuously increasing width of the resonance with temperature gives a better agreement with experiment near the centroid of the resonance but overpredicts the {gamma} spectra at higher energies. The best account of the data is given by assuming a cutoff of {gamma} emission from the resonance above an excitation energy of approximately 250 MeV. This cutoff is discussed in terms of the time necessary to equilibrate the dipole oscillations with the hot compound nucleus. Finally, some evidence is given for a possible new low-energy component of the dipole strength at very high temperatures. {copyright} {ital 1996 The American Physical Society.}

  4. Galaxy And Mass Assembly (GAMA): The effect of galaxy group environment on active galactic nuclei

    Science.gov (United States)

    Gordon, Yjan A.; Pimbblet, Kevin A.; Owers, Matt S.; Bland-Hawthorn, Joss; Brough, Sarah; Brown, Michael J. I.; Cluver, Michelle E.; Croom, Scott M.; Holwerda, Benne W.; Loveday, Jonathan; Mahajan, Smriti; Wang, Lingyu

    2018-01-01

    In galaxy clusters, efficiently accreting active galactic nuclei (AGN) are preferentially located in the infall regions of the cluster projected phase-space, and are rarely found in the cluster core. This has been attributed to both an increase in triggering opportunities for infalling galaxies, and a reduction of those mechanisms in the hot, virialised, cluster core. Exploiting the depth and completeness (98 per cent at r 9.9 in 695 groups with 11.53 ≤ log10(M200/M⊙) ≤ 14.56 at z 13.5, AGN are preferentially found in the infalling galaxy population with 3.6σ confidence. At lower halo masses we observe no difference in AGN fraction between core and infalling galaxies. These observations support a model where a reduced number of low-speed interactions, ram pressure stripping and intra-group/cluster medium temperature, the dominance of which increase with halo mass, work to inhibit AGN in the cores of groups and clusters with log10(M200/M⊙) > 13.5, but do not significantly affect nuclear activity in cores of less massive structures.

  5. Galaxy And Mass Assembly (GAMA): the effect of galaxy group environment on active galactic nuclei

    Science.gov (United States)

    Gordon, Yjan A.; Pimbblet, Kevin A.; Owers, Matt S.; Bland-Hawthorn, Joss; Brough, Sarah; Brown, Michael J. I.; Cluver, Michelle E.; Croom, Scott M.; Holwerda, Benne W.; Loveday, Jonathan; Mahajan, Smriti; Wang, Lingyu

    2018-04-01

    In galaxy clusters, efficiently accreting active galactic nuclei (AGNs) are preferentially located in the infall regions of the cluster projected phase-space, and are rarely found in the cluster core. This has been attributed to both an increase in triggering opportunities for infalling galaxies, and a reduction of those mechanisms in the hot, virialized, cluster core. Exploiting the depth and completeness (98 per cent at r 9.9 in 695 groups with 11.53 ≤ log10(M200/M⊙) ≤ 14.56 at z 13.5, AGNs are preferentially found in the infalling galaxy population with 3.6σ confidence. At lower halo masses, we observe no difference in AGN fraction between core and infalling galaxies. These observations support a model where a reduced number of low-speed interactions, ram pressure stripping and intra-group/cluster medium temperature, the dominance of which increase with halo mass, work to inhibit AGN in the cores of groups and clusters with log10(M200/M⊙) > 13.5, but do not significantly affect nuclear activity in cores of less massive structures.

  6. The effect of the mass number of the scattering nuclei on energy storage in compressed nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, N.Z.; Saad, S.S.; Omar, Kh.M.; El-Sharkawy (Tanta Univ. (Egypt). Dept. of Physics)

    1993-05-01

    The elastic scattering of [alpha]-particles on [sup 24]Mg, [sup 27]Al and [sup 28]Si has been analysed in the framework of the effective surface potential model. The effect of the mass number A of the elastic scattering nuclei on the coefficient of compressibility has been studied. (Author).

  7. Neutron-Proton Mass Difference in Nuclear Matter and in Finite Nuclei and the Nolen-Schiffer Anomaly

    Directory of Open Access Journals (Sweden)

    Yakhshiev U.T.

    2010-04-01

    Full Text Available The neutron-proton mass difference in (isospin asymmetric nuclear matter and finite nuclei is studied in the framework of a medium-modified Skyrme model. The proposed effective Lagrangian incorporates both the medium influence of the surrounding nuclear environment on the single nucleon properties and an explicit isospin-breaking effect in the mesonic sector. Energy-dependent charged and neutral pion optical potentials in the s- and p-wave channels are included as well. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it markedly decreases in neutron matter. Furthermore, the possible interplay between the effective nucleon mass in finite nuclei and the Nolen-Schiffer anomaly is discussed. In particular, we find that a correct description of the properties of mirror nuclei leads to a stringent restriction of possible modifications of the nucleon’s effective mass in nuclei.

  8. Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO

    OpenAIRE

    Abbott, B. P.; Abbott, R.; Adhikari, R. X.; Ananyeva, A.; Anderson, S. B.; Appert, S.; Arai, K.; Araya, M. C.; Barayoga, J. C.; Barish, B. C.; Berger, B. K.; Billingsley, G.; Blackburn, J. K.; Bork, R.; Brooks, A. F.

    2017-01-01

    During their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) from merging intermediate mass black hole binaries (IMBHBs). The combined results from two independent search techniques were used in this study: the first employs a matched-filter algorithm that...

  9. Measuring Intermediate-Mass Black-Hole Binaries with Advanced Gravitational Wave Detectors.

    Science.gov (United States)

    Veitch, John; Pürrer, Michael; Mandel, Ilya

    2015-10-02

    We perform a systematic study to explore the accuracy with which the parameters of intermediate-mass black-hole binary systems can be measured from their gravitational wave (GW) signatures using second-generation GW detectors. We make use of the most recent reduced-order models containing inspiral, merger, and ringdown signals of aligned-spin effective-one-body waveforms to significantly speed up the calculations. We explore the phenomenology of the measurement accuracies for binaries with total masses between 50M(⊙) and 500M(⊙) and mass ratios between 0.1 and 1. We find that (i) at total masses below ∼200M(⊙), where the signal-to-noise ratio is dominated by the inspiral portion of the signal, the chirp mass parameter can be accurately measured; (ii) at higher masses, the information content is dominated by the ringdown, and total mass is measured more accurately; (iii) the mass of the lower-mass companion is poorly estimated, especially at high total mass and more extreme mass ratios; and (iv) spin cannot be accurately measured for our injection set with nonspinning components. Most importantly, we find that for binaries with nonspinning components at all values of the mass ratio in the considered range and at a network signal-to-noise ratio of 15, analyzed with spin-aligned templates, the presence of an intermediate-mass black hole with mass >100M(⊙) can be confirmed with 95% confidence in any binary that includes a component with a mass of 130M(⊙) or greater.

  10. Measuring the accreting stellar and intermediate mass black hole populations in the Galaxy and Local Group

    NARCIS (Netherlands)

    Grindlay, J.; Barret, D.; Belloni, T.; Corbel, S.; Kaaret, P.; Allen, B.; Bazzano, A.; Berger, E.; Bignami, G.; Caraveo, P.; De Luca, A.; Fabbiano, P.; Finger, M.; Feroci, M.; Hong, J.; Jernigan, G.; van der Klis, M.; Kouveliotou, C.; Kutyrev, A.; Loeb, A.; Paizis, A.; Pareschi, G.; Skinner, G.; Di Stefano, R.; Ubertini, P.; Wilson-Hodge, C.A.

    2010-01-01

    The population of stellar black holes (SBHs) in the Galaxy and galaxies generally is poorly known in both number and distribution. SBHs are the fossil record of the massive stars in galaxy evolution and may have produced some (if not all) of the intermediate mass (≳100M⊙) black holes (IMBHs) and, in

  11. The 90-110 mu m dust feature in low to intermediate mass protostars : Calcite?

    NARCIS (Netherlands)

    Chiavassa, A; Ceccarelli, C; Tielens, AGGM; Caux, E; Maret, S

    We present ISO spectra between 60 and 180 mum of 32 protostars of low to intermediate mass. About half of the spectra present a dust feature between similar to90 and similar to110 mum. We describe the observational characteristics of this feature, which seems to be due to one single carrier. In

  12. Elastic scattering of the intermediate energy kaon mesons on the nuclei and coulomb's effects

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhenqiu; Kong Lingjiang; Liu Xianhui

    1985-05-01

    In the frame of the eikonal scattering theory, using the basic parameters which are given by the different authors, the elastic scattering of the intermediate energy kaon mesons /sup 12/C and /sup 40/Ca are studied. The Coulomb effect is calculated too. The results are agreement with the experimental data. The Coulombv effect does not only enhance the small angle differential cross section, but also fill up the dip of the differential cross section.

  13. The Metallicity Evolution of Low Mass Galaxies: New Contraints at Intermediate Redshift

    Science.gov (United States)

    Henry, Alaina; Martin, Crystal L.; Finlator, Kristian; Dressler, Alan

    2013-01-01

    We present abundance measurements from 26 emission-line-selected galaxies at z approx. 0.6-0.7. By reaching stellar masses as low as 10(exp 8) M stellar mass, these observations provide the first measurement of the intermediate-redshift mass-metallicity (MZ) relation below 10(exp 9)M stellar mass. For the portion of our sample above M is greater than 10(exp 9)M (8/26 galaxies), we find good agreement with previous measurements of the intermediate-redshift MZ relation. Compared to the local relation, we measure an evolution that corresponds to a 0.12 dex decrease in oxygen abundances at intermediate redshifts. This result confirms the trend that metallicity evolution becomes more significant toward lower stellar masses, in keeping with a downsizing scenario where low-mass galaxies evolve onto the local MZ relation at later cosmic times. We show that these galaxies follow the local fundamental metallicity relation, where objects with higher specific (mass-normalized) star formation rates (SFRs) have lower metallicities. Furthermore, we show that the galaxies in our sample lie on an extrapolation of the SFR-M* relation (the star-forming main sequence). Leveraging the MZ relation and star-forming main sequence (and combining our data with higher-mass measurements from the literature), we test models that assume an equilibrium between mass inflow, outflow, and star formation.We find that outflows are required to describe the data. By comparing different outflow prescriptions, we show that momentum, driven winds can describe the MZ relation; however, this model underpredicts the amount of star formation in low-mass galaxies. This disagreement may indicate that preventive feedback from gas heating has been overestimated, or it may signify a more fundamental deviation from the equilibrium assumption.

  14. Search for η′ mesic nuclei by missing-mass spectroscopy of the 12C(p,d reaction

    Directory of Open Access Journals (Sweden)

    Tanaka Yoshiki K.

    2016-01-01

    Full Text Available We performed a missing-mass spectroscopy experiment of the 12C(p, d reaction at 2.5 GeV proton energy in order to search for η′ mesic nuclei. An excitation-energy spectrum of 11C was obtained around the η′ production threshold. As no significant peak structure was observed in the spectrum, upper limits of the formation cross section of η′ mesic nuclei have been determined. Preliminary results of the experiment as well as future prospects are given.

  15. Detection of late intermediates in virus capsid assembly by charge detection mass spectrometry.

    Science.gov (United States)

    Pierson, Elizabeth E; Keifer, David Z; Selzer, Lisa; Lee, Lye Siang; Contino, Nathan C; Wang, Joseph C-Y; Zlotnick, Adam; Jarrold, Martin F

    2014-03-05

    The assembly of hundreds of identical proteins into an icosahedral virus capsid is a remarkable feat of molecular engineering. How this occurs is poorly understood. Key intermediates have been anticipated at the end of the assembly reaction, but it has not been possible to detect them. In this work we have used charge detection mass spectrometry to identify trapped intermediates from late in the assembly of the hepatitis B virus T = 4 capsid, a complex of 120 protein dimers. Prominent intermediates are found with 104/105, 110/111, and 117/118 dimers. Cryo-EM observations indicate the intermediates are incomplete capsids and, hence, on the assembly pathway. On the basis of their stability and kinetic accessibility we have proposed plausible structures. The prominent trapped intermediate with 104 dimers is attributed to an icosahedron missing two neighboring facets, the 111-dimer species is assigned to an icosahedron missing a single facet, and the intermediate with 117 dimers is assigned to a capsid missing a ring of three dimers in the center of a facet.

  16. Ion Mobility-Mass Spectrometry Reveals the Energetics of Intermediates that Guide Polyproline Folding

    Science.gov (United States)

    Shi, Liuqing; Holliday, Alison E.; Glover, Matthew S.; Ewing, Michael A.; Russell, David H.; Clemmer, David E.

    2016-01-01

    Proline favors trans-configured peptide bonds in native proteins. Although cis/ trans configurations vary for non-native and unstructured states, solvent also influences these preferences. Water induces the all- cis right-handed polyproline-I (PPI) helix of polyproline to fold into the all- trans left-handed polyproline-II (PPII) helix. Our recent work has shown that this occurs via a sequential mechanism involving six resolved intermediates [Shi, L., Holliday, A.E., Shi, H., Zhu, F., Ewing, M.A., Russell, D.H., Clemmer, D.E.: Characterizing intermediates along the transition from PPI to PPII using ion mobility-mass spectrometry. J. Am. Chem. Soc. 136, 12702-12711 (2014)]. Here, we use ion mobility-mass spectrometry to make the first detailed thermodynamic measurements of the folding intermediates, which inform us about how and why this transition occurs. It appears that early intermediates are energetically favorable because of the hydration of the peptide backbone, whereas late intermediates are enthalpically unfavorable. However, folding continues, as the entropy of the system increases upon successive formation of each new structure. When PPII is immersed in 1-propanol, the PPII→PPI transition occurs, but this reaction occurs through a very different mechanism. Early on, the PPII population splits onto multiple pathways that eventually converge through a late intermediate that continues on to the folded PPI helix. Nearly every step is endothermic. Folding results from a stepwise increase in the disorder of the system, allowing a wide-scale search for a critical late intermediate. Overall, the data presented here allow us to establish the first experimentally determined energy surface for biopolymer folding as a function of solution environment.

  17. The Black Hole Mass-Bulge Luminosity Relationship for Active Galactic Nuclei From Reverberation Mapping and Hubble Space Telescope Imaging

    DEFF Research Database (Denmark)

    Bentz, Misty C.; Peterson, Bradley M.; Pogge, Richard W.

    2009-01-01

    We investigate the relationship between black hole mass and bulge luminosity for active galactic nuclei (AGNs) with reverberation-based black hole mass measurements and bulge luminosities from two-dimensional decompositions of Hubble Space Telescope host galaxy images. We find that the slope...... of the relationship for AGNs is 0.76-0.85 with an uncertainty of ~0.1, somewhat shallower than the M BH vprop L 1.0±0.1 relationship that has been fit to nearby quiescent galaxies with dynamical black hole mass measurements. This difference is somewhat perplexing, as the AGN black hole masses include an overall...

  18. Ground state properties of exotic nuclei in deformed medium mass region

    International Nuclear Information System (INIS)

    Manju; Chatterjee, R.; Singh, Jagjit; Shubhchintak

    2017-01-01

    The dipole moment, size of the nucleus and other ground state properties of deformed nuclei 37 Mg and 31 Ne are presented. Furthermore with this deformed wave function the electric dipole strength distribution for deformed nuclei 37 Mg and 31 Ne is calculated. This will allow us to investigate the two dimensional scaling phenomenon with two parameters: quadrupole deformation and separation energy

  19. A neural mass model of basal ganglia nuclei simulates pathological beta rhythm in Parkinson's disease

    Science.gov (United States)

    Liu, Fei; Wang, Jiang; Liu, Chen; Li, Huiyan; Deng, Bin; Fietkiewicz, Chris; Loparo, Kenneth A.

    2016-12-01

    An increase in beta oscillations within the basal ganglia nuclei has been shown to be associated with movement disorder, such as Parkinson's disease. The motor cortex and an excitatory-inhibitory neuronal network composed of the subthalamic nucleus (STN) and the external globus pallidus (GPe) are thought to play an important role in the generation of these oscillations. In this paper, we propose a neuron mass model of the basal ganglia on the population level that reproduces the Parkinsonian oscillations in a reciprocal excitatory-inhibitory network. Moreover, it is shown that the generation and frequency of these pathological beta oscillations are varied by the coupling strength and the intrinsic characteristics of the basal ganglia. Simulation results reveal that increase of the coupling strength induces the generation of the beta oscillation, as well as enhances the oscillation frequency. However, for the intrinsic properties of each nucleus in the excitatory-inhibitory network, the STN primarily influences the generation of the beta oscillation while the GPe mainly determines its frequency. Interestingly, describing function analysis applied on this model theoretically explains the mechanism of pathological beta oscillations.

  20. THE M BH-L SPHEROID RELATION AT HIGH AND LOW MASSES, THE QUADRATIC GROWTH OF BLACK HOLES, AND INTERMEDIATE-MASS BLACK HOLE CANDIDATES

    International Nuclear Information System (INIS)

    Graham, Alister W.; Scott, Nicholas

    2013-01-01

    From a sample of 72 galaxies with reliable supermassive black hole masses M bh , we derive the M bh -(host spheroid luminosity, L) relation for (1) the subsample of 24 core-Sérsic galaxies with partially depleted cores, and (2) the remaining subsample of 48 Sérsic galaxies. Using K s -band Two Micron All Sky Survey data, we find the near-linear relation M bh ∝L 1.10±0.20 K s for the core-Sérsic spheroids thought to be built in additive dry merger events, while we find the relation M bh ∝L 2.73±0.55 K s for the Sérsic spheroids built from gas-rich processes. After converting literature B-band disk galaxy magnitudes into inclination- and dust-corrected bulge magnitudes, via a useful new equation presented herein, we obtain a similar result. Unlike with the M bh -(velocity dispersion) diagram, which is also updated here using the same galaxy sample, it remains unknown whether barred and non-barred Sérsic galaxies are offset from each other in the M bh -L diagram. While black hole feedback has typically been invoked to explain what was previously thought to be a nearly constant M bh /M Spheroid mass ratio of ∼0.2%, we advocate that the near-linear M bh -L and M bh -M Spheroid relations observed at high masses may have instead arisen largely from the additive dry merging of galaxies. We argue that feedback results in a dramatically different scaling relation, such that black hole mass scales roughly quadratically with the spheroid mass in Sérsic galaxies. We therefore introduce a revised cold-gas 'quasar' mode feeding equation for semi-analytical models to reflect what we dub the quadratic growth of black holes in Sérsic galaxies built amidst gas-rich processes. Finally, we use our new Sérsic M bh -L equations to predict the masses of candidate intermediate mass black holes in almost 50 low-luminosity spheroids containing active galactic nuclei, finding many masses between that of stellar mass black holes and supermassive black holes.

  1. Does Explosive Nuclear Burning Occur in Tidal Disruption Events of White Dwarfs by Intermediate-mass Black Holes?

    Energy Technology Data Exchange (ETDEWEB)

    Tanikawa, Ataru; Sato, Yushi; Hachisu, Izumi [Department of Earth Science and Astronomy, College of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Nomoto, Ken’ichi; Maeda, Keiichi [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Nakasato, Naohito, E-mail: tanikawa@ea.c.u-tokyo.ac.jp [Department of Computer Science and Engineering, University of Aizu, Tsuruga Ikki-machi Aizu-Wakamatsu, Fukushima 965-8580 (Japan)

    2017-04-20

    We investigate nucleosynthesis in tidal disruption events (TDEs) of white dwarfs (WDs) by intermediate-mass black holes. We consider various types of WDs with different masses and compositions by means of three-dimensional (3D) smoothed particle hydrodynamics (SPH) simulations. We model these WDs with different numbers of SPH particles, N , from a few 10{sup 4} to a few 10{sup 7} in order to check mass resolution convergence, where SPH simulations with N > 10{sup 7} (or a space resolution of several 10{sup 6} cm) have unprecedentedly high resolution in this kind of simulation. We find that nuclear reactions become less active with increasing N and that these nuclear reactions are excited by spurious heating due to low resolution. Moreover, we find no shock wave generation. In order to investigate the reason for the absence of a shock wave, we additionally perform one-dimensional (1D) SPH and mesh-based simulations with a space resolution ranging from 10{sup 4} to 10{sup 7} cm, using a characteristic flow structure extracted from the 3D SPH simulations. We find shock waves in these 1D high-resolution simulations, one of which triggers a detonation wave. However, we must be careful of the fact that, if the shock wave emerged in an outer region, it could not trigger the detonation wave due to low density. Note that the 1D initial conditions lack accuracy to precisely determine where a shock wave emerges. We need to perform 3D simulations with ≲10{sup 6} cm space resolution in order to conclude that WD TDEs become optical transients powered by radioactive nuclei.

  2. A new Time-of-Flight mass measurement project for exotic nuclei and ultra-high precision detector development

    Directory of Open Access Journals (Sweden)

    Sun Bao-Hua

    2016-01-01

    Full Text Available The time-of-flight (TOF mass spectrometry (MS, a high-resolution magnetic spectrometer equipped with a fast particle tracking system, is well recognized by its ability in weighing the most exotic nuclei. Currently such TOF-MS can achieve a mass resolution power of about 2×10−4. We show that the mass resolution can be further improved by one order of magnitude with augmented timing and position detectors. We report the progress in developing ultra-fast detectors to be used in TOF-MS.

  3. A prevalence of dynamo-generated magnetic fields in the cores of intermediate-mass stars.

    Science.gov (United States)

    Stello, Dennis; Cantiello, Matteo; Fuller, Jim; Huber, Daniel; García, Rafael A; Bedding, Timothy R; Bildsten, Lars; Aguirre, Victor Silva

    2016-01-21

    Magnetic fields play a part in almost all stages of stellar evolution. Most low-mass stars, including the Sun, show surface fields that are generated by dynamo processes in their convective envelopes. Intermediate-mass stars do not have deep convective envelopes, although 10 per cent exhibit strong surface fields that are presumed to be residuals from the star formation process. These stars do have convective cores that might produce internal magnetic fields, and these fields might survive into later stages of stellar evolution, but information has been limited by our inability to measure the fields below the stellar surface. Here we report the strength of dipolar oscillation modes for a sample of 3,600 red giant stars. About 20 per cent of our sample show mode suppression, by strong magnetic fields in the cores, but this fraction is a strong function of mass. Strong core fields occur only in red giants heavier than 1.1 solar masses, and the occurrence rate is at least 50 per cent for intermediate-mass stars (1.6-2.0 solar masses), indicating that powerful dynamos were very common in the previously convective cores of these stars.

  4. Experimental study of high spin states in low-medium mass nuclei by use of charge particle induced reactions

    International Nuclear Information System (INIS)

    Alenius, N.G.

    1975-01-01

    For the test of nuclear models the study of the properties of nuclear states of high angular momentum is especially important, because such states can often be given very simple theoretical descriptions. High spin states are easily populated by use of reactions initiated by alpha particles or heavy ions. In this thesis a number of low-medium mass nuclei have been studied, with emphasis on high spin states. (Auth.)

  5. Seniority four admixures in the low-lying 0+ states of even-mass tin and lead nuclei

    International Nuclear Information System (INIS)

    Quesne, C.; Salmon, Y.; Spitz, S.

    1977-01-01

    New statistical measures of symmetry breaking are used to evaluate the total seniority four admixtures in the low-lying 0 + states of even-mass tin and lead nuclei. This approach is based on the centroid energies and partial widths of fixed total seniority and parity spectral distributions. Some seniority four states are found to be surprisingly low. However, the ground state is always a very pure seniority zero state

  6. Ultra-luminous X-ray sources and intermediate-mass black holes

    International Nuclear Information System (INIS)

    Cseh, David

    2012-01-01

    More than ten years ago, the discovery of Ultra-luminous X-ray sources (ULXs) has opened up an entirely new field in astrophysics. Many ideas were developed to explain the nature of these sources, like their emission mechanism, mass, and origin, without any strong conclusions. Their discovery boosted the fields of X-ray binaries, accretion physics, stellar evolution, cosmology, black hole formation and growth, due to the concept of intermediate-mass black holes (IMBHs). Since their discovery is related to the domain of X-ray astrophysics, there have been very few studies made in other wavelengths. This thesis focuses on the multiwavelength nature of Ultra-luminous X-ray sources and intermediate-mass black holes from various aspects, which help to overcome some difficulties we face today. First, I investigated the accretion signatures of a putative intermediate-mass black hole in a particular globular cluster. To this purpose, I characterized the nature of the innermost X-ray sources in the cluster. Then I calculated an upper limit on the mass of the black hole by studying possible accretion efficiencies and rates based on the dedicated X-ray and radio observations. The accreting properties of the source was described with standard spherical accretion and in the context of inefficient accretion. Secondly, I attempted to dynamically measure the mass of the black hole in a particular ULX via optical spectroscopy. I discovered that a certain emission line has a broad component that markedly shifts in wavelength. I investigated the possibility whether this line originates in the accretion disk, and thus might trace the orbital motion of the binary system. I also characterized the parameters of the binary system, such as the mass function, possible orbital separation, the size of the line-emitting region, and an upper limit on the mass of the black hole. Then I studied the environment of a number of ULXs that are associated with large-scale optical and radio nebulae. I

  7. Parasites favour intermediate nestling mass and brood size in cliff swallows.

    Science.gov (United States)

    Brown, Charles R; Brown, Mary Bomberger

    2018-02-01

    A challenge of life-history theory is to explain why animal body size does not continue to increase, given various advantages of larger size. In birds, body size of nestlings and the number of nestlings produced (brood size) have occasionally been shown to be constrained by higher predation on larger nestlings and those from larger broods. Parasites also are known to have strong effects on life-history traits in birds, but whether parasitism can be a driver for stabilizing selection on nestling body size or brood size is unknown. We studied patterns of first-year survival in cliff swallows (Petrochelidon pyrrhonota) in western Nebraska in relation to brood size and nestling body mass in nests under natural conditions and in those in which hematophagous ectoparasites had been removed by fumigation. Birds from parasitized nests showed highest first-year survival at the most common, intermediate brood-size and nestling-mass categories, but cliff swallows from nonparasitized nests had highest survival at the heaviest nestling masses and no relationship with brood size. A survival analysis suggested stabilizing selection on brood size and nestling mass in the presence (but not in the absence) of parasites. Parasites apparently favour intermediate offspring size and number in cliff swallows and produce the observed distributions of these traits, although the mechanisms are unclear. Our results emphasize the importance of parasites in life-history evolution. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  8. Analytical mass formula and nuclear surface properties in the ETF approximation. Part II: asymmetric nuclei

    Science.gov (United States)

    Aymard, François; Gulminelli, Francesca; Margueron, Jérôme

    2016-08-01

    We have recently addressed the problem of the determination of the nuclear surface energy for symmetric nuclei in the framework of the extended Thomas-Fermi (ETF) approximation using Skyrme functionals. We presently extend this formalism to the case of asymmetric nuclei and the question of the surface symmetry energy. We propose an approximate expression for the diffuseness and the surface energy. These quantities are analytically related to the parameters of the energy functional. In particular, the influence of the different equation of state parameters can be explicitly quantified. Detailed analyses of the different energy components (local/non-local, isoscalar/isovector, surface/curvature and higher order) are also performed. Our analytical solution of the ETF integral improves previous models and leads to a precision of better than 200 keV per nucleon in the determination of the nuclear binding energy for dripline nuclei.

  9. Fission fragments mass distributions of nuclei populated by the multinucleon transfer channels of the 18O+232Th reaction

    Directory of Open Access Journals (Sweden)

    R. Léguillon

    2016-10-01

    Full Text Available It is shown that the multinucleon transfer reactions is a powerful tool to study fission of exotic neutron-rich actinide nuclei, which cannot be accessed by particle-capture or heavy-ion fusion reactions. In this work, multinucleon transfer channels of the 18O+232Th reaction are used to study fission of fourteen nuclei 231,232,233,234Th, 232,233,234,235,236Pa, and 234,235,236,237,238U. Identification of fissioning nuclei and of their excitation energy is performed on an event-by-event basis, through the measurement of outgoing ejectile particle in coincidence with fission fragments. Fission fragment mass distributions are measured for each transfer channel, in selected bins of excitation energy. In particular, the mass distributions of 231,234Th and 234,235,236Pa are measured for the first time. Predominantly asymmetric fission is observed at low excitation energies for all studied cases, with a gradual increase of the symmetric mode towards higher excitation energy. The experimental distributions are found to be in general agreement with predictions of the fluctuation–dissipation model.

  10. Two-proton radioactivity with 2p halo in light mass nuclei A=18–34

    Directory of Open Access Journals (Sweden)

    G. Saxena

    2017-12-01

    Full Text Available Two-proton radioactivity with 2p halo is reported theoretically in light mass nuclei A=18–34. We predict 19Mg, 22Si, 26S, 30Ar and 34Ca as promising candidates of ground state 2p-radioactivity with S2p0. Observation of extended tail of spatial charge density distribution, larger charge radius and study of proton single particle states, Fermi energy and the wave functions indicate 2p halo like structure which supports direct 2p emission. The Coulomb and centrifugal barriers in experimentally identified 2p unbound 22Si show a quasi-bound state that ensures enough life time for such experimental probes. Our predictions are in good accord with experimental and other theoretical data available so far. Keywords: Relativistic mean-field theory, Nilson Strutinsky approach, Two-proton radioactivity, One- and two-proton separation energy, Halo nuclei, Proton drip-lines

  11. Role of nuclear reactions on stellar evolution of intermediate-mass stars

    Science.gov (United States)

    Möller, H.; Jones, S.; Fischer, T.; Martínez-Pinedo, G.

    2018-01-01

    The evolution of intermediate-mass stars (8 - 12 solar masses) represents one of the most challenging subjects in nuclear astrophysics. Their final fate is highly uncertain and strongly model dependent. They can become white dwarfs, they can undergo electron-capture or core-collapse supernovae or they might even proceed towards explosive oxygen burning and a subsequent thermonuclear explosion. We believe that an accurate description of nuclear reactions is crucial for the determination of the pre-supernova structure of these stars. We argue that due to the possible development of an oxygen-deflagration, a hydrodynamic description has to be used. We implement a nuclear reaction network with ∼200 nuclear species into the implicit hydrodynamic code AGILE. The reaction network considers all relevant nuclear electron captures and beta-decays. For selected relevant nuclear species, we include a set of updated reaction rates, for which we discuss the role for the evolution of the stellar core, at the example of selected stellar models. We find that the final fate of these intermediate-mass stars depends sensitively on the density threshold for weak processes that deleptonize the core.

  12. Accurate mass measurements of very short-lived nuclei. Prerequisites for high-accuracy investigations of superallowed β-decays

    International Nuclear Information System (INIS)

    Herfurth, F.; Kellerbauer, A.; Sauvan, E.; Ames, F.; Engels, O.; Audi, G.; Lunney, D.; Beck, D.; Blaum, K.; Kluge, H.J.; Scheidenberger, C.; Sikler, G.; Weber, C.; Bollen, G.; Schwarz, S.; Moore, R.B.; Oinonen, M.

    2002-01-01

    Mass measurements of 34 Ar, 73-78 Kr, and 74,76 Rb were performed with the Penning-trap mass spectrometer ISOLTRAP. Very accurate Q EC -values are needed for the investigations of the Ft-value of 0 + → 0 + nuclear β-decays used to test the standard model predictions for weak interactions. The necessary accuracy on the Q EC -value requires the mass of mother and daughter nuclei to be measured with δm/m ≤ 3 . 10 -8 . For most of the measured nuclides presented here this has been reached. The 34 Ar mass has been measured with a relative accuracy of 1.1 .10 -8 . The Q EC -value of the 34 Ar 0 + → 0 + decay can now be determined with an uncertainty of about 0.01%. Furthermore, 74 Rb is the shortest-lived nuclide ever investigated in a Penning trap. (orig.)

  13. Physical properties of low-mass star-forming galaxies at intermediate redshifts (z <1)

    Science.gov (United States)

    Gallego, J.; Rodríguez-Muñoz, L.; Pacifici, C.; Tresse, L.; Charlot, S.; Gil de Paz, A.; Barro, G.; Villar, V.

    2015-05-01

    In this poster we present the physical properties of a sample of low-mass star-forming galaxies at intermediate redshifts (zstructures that hierarchical models predict to form first in the Universe (Dekel & Silk 1986) and that are responsible for the reionization process (Bouwens et al. 2012); and (2) the way or epoch they form and how they evolve are still open questions of modern astrophysics. We selected the sample on the CDFS field. Photometry (40 bands, from UV to far-IR) and preliminary photometric redshifts and stellar masses were obtained from RAINBOW database (Pérez-González et al. 2008). Morphology fom Griffith et al. (2012). Main selection was done by stellar mass, selecting those galaxies with stellar mass M_*MOS spectroscopy with the VIMOS spectrograph at VLT. The average spectrum is characterized by a faint, blue and flat continuum and strong emission lines, revealing that the systems are dominated by an undergoing star formation burst. SFRs and stellar masses are consistent with the SF main-squence over a 2 dex range. More massive objects show higher SFRs than low-mass objects, following the SF main sequence. Distant dwarfs and BCDs follow the overall star-forming sequence in the excitation-luminosity diagram, populating the high excitation, low metallicity and high strength region.

  14. Intermediate-mass-ratio black-hole binaries: numerical relativity meets perturbation theory.

    Science.gov (United States)

    Lousto, Carlos O; Nakano, Hiroyuki; Zlochower, Yosef; Campanelli, Manuela

    2010-05-28

    We study black-hole binaries in the intermediate-mass-ratio regime 0.01≲q≲0.1 with a new technique that makes use of nonlinear numerical trajectories and efficient perturbative evolutions to compute waveforms at large radii for the leading and nonleading (ℓ, m) modes. As a proof-of-concept, we compute waveforms for q=1/10. We discuss applications of these techniques for LIGO and VIRGO data analysis and the possibility that our technique can be extended to produce accurate waveform templates from a modest number of fully nonlinear numerical simulations.

  15. Direct mass and lifetime measurements of neutron-rich nuclei up to A∼100 using the TOFI spectrometer at LAMPF

    International Nuclear Information System (INIS)

    Lind, V.G.

    1993-01-01

    This project was directed toward the study of neutron-rich nuclei using the experimental facilities at LAMPF, which is a part of LANL. The principal results of the investigation include the discovery of many new isotopes along with a measurement of their masses and in particular those nuclides in the Z = 7--19 and 14 --26 regions of the chart of the nuclides.Thirty-four new nuclides were detected and studied with their masses being measured with relatively high accuracy, and an additional twenty-six that were previously known and measured were remeasured to an improved accuracy. Besides providing new information about the mass surface in new and extended redons of the chart of the nuclides, this investigation enabled properties and previously unknown structure of some of the nuclei to be determined such as nuclear deformation among some of the nuclides. Also a study of the neutron pairing gaps and the proton pairing gaps among these nuclides was made. Other developments also achieved included instrument (TOFI) improvements and upgrades and theoretical investigations into the masses of the hadrons

  16. A dye laser-cryogenic helium jet system and recoil-mass-separator for studies of nuclei far from stability

    CERN Document Server

    Clark, D L; Cormier, T M; Hermann, G; Lin, B S; Martin, A G; Nicolis, N G; Stwertka, P M

    1981-01-01

    Most of the recent applications of lasers to on-line measurements of hyperfine interactions and isotope shifts have been made using high energy proton beams to produce large fluxes of a wide range of unstable atoms. On-line mass separators select the atomic species of interest. At NSRL the authors have in the final stages of development an on-line laser spectroscopy system for the upgraded MP tandem. The system is based on the use of more selective heavy-ion reactions so that mass separation is not usually required, and very sensitive detection techniques so that measurements are possible with small fluxes of atoms. A recoil mass separator is also near completion and will be used for a variety of studies of nuclei far from stability, including providing, when necessary, mass separated reaction products for study using the laser system. The heavy ion beam energy available from the upgraded MP allows production of neutron deficient nuclei by means of fusion-evaporation reactions that is limited only by the onse...

  17. Characterizing Intermediate-Mass, Pre-Main-Sequence Stars via X-Ray Emision

    Science.gov (United States)

    Haze Nunez, Evan; Povich, Matthew Samuel; Binder, Breanna Arlene; Broos, Patrick; Townsley, Leisa K.

    2018-01-01

    The X-ray emission from intermediate-mass, pre-main-sequence stars (IMPS) can provide useful constraints on the ages of very young (${Project. The Carina massive star-forming complex is of special interest due to the wide variation of star formation stages within the region. Candidate IMPS were identified using infrared spectral energy distribution (SED) models. X-ray properties, including thermal plasma temperatures and absorption-corrected fluxes, were derived from XSPEC fits performed using absorption ($N_{H}$) constrained by the extinction values returned by the infrared SED fits. We find that IMPS have systematically higher X-ray luminosities compared to their lower-mass cousins, the TTauri stars.This work is supported by the National Science Foundation under grant CAREER-1454334 and by NASA through Chandra Award 18200040.

  18. Systematic of triaxial moment of inertia in even nuclei of mass region A = 90 - 120

    International Nuclear Information System (INIS)

    Bihari, Chhail; Sharma, Aparna; Varshney, A.K.; Singh, M.; Gupta, D.K.; Varshney, Mani; Singh, Yuvraj; Gupta, K.K.

    2011-01-01

    The Ru - isotopes with Z > 50 lie in a region of structural change that has been a challenge to theoretical interpretations. The Zr and Sr - isotopes near A ∼ 100 undergo the most rapid spherical deformed transition in heavy nuclei. The rate of change of structure with neutron number becomes more gradual with increasing proton number in Mo, Ru, Pd and Cd - nuclei. The qualitative trend of 'a' versus N p N n are found similar in Ru and Pd isotopes. The present study points out a systematic difference in the rates of growth of collectivity in different regions i.e. particle-particle and hole-hole (P,P and P,H) that seems not to have been noted before in moment of inertia 'a'

  19. Determination of Protein Folding Intermediate Structures Consistent with Data from Oxidative Footprinting Mass Spectrometry.

    Science.gov (United States)

    Heinkel, Florian; Gsponer, Jörg

    2016-01-29

    The mapping of folding landscapes remains an important challenge in protein chemistry. Pulsed oxidative labeling of exposed residues and their detection via mass spectrometry provide new means of taking time-resolved "snapshots" of the structural changes that occur during protein folding. However, such experiments have been so far only interpreted qualitatively. Here, we report the detailed structural interpretation of mass spectrometry data from fast photochemical oxidation of proteins (FPOP) experiments at atomic resolution in a biased molecular dynamics approach. We are able to calculate structures of the early folding intermediate of the model system barstar that are fully consistent with FPOP data and Φ values. Furthermore, structures calculated with both FPOP data and Φ values are significantly less compact and have fewer helical residues than intermediate structures calculated with Φ values only. This improves the agreement with the experimental β-Tanford value and CD measurements. The restraints that we introduce facilitate the structural interpretation of FPOP data and provide new means for refined structure calculations of transiently sampled states on protein folding landscapes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Evidence for an Intermediate Mass Black Hole in NGC 5408 X-1

    Science.gov (United States)

    Strohmayer, Tod E.; Mushotzky, Richard F.

    2009-01-01

    intermediate mass black hole.

  1. Structure of nuclei with masses 76 and 82 and nuclear matrix elements of neutrinoless double beta decay

    Science.gov (United States)

    Yoshinaga, N.; Yanase, K.; Higashiyama, K.; Teruya, E.; Taguchi, D.

    2018-02-01

    Nuclear shell-model calculations are carried out for isobaric nuclei with masses 76 and 82. Energy spectra and electromagnetic transition rates are compared with the experimental data. Using the wavefunctions thus obtained, nuclear matrix elements for the neutrinoless double beta decay are estimated. In order to investigate the model dependence on the nuclear matrix elements, pair-truncated shell-model calculations are also performed. By comparing the results with those in other models, the nuclear matrix elements are found to be sensitive to the ground-state correlations. In particular, nuclear matrix elements have strong correlations with pairing gaps.

  2. Interferometric measurements of dry mass content in nuclei and cytoplasm in the life cycle of antheridial filaments cells of Chara vulgaris L. in their successive developmental stages

    Directory of Open Access Journals (Sweden)

    Hanna Kuran

    2015-01-01

    Full Text Available Interferometric measurements of the nucleus and cytoplasm dry mass during interphase in the successive stages of development of antheridial filaments of Chara vulgaris demonstrated that the dry mass and surface area of cell nuclei double in size in each of the successive generations of the filaments, whereas neither the surface nor the dry mass of the cytoplasm increase in such proportion in the same period. In the successive stages of development of the antheridial filaments the dry mass and surface area of the nuclei and cytoplasm gradually diminish.

  3. X-ray Emission Properties of Intermediate-Mass, Pre-Main-Sequence Stars

    Science.gov (United States)

    Povich, Matthew S.; Binder, Breanna; Townsley, Leisa K.; Broos, Patrick S.

    2017-08-01

    Intermediate-mass (2-8 M⊙) main-sequence stars with A to mid-B spectral types occupy an X-ray "desert" of weak intrinsic emission between low- and high-mass stars. Lacking the wind-shock driven emission of massive, O and early B stars or the convectively-driven magnetic reconnection flaring activity of later-type stars, X-ray detections of (non-peculiar) main-sequence AB stars are typically ascribed to the presence of unresolved, lower-mass binary companions. There is mounting evidence, however, that intermediate-mass, pre-main sequence stars (IMPS) with GK spectral types produce intrinsic X-ray emission that rapidly decays with time following the development of a radiative zone as IMPS approach the ZAMS as AB stars. This suggests that X-ray emission from IMPS may be a more luminous analog of the well-studied coronal X-ray emission from lower-mass, T Tauri stars. Statistical studies of young IMPS have been hampered by their scarcety in nearby, unobscured star-forming regions. We present the first results from a spectral-fitting study to measure absorption-corrected X-ray luminosities and plasma temperatures for hundreds of candidate X-ray emitting IMPS found in the MYStIX and MAGiX surveys of massive Galactic star forming regions. Candidate IMPS are placed on the HR diagram via a novel infrared spectral energy distribution modeling technique designed for highly-obscured, young massive star-forming regions. The rapid decay of X-ray emission from these objects has the potential to provide an independent chronometer to constrain star formation rates, and may produce an age-dependent bias in the relationship between the stellar X-ray luminosity function and mass function in distant (>2 kpc) regions observed with relatively shallow X-ray observations.This work is supported by the National Science Foundation under grant CAREER-1454334 and by NASA through Chandra Award 18200040.

  4. Understanding the environment around the intermediate mass black hole candidate ESO 243-49 HLX-1

    Science.gov (United States)

    Webb, N. A.; Guérou, A.; Ciambur, B.; Detoeuf, A.; Coriat, M.; Godet, O.; Barret, D.; Combes, F.; Contini, T.; Graham, Alister W.; Maccarone, T. J.; Mrkalj, M.; Servillat, M.; Schroetter, I.; Wiersema, K.

    2017-06-01

    Aims: ESO 243-49 HLX-1, otherwise known as HLX-1, is an intermediate mass black hole (IMBH) candidate located 8'' (3.7 Kpc) from the centre of the edge-on S0 galaxy ESO 243-49. How the black hole came to be associated with this galaxy, and the nature of the environment in which it resides, remain unclear. Using multi-wavelength observations we aim to investigate the nature of the medium surrounding HLX-1, search for evidence of past mergers with ESO 243-49 and constrain parameters of the galaxy, including the mass of the expected central supermassive black hole, essential for future modelling of the interaction of the IMBH and ESO 243-49. Methods: We have reduced and analysed integral field unit observations of ESO 243-49 that were taken with the MUSE instrument on the VLT. Using complementary multi-wavelength data, including X-shooter, HST, Swift, Chandra and ATCA data, we have further examined the vicinity of HLX-1. We additionally examined the nature of the host galaxy and estimate the mass of the central supermassive black hole in ESO 243-49 using (black hole mass)-(host spheroid) scaling relations and the fundamental plane of black hole activity. Results: No evidence for a recent minor-merger that could result in the presence of the IMBH is discerned, but the data are compatible with a scenario in which minor mergers may have occurred in the history of ESO 243-49. The MUSE data reveal a rapidly rotating disc in the centre of the galaxy, around the supermassive black hole. The mass of the supermassive black hole at the centre of ESO 243-49 is estimated to be 0.5-23 × 107M⊙. Studying the spectra of HLX-1, that were taken in the low and hard state, we determine Hα flux variability to be at least a factor 6, compared to observations taken during the high and soft state. This Hα flux variability over one year indicates that the line originates close to the intermediate mass black hole, excluding the possibility that the line emanates from a surrounding nebula

  5. Liquid Chromatography with Tandem Mass Spectrometry: A Sensitive Method for the Determination of Dehydrodiisoeugenol in Rat Cerebral Nuclei

    Directory of Open Access Journals (Sweden)

    You-Bo Zhang

    2016-03-01

    Full Text Available A new liquid chromatography–tandem mass spectrometry (LC-MS/MS method is developed for the quantification of dehydrodiisoeugenol (DDIE in rat cerebral nuclei after single intravenous administration. DDIE and daidzein (internal standard were separated on a Diamonsil™ ODS C18 column with methanol–water containing 0.1% formic acid (81:19, v/v as a mobile phase. Detection of DDIE was performed on a positive electrospray ionization source using a triple quadrupole mass spectrometer. DDIE and daidzein were monitored at m/z 327.2→188.0 and m/z 255.0→199.2, respectively, in multiple reaction monitoring mode. This method enabled quantification of DDIE in various brain areas, including, cortex, hippocampus, striatum, hypothalamus, cerebellum and brainstem, with high specificity, precision, accuracy, and recovery. The data herein demonstrate that our new LC-MS/MS method is highly sensitive and suitable for monitoring cerebral nuclei distribution of DDIE.

  6. EVIDENCE FOR AN INTERMEDIATE-MASS BLACK HOLE IN NGC 5408 X-1

    International Nuclear Information System (INIS)

    Strohmayer, Tod E.; Mushotzky, Richard F.

    2009-01-01

    We report the discovery with XMM-Newton of correlated spectral and timing behavior in the ultraluminous X-ray source (ULX) NGC 5408 X-1. An ∼100 ks pointing with XMM/Newton obtained in 2008 January reveals a strong 10 mHz quasi-periodic oscillation (QPO) in the >1 keV flux, as well as flat-topped, band-limited noise breaking to a power law. The energy spectrum is again dominated by two components, a 0.16 keV thermal disk and a power law with an index of ∼2.5. These new measurements, combined with results from our previous 2006 January pointing in which we first detected QPOs, show for the first time in a ULX a pattern of spectral and temporal correlations strongly analogous to that seen in Galactic black hole (BH) sources, but at much higher X-ray luminosity and longer characteristic timescales. We find that the QPO frequency is proportional to the inferred disk flux, while the QPO and broadband noise amplitude (rms) are inversely proportional to the disk flux. Assuming that QPO frequency scales inversely with the BH mass at a given power-law spectral index we derive mass estimates using the observed QPO frequency-spectral index relations from five stellar-mass BH systems with dynamical mass constraints. The results from all sources are consistent with a mass range for NGC 5408 X-1 from 1000 to 9000 M sun . We argue that these are conservative limits, and a more likely range is from 2000 to 5000 M sun . Moreover, the recent relation from Gierlinski et al. that relates the BH mass to the strength of variability at high frequencies (above the break in the power spectrum) is also indicative of such a high mass for NGC 5408 X-1. Importantly, none of the above estimates appears consistent with a BH mass less than ∼1000 M sun for NGC 5408 X-1. We argue that these new findings strongly support the conclusion that NGC 5408 X-1 harbors an intermediate-mass BH.

  7. Intermediate-mass-ratio inspirals in the Einstein Telescope. II. Parameter estimation errors

    International Nuclear Information System (INIS)

    Huerta, E. A.; Gair, Jonathan R.

    2011-01-01

    We explore the precision with which the Einstein Telescope will be able to measure the parameters of intermediate-mass-ratio inspirals, i.e., the inspirals of stellar mass compact objects into intermediate-mass black holes (IMBHs). We calculate the parameter estimation errors using the Fisher Matrix formalism and present results of Monte Carlo simulations of these errors over choices for the extrinsic parameters of the source. These results are obtained using two different models for the gravitational waveform which were introduced in paper I of this series. These two waveform models include the inspiral, merger, and ringdown phases in a consistent way. One of the models, based on the transition scheme of Ori and Thorne [A. Ori and K. S. Thorne, Phys. Rev. D 62, 124022 (2000).], is valid for IMBHs of arbitrary spin; whereas, the second model, based on the effective-one-body approach, has been developed to cross-check our results in the nonspinning limit. In paper I of this series, we demonstrated the excellent agreement in both phase and amplitude between these two models for nonspinning black holes, and that their predictions for signal-to-noise ratios are consistent to within 10%. We now use these waveform models to estimate parameter estimation errors for binary systems with masses 1.4M · +100M · , 10M · +100M · , 1.4M · +500M · , and 10M · +500M · and various choices for the spin of the central IMBH. Assuming a detector network of three Einstein Telescopes, the analysis shows that for a 10M · compact object inspiralling into a 100M · IMBH with spin q=0.3, detected with a signal-to-noise ratio of 30, we should be able to determine the compact object and IMBH masses, and the IMBH spin magnitude to fractional accuracies of ∼10 -3 , ∼10 -3.5 , and ∼10 -3 , respectively. We also expect to determine the location of the source in the sky and the luminosity distance to within ∼0.003 steradians and ∼10%, respectively. We also compute results for

  8. Intermediate-mass Higgs boson and isosinglet neutral heavy lepton signals at hadron supercolliders

    International Nuclear Information System (INIS)

    Bhattacharya, G.

    1992-01-01

    The signals for the Standard Model intermediate-mass Higgs boson and isosinglet neutral heavy leptons at the forthcoming hadron supercolliders-the Superconducting Super Collider (SSC) and the CERN Large Hadron Collider (LHC), are studied. The author studies inclusive production of the Standard Model Higgs boson in the intermediate-mass region (M W approx-lt m H approx-lt 2M Z ) and its subsequent decay into two on- or off-shell W bosons that decay leptonically. Backgrounds from continuum W pair production and top quark pair production with semileptonic decays are investigated. The author concludes the Higgs boson signal may be observed via the decay H → W*W* → (ell bar v ell ) (bar ell' v' ell ) at the SSC for 145 GeV H approx-lt 2M Z and at the LHC for 150 GeV H approx-lt 2M Z if m t > 150 GeV. The author analyzes the search and discovery potential of isosinglet neutral heavy leptons (NHLs) produced via real or virtual W decay at pp supercolliders. The author considers the signal resulting from the leptonic decay of the NHL, and the two major backgrounds-continuum WZ, Wγ production and t bar tj production, where j is a hadronic jet. The decay patterns of NHL depend on its mass M N , and different search strategies are needed for the two mass regions M N W and M N > M Z . The author finds for m t ≥ 150 (200) GeV the signal is observable for M N ≤ 60 (70) GeV in the mass-region M N W , and up to M N ≅ 110 GeV for M N > M W , at both SSC and LHC. It is shown the non-observance of the signal (with a 4σ statistical significance) in the region M N W could put upper limits on the NHL coupling constants that would be an improvement over the limits obtainable from the CERN Large Electron Positron Collider (LEP I)

  9. Evidence from K2 for Rapid Rotation in the Descendant of an Intermediate-mass Star

    Science.gov (United States)

    Hermes, J. J.; Kawaler, Steven D.; Romero, A. D.; Kepler, S. O.; Tremblay, P.-E.; Bell, Keaton J.; Dunlap, B. H.; Montgomery, M. H.; Gänsicke, B. T.; Clemens, J. C.; Dennihy, E.; Redfield, S.

    2017-05-01

    Using patterns in the oscillation frequencies of a white dwarf observed by K2, we have measured the fastest rotation rate (1.13 ± 0.02 hr) of any isolated pulsating white dwarf known to date. Balmer-line fits to follow-up spectroscopy from the SOAR telescope show that the star (SDSSJ0837+1856, EPIC 211914185) is a 13,590+/- 340 K, 0.87 ± 0.03 M ⊙ white dwarf. This is the highest mass measured for any pulsating white dwarf with known rotation, suggesting a possible link between high mass and fast rotation. If it is the product of single-star evolution, its progenitor was a roughly 4.0 M ⊙ main-sequence B star; we know very little about the angular momentum evolution of such intermediate-mass stars. We explore the possibility that this rapidly rotating white dwarf is the byproduct of a binary merger, which we conclude is unlikely given the pulsation periods observed.

  10. Evaluation in the resonance range of nuclei with a mass number above 220

    International Nuclear Information System (INIS)

    Ribon, P.

    1970-01-01

    The author discusses the problems posed by the evaluation of neutron data for fissile or fertile nuclei in the range of resolved or unresolved resonances. It appears to take several years until the data of an experiment are used by the reactor physicists. If one wants to have recent data at one's disposal, one cannot have recourse to evaluated-data libraries. Moreover, the existing parameter sets are only fragmentary. A new evaluation is, therefore, necessary for nearly all of these nuclei, but it cannot be based upon different parameter sets; these are indeed contradictory, and the evaluator will have to go back to the original data. The author shows for the set of σ f of 235 U, that a careful comparison of the data shows up unsuspected local defects. Some examples illustrate the deviation between analyses carried out by different methods and between the results on the established divergences. The parameters or cross-sections are far from being known with the precision one would desire. This fact gives rise to anomalies in the interpretation of data necessary for understanding and simulation in the range of unresolved resonances. But the introduction of concepts connected with sub-threshold fission noticeably furthers this understanding. Therefore a comparison of the methods of analysis must be made in more and more accurate measurements (evaluation and correction of systematic errors). (author) [fr

  11. NO EVIDENCE FOR INTERMEDIATE-MASS BLACK HOLES IN GLOBULAR CLUSTERS: STRONG CONSTRAINTS FROM THE JVLA

    International Nuclear Information System (INIS)

    Strader, Jay; Chomiuk, Laura; Maccarone, Thomas J.; Miller-Jones, James C. A.; Seth, Anil C.; Heinke, Craig O.; Sivakoff, Gregory R.

    2012-01-01

    With a goal of searching for accreting intermediate-mass black holes (IMBHs), we report the results of ultra-deep Jansky Very Large Array radio continuum observations of the cores of three Galactic globular clusters: M15, M19, and M22. We reach rms noise levels of 1.5-2.1 μJy beam –1 at an average frequency of 6 GHz. No sources are observed at the center of any of the clusters. For a conservative set of assumptions about the properties of the accretion, we set 3σ upper limits on IMBHs from 360 to 980 M ☉ . These limits are among the most stringent obtained for any globular cluster. They add to a growing body of work that suggests either (1) IMBHs ∼> 1000 M ☉ are rare in globular clusters or (2) when present, IMBHs accrete in an extraordinarily inefficient manner.

  12. No Evidence for Intermediate-mass Black Holes in Globular Clusters: Strong Constraints from the JVLA

    Science.gov (United States)

    Strader, Jay; Chomiuk, Laura; Maccarone, Thomas J.; Miller-Jones, James C. A.; Seth, Anil C.; Heinke, Craig O.; Sivakoff, Gregory R.

    2012-05-01

    With a goal of searching for accreting intermediate-mass black holes (IMBHs), we report the results of ultra-deep Jansky Very Large Array radio continuum observations of the cores of three Galactic globular clusters: M15, M19, and M22. We reach rms noise levels of 1.5-2.1 μJy beam-1 at an average frequency of 6 GHz. No sources are observed at the center of any of the clusters. For a conservative set of assumptions about the properties of the accretion, we set 3σ upper limits on IMBHs from 360 to 980 M ⊙. These limits are among the most stringent obtained for any globular cluster. They add to a growing body of work that suggests either (1) IMBHs >~ 1000 M ⊙ are rare in globular clusters or (2) when present, IMBHs accrete in an extraordinarily inefficient manner.

  13. Probing Intermediate Mass Higgs Interactions at the CERN Large Hadron Collider

    CERN Document Server

    Éboli, Oscar J P; Lietti, S M; Novaes, S F

    2000-01-01

    We analyze the potentiality of the CERN Large Hadron Collider to probe the Higgs boson couplings to the electroweak gauge bosons. We parametrize the possible deviations of these couplings due to new physics in a model independent way, using the most general dimension--six effective lagrangian where the SU(2)_L x U(1)_Y is realized linearly. For intermediate Higgs masses, the decay channel into two photons is the most important one for Higgs searches at the LHC. We study the effects of these new interactions on the Higgs production mechanism and its subsequent decay into two photons. We show that the LHC will be sensitive to new physics scales beyond the present limits extracted from the LEP and Tevatron physics.

  14. Intermediate-mass single stars and accreting white dwarfs as sources of neutron-rich isotopes

    International Nuclear Information System (INIS)

    Iben, I. Jr.

    1981-01-01

    During the most luminous portion of the asymptotic giant-branch phase, models of intermediate-mass stars first become carbon stars and then produce s-process isotopes in the solar-system distribution. Recent observations of the optically most luminous carbon stars in the Magellanic Clouds introduce the possibility that real intermediate-mass stars lose their hydrogen-rich envelopes during the asymptotic giant-branch phase before they have made s-process isotopes both in large quantities and in the solar system distribution. This encourages a search for alternate sources of these isotopes. A promising site for the production of some neutron-rich isotopes isthe convective helium-carbon region that appears in accreting white dwarfs during helium shell flashes. For appropriate accretion rates, overlap of matter in successive convective zones may lead to an exponential distribution of exposures. Further, because of a small entropy barrier between the convective shell and the hydrogen-rich envelope, protons enter the shell and provide a source of neutrons that, for appropriate accretion rates, is repetitive in strength and either dominates or is complementary to the 22 Ne(α,n) 25 Mg source. This permits an estimate of the distribution of neutron-rich isotopes that is formed after many flashes. The distribution, in most instances, tends to be weighted more toward heavier elements than is the case when 22 Ne(α, n) 25 Mg is the sole source of neutrons. Hence, accreting white dwarfs cannot be major contributors to the enrichment of the interstellar medium in most s-process isotopes. Considerable effort should be devoted toward demonstrating whether or not the bolometrically most lumious asymptotic giant branch stars in local systems obey M/sub BOL/ /sup min/ -6.5, then either the source of most Galactic s-process isotopes is as yet unknown, or the rate of the 22 Ne(α, n) 25 Mg reaction has been underestimated

  15. Design, construction and commissioning of an ortho-TOF mass spectrometer for investigations of exotic nuclei

    International Nuclear Information System (INIS)

    Eliseev, S.

    2004-01-01

    Precise atomic mass measurements are very important in many disciplines of science, e.g. in physics, biochemistry, medicine, archaeology and environmental research. In nuclear physics, mass measurements of nuclides are essential for testing nuclear mass models. From the knowledge of the mass of a nuclide the nuclear binding energy can be derived. The mass measurements provide a better knowledge of the strong interaction between the constituents in the nucleus. In nuclear astrophysics, mass measurements of exotic nuclides are of great importance for our understanding of the synthesis of the elements. In biochemistry and medicine, mass measurement methods are helpful in a structural analysis of complex biomolecules. Mass measurement techniques are widely used in the trace analysis of poisonous substances in environmental research. Leak searchers and rest gas analysers are also based on the principles of mass measurements. The most precise methods of mass measurements, employed in nuclear physics, are based either on the determination of the time of flight (TOF), the revolution frequency (RF), or cyclotron frequency (CF) of the ion in mass spectrometers. Nowadays, there are several scientific centers such as GSI, CERN, GANIL and ANL employing these techniques. The RF-technique is realized at GSI in the Experimental Storage Ring (ESR) (Schottky Mass Spectrometry SMS and Isochronous Mass Spectrometry IMS) for ions produced in the in-flight FRagment Separator (FRS). At GANIL, the TOF-technique is employed at the Second Separated-Sector Cyclotron (CSS2) and at the Spectrometre a Perte d'Energie du Ganil (SPEG). The CF-technique is implemented in MISTRALand in Penning traps ISOLTRAP at ISOLDE (CERN). The CF- technique is also used at SHIPTRAP at GSI and at the Canadian Penning Trap (CPT), coupled to the Argonne Tandem Linac Accelerating System (ATLAS) at ANL. In the following the relative accuracy of mass determination achieved by the above mentioned techniques and typical

  16. Design, construction and commissioning of an ortho-TOF mass spectrometer for investigations of exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, S.

    2004-07-01

    Precise atomic mass measurements are very important in many disciplines of science, e.g. in physics, biochemistry, medicine, archaeology and environmental research. In nuclear physics, mass measurements of nuclides are essential for testing nuclear mass models. From the knowledge of the mass of a nuclide the nuclear binding energy can be derived. The mass measurements provide a better knowledge of the strong interaction between the constituents in the nucleus. In nuclear astrophysics, mass measurements of exotic nuclides are of great importance for our understanding of the synthesis of the elements. In biochemistry and medicine, mass measurement methods are helpful in a structural analysis of complex biomolecules. Mass measurement techniques are widely used in the trace analysis of poisonous substances in environmental research. Leak searchers and rest gas analysers are also based on the principles of mass measurements. The most precise methods of mass measurements, employed in nuclear physics, are based either on the determination of the time of flight (TOF), the revolution frequency (RF), or cyclotron frequency (CF) of the ion in mass spectrometers. Nowadays, there are several scientific centers such as GSI, CERN, GANIL and ANL employing these techniques. The RF-technique is realized at GSI in the Experimental Storage Ring (ESR) (Schottky Mass Spectrometry SMS and Isochronous Mass Spectrometry IMS) for ions produced in the in-flight FRagment Separator (FRS). At GANIL, the TOF-technique is employed at the Second Separated-Sector Cyclotron (CSS2) and at the Spectrometre a Perte d'Energie du Ganil (SPEG). The CF-technique is implemented in MISTRALand in Penning traps ISOLTRAP at ISOLDE (CERN). The CF- technique is also used at SHIPTRAP at GSI and at the Canadian Penning Trap (CPT), coupled to the Argonne Tandem Linac Accelerating System (ATLAS) at ANL. In the following the relative accuracy of mass determination achieved by the above mentioned techniques and

  17. New discovery: quantization of atomic and nuclear rest mass differences and self-organization of atoms and nuclei

    International Nuclear Information System (INIS)

    Gareev, F.A.; Zhidkova, I.E.; )

    2007-01-01

    Full text: We come to the conclusion that all atomic models based on either the Newton equation and the Kepler laws, or the Maxwell equations, or the Schroedinger and Dirac equations are in reasonable agreement with experimental data. We can only suspect that these equations are grounded on the same fundamental principles which are not known or these equations can be transformed into each other. We proposed a new mechanism of LENR: cooperative processes in the whole system - nuclei + atoms + condensed matter - nuclear reactions in plasma - can occur at smaller threshold energies than the corresponding ones on free constituents. We were able to quantize phenomenologically the first time the differences between atomic and nuclear rest masses by the formula: ΔΔM = n 1 /n 2 ·0.0076294 (in MeV/ ), n i =1,.2,3... Note that this quantization rule is justified for atoms and nuclei with different A, N and Z and the nuclei and atoms represent a coherent synchronized open systems - a complex of coupled oscillators (resonators). The cooperative resonance synchronization mechanisms are responsible for explanation of how the electron volt world can influence on the nuclear mega electron volt world. It means that we created new possibilities for inducing and controlling nuclear reactions by atomic processes grounded on the fundamental low of physics - conservation law of energy. The results of these research field can provide new ecologically pure mobile sources of energy independent from oil, gas and coal, new substances, and technologies. For example, this discovery gives us a simple and cheep method for utilization of nuclear waste

  18. Gravitational Waves and Intermediate-mass Black Hole Retention in Globular Clusters

    Science.gov (United States)

    Fragione, Giacomo; Ginsburg, Idan; Kocsis, Bence

    2018-04-01

    The recent discovery of gravitational waves (GWs) has opened new horizons for physics. Current and upcoming missions, such as LIGO, VIRGO, KAGRA, and LISA, promise to shed light on black holes of every size from stellar mass (SBH) sizes up to supermassive black holes. The intermediate-mass black hole (IMBH) family has not been detected beyond any reasonable doubt. Recent analyses suggest observational evidence for the presence of IMBHs in the centers of two Galactic globular clusters (GCs). In this paper, we investigate the possibility that GCs were born with a central IMBH, which undergoes repeated merger events with SBHs in the cluster core. By means of a semi-analytical method, we follow the evolution of the primordial cluster population in the galactic potential and the mergers of the binary IMBH-SBH systems. Our models predict ≈1000 IMBHs within 1 kpc from the galactic center and show that the IMBH-SBH merger rate density changes from { \\mathcal R }≈ 1000 Gpc‑3 yr‑1 beyond z ≈ 2 to { \\mathcal R }≈ 1{--}10 Gpc‑3 yr‑1 at z ≈ 0. The rates at low redshifts may be significantly higher if young massive star clusters host IMBHs. The merger rates are dominated by IMBHs with masses between 103 and 104 M ⊙. Currently, there are no LIGO/VIRGO upper limits for GW sources in this mass range, but our results show that at design sensitivity, these instruments will detect IMBH-SBH mergers in the coming years. LISA and the Einstein Telescope will be best suited to detect these events. The inspirals of IMBH-SBH systems may also generate an unresolved GW background.

  19. Study of mass=28 isobaric nuclei. 28Si and 28P excited states

    International Nuclear Information System (INIS)

    Miehe, Christiane.

    1975-01-01

    A study of the electromagnetic decay of the excited states of 28 Si and 28 P was done using the reactions 27 Al(p,γ) 28 Si, 24 Mg(α,γ) 28 Si, 25 Mg(α,nγ) 28 Si, 26 Mg(tau,nγ) 28 Si, 27 Al(d,nγ) 28 Si and 28 Si(p,n) 28 P. Special interest was devoted to negative parity level structure and the T=1 states of 28 Si. The location and γ-decay of 28 P levels led to several isospin triplets identification and yields a measurement of Coulomb deplacement energy in the nuclei A=28 [fr

  20. ΔI = 1 Signature Splitting in Signature Partners of Odd Mass Superdeformed Nuclei

    Directory of Open Access Journals (Sweden)

    Khalaf A. M.,

    2013-07-01

    Full Text Available The spins, transition energies, rotational frequencies, kinematic and dynamic moment of inertia of rotational bands of signature partners pairs of odd–A superdeformed bands in A190 region were calculated by proposing a simple model based on collective rotational model. Simulated search program was written to determine the model parameters. The calculated results agree with experimental data for fourteen signature partner pairs in Hg/Tl/Pb/Bi/nuclei. We investigated the ∆I=1 signature splitting by extracted the difference between the average transitions I+2 ! I and I ! I-2 energies in one band and the transition I+1 ! I-1 energies in its signature partner. Most of the signature partners in this region show large amplitude staggering. The signature splitting has the effect of increasing dynamical moment of inertia J 2 for favored band and decreasing J 2 for the unfavored band.

  1. A Tidal Disruption Event in a Nearby Galaxy Hosting an Intermediate Mass Black Hole

    Science.gov (United States)

    Donato, D; Cenko, S. B.; Covino, S.; Troja, E.; Pursimo, T.; Cheung, C. C.; Fox, O.; Kutyrev, A.; Campana, S.; Fugazza, D.; hide

    2014-01-01

    We report the serendipitous discovery of a bright point source flare in the Abell cluster A1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 kiloelectronvolt flux declined by a factor of approximately 2300 over a time span of 6 years, following a power-law decay with index approximately equal to 2.44 plus or minus 0.40. The Chandra data alone vary by a factor of approximately 20. The spectrum is well fit by a blackbody with a constant temperature of kiloteslas approximately equal to 0.09 kiloelectronvolts (approximately equal to 10 (sup 6) Kelvin). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the 1 sigma level with the cluster (redshift = 0.062476).We argue that these properties are indicative of a tidal disruption of a star by a black hole (BH) with log(M (sub BH) / M (sub 1 solar mass)) approximately equal to 5.5 plus or minus 0.5. If so, such a discovery indicates that tidal disruption flares may be used to probe BHs in the intermediate mass range, which are very difficult to study by other means.

  2. Constructing effective one-body dynamics with numerical energy flux for intermediate-mass-ratio inspirals

    International Nuclear Information System (INIS)

    Han Wenbiao; Cao Zhoujian

    2011-01-01

    A new scheme for computing dynamical evolutions and gravitational radiations for intermediate-mass-ratio inspirals (IMRIs) based on an effective one-body (EOB) dynamics plus Teukolsky perturbation theory is built in this paper. In the EOB framework, the dynamic essentially affects the resulted gravitational waveform for a binary compact star system. This dynamic includes two parts. One is the conservative part, which comes from effective one-body reduction. The other part is the gravitational backreaction, which contributes to the shrinking process of the inspiral of a binary compact star system. Previous works used an analytical waveform to construct this backreaction term. Since the analytical form is based on post-Newtonian expansion, the consistency of this term is always checked by numerical energy flux. Here, we directly use numerical energy flux by solving the Teukolsky equation via the frequency-domain method to construct this backreaction term. The conservative correction to the leading order terms in mass-ratio is included in the deformed-Kerr metric and the EOB Hamiltonian. We try to use this method to simulate not only quasicircular adiabatic inspiral, but also the nonadiabatic plunge phase. For several different spinning black holes, we demonstrate and compare the resulted dynamical evolutions and gravitational waveforms.

  3. THE BLACK HOLE MASS-BULGE LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI FROM REVERBERATION MAPPING AND HUBBLE SPACE TELESCOPE IMAGING

    International Nuclear Information System (INIS)

    Bentz, Misty C.; Peterson, Bradley M.; Pogge, Richard W.; Vestergaard, Marianne

    2009-01-01

    We investigate the relationship between black hole mass and bulge luminosity for active galactic nuclei (AGNs) with reverberation-based black hole mass measurements and bulge luminosities from two-dimensional decompositions of Hubble Space Telescope host galaxy images. We find that the slope of the relationship for AGNs is 0.76-0.85 with an uncertainty of ∼0.1, somewhat shallower than the M BH ∝ L 1.0±0.1 relationship that has been fit to nearby quiescent galaxies with dynamical black hole mass measurements. This difference is somewhat perplexing, as the AGN black hole masses include an overall scaling factor that brings the AGN M BH -σ * relationship into agreement with that of quiescent galaxies. We discuss biases that may be inherent to the AGN and quiescent galaxy samples and could cause the apparent inconsistency in the forms of their M BH -L bulge relationships. Recent work by Graham, however, presents a similar slope of ∼0.8 for the quiescent galaxies and may bring the relationship for AGNs and quiescent galaxies into agreement.

  4. Systematic study of electric-dipole excitations with fully self-consistent Skyrme HF plus RPA from light-to-medium-mass deformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Inakura, T. [University of Tsukuba, Institute for Physics, Tsukuba (Japan); Nakatsukasa, T. [RIKEN Nishina Center, Theoretical Nuclear Physics Laboratory, Wako (Japan); Yabana, K. [University of Tsukuba, Institute for Physics, Tsukuba (Japan); University of Tsukuba, Center for Computational Sciences, Tsukuba (Japan)

    2009-12-15

    We undertake a systematic calculation on electric-dipole responses of even-even nuclei for a wide mass region employing a fully self-consistent Hartree-Fock plus RPA approach. For an easy implementation of the fully self-consistent calculation, the finite-amplitude method which we have proposed recently is employed. We calculated dipole responses in Cartesian mesh representation, which can deal with deformed nuclei but do not include pairing correlation. The systematic calculation has reached Nickel isotopes. The calculated results show reasonable agreement for heavy nuclei while the average excitation energies are underestimated for light nuclei. We show a systematic comparison of the splitting of the peak energy with the ground-state deformation. (orig.)

  5. Black Hole Masses for Type I Active Galactic Nuclei in the Chandra Cosmos Legacy Survey

    Science.gov (United States)

    Nagaraj, Gautam; Fornasini, Francesca; Civano, Francesca Maria

    2018-01-01

    Tight local relations between SMBH masses and galaxy properties have established the fundamental connection between SMBHs and their host galaxies. However, in order to better understand the coevolution of SMBHs and their host galaxies over cosmic time, we need measurements of black hole masses, AGN luminosities, and galaxy stellar masses from sizable samples of AGN covering lower luminosities than the brightest quasars spanning a wide redshift range. In this study, we report masses of the SMBHs of 224 Type I AGNs from the Chandra COSMOS Legacy Survey as determined by the line widths of Mg II 2798, Hb 4862, and Ha 6564 via scaling relations derived from reverberation mapping. Preliminary comparison with host galaxy luminosities and stellar masses suggests an increase in Eddington ratio with redshift, consistent with previous studies. In addition, our derived SMBH masses fall above the local AGN MBH--M* (galactic stellar mass) relation from Reines & Volonteri (2015), but it is still not clear whether this results from redshift evolution of the MBH--M* relation or from the incompleteness of the spectroscopic surveys available. The SAO REU program is funded by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant AST-1659473, and by the Smithsonian Institution.

  6. High mass asymmetry in spontaneous and induced desintegration of heavy nuclei

    International Nuclear Information System (INIS)

    Tavares, O.A.P.

    1978-01-01

    The experimental and theoretical results related to a new rupture mode of heavy ions (A>230) in mass fragments more different than ordinary ission products, are presented and disussed. Experiences of long exposure time by nuclear emulsion technique, show that, the U 238 is also a spontaneous emitter of ions with mass number between 20 and 70. The results are interpreted as a high mass asymmetry in fission process or as a nucleon cluster emission mechanism by potential barrier penetration. Preliminary estimation show good agreement with experimental results for U 238 . Glass laminas with uranium thin films prepared 16 years ago, are also analysed aiming to confirm these results. Several experiences with nuclear emulsions and mica sandwich, and radiochemical data show to be possible heavy ion emission from U 238 induced by photons of low energy as well as neutrons of reactor (M.C.K.) [pt

  7. Evolving ONe WD+He star systems to intermediate-mass binary pulsars

    Science.gov (United States)

    Liu, D.; Wang, B.; Chen, W.; Zuo, Z.; Han, Z.

    2018-03-01

    It has been suggested that accretion-induced collapse (AIC) is a non-negligible path for the formation of the observed neutron stars (NSs). An ONe white dwarf (WD) that accretes material from a He star may experience AIC process and eventually produce intermediate-mass binary pulsars (IMBPs), named as the ONe WD+He star scenario. Note that previous studies can only account for part of the observed IMBPs with short orbital periods. In this work, we investigate the evolution of about 900 ONe WD+He star binaries to explore the distribution of IMBPs. We found that the ONe WD+He star scenario could form IMBPs including pulsars with 5-340 ms spin periods and 0.75-1.38 M_{⊙} WD companions, in which the orbital periods range from 0.04 to 900 d. Compared with the 20 observed IMBPs, this scenario can cover the parameters of 13 sources in the final orbital period-WD mass plane and the Corbet diagram, most of which has short orbital periods. We found that the ONe WD+He star scenario can explain almost all the observed IMBPs with short orbital periods. This work can well match the observed parameters of PSR J1802-2124 (one of the two precisely observed IMBPs), providing a possible evolutional path for its formation. We also speculate that the compact companion of HD 49798 (a hydrogen depleted sdO6 star) may be not a NS based on the present work.

  8. INTERMEDIATE-MASS HOT CORES AT {approx}500 AU: DISKS OR OUTFLOWS?

    Energy Technology Data Exchange (ETDEWEB)

    Palau, Aina; Girart, Josep M. [Institut de Ciencies de l' Espai (CSIC-IEEC), Campus UAB-Facultat de Ciencies, Torre C5-parell 2, 08193 Bellaterra, Catalunya (Spain); Fuente, Asuncion; Alonso-Albi, Tomas [Observatorio Astronomico Nacional, P.O. Box 112, 28803 Alcala de Henares, Madrid (Spain); Fontani, Francesco; Sanchez-Monge, Alvaro [Osservatorio Astrofisico di Arcetri, INAF, Largo E. Fermi 5, 50125 Firenze (Italy); Boissier, Jeremie [Istituto di Radioastronomia, INAF, Via Gobetti 101, Bologna (Italy); Pietu, Vincent; Neri, Roberto [IRAM, 300 Rue de la piscine, 38406 Saint Martin d' Heres (France); Busquet, Gemma [Istituto di Fisica dello Spazio Interplanetario, INAF, Area di Recerca di Tor Vergata, Via Fosso Cavaliere 100, 00133 Roma (Italy); Estalella, Robert [Departament d' Astronomia i Meteorologia (IEEC-UB), Institut Ciencies Cosmos, Universitat Barcelona, Marti Franques 1, 08028 Barcelona (Spain); Zapata, Luis A. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, P.O. Box 3-72, 58090 Morelia, Michoacan (Mexico); Zhang, Qizhou; Ho, Paul T. P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Audard, Marc, E-mail: palau@ieec.uab.es [Geneva Observatory, University of Geneva, Ch. des Maillettes 51, 1290 Versoix (Switzerland)

    2011-12-20

    Observations with the Plateau de Bure Interferometer in the most extended configuration toward two intermediate-mass star-forming regions, IRAS 22198+6336 and AFGL 5142, reveal the presence of several complex organic molecules at {approx}500 AU scales, confirming the presence of hot cores in both regions. The hot cores are not rich in CN-bearing molecules, as often seen in massive hot cores, and are mainly traced by CH{sub 3}CH{sub 2}OH, (CH{sub 2}OH){sub 2}, CH{sub 3}COCH{sub 3}, and CH{sub 3}OH, with, additionally, CH{sub 3}CHO, CH{sub 3}OD, and HCOOD for IRAS 22198+6336, and C{sub 6}H and O{sup 13}CS for AFGL 5142. The emission of complex molecules is resolved down to sizes of {approx}300 and {approx}600 AU, for IRAS 22198+6336 and AFGL 5142, respectively, and most likely is tracing protostellar disks rather than flattened envelopes or toroids as is usually found. This is especially clear for the case of IRAS 22198+6336, where we detect a velocity gradient for all the mapped molecules perpendicular to the most chemically rich outflow of the region, yielding a dynamic mass {approx}> 4 M{sub Sun }. As for AFGL 5142, the hot core emission is resolved into two elongated cores separated {approx}1800 AU. A detailed comparison of the complex molecule peaks to the new CO (2-1) data and H{sub 2}O maser data from the literature suggests also that for AFGL 5142 the complex molecules are mainly associated with disks, except for a faint and extended molecular emission found to the west, which is possibly produced in the interface between one of the outflows and the dense surrounding gas.

  9. Clinical impact of body mass index on prostate biopsy in patients with intermediate PSA levels

    International Nuclear Information System (INIS)

    Sekita, Nobuyuki; Chin, Kensei; Fujimura, Masaaki; Mikami, Kazuo; Suzuki, Hiroyoshi; Kamijima, Shuichi

    2008-01-01

    From April 2005 to September 2007, 480 patients underwent transrectal prostate biopsy at our institution. The clinical data including age, serum prostate specific antigen (PSA) level, prostate volume and body mass index (BMI) were obtained, and the cancer detection rates and pathological findings were evaluated in 305 cases with a PSA concentration of 4.0 to 10.0 ng/ml. Prostate volume was calculated from magnetic resonance imaging (MRI) findings. The 305 patients were categorized according to their BMI into three groups (normal, less than 22 kg/m 2 ; overweight, 22-25 kg/m 2 ; and obese, more than 25 kg/m 2 ). Cancer detection rates and histopathologic findings were compared between the groups. Multivariate logistic regression analysis was also performed. Prostate cancer was detected in 127 patients. No significant differences in BMI were observed between biopsy-positive and biopsy-negative cases (p=0.965), and the detection rates of prostate cancer observed in the three groups were not significantly different. There was a significant association between BMI and the findings of high Gleason score (more than 4+3) (p=0.048). BMI was not a contributory factor of prostate cancer detection for cases with intermediate PSA levels; however, patients with high BMI may have high-grade malignancy features. (author)

  10. Prompt emission from tidal disruptions of white dwarfs by intermediate mass black holes

    Directory of Open Access Journals (Sweden)

    Laguna P.

    2012-12-01

    Full Text Available We present a qualitative picture of prompt emission from tidal disruptions of white dwarfs (WD by intermediate mass black holes (IMBH. The smaller size of an IMBH compared to a supermassive black hole and a smaller tidal radius of a WD disruption lead to a very fast event with high peak luminosity. Magnetic field is generated in situ following the tidal disruption, which leads to effective accretion. Since large-scale magnetic field is also produced, geometrically thick super-Eddington inflow leads to a relativistic jet. The dense jet possesses a photosphere, which emits quasi-thermal radiation in soft X-rays. The source can be classified as a long low-luminosity gamma-ray burst (ll-GRB. Tidal compression of a WD causes nuclear ignition, which is observable as an accompanying supernova. We suggest that GRB060218 and SN2006aj is such a pair of ll-GRB and supernova. We argue that in a flux-limited sample the disruptions of WDs by IMBHs are more frequent then the disruptions of other stars by IMBHs.

  11. Searching for Intermediate Mass Black Holes in Ultraluminous X-ray Binaries

    Science.gov (United States)

    Fritze, Hannah; Wright, Simon; Kilgard, Roy

    2018-01-01

    X-ray observations of nearby galaxies provide one of the best laboratories in the universe for studying two exotic classes of object: black holes and neutron stars. These observations allow us to study the dramatic effect such objects have on their surroundings, as well as the high-energy physics involved in their emission. We conduct a volume-limited archival survey of X-ray sources in all galaxies observed with the Chandra X-ray observatory within 15 Mpc, and identify a set of ultraluminous X-ray sources for detailed spectral analysis. We perform this analysis with the aim of searching for signatures of spectral state transitions and super-Eddington accretion that could indicate the presence of an Intermediate Mass Black Hole (IMBH) binary system. Here, we identify 43 potential IMBH sources that have signatures of super-Eddington accretion. We plan to follow up this initial selection with a multiwavelength analysis of these sources, in order to place further constraints on their nature and surrounding environment.

  12. Search for gravitational wave ringdowns from perturbed intermediate mass black holes in LIGO-Virgo data from 2005-2010

    NARCIS (Netherlands)

    Aasi, J.; Agathos, M.; Beker, M.G.; Bertolini, A.; Bulten, H.J.; Del Pozzo, W.; Jonker, R.; Meidam, J.; van den Brand, J.F.J.; LIGO Sci, Collaboration; Virgo, Collaboration

    2014-01-01

    We report results from a search for gravitational waves produced by perturbed intermediate mass black holes (IMBH) in data collected by LIGO and Virgo between 2005 and 2010. The search was sensitive to astrophysical sources that produced damped sinusoid gravitational wave signals, also known as

  13. Simultaneous determination of the intermediates of the citric acid cycle by gas chromatography--mass fragmentography using deuterated internal standards

    International Nuclear Information System (INIS)

    Lee, C.R.; Pollitt, R.J.

    1977-01-01

    Current developments in the use of gas chromatography and mass spectroscopy in studying the intermediates in the Krebs tricarboxylic acid cycle are outlined. The methods developed make use of deuterated internal standards and multiple-ion monitoring to obtain sensitivity comparable to that of the better fluorimetric enzymatic assays. The problems still remaining are indicated

  14. Individual and collective excitations in the superdeformed nuclei of the 190 mass region; Excitations individuelles et collectives dans les noyaux superdeformes de la region de masse 190

    Energy Technology Data Exchange (ETDEWEB)

    Bouneau, Sandra [Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

    1997-04-11

    This work aims at the study of different excitation modes, individual and collective, in superdeformed (SD) nuclei in the mass 190 region. The study of {sup 193}Tl and {sup 195,196,197}Bi SD nuclei brought information concerning individual excitation around the proton and neutron SD gaps Z = 80 - 82 and N = 112. Also, the study of the nucleus {sup 196}Pb revealed excited SD states built on collective vibrations. Concerning the isotope {sup 193}Tl, magnetic property analysis has been performed and allowed us to identify the proton intruder orbital {pi}i{sub 13/2} on which the two known SD the bands of the nucleus are build. It was possible to separate experimentally the relative contribution of proton and neutron pairing to the dynamic moment of inertia. Several {gamma} transition of high energy (about 3 MeV) linking SD states to normal deformed states (ND) and three new SD bands have been found in this nucleus. These SD bands have been interpreted in terms of individual excitations of the single proton on different orbitals identified above the proton SD gap Z = 80. An interaction between the states of two excited SD band have been observed and its strength measured. All these results (gyromagnetic factor, the role of nuclear pairing, excitation energy of the SD well, the interaction between two orbitals) represent information of theoretical interest. In each isotope {sup 195-197}Bi, one SD band has been discovered. They have been also interpreted in terms of individual excitation implying the same proton state. The study of this nuclei brought the first experimental proof that the superdeformation phenomenon persists above the shell closure Z = 82. In {sup 196}Pb nucleus a new excited SD band has been discovered. Observations are mentioned suggesting that we have to consider excitations different from those based on individual ones. An interpretation based on vibrational modes can explain both the low energy measured of the excited states in respect with the SD

  15. Measuring the masses of Intermediate Polars with NuSTAR: V709 Cas, NY Lup and V1223 Sgr

    OpenAIRE

    Shaw, A. W.; Heinke, C. O.; Mukai, K.; Sivakoff, G. R.; Tomsick, J. A.; Rana, V.

    2018-01-01

    The X-ray spectra of intermediate polars can be modelled to give a direct measurement of white dwarf mass. Here we fit accretion column models to NuSTAR spectra of three intermediate polars; V709 Cas, NY Lup and V1223 Sgr in order to determine their masses. From fits to 3-78 keV spectra, we find masses of $M_{\\rm WD}=0.88^{+0.05}_{-0.04}M_{\\odot}$, $1.16^{+0.04}_{-0.02}M_{\\odot}$ and $0.75\\pm0.02M_{\\odot}$ for V709 Cas, NY Lup and V1223 Sgr, respectively. Our measurements are generally in agr...

  16. The impact of body mass index on treatment outcomes for patients with low-intermediate risk prostate cancer

    International Nuclear Information System (INIS)

    Yamoah, Kosj; Zeigler-Johnson, Charnita M.; Jeffers, Abra; Malkowicz, Bruce; Spangler, Elaine; Park, Jong Y.; Whittemore, Alice; Rebbeck, Timothy R.

    2016-01-01

    Little is known about the relationship between preoperative body mass index and need for adjuvant radiation therapy (RT) following radical prostatectomy. The goal of this study was to evaluate the utility of body mass index in predicting adverse clinical outcomes which require adjuvant RT among men with organ-confined prostate cancer (PCa). We used a prospective cohort of 1,170 low-intermediate PCa risk men who underwent radical prostatectomy and evaluated the effect of body mass index on adverse pathologic features and freedom from biochemical failure (FFbF). Clinical and pathologic variables were compared across the body mass index groups using an analysis of variance model for continuous variables or χ 2 for categorical variables. Factors related to adverse pathologic features were examined using logistic regression models. Time to biochemical recurrence was compared across the groups using a log-rank survivorship analysis. Multivariable analysis predicting biochemical recurrence was conducted with a Cox proportional hazards model. Patients with elevated body mass index (defined as body mass index ≥25 kg/m 2 ) had greater extraprostatic extension (p = 0.004), and positive surgical margins (p = 0.01). Elevated body mass index did not correlate with preoperative risk groupings (p = 0.94). However, when compared with non-obese patients (body mass index <30 kg/m 2 ), obese patients (body mass index ≥30 kg/m 2 ) were much more likely to have higher rate of adverse pathologic features (p = 0.006). In patients with low- and intermediate- risk disease, obesity was strongly associated with rate of pathologic upgrading of tumors (p = 0.01 and p = 0.02), respectively. After controlling for known preoperative risk factors, body mass index was independently associated with ≥2 adverse pathologic features (p = 0.002), an indicator for adjuvant RT as well as FFbF (p = 0.001). Body mass index of ≥30 kg/m 2 is independently associated with adverse pathologic features

  17. Measurement of light charged particles in the decay channels of medium-mass excited compound nuclei

    International Nuclear Information System (INIS)

    Valdre, S.; Pasquali, G.; Carboni, S.; Bini, M.; Poggi, G.; Barlini, S.; Casini, G.; Piantelli, S.; Bardelli, L.; Nannini, A.; Cinausero, M.; Gramegna, F.; Degerlier, M.; Kravchuk, V.L.; Marchi, T.; Baiocco, G.; Bruno, M.; D'Agostino, M.; Morelli, L.; Vannini, G.; Benzoni, G.; Blasi, N.; Brambilla, S.; Wieland, O.; Bracco, A.; Camera, F.; Corsi, A.; Crespi, F.; Leoni, S.; Million, B.; Nicolini, R.; Montanari, D.; Bednarczyk, P.; Ciemala, M.; Fornal, B.; Kmiecik, M.; Maj, A.; Matejska-Minda, M.; Mazurek, K.; Meczynski, W.; Myalski, S.; Styczen, J.; Zieblinski, M.; Dudek, J.

    2014-01-01

    The 48 Ti on 40 Ca reactions have been studied at 300 and 600 MeV focusing on the fusion-evaporation (FE) and fusion-fission (FF) exit channels. Energy spectra and multiplicities of the emitted light charged particles have been compared to Monte Carlo simulations based on the statistical model. Proton emission in the FE channel is well reproduced by the Gemini++ statistical code run with standard input values. An excess of particles has been found at both bombarding energies also associated to a slightly different CM-energy spectrum with respect to the predicted one. Indeed, in this mass region (A ∼ 100) models predict that shape transitions can occur at high spin values and relatively scarce data exist in the literature about coincidence measurements between evaporation residues and light charged particles. Signals of shape transitions can be found in the variations of the lineshape of high energy gamma rays emitted from the de-excitation of GDR states gated on different regions of angular momenta. For this purpose it is important to keep under control the FE and FF processes, to regulate the statistical model parameters and to control the onset of possible preequilibrium emissions from 300 to 600 MeV bombarding energy

  18. Realistic calculations for c-coefficients of the isobaric mass multiplet equation in 1 p 0 f shell nuclei

    Science.gov (United States)

    Ormand, Erich; Brown, Alex; Hjorth-Jensen, Morten

    2017-09-01

    We present calculations for the c-coefficients of the isobaric mass multiplet equation for nuclei from A = 42 to A = 54 based on two-body effective interactions derived from three realistic nucleon-nucleon interactions: CD-Bonn, N3LO, and Argonne V18. The two-body effective interactions were derived using G-matrix or Vlowk augmented by perturbation theory extended to third order. We demonstrate a clear dependence in the c-coefficients on the short-ranged charge-symmetry breaking (CSB) part of the strong interaction, which is required to reproduce their overall behavior as a function of excitation (angular momentum). We find, however, that the CSB component in all three realistic nucleon-nucleon interactions is too large when compared to experiment, and that, furthermore, there is significant disagreement between each of the three interactions. This implies either: 1) a deficiency in our understanding of isospin-symmetry breaking in the nucleon-nucleon interaction, 2) significant isospin-symmetry breaking in the initial three-nucleon interaction, or 3) large contributions to isospin-symmetry breaking in three-nucleon interactions induced by the renormalization procedure. This work performed for the U.S. DOE by LLNL under Contract DE-AC52-07NA27344. WEO: DOE/NP FWP SCW0498. BAB: NSF Grant No. PHY-1404442. MHJ: NSF Grant No. PHY-1404159 and the Research Council of Norway contract ISP-Fysikk/216699.

  19. Search for gravitational wave ringdowns from perturbed intermediate mass black holes in LIGO-Virgo data from 2005-2010

    OpenAIRE

    Aasi, J.; Abbott, B.; Abbott, R.; Abbott, T.; Abernathy, M.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R.; Affeldt, C.; Agathos, M.; Aggarwal, N.; Aguiar, O.

    2014-01-01

    We report results from a search for gravitational waves produced by perturbed intermediate mass black holes (IMBH) in data collected by LIGO and Virgo between 2005 and 2010. The search was sensitive to astrophysical sources that produced damped sinusoid gravitational wave signals, also known as ringdowns, with frequency $50\\le f_{0}/\\mathrm{Hz} \\le 2000$ and decay timescale $0.0001\\lesssim \\tau/\\mathrm{s} \\lesssim 0.1$ characteristic of those produced in mergers of IMBH pairs. No significant ...

  20. Observation of the intermediates of in-source aldolization reaction in electrospray ionization mass spectrometry analysis of heteroaromatic aldehydes.

    Science.gov (United States)

    Jiang, Kezhi; Zhang, Xiaoping; Bai, Xingfeng; Lv, Huiqing; Li, Zuguang; Lee, Maw-Rong

    2015-01-01

    Electrospray ionization mass spectrometry (ESI-MS) analyses of 2-(1,2,4-triazole-1-yl)-6-methyl-3- quinolinecarboxaldehyde were carried out by using an ion trap mass spectrometer in a positive-ion mode. Interestingly, several unusual [M + 15](+), [M + 33](+), and [M + 47](+) ions were observed with a high abundance in the ESI-MS spectrum when methanol was used as the ESI solvent. However, only the protonated molecule was obtained with acetonitrile as the ESI solvent. These unusual ions have been proposed as the intermediates of an aldolization reaction occurring in the ESI source, which have been validated by a tandem mass spectrometry experiment, high-performance liquid chromatography/mass spectrometry analysis, and theoretical calculations. A full understanding of this reaction can contribute to the avoidance of analysis errors in the ESI-MS analysis of unknown heteroaromatic aldehydes.

  1. Electron scattering and reactions from exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Karataglidis, S. [University of Johannesburg, Department of Physics, Auckland Park (South Africa); University of Melbourne, School of Physics, Victoria (Australia)

    2017-04-15

    The SCRIT and FAIR/ELISe experiments are the first to attempt to measure directly electron scattering form factors from nuclei far from stability. This will give direct information for the (one-body) charge densities of those systems, about which there is little information available. The SCRIT experiment will be taking data for medium-mass exotic nuclei, while the electron-ion collider at ELISe, when constructed, will be able to measure form factors for a wide range of exotic nuclei, as available from the radioactive ion beams produced by the FAIR experiment. Other facilities are now being proposed, which will also consider electron scattering from exotic nuclei at higher energies, to study short-range correlations in exclusive reactions. This review will consider all available information concerning the current status (largely theoretical) of electron scattering from exotic nuclei and, where possible, complement such information with equivalent information concerning the neutron densities of those exotic systems, as obtained from intermediate energy proton scattering. The issue of long- and short-range correlations will be discussed, and whether extending such studies to the exotic sector will elicit new information. (orig.)

  2. Search for Gravitational Wave Ringdowns from Perturbed Intermediate Mass Black Holes in LIGO-Virgo Data from 2005-2010

    Science.gov (United States)

    Aasi, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Acernese, F.; Blackburn, Lindy L.; Camp, J. B.; Gehrels, N.; Graff, P. B.

    2014-01-01

    We report results from a search for gravitational waves produced by perturbed intermediate mass black holes (IMBH) in data collected by LIGO and Virgo between 2005 and 2010. The search was sensitive to astrophysical sources that produced damped sinusoid gravitational wave signals, also known as ringdowns, with frequency 50 less than or equal to italic f0/Hz less than or equal to 2000 and decay timescale 0.0001 approximately less than t/s approximately less than 0.1 characteristic of those produced in mergers of IMBH pairs. No significant gravitational wave candidate was detected. We report upper limits on the astrophysical coalescence rates of IMBHs with total binary mass 50 less than or equal to M/solar mass less than or equal to 450 and component mass ratios of either 1:1 or 4:1. For systems with total mass 100 less than or equal to M/solar mass 150, we report a 90%-confidence upper limit on the rate of binary IMBH mergers with non-spinning and equal mass components of 6:9 x 10(exp 8) Mpc(exp -3)yr(exp -1). We also report a rate upper limit for ringdown waveforms from perturbed IMBHs, radiating 1% of their mass as gravitational waves in the fundamental, l=m=2, oscillation mode, that is nearly three orders of magnitude more stringent than previous results.

  3. Primordial nuclei

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The recent detection of intergalactic helium by NASA's Astro-2 mission backs up two earlier measurements by ESA and the University of California, San Diego, using instruments aboard the Hubble Space Telescope. Taken together, these results give strong evidence that this helium is primordial, confirming a key prediction of the Big Bang theory. The amount of helium the results imply could also account for some of the Universe's invisible dark matter - material which affects galactic motion but is otherwise undetectable. According to theory, helium nuclei formed at around 100 seconds after the Big Bang, but the amount of helium depended on even earlier events. Initially, protons turned into neutrons with the same probability that neutrons turned into protons. But after about one second, the Universe had cooled down enough for the weak interaction to freeze out. Neutrons continued to decay into the slightly lighter protons, whilst the opposite reaction became much more scarce. At around 100 seconds, thermonuclear fusion reactions could begin, and all the neutrons that were left became absorbed into helium nuclei, leaving the remaining protons locked up in hydrogen. The ratio of helium to hydrogen was therefore determined by events occurring when the Universe was just one second old. Standard models of primordial nucleosynthesis fix this ratio at slightly less than 2 5% by mass. All heavier elements were cooked up much later in the stars, and amount to less than 1 % of the Universe's mass. These predictions have been borne out remarkably well by observation, although proof of the primordial origins of hydrogen and helium has remained elusive until now. Big Bang nucleosynthesis goes on to estimate that primordial baryonic matter in the form of light nuclei could account for around 10% of the Universe's dark matter. All three recent measurements used the same technique of looking at distant quasars, some of the most luminous objects in the Universe, to

  4. Interferometric diameters of five evolved intermediate-mass planet-hosting stars measured with PAVO at the CHARA Array

    Science.gov (United States)

    White, T. R.; Huber, D.; Mann, A. W.; Casagrande, L.; Grunblatt, S. K.; Justesen, A. B.; Silva Aguirre, V.; Bedding, T. R.; Ireland, M. J.; Schaefer, G. H.; Tuthill, P. G.

    2018-04-01

    Debate over the planet occurrence rates around intermediate-mass stars has hinged on the accurate determination of masses of evolved stars, and has been exacerbated by a paucity of reliable, directly-measured fundamental properties for these stars. We present long-baseline optical interferometry of five evolved intermediate-mass (˜ 1.5 M⊙) planet-hosting stars using the PAVO beam combiner at the CHARA Array, which we combine with bolometric flux measurements and parallaxes to determine their radii and effective temperatures. We measured the radii and effective temperatures of 6 Lyncis (5.12±0.16 R⊙, 4949±58 K), 24 Sextantis (5.49±0.18 R⊙, 4908±65 K), κ Coronae Borealis (4.77±0.07 R⊙, 4870±47 K), HR 6817 (4.45±0.08 R⊙, 5013±59 K), and HR 8641 (4.91±0.12 R⊙, 4950±68 K). We find disagreements of typically 15 % in angular diameter and ˜ 200 K in temperature compared to interferometric measurements in the literature, yet good agreement with spectroscopic and photometric temperatures, concluding that the previous interferometric measurements may have been affected by systematic errors exceeding their formal uncertainties. Modelling based on BaSTI isochrones using various sets of asteroseismic, spectroscopic, and interferometric constraints tends to favour slightly (˜ 15 %) lower masses than generally reported in the literature.

  5. Planck intermediate results: III. the relation between galaxy cluster mass and Sunyaev-Zeldovich signal

    DEFF Research Database (Denmark)

    Bartlett, J.G.; Bucher, M.; Cardoso, J.-F.

    2013-01-01

    on hydrostatic X-ray mass-proxy relations. We verify that our SZ effect measurements are in excellent agreement with previous determinations from Planck data. For the present sample, the hydrostatic X-ray masses at R500 are on average ~ 20 percent larger than the corresponding weak lensing masses, which......We examine the relation between the galaxy cluster mass M and Sunyaev-Zeldovich (SZ) effect signal DA2 Y500 for a sample of 19 objects for which weak lensing (WL) mass measurements obtained from Subaru Telescope data are available in the literature. Hydrostatic X-ray masses are derived from XMM......-Newton archive data, and the SZ effect signal is measured from Planck all-sky survey data. We find an MWL-D A2 Y500 relation that is consistent in slope and normalisation with previous determinations using weak lensing masses; however, there is a normalisation offset with respect to previous measures based...

  6. Systematics of triaxial moment of inertia and deformation parameters (β, γ) in even-even nuclei of mass region A = 90-120

    International Nuclear Information System (INIS)

    Singh, Yuvraj; Gupta, D.K.; Singh, M.; Gupta, K.K.; Bihari, Chhail; Varshney, A.K.; Dhiman, S.K.

    2012-01-01

    The deformation parameter β and γ of the collective model of Bohr and Mottelson are basic descriptors of the nuclear equilibrium shape and structure. In recent past the sets of deformation parameters ((β, γ) have been extracted from both level energies and E2 transition rates in even Xe, Ba and Ce nuclei (A∼120-140) and Hf, W, Os, Pt and Hg nuclei (A∼160-200) using rigid triaxial rotor model of Davydov-Filippov (DF). Researcher have found that the values of β obtained separately from energy and transition rate (β e and β b respectively), though, are found almost equal in heavy mass region (A ∼160-200) but, not so in medium mass (A∼120-140) nuclei. This observation puts a question mark whether the ββ dependence of moment of inertia in hydrodynamic model is reliable. The purpose of the present work is to study a relatively lighter mass region (A∼90-120) where the gap between values of two sets of β may further increase. To improve the calculations for extracting β e , the use of Grodzins rule will be made along with uncertainties, since only through this rule the E2 1 + is related with β G (value of β for symmetric nucleus and evaluated using Grodzins rule)

  7. Discoveries of high-frequency QPOs from intermediate-mass black holes with XMM, RXTE and NICER

    Science.gov (United States)

    Ranga Reddy Pasham, Deeraj; Strohmayer, Tod E.; Steiner, James F.

    2017-08-01

    Stable, twin-peak X-ray quasi-periodic oscillations (QPOs; frequency range of 100-450 Hz) in a 3:2 frequency ratio have been observed from a sample of stellar-mass black holes (e.g., Belloni et al. 2012). These frequencies scale inversely with the black hole mass as expected from general relativistic motion near a black hole. Under the black hole unification paradigm, it has been argued that intermediate-mass black holes (IMBH) should also exhibit the 3:2 ratio high-frequency QPOs, but at frequencies lower than stellar-mass black holes. Thence, such QPOs will provide an accurate measurement of IMBH masses (Abramowicz et al. 2004).Combining all the entire archival RXTE/PCA observations of the ultraluminous X-ray source (ULX) M82 X-1, we discovered stable, twin-peak X-ray QPOs at 3.3 and 5 Hz (3:2 frequency ratio). Scaling these frequencies to the oscillations of the stellar-mass black holes of known mass implies that M82 X-1's black hole is 428+-105 solar masses (Pasham, Strohmayer & Mushotzky 2014). We discovered similar 3:2 frequency ratio QPOs from another ULX NGC 1313 X-1 (0.30 and 0.45 Hz). These frequencies imply a black hole mass of 5000+-1300 solar masses in NGC 1313 X-1 (Pasham et al. 2015b). In addition to these results I will discuss some early results from NICER observations of ULXs.

  8. THE DISCOVERY OF THE YOUNGEST MOLECULAR OUTFLOW ASSOCIATED WITH AN INTERMEDIATE-MASS PROTOSTELLAR CORE, MMS-6/OMC-3

    International Nuclear Information System (INIS)

    Takahashi, Satoko; Ho, Paul T. P.

    2012-01-01

    We present subarcsecond resolution HCN (4-3) and CO (3-2) observations made with the Submillimeter Array, toward an extremely young intermediate-mass protostellar core, MMS 6-main, located in the Orion Molecular Cloud 3 region (OMC-3). We have successfully imaged a compact molecular outflow lobe (≈1000 AU) associated with MMS 6-main, which is also the smallest molecular outflow ever found in the intermediate-mass protostellar cores. The dynamical timescale of this outflow is estimated to be ≤100 yr. The line width dramatically increases downstream at the end of the molecular outflow (Δv ∼ 25 km s –1 ) and clearly shows the bow-shock-type velocity structure. The estimated outflow mass (≈10 –4 M ☉ ) and outflow size are approximately two to four orders and one to three orders of magnitude smaller, respectively, while the outflow force (≈10 –4 M ☉ km s –1 yr –1 ) is similar, compared to the other molecular outflows studied in OMC-2/3. These results show that MMS 6-main is a protostellar core at the earliest evolutionary stage, most likely shortly after the second core formation.

  9. Fission fragments mass distributions of nuclei populated by the multinucleon transfer channels of the {sup 18}O + {sup 232}Th reaction

    Energy Technology Data Exchange (ETDEWEB)

    Léguillon, R. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Nishio, K., E-mail: nishio.katsuhisa@jaea.go.jp [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Hirose, K.; Makii, H.; Nishinaka, I.; Orlandi, R.; Tsukada, K. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Smallcombe, J. [Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Chiba, S. [Laboratory for Advanced Nuclear Energy, Institute for Innovative Research, Tokyo Institute of Technology, N1-9, 2-12-1 Ookayama, Meguro, Tokyo 152-8550 (Japan); Aritomo, Y. [Faculty of Science and Engineering, Kindai University, Higashi-Osaka, 577-8502 (Japan); Ohtsuki, T. [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennangun, Osaka 590-0494 (Japan); Tatsuzawa, R.; Takaki, N. [Graduate School of Engineering, Tokyo City University, Tokyo 158-8557 (Japan); Tamura, N.; Goto, S. [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Tsekhanovich, I. [University of Bordeaux, 351 Cours de la Libration, 33405 Talence Cedex (France); Petrache, C.M. [Centre des Sciences Nucléaire et des Sciences de la Matière, Université Paris-Saclay, CNRS/IN2P3, 91406 Orsay (France); Andreyev, A.N. [Department of Physics, University of York, Heslington, York, YO10 5DD (United Kingdom); Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan)

    2016-10-10

    It is shown that the multinucleon transfer reactions is a powerful tool to study fission of exotic neutron-rich actinide nuclei, which cannot be accessed by particle-capture or heavy-ion fusion reactions. In this work, multinucleon transfer channels of the {sup 18}O + {sup 232}Th reaction are used to study fission of fourteen nuclei {sup 231,232,233,234}Th, {sup 232,233,234,235,236}Pa, and {sup 234,235,236,237,238}U. Identification of fissioning nuclei and of their excitation energy is performed on an event-by-event basis, through the measurement of outgoing ejectile particle in coincidence with fission fragments. Fission fragment mass distributions are measured for each transfer channel, in selected bins of excitation energy. In particular, the mass distributions of {sup 231,234}Th and {sup 234,235,236}Pa are measured for the first time. Predominantly asymmetric fission is observed at low excitation energies for all studied cases, with a gradual increase of the symmetric mode towards higher excitation energy. The experimental distributions are found to be in general agreement with predictions of the fluctuation–dissipation model.

  10. Abundances in Planetary Nebulae: an Autopsy of Low and Intermediate Mass Stars

    Science.gov (United States)

    Buell, James Francis

    In this work we report on the results of synthetic thermally pulsing asymptotic giant branch models (TP-AGB) and compare the results to the abundance ratios in a sample of planetary nebulae. We use updated the input parameters for mass-loss, the stellar luminosity, and dredge-up. We calculated models with masses between 0.8 solar masses and 8 solar masses. We also calculated models with (Fe/H) between -2.5 and 0.3. The effect of the first, second, and third dredge-up as well as hot-bottom burning are reported on. The analysis of a sample of Galactic bulge and disk planetary nebulae is also reported on.

  11. Evolution, Nucleosynthesis, and Yields of AGB Stars at Different Metallicities. III. Intermediate-mass Models, Revised Low-mass Models, and the ph-FRUITY Interface

    Science.gov (United States)

    Cristallo, S.; Straniero, O.; Piersanti, L.; Gobrecht, D.

    2015-08-01

    We present a new set of models for intermediate-mass asymptotic giant branch (AGB) stars (4.0, 5.0, and 6.0 M⊙) at different metallicities (-2.15 ≤ [Fe/H] ≤ +0.15). This set integrates the existing models for low-mass AGB stars (1.3 ≤ M/M⊙ ≤ 3.0) already included in the FRUITY database. We describe the physical and chemical evolution of the computed models from the main sequence up to the end of the AGB phase. Due to less efficient third dredge up episodes, models with large core masses show modest surface enhancements. This effect is due to the fact that the interpulse phases are short and, therefore, thermal pulses (TPs) are weak. Moreover, the high temperature at the base of the convective envelope prevents it from deeply penetrating the underlying radiative layers. Depending on the initial stellar mass, the heavy element nucleosynthesis is dominated by different neutron sources. In particular, the s-process distributions of the more massive models are dominated by the 22Ne(α,n)25Mg reaction, which is efficiently activated during TPs. At low metallicities, our models undergo hot bottom burning and hot third dredge up. We compare our theoretical final core masses to available white dwarf observations. Moreover, we quantify the influence intermediate-mass models have on the carbon star luminosity function. Finally, we present the upgrade of the FRUITY web interface, which now also includes the physical quantities of the TP-AGB phase for all of the models included in the database (ph-FRUITY).

  12. Klaus Blaum, of GSI Darmstadt and project leader of the ISOLTRAP experiment at CERN, will receive the 2004 Gustav-Hertz-Prize for his outstanding work on the mass determination of unstable atomic nuclei

    CERN Multimedia

    2004-01-01

    Klaus Blaum, of GSI Darmstadt and project leader of the ISOLTRAP experiment at CERN, will receive the 2004 Gustav-Hertz-Prize for his outstanding work on the mass determination of unstable atomic nuclei

  13. Exotic nuclei

    International Nuclear Information System (INIS)

    Villari, A.C.C.

    1990-01-01

    The actual tendencies to study exotic nuclei; applications of exotic nuclei beams in material study and medicine; recent results obtained by GANIL and Berkeley Laboratories of measurements of binding energy and radii of light nuclei; the future experiences to be carry out in several international laboratories and; proposal of studies in Brazil using Pelletron-USP accelerator and the LINAC superconductor accelerator, in construction in the same laboratory, are presented. (M.C.K.)

  14. Prospects for detection of intermediate-mass black holes in globular clusters using integrated-light spectroscopy

    Science.gov (United States)

    de Vita, R.; Trenti, M.; Bianchini, P.; Askar, A.; Giersz, M.; van de Ven, G.

    2017-06-01

    The detection of intermediate-mass black holes (IMBHs) in Galactic globular clusters (GCs) has so far been controversial. In order to characterize the effectiveness of integrated-light spectroscopy through integral field units, we analyse realistic mock data generated from state-of-the-art Monte Carlo simulations of GCs with a central IMBH, considering different setups and conditions varying IMBH mass, cluster distance and accuracy in determination of the centre. The mock observations are modelled with isotropic Jeans models to assess the success rate in identifying the IMBH presence, which we find to be primarily dependent on IMBH mass. However, even for an IMBH of considerable mass (3 per cent of the total GC mass), the analysis does not yield conclusive results in one out of five cases, because of shot noise due to bright stars close to the IMBH line of sight. This stochastic variability in the modelling outcome grows with decreasing BH mass, with approximately three failures out of four for IMBHs with 0.1 per cent of total GC mass. Finally, we find that our analysis is generally unable to exclude at 68 per cent confidence an IMBH with mass of 103 M⊙ in snapshots without a central BH. Interestingly, our results are not sensitive to GC distance within 5-20 kpc, nor to misidentification of the GC centre by less than 2 arcsec (<20 per cent of the core radius). These findings highlight the value of ground-based integral field spectroscopy for large GC surveys, where systematic failures can be accounted for, but stress the importance of discrete kinematic measurements that are less affected by stochasticity induced by bright stars.

  15. Signal and background in NLO QCD for the search of the intermediate mass Higgs boson at the SSC

    International Nuclear Information System (INIS)

    Bailey, B.

    1993-01-01

    The signal and background for the search of the Standard Model Higgs boson in the intermediate mass range 80 GeV H Z is studied based on calculations of the cross sections in next-to-leading order QCD perturbation theory for the production of the Higgs boson via gluon-gluon fusion and for the hadronic two-photon production. The method of Monte-Carlo integration allows the application of realistic cuts (p T , rapidity, photon isolation) to the cross section. Results are given for the K-factors of the signal and the background. It turns out that the NLO corrections improve the situation for a Higgs boson mass in the range of 80--120 GeV. Furthermore, the influence of a cut on the transverse momentum of the additional jet produced in the processes gg → Hg, gq → Hq, q bar q → Hg is compared to a similar cut for the background

  16. On the infant weight loss of low- to intermediate-mass star clusters

    Science.gov (United States)

    Weidner, C.; Kroupa, P.; Nürnberger, D. E. A.; Sterzik, M. F.

    2007-04-01

    Star clusters are born in a highly compact configuration, typically with radii of less than about 1 pc roughly independently of mass. Since the star formation efficiency is less than 50 per cent by observation and because the residual gas is removed from the embedded cluster, the cluster must expand. In the process of doing so it only retains a fraction fst of its stars. To date there are no observational constraints for fst, although N-body calculations by Kroupa, Aarseth & Hurley suggest it to be about 20-30 per cent for Orion-type clusters. Here we use the data compiled by Testi et al., Testi, Palla & Natta and Testi, Palla & Natta for clusters around young Ae/Be stars and by de Wit et al. and de Wit et al. around young O stars and the study of de Zeeuw et al. of OB associations and combine these measurements with the expected number of stars in clusters with primary Ae/Be and O stars, respectively, using the empirical correlation between maximal stellar mass and star cluster mass of Weidner & Kroupa. We find that fst < 50 per cent with a decrease to higher cluster masses/more massive primaries. The interpretation would be that cluster formation is very disruptive. It appears that clusters with a birth stellar mass in the range 10-103Msolar keep at most 50 per cent of their stars.

  17. Light-Nuclei Spectra from Chiral Dynamics

    Science.gov (United States)

    Piarulli, M.; Baroni, A.; Girlanda, L.; Kievsky, A.; Lovato, A.; Lusk, Ewing; Marcucci, L. E.; Pieper, Steven C.; Schiavilla, R.; Viviani, M.; Wiringa, R. B.

    2018-02-01

    In recent years local chiral interactions have been derived and implemented in quantum Monte Carlo methods in order to test to what extent the chiral effective field theory framework impacts our knowledge of few- and many-body systems. In this Letter, we present Green's function Monte Carlo calculations of light nuclei based on the family of local two-body interactions presented by our group in a previous paper in conjunction with chiral three-body interactions fitted to bound- and scattering-state observables in the three-nucleon sector. These interactions include Δ intermediate states in their two-pion-exchange components. We obtain predictions for the energy levels and level ordering of nuclei in the mass range A =4 - 12 , accurate to ≤2 % of the binding energy, in very satisfactory agreement with experimental data.

  18. Analysis for mass distribution of proton-induced reactions in intermediate energy range

    CERN Document Server

    Xiao Yu Heng

    2002-01-01

    The mass and charge distribution of residual products produced in the spallation reactions needs to be studied, because it can provide useful information for the disposal of nuclear waste and residual radioactivity generated by the spallation neutron target system. In present work, the Many State Dynamical Model (MSDM) is based on the Cascade-Exciton Model (CEM). The authors use it to investigate the mass distribution of Nb, Au and Pb proton-induced reactions in energy range from 100 MeV to 3 GeV. The agreement between the MSDM simulations and the measured data is good in this energy range, and deviations mainly show up in the mass range of 90 - 150 for the high energy proton incident upon Au and Pb

  19. Direct mass measurements of {sup 100}Sn and magic nuclei near the N=Z line; Mesures directes des masses de {sup 100}Sn et de noyaux exotiques proches de la ligne N = Z

    Energy Technology Data Exchange (ETDEWEB)

    Chartier, M.

    1996-10-31

    The masses of nuclei far from stability are of particular interest in nuclear structure studies, and many methods of varying precision have been developed to undertake their measurement. A direct time of flight technique in conjunction with the SPEG spectrometer at GANIL has been extended to the mass measurement of proton-rich nuclei near N = Z line in the mass region A {approx_equal} 60-80 known to provide input for astrophysical modelling of the rp-process and information relevant to the nuclear structure in a region of high deformation. The radioactive beams were produced via the fragmentation of a {sup 78}Kr beam on a {sup nat}Ni target, using the new SISSI device. A purification method based on the stripping of the secondary ions was successfully used for the first time, and the masses of {sup 70}Se and {sup 71}Se were measured. In order to improve the mass resolution for heavier nuclei, another method using the second cyclotron of GANIL (CSS2) as a high resolution spectrometer has been developed. An experiment aimed at measuring the masses of A 100 isobars in the vicinity of the doubly magic nucleus {sup 100}Sn was successfully performed, using this original technique. Secondary ions of {sup 100}Ag, {sup 100}Cd, {sup 100}In and {sup 100}Sn produced via fusion-evaporation reaction {sup 50}Cr + {sup 58}Ni and simultaneously accelerated in the CSS2 cyclotron. The mass of {sup 100}Cd and, for the first time, the masses of {sup 100}Sn were determined directly with respect to the reference mass of {sup 100}Ag. These results have been compared to various theoretical predictions and open the discussion on considerations of spin-isospin symmetry. (author). 96 refs.

  20. Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO

    NARCIS (Netherlands)

    Abbott, B. P.; Abbott, R.; Abbott, T. D.; Acernese, F.; Ackley, K.; Adams, C.; Phythian-Adams, A.T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agatsuma, K.; Aggarwal, N.T.; Aguiar, O. D.; Aiello, L.; Ain, A.; Allen, B.; Allen, G; Allocca, A.; Almoubayyed, H.; Altin, P. A.; Amato, A.; Ananyeva, A.; Anderson, S. B.; Anderson, W. G.; Antier, S.; Appert, S.; Arai, K.; Araya, M. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; AultONeal, K.; Avila-Alvarez, A.; Babak, S.; Bacon, P.; Bader, M. K. M.; Bae, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Banagiri, S.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, R.D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bawaj, M.; Bazzan, M.; Becsy, B.; Beer, C.; Bejger, M.; Belahcene, I.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Billman, C. R.; Birch, D J; Birney, R.; Birnholtz, O.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blackman, J.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bode, N.; Boer, M.; Bogaert, J.G.; Bohe, A.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, A.D.; Brown, D.; Brown, N. M.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Bustillo, J. Calderon; Callister, T. A.; Calloni, E.; Camp, J. B.; Canepa, M.; Canizares, P.; Cannon, K. C.; Cao, H.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Carney, M. F.; Diaz, J. Casanueva; Casentini, C.; Caudill, S.; Cavaglia, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Baiardi, L. Cerboni; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, D. S.; Charlton, P.; Chassande-Mottin, E.; Chatterjee, D.; Cheeseboro, B. D.; Chen, H. Y.; Chen, Y; Cheng, H. -P.; Chincarini, A.; Chiummo, A.; Chmiel, T.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, A. J. K.; Chua, S. S. Y.; Chung, A. K. W.; Chung, S.; Ciani, G.; Ciolfi, R.; Cirelli, C. E.; Cirone, A.; Clara, F.; Clark, J. A.; Cleva, F.; Cocchieri, C.; Coccia, E.; Cohadon, P. -F.; Colla, A.; Collette, C. G.; Cominsky, L. R.; Constancio, M., Jr.; Conti, L.; Cooper, S. J.; Corban, P.; Corbitt, T. R.; Corley, K. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J. -P.; Countryman, S. T.; Couvares, P.; Covas, P. B.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cullen, T. J.; Cumming, A.; Cunningham, Laura; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dasgupta, A.; Costa, C. F. Da Silva; Dattilo, V.; Dave, I.; Davier, M.; Davies, G. S.; Davis, D.; Daw, E. J.; Day, B.; De, S.; Debra, D.; Deelman, E; Degallaix, J.; De laurentis, M.; Deleglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.A.; Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Devenson, J.; Devine, R. C.; Dhurandhar, S.; Diaz, M. C.; Di Fiore, L.; Giovanni, M. Di; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Renzo, F.; Doctor, Z.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Dorrington, I.; Douglas, R.; Alvarez, M. Dovale; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Duncan, J.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H. -B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Eisenstein, R. A.; Essick, R. C.; Etienne, Z. B.; Etzel, T.; Evans, M.; Evans, T. M.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Farinon, S.; Farr, B.; Farr, W. M.; Fauchon-Jones, E. J.; Favata, M.; Fays, M.; Fehrmann, H.; Feicht, J.; Fejer, M. M.; Fernandez-Galiana, A.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M; Fong, H.; Forsyth, P. W. F.; Forsyth, S. S.; Fournier, J. -D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fries, E. M.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H.; Gabel, M.; Gadre, B. U.; Gaebel, S. M.; Gair, J. R.; Gammaitoni, L.; Ganija, M. R.; Gaonkar, S. G.; Garufi, F.; Gaudio, S.; Gaur, G.; Gayathri, V.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, D.J.; George, J.; Gergely, L.; Germain, V.; Ghonge, S.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.P.; Glover, L.; Goetz, E.; Goetz, R.; Gomes, A.S.P.; Gonzalez, Idelmis G.; Castro, J. M. Gonzalez; Gopakumar, A.; Gorodetsky, M. L.; Gossan, S. E.; Lee-Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.M.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Gruning, P.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hannuksela, O. A.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Haster, C. -J.; Haughian, K.; Healy, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Henry, J.A.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Horst, C.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Ingram, D. R.; Inta, R.; Intini, G.; Isa, H. N.; Isac, J. -M.; Isi, M.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jimenez-Forteza, F.; Johnson, W.; Jones, I.D.; Jones, R.; Jonker, R. J. G.; Ju, L.; Junker, J.; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Katolik, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kawabe, K.; Kefelian, F.; Keitel, D.; Kemball, A. J.; Kennedy, R.E.; Kent, C.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan., S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J. C.; Kim, W.; Kim, S.W.; Kim, Y.M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kirchhoff, R.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Koch, P.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kraemer, H.C.; Kringel, V.; Krishnan, B.; Krolak, A.; Kuehn, G.; Kumar, P.; Kumar, R.; Kumar, S.; Kuo, L.; Kutynia, A.; Kwang-Cheol, S.; Lackey, B. D.; Lai, K. H.; Landry, M.; Lang, R. N.; Lange, J.; Lantz, B.; Lanza, R. K.; Lartaux-Vollard, A.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lee, C.H.; Lee, K.H.; Lee, M.H.; Lee, W. H.; Lee, K.; Lehmann, J.; Lenon, A.; Leonardi, M.; Leroy, N.; Letendre, N.; Levin, Y.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Liu, J.; Lockerbie, N. A.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lovelace, G.; Lueck, H.; Lumaca, D.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macfoy, S.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Hernandez, I. Magana; Magana-Sandoval, F.; Zertuche, L. Magana; Magee, R. M.; Majorana, E.; Maksimovic, I.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marka, S.; Marka, Z.; Markakis, C.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matas, A.; Matichard, F.; Matone, L.; Mavalvala, N.; Mayani, R.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McCuller, L.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Mejuto-Villa, E.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, A.; Miller, B. B.; Miller, J.; Millhouse, M.; Minazzoli, O.; Minenkov, Y.; Ming, J.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B.C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, S.D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Muniz, E. A. M.; Murray, P.G.; Napier, K.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Nelemans, G.; Nelson, T. J. N.; Gutierrez-Neri, M.; Nery, M.; Neunzert, A.; Newport, J. M.; Newton, G.; Ng, K. K. Y.; Nguyen, T. T.; Nichols, D.; Nielsen, A. B.; Nissanke, S.; Noack, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; Ormiston, R.; Ortega, L. F.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pace, A. E.; Page, J.; Page, M. A.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pang, B.; Pang, P. T. H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.S; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Castro-Perez, J.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poggiani, R.; Popolizio, P.; Porter, E. K.; Post, A.; Powell, J.; Prasad, J.; Pratt, J. W. W.; Predoi, V.; Prestegard, T.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Puerrer, M.; Qi, H.; Qin, J.; Qiu, S.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rakhmanov, M.; Ramirez, K. E.; Rapagnani, P.; Raymond, V.; Razzano, M.; Read, J.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Ricci, F.; Ricker, P. M.; Rieger, S.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romel, C. L.; Romie, J. H.; Rosinska, D.; Ross, M. P.; Rowan, S.; Ruediger, A.; Ruggi, P.; Ryan, K.; Rynge, M.; Sachdev, Perminder S; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sampson, L. M.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Scheuer, J.; Schmidt, E.; Schmidt, J; Schmidt, P.; Schnabel, R.B.; Schofield, R. M. S.; Schoenbeck, A.; Schreiber, K.E.C.; Schuette, D.; Schulte, B. W.; Schutz, B. F.; Schwalbe, S. G.; Scott, J.; Scott, S. M.; Seidel, E.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Shaddock, D. A.; Shaffer, T. J.; Shah, A.; Shahriar, M. S.; Shao, L.P.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, António Dias da; Singer, A; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, B.; Smith, R. J. E.; Smith, R. J. E.; Son, E. J.; Sonnenberg, J. A.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Spencer, A. P.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stone, R.; Strain, K. A.; Stratta, G.; Strigin, S. E.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Sutton, P. J.; Swinkels, B. L.; Szczepanczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tapai, M.; Taracchini, A.; Taylor, J. A.; Taylor, W.R.; Theeg, T.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tonelli, M.; Tornasi, Z.; Torrie, C. I.; Toyra, D.; Travasso, F.; Traylor, G.; Trifiro, D.; Trinastic, J.; Tringali, M. C.; Trozzo, L.; Tsang, K. W.; Tse, M.; Tso, R.; Tuyenbayev, D.; Ueno, K.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahi, K.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; Van Beuzekom, Martin; van den Brand, J. F. J.; Van Den Broeck, C.F.F.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Varma, V.; Vass, S.; Vasuth, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P.J.; Venkateswara, K.; Venugopalan, G.; Verkindt, D.; Vetrano, F.; Vicere, A.; Viets, A. D.; Vinciguerra, S.; Vine, D. J.; Vinet, J. -Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, MT; Walet, R.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, J. Z.; Wang, M.; Wang, Y. -F.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Watchi, J.; Weaver, B.; Wei, L. -W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wessel, E. K.; Wessels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Whittle, C.; Williams, D.; Williams, D.R.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Wofford, J.; Wong, G.W.K.; Worden, J.; Wright, J.L.; Wu, D.S.; Wu, G.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yap, M. J.; Yu, Hang; Yu, Haocun; Yvert, M.; Zadrozny, A.; Zanolin, M.; Zelenova, T.; Zendri, J. -P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, T.; Zhang, Y. -H.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zweizig, J.

    2017-01-01

    During their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves

  1. A new direction for dark matter research: intermediate-mass compact halo objects

    Science.gov (United States)

    Chapline, George F.; Frampton, Paul H.

    2016-11-01

    The failure to find evidence for elementary particles that could serve as the constituents of dark matter brings to mind suggestions that dark matter might consist of massive compact objects (MACHOs). In particular, it has recently been argued that MACHOs with masses > 15Msolar may have been prolifically produced at the onset of the big bang. Although a variety of astrophysical signatures for primordial MACHOs with masses in this range have been discussed in the literature, we favor a strategy that uses the potential for magnification of stars outside our galaxy due to gravitational microlensing of these stars by MACHOs in the halo of our galaxy. We point out that the effect of the motion of the Earth on the shape of the micro-lensing brightening curves provides a promising approach to testing over the course of next several years the hypothesis that dark matter consists of massive compact objects.

  2. Influence of mass asymmetry in fusion cross section of intermediate weight ions

    International Nuclear Information System (INIS)

    Anjos, R.M. dos.

    1987-01-01

    The mass asymmetry degree effect on fusion, was investigated for different systems involving nucleus A projectie , A target ≤ 40, populating a compound nucleus. The following systems were studied: ( 19 F + 19 F), ( 12 C + 26 Mg) and ( 19 F + 12 C, 16 O, 27 Al, 40 Ca) in the energy range of 32 ≤ E lab ≤ 72 MeV and angular range 6 0 ≤ Θ lab ≤ 28 0 . The experimental method employed the time of flight technique, of the evaporation residuals. Analysis of excitation function indicate different behavior for symmetric and asymmetric systems suggesting that the presence of other more competitive processes is more pronounced in asymmetric entrance channels at high energies. These behaviors indicate that mass asymmetry is an important point in complete and incomplete fusion processes. (A.C.A.S.) [pt

  3. Mass measurement project by determination of Q{sub {beta}} for neutron-rich nuclei; Projet de mesure des masses par determination des Q{sub {beta}} pour des noyaux tres riches en neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Pautrat, M.; Lagrange, J.M.; Petizon, L. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Vanhorenbeeck, J.; Duhamel, P. [Brussels Univ. (Belgium). Inst. d`Astronomie et d`Astrophysique; Binon, F. [Universite Libre de Bruxelles (Belgium)

    1993-12-31

    The aim of the project described hereafter is to collect new data on the exotic neutron rich nuclei of the Fe to Zn region, and in particular to determine their masses, for both nuclear physics and astrophysics purposes. These isotopes will be produced through projectile fragmentation at the GANIL facility and selected by the LISE3 spectrometer. Their half-lives will be measured as well as the energy of their main {gamma} rays; {gamma} - {gamma} coincidences will then allow to build a preliminary level scheme. The analysis of {beta} spectra and {beta} - {gamma} coincidences will finally provide the maximum {beta} decay energies of the studied nuclei leading to their masses. The difficulties arising from the low production rates, the {beta} detection, the data handling are discussed together with the solutions proposed to overcome them. (authors). 17 refs.

  4. The properties of atomic nuclei at the boundary of proton instability, discussed at the example of very neutron deficient isotopes in the mass range 100-150

    International Nuclear Information System (INIS)

    Roeckl, E.

    1981-10-01

    In this paper it shall be tried to strike the balance after the first years of experimenting at the on-line mass separator of the GSI Darmstadt and to present the main results of the study of very neutron deficient isotopes in the mass range 90-150 as well as the resulting questions for further experiments. First some foundations concerning the properties of neutron deficient nuclei and the measuring method are explained. The results and their interpretation are discussed using examples for the alpha decay, the beta decay, the mass-energy-area, and the proton-drip line. Finally the obtained results are summarized, and an outlook to further studies of nuclear properties far from beta stability is given. (orig.) [de

  5. Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database

    DEFF Research Database (Denmark)

    Peterson, B. M.; Ferrarese, L.; Gilbert, K. M.

    2004-01-01

    velocity dispersion. The scatter around this relationship implies that the typical systematic uncertainties in reverberation-based black hole masses are smaller than a factor of three. We present a preliminary version of a mass-luminosity relationship that is much better defined than any previous attempt......We present improved black hole masses for 35 active galactic nuclei (AGNs) based on a complete and consistent reanalysis of broad emission-line reverberation-mapping data. From objects with multiple line measurements, we find that the highest precision measure of the virial product is obtained...... by using the cross-correlation function centroid (as opposed to the cross-correlation function peak) for the time delay and the line dispersion (as opposed to full width half maximum) for the line width and by measuring the line width in the variable part of the spectrum. Accurate line-width measurement...

  6. Wandering off the centre: a characterization of the random motion of intermediate-mass black holes in star clusters

    Science.gov (United States)

    de Vita, Ruggero; Trenti, Michele; MacLeod, Morgan

    2018-04-01

    Despite recent observational efforts, unequivocal signs for the presence of intermediate-mass black holes (IMBHs) in globular clusters (GCs) have not been found yet. Especially when the presence of IMBHs is constrained through dynamical modelling of stellar kinematics, it is fundamental to account for the displacement that the IMBH might have with respect to the GC centre. In this paper, we analyse the IMBH wandering around the stellar density centre using a set of realistic direct N-body simulations of star cluster evolution. Guided by the simulation results, we develop a basic yet accurate model that can be used to estimate the average IMBH radial displacement (〈rbh〉) in terms of structural quantities as the core radius (rc), mass (Mc), and velocity dispersion (σc), in addition to the average stellar mass (mc) and the IMBH mass (Mbh). The model can be expressed by the equation /r_c=A(m_c/M_bh)^α [σ _c^2r_c/(GM_c)]^β, in which the free parameters A, α, and β are calculated through comparison with the numerical results on the IMBH displacement. The model is then applied to Galactic GCs, finding that for an IMBH mass equal to 0.1 per cent of the GC mass, the typical expected displacement of a putative IMBH is around 1 arcsec for most Galactic GCs, but IMBHs can wander to larger angular distances in some objects, including a prediction of a 2.5 arcsec displacement for NGC 5139 (ω Cen), and >10 arcsec for NGC5053, NGC6366, and ARP2.

  7. Hunting for the intermediate-mass Higgs boson in a hadron collider

    International Nuclear Information System (INIS)

    Gunion, J.F.; Kalyniak, P.; Soldate, M.; Galison, P.

    1985-01-01

    We examine the feasibility of identifying in a hadron machine the standard, neutral Higgs boson, produced in association with a W, when the mass of the Higgs is between approximately 100 GeV and 2m/sub W/. The production cross section is calculated with quasirealistic cuts imposed under the assumption that the Higgs decays into tt-bar. Possible backgrounds arising from the continuum production of tt-bar, tb-bar, or t-barb accompanied by a W are computed as well

  8. Development of the helium-jet fed on-line mass separator RAMA and its application to studies of T/sub z/ = -2 nuclei

    International Nuclear Information System (INIS)

    Moltz, D.M.

    1979-10-01

    The study of nuclei far from beta stability is hampered greatly when the nuclide of interest decays in a manner identical to that of a nuclide produced in greater yield in the same bombardment. Attempts to observe the protons associated with the decay of the A = 4n, T/sub z/ = -2 series of beta-delayed proton emitters failed because of the large number of protons arising from the strong beta-delayed proton decay of the A = 4n + 1, T/sub z/ = -3/2 nuclides. One solution to this problem is through the use of an on-line mass separator. Development of the Berkelely helium-jet fed on-line mass separator RAMA is discussed as applied to studies of the A = 4n, T/sub z/ = -2 nuclides. RAMA (Recoil Atom Mass Analyzer) has typical efficiencies of 0.1% for approx. 75 elements with melting points less than or equal to 2000 0 C. This efficiency permits decay studies to be readily performed on nuclei with production cross sections greater than or equal to 500 μb for γ-ray spectroscopy and greater than or equal to 1 μb for discrete energy charged particle spectroscopy. The mass range on the normalized RAMA focal plane is +- 10%. The quoted efficiency is for a mass resolution of M/ΔM approx. 300. RAMA has been used to observe two members of the A = 4n, T/sub z/ = -2 series of beta-delayed proton emitters, 20 Mg and 24 Si. Observation of beta-delayed protons from a mass-separated sample of 20 Mg(t/sub 1/2/ approx. 95 ms) establishes the mass-excess of the lowest T = 2 (0 + ) state in 20 Na (13.42 +- .05 MeV), thereby completing the mass twenty isospin quintet. A similar measurement of the decay of 24 Si (t/sub 1/2/ approx. 100 ms) establishes the mass-excess of the lowest T = 2 (0 + ) state in 24 Al (5.903 +- 0.009 MeV). The mass 24 isospin quintet is incomplete because the mass of 24 Si remains unknown

  9. Measurement of Fragment Mass Distributions in Neutron-induced Fission of 238U and 232Th at Intermediate Energies

    International Nuclear Information System (INIS)

    Simutkin, V.D.

    2008-01-01

    Conceptual analysis of accelerator-driven systems assumes extensive use of nuclear data on neutron-induced reactions at intermediate energies. In particular, information about the fission fragment yields from the 238 U(n,f) and 232 Th(n,f) reactions is of particular interest at neutron energies from 10 to 200 MeV. However, there is a lack of such data for both 238 U and 232 Th. Up to now, the intermediate energy measurements have been performed for 238 U only, and there are no data for the 232 Th(n,f) reaction. The aim of the work is to provide such data. Fission fragment mass distributions for the 232 Th(n,f) and 238 U(n,f) reactions have been measured for the incident neutron energies 32.8 MeV, 45.3 MeV and 59.9 MeV. The experiments have been performed at the neutron beam facility of the Universite Catholique de Louvain, Belgium. A multi-section Frisch-gridded ionization chamber has been used as a fission fragment detector. The data obtained have been interpreted in terms of the multimodal random neck-rupture model (MMRNRM). (authors)

  10. Intermediate-mass Elements in Young Supernova Remnants Reveal Neutron Star Kicks by Asymmetric Explosions

    Science.gov (United States)

    Katsuda, Satoru; Morii, Mikio; Janka, Hans-Thomas; Wongwathanarat, Annop; Nakamura, Ko; Kotake, Kei; Mori, Koji; Müller, Ewald; Takiwaki, Tomoya; Tanaka, Masaomi; Tominaga, Nozomu; Tsunemi, Hiroshi

    2018-03-01

    The birth properties of neutron stars (NSs) yield important information about the still-debated physical processes that trigger the explosion as well as on intrinsic neutron-star physics. These properties include the high space velocities of young neutron stars with average values of several 100 km s‑1, with an underlying “kick” mechanism that is not fully clarified. There are two competing possibilities that could accelerate NSs during their birth: anisotropic ejection of either stellar debris or neutrinos. Here we present new evidence from X-ray measurements that chemical elements between silicon and calcium in six young gaseous supernova remnants are preferentially expelled opposite to the direction of neutron star motion. There is no correlation between the kick velocities and magnetic field strengths of these neutron stars. Our results support a hydrodynamic origin of neutron-star kicks connected to asymmetric explosive mass ejection, and they conflict with neutron-star acceleration scenarios that invoke anisotropic neutrino emission caused by particle and nuclear physics in combination with very strong neutron-star magnetic fields.

  11. Exclusive description of multiple production on nuclei in the additive quark model. Multiplicity distributions in interactions with heavy nuclei

    International Nuclear Information System (INIS)

    Levchenko, B.B.; Nikolaev, N.N.

    1985-01-01

    In the framework of the additive quark model of multiple production on nuclei we calculate the multiplicity distributions of secondary particles and the correlations between secondary particles in πA and pA interactions with heavy nuclei. We show that intranuclear cascades are responsible for up to 50% of the nuclear increase of the multiplicity of fast particles. We analyze the sensitivity of the multiplicities and their correlations to the choice of the quark-hadronization function. We show that with good accuracy the yield of relativistic secondary particles from heavy and intermediate nuclei depends only on the number N/sub p/ of protons knocked out of the nucleus, and not on the mass number of the nucleus (N/sub p/ scaling)

  12. Measurement of beta decay energies of short-lived neutron rich atomic nuclei in the mass range 101 ≤ A ≤ 106 and A=109

    International Nuclear Information System (INIS)

    Weikard, H.

    1986-01-01

    At the mass separator LOHENGRIN of the Laue-Langevin institute in Grenoble for 18 nuclei (Zr, Nb, Mo, Tc, Ru, and Rh nuclides) with masses 101 ≤ A ≤ 106 and A=109 Q β values were determined from measurement of beta decay energies. From the study of the isomerism in 102 Nb resulted that the energetic distance of the two isomers is certainly smaller than 200 keV, that it is probably even smaller than 100 keV. The decay scheme for 102 Nb could be extended by one level which is depopulated by two gamma lines. For the decay of the 109 Ru the approach of a decay scheme is given: Five new levels are proposed. The diagrams of the two-particle separation energies which could be extended in this thesis confirm the continuation of the deformation in the considered region. A deformed subshell at N=62 however cannot yet be clearly detected. (orig./HSI) [de

  13. Analysis of triacetone triperoxide (TATP) and TATP synthetic intermediates by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Sigman, Michael E; Clark, C Douglas; Caiano, Tara; Mullen, Rebecca

    2008-01-01

    The explosive triacetone triperoxide (TATP) has been analyzed by electrospray ionization mass spectrometry (ESI-MS) on a linear quadrupole instrument, giving a 62.5 ng limit of detection in full scan positive ion mode. In the ESI interface with no applied fragmentor voltage the m/z 245 [TATP + Na](+) ion was observed along with m/z 215 [TATP + Na - C(2)H(6)](+) and 81 [(CH(3))(2)CO + Na](+). When TATP was ionized by ESI with an applied fragmentor voltage of 75 V, ions at m/z 141 [C(4)H(6)O(4) + Na](+) and 172 [C(5)H(9)O(5) + Na](+) were also observed. When the precipitates formed in the synthesis of TATP were analyzed before the reaction was complete, a new series of ions was observed in which the ions were separated by 74 m/z units, with ions occurring at m/z 205, 279, 353, 427, 501, 575, 649 and 723. The series of evenly spaced ions is accounted for as oligomeric acetone carbonyl oxides terminated as hydroperoxides, [HOOC(CH(3))(2){OOC(CH(3))(2)}(n)OOH + Na](+) (n = 1, 2 ... 8). The ESI-MS spectra for this homologous series of oligoperoxides have previously been observed from the ozonolysis of tetramethylethylene at low temperatures. Precipitates from the incomplete reaction mixture, under an applied fragmentor voltage of 100 V in ESI, produced an additional ion observed at m/z 99 [C(2)H(4)O(3) + Na](+), and a set of ions separated by 74 m/z units occurring at m/z 173, 247, 321, 395, 469 and 543, proposed to correspond to [CH(3)CO{OOC(CH(3))(2)}(n)OOH + Na](+) (n = 1,2 ... 5). Support for the assigned structures was obtained through the analysis of both protiated and perdeuterated TATP samples. Copyright (c) 2007 John Wiley & Sons, Ltd.

  14. CHEMICAL COMPOSITION OF INTERMEDIATE-MASS STAR MEMBERS OF THE M6 (NGC 6405) OPEN CLUSTER

    Energy Technology Data Exchange (ETDEWEB)

    Kılıçoğlu, T.; Albayrak, B. [Ankara University, Faculty of Science, Department of Astronomy and Space Sciences, 06100, Tandoğan, Ankara (Turkey); Monier, R. [LESIA, UMR 8109, Observatoire de Paris Meudon, Place J. Janssen, Meudon (France); Richer, J. [Département de physique, Université de Montréal, 2900, Boulevard Edouard-Montpetit, Montréal QC, H3C 3J7 (Canada); Fossati, L., E-mail: tkilicoglu@ankara.edu.tr, E-mail: balbayrak@ankara.edu.tr, E-mail: Richard.Monier@obspm.fr, E-mail: Jacques.Richer@umontreal.ca, E-mail: lfossati@astro.uni-bonn.de [Argelander-Institut für Astronomie der Universität Bonn, Auf dem Hügel 71, D-53121, Bonn (Germany)

    2016-03-15

    We present here the first abundance analysis of 44 late B-, A-, and F-type members of the young open cluster M6 (NGC 6405, age about 75 Myr). Low- and medium-resolution spectra, covering the 4500–5840 Å wavelength range, were obtained using the FLAMES/GIRAFFE spectrograph attached to the ESO Very Large Telescopes. We determined the atmospheric parameters using calibrations of the Geneva photometry and by adjusting the H{sub β} profiles to synthetic ones. The abundances of up to 20 chemical elements, from helium to mercury, were derived for 19 late B, 16 A, and 9 F stars by iteratively adjusting synthetic spectra to the observations. We also derived a mean cluster metallicity of [Fe/H] = 0.07 ± 0.03 dex from the iron abundances of the F-type stars. We find that for most chemical elements, the normal late B- and A-type stars exhibit larger star-to-star abundance variations than the F-type stars probably because of the faster rotation of the B and A stars. The abundances of C, O, Mg, Si, and Sc appear to be anticorrelated with that of Fe, while the opposite holds for the abundances of Ca, Ti, Cr, Mn, Ni, Y, and Ba as expected if radiative diffusion is efficient in the envelopes of these stars. In the course of this analysis, we discovered five new peculiar stars: one mild Am, one Am, and one Fm star (HD 318091, CD-32 13109, GSC 07380-01211, CP1), one HgMn star (HD 318126, CP3), and one He-weak P-rich (HD 318101, CP4) star. We also discovered a new spectroscopic binary, most likely a SB2. We performed a detailed modeling of HD 318101, the new He-weak P-rich CP star, using the Montréal stellar evolution code XEVOL which self-consistently treats all particle transport processes. Although the overall abundance pattern of this star is properly reproduced, we find that detailed abundances (in particular the high P excess) resisted modeling attempts even when a range of turbulence profiles and mass-loss rates were considered. Solutions are proposed which are

  15. Chemical Composition of Intermediate-mass Star Members of the M6 (NGC 6405) Open Cluster

    Science.gov (United States)

    Kılıçoğlu, T.; Monier, R.; Richer, J.; Fossati, L.; Albayrak, B.

    2016-03-01

    We present here the first abundance analysis of 44 late B-, A-, and F-type members of the young open cluster M6 (NGC 6405, age about 75 Myr). Low- and medium-resolution spectra, covering the 4500-5840 Å wavelength range, were obtained using the FLAMES/GIRAFFE spectrograph attached to the ESO Very Large Telescopes. We determined the atmospheric parameters using calibrations of the Geneva photometry and by adjusting the Hβ profiles to synthetic ones. The abundances of up to 20 chemical elements, from helium to mercury, were derived for 19 late B, 16 A, and 9 F stars by iteratively adjusting synthetic spectra to the observations. We also derived a mean cluster metallicity of [Fe/H] = 0.07 ± 0.03 dex from the iron abundances of the F-type stars. We find that for most chemical elements, the normal late B- and A-type stars exhibit larger star-to-star abundance variations than the F-type stars probably because of the faster rotation of the B and A stars. The abundances of C, O, Mg, Si, and Sc appear to be anticorrelated with that of Fe, while the opposite holds for the abundances of Ca, Ti, Cr, Mn, Ni, Y, and Ba as expected if radiative diffusion is efficient in the envelopes of these stars. In the course of this analysis, we discovered five new peculiar stars: one mild Am, one Am, and one Fm star (HD 318091, CD-32 13109, GSC 07380-01211, CP1), one HgMn star (HD 318126, CP3), and one He-weak P-rich (HD 318101, CP4) star. We also discovered a new spectroscopic binary, most likely a SB2. We performed a detailed modeling of HD 318101, the new He-weak P-rich CP star, using the Montréal stellar evolution code XEVOL which self-consistently treats all particle transport processes. Although the overall abundance pattern of this star is properly reproduced, we find that detailed abundances (in particular the high P excess) resisted modeling attempts even when a range of turbulence profiles and mass-loss rates were considered. Solutions are proposed which are still under

  16. Rapid quantification of metabolic intermediates in blood by liquid chromatography-tandem mass spectrometry to investigate congenital lactic acidosis.

    Science.gov (United States)

    Peng, Minzhi; Cai, Yanna; Fang, Xiefan; Liu, Li

    2016-10-26

    A novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been established to quantify metabolic intermediates, including lactate (Lac), pyruvate (Pyr), acetoacetate (ACAC) and 3-hydroxybutyrate (3-HB) in blood. Samples were deproteinized with methanol-acetonitrile solution, and analytes were separated on an adamantyl group-bonded reverse phase column and detected in multiple reaction monitoring mode. Total analysis time was 4 min per sample. Method validation results displayed that limits of quantification were 10.0 μmol L -1 for Lac and Pyr, and 5.0 μmol L -1 for ACAC and 3-HB. The within- and between-run coefficients of variation were in the range of 1.2-6.4% for all analytes. The recoveries were ranged from 95.6 to 111.5%. The reference values of analytes were determined for the pediatric population. Duo to instability of Lac, Pyr and ACAC in vitro, a comprehensive stability assay was performed to determine optimal conditions for sample collection, pretreatment and storage. Results showed that precipitation of protein in blood at bedside combined with low storage temperature could effectively preserve the integrity of Lac, Pyr and 3-HB, but the precipitated protein accelerated degradation of ACAC. Isolation of supernatant fluid slowed degradation of ACAC. Supernatant samples could store at -20 °C for 10 days. The use of plasma or serum to determine these intermediates was not recommended. In this study, 450 samples from patients were analyzed, and 7 patients were diagnosed as congenital lactic acidosis. With the advantages of rapid, accurate and reliable, this method is very suitable for congenital lactic acidosis screening and researches related to energy metabolism. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Emsission of intermediate mass fragments in the p(1.9 GeV)+natNI reaction

    International Nuclear Information System (INIS)

    Bubak, A.

    2004-06-01

    The emission of the intermediate mass fragments (IMFs; 2 ≤ Z ≤ 14) produced in the interaction of 1.9 GeV protons with nickel ( nat Ni) has been a subject of interest of the present study. Energy spectra of isotopically and elementally identified ejectiles have been measured at angles 15 and 120 with the respect to the beam direction. The identification of the emitted IMFs has been performed by means of the Bragg curve spectroscopy and the time-of-flight technique (TOF). The Bragg curve detectors (BCDs) were employed for the charge identification, whereas the TOF method combined with the BCD, for the mass identification. The main task of the present PhD thesis was to built appropriate data acquisition system, to perform the experiment on the internal beam of the COSY accelerator, to propose the methodology of the off-line analysis of the data, to apply it to the event-by-event stored data, and to perform the phenomenological analysis of the obtained data. The results, experimental procedures, and different techniques of the element and isotope identification by means of the BCD + TOF are presented. The determination of the power law parameter τ characterizing the mass and charge distributions of the reaction products is discussed. Various methods of the nuclear matter temperature determination, the comparison between nuclear matter thermometers, and the discussion of the obtained results, shown in the energy-temperature diagram (the so called caloric curve), are presented as well. The results suggest two different mechanisms of the IMFs production: from the equilibrated (IMFs measured at 120 ), and non-equilibrated (IMFs measured at 15 ) state of the nucleus. (orig.)

  18. Determination of the nuclear level densities and radiative strength function for 43 nuclei in the mass interval 28≤A≤200

    Science.gov (United States)

    Knezevic, David; Jovancevic, Nikola; Sukhovoj, Anatoly M.; Mitsyna, Ludmila V.; Krmar, Miodrag; Cong, Vu D.; Hambsch, Franz-Josef; Oberstedt, Stephan; Revay, Zsolt; Stieghorst, Christian; Dragic, Aleksandar

    2018-03-01

    The determination of nuclear level densities and radiative strength functions is one of the most important tasks in low-energy nuclear physics. Accurate experimental values of these parameters are critical for the study of the fundamental properties of nuclear structure. The step-like structure in the dependence of the level densities p on the excitation energy of nuclei Eex is observed in the two-step gamma cascade measurements for nuclei in the 28 ≤ A ≤ 200 mass region. This characteristic structure can be explained only if a co-existence of quasi-particles and phonons, as well as their interaction in a nucleus, are taken into account in the process of gamma-decay. Here we present a new improvement to the Dubna practical model for the determination of nuclear level densities and radiative strength functions. The new practical model guarantees a good description of the available intensities of the two step gamma cascades, comparable to the experimental data accuracy.

  19. Determination of the nuclear level densities and radiative strength function for 43 nuclei in the mass interval 28≤A≤200

    Directory of Open Access Journals (Sweden)

    Knezevic David

    2018-01-01

    Full Text Available The determination of nuclear level densities and radiative strength functions is one of the most important tasks in low-energy nuclear physics. Accurate experimental values of these parameters are critical for the study of the fundamental properties of nuclear structure. The step-like structure in the dependence of the level densities p on the excitation energy of nuclei Eex is observed in the two-step gamma cascade measurements for nuclei in the 28 ≤ A ≤ 200 mass region. This characteristic structure can be explained only if a co-existence of quasi-particles and phonons, as well as their interaction in a nucleus, are taken into account in the process of gamma-decay. Here we present a new improvement to the Dubna practical model for the determination of nuclear level densities and radiative strength functions. The new practical model guarantees a good description of the available intensities of the two step gamma cascades, comparable to the experimental data accuracy.

  20. Quarks in Few Body Nuclei

    Directory of Open Access Journals (Sweden)

    Holt Roy J.

    2016-01-01

    Full Text Available Electron scattering at very high Bjorken x from hadrons provides an excellent test of models, has an important role in high energy physics, and from nuclei, provides a window into short range correlations. Light nuclei have a key role because of the relatively well-known nuclear structure. The development of a novel tritium target for Jefferson Lab has led to renewed interest in the mass three system. For example, deep inelastic scattering experiments in the light nuclei provide a powerful means to determine the neutron structure function. The isospin dependence of electron scattering from mass-3 nuclei provide information on short range correlations in nuclei. The program using the new tritium target will be presented along with a summary of other experiments aimed at revealing the large-x structure of the nucleon.

  1. Intermediate mass dimuon events

    International Nuclear Information System (INIS)

    Moser, H.-G.

    1985-01-01

    We report the observation of 67 dimuon events at the CERN p anti p collider with the UA1 detector. The events will be interpreted in terms of the Drell-Yan mechanism, J/PSI and UPSILON decays and heavy flavour production. (author)

  2. Structure of tellurium nuclei

    International Nuclear Information System (INIS)

    Cizewski, J.A.; Henry, R.G.; Lee, C.S.

    1991-01-01

    The tellurium nuclei with two protons outside of the Z = 50 shell closure exhibit a complicated structure with signatures of collective vibrational, two-quasiparticle, possibly moderately deformed intruder configurations. To study further the structure of the tellurium nuclei the authors made extensive measurements of the (α,xnγ) reactions on even Sn targets, populating excitations in even- and odd-mass Te nuclei up to moderate angular momenta. By examining limits on possible intraband transitions, results suggest that a possible rotational band structure is not supported by the data, since intraband transitions are of comparable E2 strength to interband transitions. In the odd-A isotopes they concentrated on identifying the higher angular momentum negative-parity states (which probe the role of the h 11/2 neutron in the core), and the search for non-yrast negative-parity states, which are a sensitive measure of the shape of the collective excitations

  3. Angular distributions of intermediate mass fragments emitted in 30 MeV/u 40Ar induced reactions

    International Nuclear Information System (INIS)

    Gou Quanbu; Zhu Yongtai; Xu Hushan; Wei Zhiyong; Lu Jun; Zhang Yuhu; Wang Qi; Li Songlin; Wu Zhongli

    1999-01-01

    The angular distributions of intermediate mass fragments with charge numbers from 3 to 24 emitted in 30 MeV/u 40 Ar + 58,64 Ni and 115 In reactions over an angular range of 5 degree-140 degree have been measured. In different angular region an exponential distribution function dσ/dΩ = N exp(-θ/α) was used to fit the measured angular distributions. The decay factor α which can be connected with the interaction time τ and the factor N which is related to the intensity of the emission sources have been extracted. The relationship of α(Z) and N(Z) with Z for different reaction systems and different angular regions has been discussed. The different behavior of dσ/dΩ, α(Z), and N(Z) for the three studied reaction systems exists mainly in the middle and backward angular regions. The dependencies of angular distributions on isospin and the size of reaction systems have also been discussed

  4. Multiplicity correlations of intermediate-mass fragments with pions and fast protons in 12C + 197AU

    International Nuclear Information System (INIS)

    Turzo, K.; Begemann-Blaich, M.L.; Auger, G.

    2003-12-01

    Low-energy π + (E π 12 C+ 197 Au collisions at incident energies from 300 to 1800 MeV per nucleon were detected with the Si-Si(Li)-CsI(Tl) calibration telescopes of the INDRA multidetector. The inclusive angular distributions are approximately isotropic, consistent with multiple rescattering in the target spectator. The multiplicity correlations of the low-energy pions and of energetic protons (E p >or ≤ 150 MeV) with intermediate-mass fragments were determined from the measured coincidence data. The deduced correlation functions 1 + R ∼ 1.3 for inclusive event samples reflect the strong correlations evident from the common impact-parameter dependence of the considered multiplicities. For narrow impact-parameter bins (based on charged-particle multiplicity), the correlation functions are close to unity and do not indicate strong additional correlations. Only for pions at high particle multiplicities (central collisions) a weak anticorrelation is observed, probably due to a limited competition between these emissions. Overall, the results are consistent with the equilibrium assumption made in statistical multifragmentation scenarios. Predictions obtained with intranuclear cascade models coupled to the statistical multifragmentation model are in good agreement with the experimental data. (orig.)

  5. A YOUNG MASSIVE STELLAR POPULATION AROUND THE INTERMEDIATE-MASS BLACK HOLE ESO 243-49 HLX-1

    International Nuclear Information System (INIS)

    Farrell, S. A.; Servillat, M.; Pforr, J.; Maraston, C.; Maccarone, T. J.; Knigge, C.; Godet, O.; Webb, N. A.; Barret, D.; Belmont, R.; Gosling, A. J.; Wiersema, K.

    2012-01-01

    We present Hubble Space Telescope and simultaneous Swift X-ray Telescope observations of the strongest candidate intermediate-mass black hole (IMBH) ESO 243-49 HLX-1. Fitting the spectral energy distribution from X-ray to near-infrared wavelengths showed that the broadband spectrum is not consistent with simple and irradiated disk models, but is well described by a model comprised of an irradiated accretion disk plus a ∼10 6 M ☉ stellar population. The age of the population cannot be uniquely constrained, with both young and old stellar populations allowed. However, the old solution requires excessive disk reprocessing and an extremely small disk, so we favor the young solution (∼13 Myr). In addition, the presence of dust lanes and the lack of any nuclear activity from X-ray observations of the host galaxy suggest that a gas-rich minor merger may have taken place less than ∼200 Myr ago. Such a merger event would explain the presence of the IMBH and the young stellar population.

  6. Magnetized Converging Flows toward the Hot Core in the Intermediate/High-mass Star-forming Region NGC 6334 V

    Energy Technology Data Exchange (ETDEWEB)

    Juárez, Carmen; Girart, Josep M. [Institut de Ciències de l’Espai, (CSIC-IEEC), Campus UAB, Carrer de Can Magrans, S/N, E-08193 Cerdanyola del Vallès, Catalonia (Spain); Zamora-Avilés, Manuel; Palau, Aina; Ballesteros-Paredes, Javier [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, P.O. Box 3-72, 58090, Morelia, Michoacán (Mexico); Tang, Ya-Wen; Koch, Patrick M.; Liu, Hauyu Baobab [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei, 10617, Taiwan (China); Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Qiu, Keping, E-mail: juarez@ice.cat [School of Astronomy and Space Science, Nanjing University, 163 Xianlin Avenue, Nanjing 210023 (China)

    2017-07-20

    We present Submillimeter Array (SMA) observations at 345 GHz toward the intermediate/high-mass cluster-forming region NGC 6334 V. From the dust emission we spatially resolve three dense condensations, the brightest one presenting the typical chemistry of a hot core. The magnetic field (derived from the dust polarized emission) shows a bimodal converging pattern toward the hot core. The molecular emission traces two filamentary structures at two different velocities, separated by 2 km s{sup −1}, converging to the hot core and following the magnetic field distribution. We compare the velocity field and the magnetic field derived from the SMA observations with magnetohydrodynamic simulations of star-forming regions dominated by gravity. This comparison allows us to show how the gas falls in from the larger-scale extended dense core (∼0.1 pc) of NGC 6334 V toward the higher-density hot core region (∼0.02 pc) through two distinctive converging flows dragging the magnetic field, whose strength seems to have been overcome by gravity.

  7. Magnetized Converging Flows toward the Hot Core in the Intermediate/High-mass Star-forming Region NGC 6334 V

    International Nuclear Information System (INIS)

    Juárez, Carmen; Girart, Josep M.; Zamora-Avilés, Manuel; Palau, Aina; Ballesteros-Paredes, Javier; Tang, Ya-Wen; Koch, Patrick M.; Liu, Hauyu Baobab; Zhang, Qizhou; Qiu, Keping

    2017-01-01

    We present Submillimeter Array (SMA) observations at 345 GHz toward the intermediate/high-mass cluster-forming region NGC 6334 V. From the dust emission we spatially resolve three dense condensations, the brightest one presenting the typical chemistry of a hot core. The magnetic field (derived from the dust polarized emission) shows a bimodal converging pattern toward the hot core. The molecular emission traces two filamentary structures at two different velocities, separated by 2 km s −1 , converging to the hot core and following the magnetic field distribution. We compare the velocity field and the magnetic field derived from the SMA observations with magnetohydrodynamic simulations of star-forming regions dominated by gravity. This comparison allows us to show how the gas falls in from the larger-scale extended dense core (∼0.1 pc) of NGC 6334 V toward the higher-density hot core region (∼0.02 pc) through two distinctive converging flows dragging the magnetic field, whose strength seems to have been overcome by gravity.

  8. L1188: A Promising Candidate for Cloud–Cloud Collisions Triggering the Formation of Low- and Intermediate-mass Stars

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yan; Fang, Min; Mao, Ruiqing; Zhang, Shaobo; Wang, Yuan; Su, Yang; Chen, Xuepeng; Yang, Ji; Wang, Hongchi; Lu, Dengrong, E-mail: ygong@pmo.ac.cn [Purple Mountain Observatory and Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, 2 West Beijing Road, 210008 Nanjing (China)

    2017-01-20

    We present a new large-scale (2° × 2°) simultaneous {sup 12}CO, {sup 13}CO, and C{sup 18}O (J = 1–0) mapping of L1188 with the Purple Mountain Observatory 13.7 m telescope. Our observations have revealed that L1188 consists of two nearly orthogonal filamentary molecular clouds at two clearly separated velocities. Toward the intersection showing large velocity spreads, we find several bridging features connecting the two clouds in velocity, and an open arc structure that exhibits high excitation temperatures, enhanced {sup 12}CO and {sup 13}CO emission, and broad {sup 12}CO line wings. This agrees with the scenario that the two clouds are colliding with each other. The distribution of young stellar object (YSO) candidates implies an enhancement of star formation in the intersection of the two clouds. We suggest that a cloud–cloud collision happened in L1188 about 1 Myr ago, possibly triggering the formation of low- and intermediate-mass YSOs in the intersection.

  9. Influence of i13/2 proton and j15/2 neutron intruding orbitals on the behaviour of 190 mass region superdeformed nuclei

    International Nuclear Information System (INIS)

    Duprat, J.

    1995-01-01

    This work concerns the study of the nuclear superdeformation phenomenon in the A = 190 mass region. The superdeformed (SD) states in 193 Tl, 194 Tl 195 Tl were produced via heavy-ion induced reactions and studied with the EUROGAM gamma multidetector array. The analysis of high-multiplicity events allowed the study of the magnetic properties of the SD states in these nuclei. For the first time, the g-factor of a proton orbital in a SD nucleus in the A = 190 mass region has been extracted. This measurement indicates that the two known bands in 195 Tl-SD are built on the i 13/2 proton intruder orbital. A new SD band has been found in this isotope: it is the first SD band built on an excited proton state found in the A = 190 region. Finally an interaction between two pairs of bands has been established in 194 Tl; this interaction indicate the crossing of two neutron orbitals above the N = 112 gap. The magnetic properties of the states of the SD bands in 194 Tl reveals that these bands are built on configurations in which the single proton and neutron intrinsic spins are aligned. Comparison between different SD bands in the Thallium isotopes shows the prominent role of the i 13/2 proton and the j 15/2 neutron intruder orbitals in the smooth increase of the dynamical moment of inertia as a function of the rotational frequency. In addition, this work reports on the first observation of a SD rotational band produced in a (HI, αxn) reaction channel. The study of the maximum spin reached by the SD bands indicates both a competition between alpha emission and fission of the compound nucleus, and the limitation due to the fission process in the population of the SD nuclei in the A = 190 region. (author). 120 refs., 112 figs., 22 tabs., 2 ann

  10. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    The pion production processes from nucleons and nuclei at intermediate energies are important tools to study the hadronic structure. The dynamic models of the hadronic structure are used to calculate the various nucleon and transition form factors which are tested by using the experimental data on photo, electro and.

  11. The structure of protoplanetary disks surrounding three young intermediate mass stars: I. Resolving the disk rotation in the [OI] 6300 Å line

    NARCIS (Netherlands)

    van der Plas, G.; van den Ancker, M.E.; Fedele, D.; Acke, B.; Dominik, C.; Waters, L.B.F.M.; Bouwman, J.

    2008-01-01

    We present high-spectral-resolution, optical spectra of three young, intermediate-mass stars, in all of which we spectrally resolve the 6300 Å [OI] emission line. Two of these have a double-peaked line-profile. We attempt to fit these data using a simple model of [OI] emission, which is generated by

  12. Prediction of energies of yrast band in some even-even nuclei

    International Nuclear Information System (INIS)

    Varshney, A.K.; Singh, Yuvraj; Gupta, D.K.; Singh, M.; Gupta, K.K.; Bihari, Chhail; Dhiman, S.K.

    2012-01-01

    The deformation parameter β and γ of the collective model of Bohr and Mottelson are basic descriptors of the nuclear equilibrium shape and structure. The researchers found that the values of γ obtained from energies (= γ e ) are nearly equal to the value of γ derived from transition rate (= γ b ) in even Xe, Ba and Ce nuclei (A∼120-140) and Hf, W, Os, Pt and Hg nuclei (A∼160-200) using rigid triaxial rotor model of Davydov-Filippov. In the present study, the relatively light mass nuclei (Mo, Ru and Pd) have been taken. As far as γ is concerned, it is known that the Ru chains of nuclei is intermediate between the two having opposite trends for parameter γ, decreasing for Mo and increasing for Pd, and has an irregular behaviour in itself with the increase of neutron number

  13. Assessing the fundamental limits of multiple star formation: An imaging search for the lowest mass stellar companions to intermediate-mass stars

    Science.gov (United States)

    Duchene, Gaspard; Tzern Oon, Jner; Kantorski, Patrick; De Rosa, Robert J.; Thomas, Sandrine; Patience, Jennifer; Pueyo, Laurent; Nielsen, Eric L.; Konopacky, Quinn M.

    2017-01-01

    Stellar binaries are a common byproduct of star formation and therefore inform us on the processes of collapse and fragmentation of prestellar cores. While multiplicity surveys generally reveal an extensive diversity of multiple systems, with broad ranges of semi-major axis, mass ratio and eccentricities, one remarkable feature that was identified in the last two decades is the so-called brown dwarf desert, i.e., the apparent paucity of (non-planetary) substellar companions to solar-type stars. This "desert" was primarily identified among spectroscopic binaries but also appears to be a significant feature of wider, visual binaries. The physical origin of this feature has not been fully accounted for but is likely established during the formation of the systems. One way to shed new light on this question is to study the frequency of low-mass stellar companions to intermediate-mass star (late-B type, or 3-5 Msun), as those form through a similar, albeit scaled-up, mechanism as solar-type stars. Here we present preliminary results from two adaptive-optics based surveys to search for such multiple systems. Specifically, we are using the new ShaneAO system on the Lick3m telescope (~100 stars observed to date) and the Gemini Planet Imager (45 stars observed). We are targeting stars located both in open clusters and scattered in the Galactic field to search for potential evidence of dynamic evolution. To identify candidate low-mass companions as close in to target stars, we use advanced point spread function (PSF) subtraction algorithms, specifically implementations of the LOCI and KLIP algorithms. In the case of the ShaneAO observations, which do not allow for field rotation, we use LOCI in combination with Reference Differential Imaging (ADI), using our library of science images as input for PSF subtraction. In this contribution, we will discuss the potential of ShaneAO to reveal faint, subarcsecond companions in this context and present candidate companions from both

  14. From Q-value measurements to mass and structure of proton-rich nuclei in the tin region

    International Nuclear Information System (INIS)

    Grant, I.S.; Kirchner, R.; Klepper, O.; Koslowsky, V.T.; Rathke, G.E.; Roeckl, E.; Rykaczewski, K.; Schardt, D.; Larsson, P.O.; Nyman, G.; Tidemand-Petersson, P.; Zganjar, E.F.; Spanier, L.; Nolte, E.; Plochocki, A.; Zylicz, J.

    1984-01-01

    The authors have measured the electron capture decay energies for the isotopes sup(108,) sup(106,) 104 Sn, 96 Pd, and 111 Te. From these values the mass defects were derived. For 105 Sn an improved half-live of 28 + 35 was obtained. (HSI)

  15. Colliding nuclei

    International Nuclear Information System (INIS)

    Balian, Roger; Remaud, Bernard; Suraud, E.; Durand, Dominique; Tamain, Bernard; Gobbi, A.; Cugnon, J.; Drapier, Olivier; Govaerts, Jan; Prieels, Rene

    1995-09-01

    This 14. international school Joliot-Curie of nuclear physic deals with nuclei in collision at high energy. Nine lectures are included in the proceedings of this summer school: 1 - From statistical mechanics outside equilibrium to transport equations (Balian, R.); 2 - Modeling of heavy ions reactions (Remaud, B.); 3 - Kinetic equations in heavy ions physics (Suraud, E.); 4 - Colliding nuclei near the Fermi energy (Durand, D.; Tamain, B.); 5 - From the Fermi to the relativistic energy domain: which observable? For which physics? (Gobbi, A.); 6 - Collisions at relativistic and ultra relativistic energies, Theoretical aspects (Cugnon, J.); 7 - Quark-gluon plasma: experimental signatures (Drapier, O.); 8 - Electroweak interaction: a window on physics beyond the standard model (Govaerts, J.); 9 - Symmetry tests in β nuclear process: polarization techniques (Prieels, R.)

  16. The central dynamics of M3, M13, and M92: stringent limits on the masses of intermediate-mass black holes

    Science.gov (United States)

    Kamann, S.; Wisotzki, L.; Roth, M. M.; Gerssen, J.; Husser, T.-O.; Sandin, C.; Weilbacher, P.

    2014-06-01

    We used the PMAS integral field spectrograph to obtain large sets of radial velocities in the central regions of three northern Galactic globular clusters: M3, M13, and M92. By applying the novel technique of crowded field 3D spectroscopy, we measured radial velocities for about 80 stars within the central ~10″ of each cluster. These are by far the largest spectroscopic datasets obtained in the innermost parts of these clusters up to now. To obtain kinematical data across the whole extent of the clusters, we complement our data with measurements available in the literature. We combine our velocity measurements with surface brightness profiles to analyse the internal dynamics of each cluster using spherical Jeans models, and investigate whether our data provide evidence for an intermediate-mass black hole in any of the clusters. The surface brightness profiles reveal that all three clusters are consistent with a core profile, although shallow cusps cannot be excluded. We find that spherical Jeans models with a constant mass-to-light ratio provide a good overall representation of the kinematical data. A massive black hole is required in none of the three clusters to explain the observed kinematics. Our 1σ (3σ) upper limits are 5300 M⊙ (12 000 M⊙) for M3, 8600 M⊙ (13 000 M⊙) for M13, and 980 M⊙ (2700 M⊙) for M92. A puzzling circumstance is the existence of several potential high velocity stars in M3 and M13, as their presence can account for the majority of the discrepancies that we find in our mass limits compared to M92. Based on observations collected at the Centro Astronómico Hispano-Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC).Appendices are available in electronic form at http://www.aanda.orgTables D.1 to D.6 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc

  17. Design, simulations and test of a Time-of-Flight spectrometer for mass measurement of exotic beams from SPIRAL1/SPIRAL2 and γ-ray spectroscopy of N=Z nuclei close to 100Sn

    International Nuclear Information System (INIS)

    Chauveau, Pierre

    2016-01-01

    The new generation of nuclear facilities calls for new technological developments to produce, accelerate, manipulate and analyse exotic nuclei. The main topic of this thesis work was the simulation, design and test of a Multi-Reflection Time-of-Flight Mass spectrometer (MR-ToFMS) for fast mass separation and fast mass measurement of radioactive ions in the installations S3 and DESIR at SPIRAL2. Such a device could separate isobaric nuclei and provide SPIRAL2 with high purity beams. Also, its mass measurement capabilities would help to determine binding energies of exotic and superheavy nuclei with a high precision. This apparatus has been simulated with the SIMION 8.1 software and designed accordingly. First offline tests have been performed with a stable ion source at LPC Caen. In addition a low-aberration electrostatic deflector has been simulated and designed to operate with this MR-ToF-MS without spoiling its performances. This work also describes the analysis and results of the first online tests of a FEBIAD-type ion source intended to provide SPIRAL1 and SPIRAL2 radioactive beams of competitive intensities. Finally, we describe the analysis of a nuclear physics experiment, including the calibration of the different detectors and the gamma-spectroscopy of nuclei in the vicinity of the doubly magic 100 Sn. (author) [fr

  18. Mass fragmentographic quantitation of glutamic acid and gamma-aminobutyric acid in cerebellar nuclei and sympathetic ganglia of rats.

    Science.gov (United States)

    Bertilsson, L; Costa, E

    1976-04-07

    A method for the simultaneous quantitation of glutamic acid and gamma-aminobutyric acid (GABA) in tissue by mass fragmentography has been developed. The amino and carboxylic groups of the two amino acids were in a convenient one-step reaction derivatized with pentafluoropropionic anhydride and hexafluoroisopropanol. Deuterium-labeled glutamic acid and GABA and a homologue of GABA have been used as internal standards. The usefulness of the technique has been demonstrated by measurements in parts of rat cerebellum and in the superior cervical ganglion.

  19. The quadrupole moments of some even–even nuclei around the mass of A ~ 80: {sup 68−80}Ge on the neighborhood of {sup 76−84}Kr and {sup 76−84}Se isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Yoruk, Abdulkadir, E-mail: yorukabdulkadir@hotmail.com [Süleyman Demirel University, Nursery Medical School (Turkey); Turkan, Nureddin, E-mail: nureddin.turkan@medeniyet.edu.tr [Istanbul Medeniyet University, Faculty of Science (Turkey)

    2016-09-15

    We have carried out the calculation of the quadrupole moments Q(2{sub 1}{sup +}) and electromagnetic transition rates B(E2) of some levels within the framework of the interacting boson model for even-mass Ge nuclei. The presented predictions of the quadrupole moments and B(E2) ratios for Ge nuclei are compared with the results of some previous experimental and theoretical ones along with those of the neighboring Kr and Se isotopes and then it was seen that they agree well with the previous experimental and theoretical ones.

  20. The asymptotic hadron spectrum, anti-nuclei, hyper-nuclei and quark phase

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1978-01-01

    The only hope of determining the hadronic spectrum in the high mass region is through a study of matter produced in very high energy nuclear collisions. Along the way, exotic nuclei, i.e., anti-nuclei and hyper-nuclei may be produced in appreciable numbers, and the detection of a quark phase may be possible. (orig.) [de

  1. Analysis of cloud condensation nuclei composition and growth kinetics using a pumped counterflow virtual impactor and aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    J. G. Slowik

    2011-08-01

    Full Text Available We present a new method of determining the size and composition of CCN-active aerosol particles. Method utility is illustrated through a series of ambient measurements. A continuous-flow thermal-gradient diffusion chamber (TGDC, pumped counterflow virtual impactor (PCVI, and Aerodyne time-of-flight mass spectrometer (AMS are operated in series. Ambient particles are sampled into the TGDC, where a constant supersaturation is maintained, and CCN-active particles grow to ~2.5 ± 0.5 μm. The output flow from the TGDC is directed into the PCVI, where a counterflow of dry N2 gas opposes the particle-laden flow, creating a region of zero axial velocity. This stagnation plane can only be traversed by particles with sufficient momentum, which depends on their size. Particles that have activated in the TGDC cross the stagnation plane and are entrained in the PCVI output flow, while the unactivated particles are diverted to a pump. Because the input gas is replaced by the counterflow gas with better than 99 % efficiency at the stagnation plane, the output flow consists almost entirely of dry N2 and water evaporates from the activated particles. In this way, the system yields an ensemble of CCN-active particles whose chemical composition and size are analyzed using the AMS. Measurements of urban aerosol in downtown Toronto identified an external mixture of CCN-active particles consisting almost entirely of ammonium nitrate and ammonium sulfate, with CCN-inactive particles of the same size consisting of a mixture of ammonium nitrate, ammonium sulfate, and organics. We also discuss results from the first field deployment of the TGDC-PCVI-AMS system, conducted from mid-May to mid-June 2007 in Egbert, Ontario, a semirural site ~80 km north of Toronto influenced both by clean air masses from the north and emissions from the city. Organic-dominated particles sampled during a major biogenic event exhibited higher CCN activity and/or faster

  2. Measurement of photonuclear cross sections from 30 to 140 MeV for intermediate and heavy mass nuclei (Sn, Ce, Ta, Pb and U)

    International Nuclear Information System (INIS)

    Lepretre, A.

    1982-06-01

    The total photonuclear absorption cross section for Sn, Ce, Ta, Pb and U has been studied from 25 to 140 MeV using a continuously variable monochromatic photon beam obtained from the annihilation in flight of monoenergetic positrons. The basic experimental results are a set of data giving sums of inclusive multiple photoneutron production cross sections of the form σsup(j) (Esub(γ) = Σsub(i=j)σ(γ,in) for neutron multiplicities ranging from j=1 to 12. From these data the total photonuclear absorption cross section σ(tot : Esub(γ)) has been deduced. It is concluded that Levinger's modified quasi-deuteron model describes the total cross sections reasonably well. When these data are combined with lower energy data and integrated to 140 MeV they indicate the need for an enhancement factor K for the Thomas-Reiche-Kuhn sum rule of 0.76+-0.10. No evidence was found that would indicate an A-dependence for the enhancement factor. From event-by-event records of observed photoneutron multiplicities it was also possible to determine the mean number of photoneutrons, antiν, for each photon energy and the widths W of the multiplicities distributions. From these measurements one also obtains the cross section for the formation of a compound nucleus state excited with the full energy of the absorbed photon [fr

  3. Physics of Unstable Nuclei

    Science.gov (United States)

    Khoa, Dao Tien; Egelhof, Peter; Gales, Sydney; Giai, Nguyen Van; Motobayashi, Tohru

    2008-04-01

    . -- Thermal pairing in nuclei / N. D. Dang -- Molecular-orbital and di-nuclei states in Ne and F isotopes / M. Kimura -- Low-momentum interactions for nuclei / A. Schwenk -- Nonrelativistic nuclear energy functionals including the tensor force / G. Colo et al. -- New aspects on dynamics in nuclei described by covariant density functional theory / P. Ring, D. Pena -- Theoretical studies on ground-state properties of superheavy nuclei / Z. Z. Ren et al. -- New results in the study of superfluid nuclei: many-body effects, spectroscopic factors / P. F. Bortignon et al. -- New Effective nucleon-nucleon interaction for the mean-field approximation / V. K. Au et al. -- Linear response calculations with the time-dependent Skyrme density functional / T. Nakatsukasa et al. -- Dissipative dynamics with exotic beams / M. Di Toro et al. -- Exploring the symmetry energy of asymmetric nuclear matter with heavy ion reactions / M. B. Tsang -- Invariant mass spectroscopy of halo nuclei / T. Nakamura et al. -- Core [symbol] structures in [symbol]C, [symbol]C and [symbol]C up to high excitation energies / H. G. Bohlen et al. -- Light neutron-rich nuclei studied by alpha-induced reactions / S. Shimoura -- Fusion and direct reactions around the Coulomb barrier for the system [symbol]He + [symbol]Zn / V. Scuderi et al. -- Analyzing power measurement for proton elastic scattering on [symbol]He / S. Sakaguchi et al. -- Knockout reaction spectroscopy of exotic nuclei / J. A. Tostevin -- Exotic nuclei, quantum phase transitions, and the evolution of structure / R. F. Casten -- Structure of exotic nuclei in the medium mass region / T. Otsuka -- Pairing correlations in halo nuclei / H. Sagawa, K. Hagino -- Experimental approach to high-temperature Stellar reactions with low-energy RI beams / S. Kubono et al. -- Transition to quark matter in neutron stars / G. X. Peng et al. -- Research at VATLY: main themes and recent results / P. N. Diep et al. -- Study of the astrophysical reaction [symbol

  4. Active galactic nuclei emission line diagnostics and the mass-metallicity relation up to redshift z ∼ 2: The impact of selection effects and evolution

    International Nuclear Information System (INIS)

    Juneau, Stéphanie; Bournaud, Frédéric; Daddi, Emanuele; Elbaz, David; Duc, Pierre-Alain; Gobat, Raphael; Jean-Baptiste, Ingrid; Le Floc'h, Émeric; Pannella, Maurilio; Schreiber, Corentin; Charlot, Stéphane; Lehnert, M. D.; Pacifici, Camilla; Trump, Jonathan R.; Brinchmann, Jarle; Dickinson, Mark

    2014-01-01

    Emission line diagnostic diagrams probing the ionization sources in galaxies, such as the Baldwin-Phillips-Terlevich (BPT) diagram, have been used extensively to distinguish active galactic nuclei (AGN) from purely star-forming galaxies. However, they remain poorly understood at higher redshifts. We shed light on this issue with an empirical approach based on a z ∼ 0 reference sample built from ∼300,000 Sloan Digital Sky Survey galaxies, from which we mimic selection effects due to typical emission line detection limits at higher redshift. We combine this low-redshift reference sample with a simple prescription for luminosity evolution of the global galaxy population to predict the loci of high-redshift galaxies on the BPT and Mass-Excitation (MEx) diagnostic diagrams. The predicted bivariate distributions agree remarkably well with direct observations of galaxies out to z ∼ 1.5, including the observed stellar mass-metallicity (MZ) relation evolution. As a result, we infer that high-redshift star-forming galaxies are consistent with having normal interstellar medium (ISM) properties out to z ∼ 1.5, after accounting for selection effects and line luminosity evolution. Namely, their optical line ratios and gas-phase metallicities are comparable to that of low-redshift galaxies with equivalent emission-line luminosities. In contrast, AGN narrow-line regions may show a shift toward lower metallicities at higher redshift. While a physical evolution of the ISM conditions is not ruled out for purely star-forming galaxies and may be more important starting at z ≳ 2, we find that reliably quantifying this evolution is hindered by selections effects. The recipes provided here may serve as a basis for future studies toward this goal. Code to predict the loci of galaxies on the BPT and MEx diagnostic diagrams and the MZ relation as a function of emission line luminosity limits is made publicly available.

  5. Active galactic nuclei emission line diagnostics and the mass-metallicity relation up to redshift z ∼ 2: The impact of selection effects and evolution

    Energy Technology Data Exchange (ETDEWEB)

    Juneau, Stéphanie; Bournaud, Frédéric; Daddi, Emanuele; Elbaz, David; Duc, Pierre-Alain; Gobat, Raphael; Jean-Baptiste, Ingrid; Le Floc' h, Émeric; Pannella, Maurilio; Schreiber, Corentin [CEA-Saclay, DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France); Charlot, Stéphane; Lehnert, M. D.; Pacifici, Camilla [UPMC-CNRS, UMR 7095, Institut d' Astrophysique de Paris, F-75014 Paris (France); Trump, Jonathan R. [University of California Observatories/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Brinchmann, Jarle [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Dickinson, Mark, E-mail: stephanie.juneau@cea.fr [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

    2014-06-10

    Emission line diagnostic diagrams probing the ionization sources in galaxies, such as the Baldwin-Phillips-Terlevich (BPT) diagram, have been used extensively to distinguish active galactic nuclei (AGN) from purely star-forming galaxies. However, they remain poorly understood at higher redshifts. We shed light on this issue with an empirical approach based on a z ∼ 0 reference sample built from ∼300,000 Sloan Digital Sky Survey galaxies, from which we mimic selection effects due to typical emission line detection limits at higher redshift. We combine this low-redshift reference sample with a simple prescription for luminosity evolution of the global galaxy population to predict the loci of high-redshift galaxies on the BPT and Mass-Excitation (MEx) diagnostic diagrams. The predicted bivariate distributions agree remarkably well with direct observations of galaxies out to z ∼ 1.5, including the observed stellar mass-metallicity (MZ) relation evolution. As a result, we infer that high-redshift star-forming galaxies are consistent with having normal interstellar medium (ISM) properties out to z ∼ 1.5, after accounting for selection effects and line luminosity evolution. Namely, their optical line ratios and gas-phase metallicities are comparable to that of low-redshift galaxies with equivalent emission-line luminosities. In contrast, AGN narrow-line regions may show a shift toward lower metallicities at higher redshift. While a physical evolution of the ISM conditions is not ruled out for purely star-forming galaxies and may be more important starting at z ≳ 2, we find that reliably quantifying this evolution is hindered by selections effects. The recipes provided here may serve as a basis for future studies toward this goal. Code to predict the loci of galaxies on the BPT and MEx diagnostic diagrams and the MZ relation as a function of emission line luminosity limits is made publicly available.

  6. Medical Advice for Sick-reported Students (MASS in intermediate vocational education schools: design of a controlled before-and-after study

    Directory of Open Access Journals (Sweden)

    Madelon K Van der Vlis

    2017-06-01

    Full Text Available Abstract Background School absenteeism, including medical absenteeism, is associated with early school dropout and may result in physical, mental, social and work-related problems in later life. Especially at intermediate vocational education schools, high rates of medical absenteeism are found. In 2012 the Dutch intervention ‘Medical Advice for Sick-reported Students’ (MASS, previously developed for pre-vocational secondary education, was adjusted for intermediate vocational education schools. The aim of the study outlined in this paper is to evaluate the effectiveness of the MASS intervention at intermediate vocational education schools in terms of reducing students’ medical absenteeism and early dropping out of school. Additionally, the extent to which biopsychosocial and other factors moderate the effectiveness of the intervention will be assessed. Methods A controlled before-and-after study will be conducted within Intermediate Vocational Education schools. Schools are allocated to be an intervention or control school based on whether the schools have implemented the MASS intervention (intervention schools or not (control schools. Intervention schools apply the MASS intervention consisting of active support for students with medical absenteeism provided by the school including a consultation with the Youth Health Care (YHC professional if needed. Control schools provide care as usual. Data will be collected by questionnaires among students in both groups meeting the criteria for extensive medical absenteeism (i.e. ‘reported sick four times in 12 school weeks or for more than six consecutive school days’ at baseline and at 6 months follow-up. Additionally, in the intervention group a questionnaire is completed after each consultation with a YHC professional, by both the student and the YHC professional. Primary outcome measures are duration and cumulative incidence of absenteeism and academic performances. Secondary outcome

  7. Medical Advice for Sick-reported Students (MASS) in intermediate vocational education schools: design of a controlled before-and-after study.

    Science.gov (United States)

    Van der Vlis, Madelon K; Lugtenberg, Marjolein; Vanneste, Yvonne T M; Berends, Wenda; Mulder, Wico; Bannink, Rienke; Van Grieken, Amy; Raat, Hein; de Kroon, Marlou L A

    2017-06-29

    School absenteeism, including medical absenteeism, is associated with early school dropout and may result in physical, mental, social and work-related problems in later life. Especially at intermediate vocational education schools, high rates of medical absenteeism are found. In 2012 the Dutch intervention 'Medical Advice for Sick-reported Students' (MASS), previously developed for pre-vocational secondary education, was adjusted for intermediate vocational education schools. The aim of the study outlined in this paper is to evaluate the effectiveness of the MASS intervention at intermediate vocational education schools in terms of reducing students' medical absenteeism and early dropping out of school. Additionally, the extent to which biopsychosocial and other factors moderate the effectiveness of the intervention will be assessed. A controlled before-and-after study will be conducted within Intermediate Vocational Education schools. Schools are allocated to be an intervention or control school based on whether the schools have implemented the MASS intervention (intervention schools) or not (control schools). Intervention schools apply the MASS intervention consisting of active support for students with medical absenteeism provided by the school including a consultation with the Youth Health Care (YHC) professional if needed. Control schools provide care as usual. Data will be collected by questionnaires among students in both groups meeting the criteria for extensive medical absenteeism (i.e. 'reported sick four times in 12 school weeks or for more than six consecutive school days' at baseline and at 6 months follow-up). Additionally, in the intervention group a questionnaire is completed after each consultation with a YHC professional, by both the student and the YHC professional. Primary outcome measures are duration and cumulative incidence of absenteeism and academic performances. Secondary outcome measures are biopsychosocial outcomes of the students. It

  8. Improvements to the on-line mass separator, RAMA, and the beta-delayed charged-particle emission of proton-rich sd shell nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ognibene, Theodore Joseph [Lawrence Berkeley National Lab., CA (United States). Nuclear Science Div.

    1996-03-01

    To overcome the extreme difficulties encountered in the experimental decay studies of proton drip line nuclei, several techniques have been utilized, including a helium-jet transport system, particle identification detectors and mass separation. Improvements to the ion source/extraction region of the He-jet coupled on-line Recoil Atom Mass Analyzer (RAMA) and its target/ion source coupling resulted in significant increases in RAMA efficiencies and its mass resolution, as well as reductions in the overall transit time. At the 88-Inch Cyclotron at LBNL, the decays of 31Cl, 27P and 28P, with half-lives of 150 msec, 260 msec and 270.3 msec, respectively, were examined using a he-jet and low-energy gas ΔE-gas ΔE-silicon E detector telescopes. Total beta-delayed proton branches of 0.3% and 0.07% in 31Cl and 27P, respectively, were estimated. Several proton peaks that had been previously assigned to the decay of 31Cl were shown to be from the decay of 25Si. In 27P, two proton groups at 459 ± 14 keV and 610 ± 11 keV, with intensities of 7 ± 3% and 92 ± 4% relative to the main (100%) group were discovered. The Gamow-Teller component of the preceding beta-decay of each observed proton transition was compared to results from shell model calculations. Finally, a new proton transition was identified, following the β-decay of 28P, at 1,444 ± 12 keV with a 1.7 ± 0.5% relative intensity to the 100% group. Using similar low-energy detector telescopes and the mass separator TISOL at TRIUMF, the 109 msec and 173 msec activities, 17Ne and 33Ar, were studied. A new proton group with energy 729 ± 15 keV was observed following the beta-decay of 17Ne. Several discrepancies between earlier works as to the energies, intensities and assignments of several proton transitions from 17Ne and 33Ar were resolved.

  9. Improvements to the on-line mass separator, RAMA, and the beta-delayed charged-particle emission of proton-rich sd shell nuclei

    International Nuclear Information System (INIS)

    Ognibene, T.J.

    1996-03-01

    To overcome the extreme difficulties encountered in the experimental decay studies of proton drip line nuclei, several techniques have been utilized, including a helium-jet transport system, particle identification detectors and mass separation. Improvements to the ion source/extraction region of the He-jet coupled on-line Recoil Atom Mass Analyzer (RAMA) and its target/ion source coupling resulted in significant increases in RAMA efficiencies and its mass resolution, as well as reductions in the overall transit time. At the 88-Inch Cyclotron at LBNL, the decays of 31 Cl, 27 P and 28 P, with half-lives of 150 msec, 260 msec and 270.3 msec, respectively, were examined using a he-jet and low-energy gas ΔE-gas ΔE-silicon E detector telescopes. Total beta-delayed proton branches of 0.3% and 0.07% in 31 Cl and 27 P, respectively, were estimated. Several proton peaks that had been previously assigned to the decay of 31 Cl were shown to be from the decay of 25 Si. In 27 P, two proton groups at 459 ± 14 keV and 610 ± 11 keV, with intensities of 7 ± 3% and 92 ± 4% relative to the main (100%) group were discovered. The Gamow-Teller component of the preceding beta-decay of each observed proton transition was compared to results from shell model calculations. Finally, a new proton transition was identified, following the β-decay of 28 P, at 1,444 ± 12 keV with a 1.7 ± 0.5% relative intensity to the 100% group. Using similar low-energy detector telescopes and the mass separator TISOL at TRIUMF, the 109 msec and 173 msec activities, 17 Ne and 33 Ar, were studied. A new proton group with energy 729 ± 15 keV was observed following the beta-decay of 17 Ne. Several discrepancies between earlier works as to the energies, intensities and assignments of several proton transitions from 17 Ne and 33 Ar were resolved

  10. Sensitivity of gravitational wave searches to the full signal of intermediate-mass black hole binaries during the first observing run of Advanced LIGO

    Science.gov (United States)

    Calderón Bustillo, Juan; Salemi, Francesco; Dal Canton, Tito; Jani, Karan P.

    2018-01-01

    The sensitivity of gravitational wave searches for binary black holes is estimated via the injection and posterior recovery of simulated gravitational wave signals in the detector data streams. When a search reports no detections, the estimated sensitivity is then used to place upper limits on the coalescence rate of the target source. In order to obtain correct sensitivity and rate estimates, the injected waveforms must be faithful representations of the real signals. Up to date, however, injected waveforms have neglected radiation modes of order higher than the quadrupole, potentially biasing sensitivity and coalescence rate estimates. In particular, higher-order modes are known to have a large impact in the gravitational waves emitted by intermediate-mass black holes binaries. In this work, we evaluate the impact of this approximation in the context of two search algorithms run by the LIGO Scientific Collaboration in their search for intermediate-mass black hole binaries in the O1 LIGO Science Run data: a matched filter-based pipeline and a coherent unmodeled one. To this end, we estimate the sensitivity of both searches to simulated signals for nonspinning binaries including and omitting higher-order modes. We find that omission of higher-order modes leads to biases in the sensitivity estimates which depend on the masses of the binary, the search algorithm, and the required level of significance for detection. In addition, we compare the sensitivity of the two search algorithms across the studied parameter space. We conclude that the most recent LIGO-Virgo upper limits on the rate of coalescence of intermediate-mass black hole binaries are conservative for the case of highly asymmetric binaries. However, the tightest upper limits, placed for nearly equal-mass sources, remain unchanged due to the small contribution of higher modes to the corresponding sources.

  11. Pion production in nuclei

    International Nuclear Information System (INIS)

    Afnan, I.R.; Thomas, A.W.

    1976-01-01

    A method has been suggested for relating μ-capture in nuclei to pion absorption through partially conserved axial vector current hypothesis. The success of the method relies heavily on the knowledge of the pion absorption amplitude at a momentum transfer equal to the μ-meson mass. That is we need to know the pion absorption amplitude off the mass-shell. The simplest nucleus for which this suggestion can be examined is μ-capture in deuterium. The Koltum-Reitan model is used to determine the pion absorption amplitude off the mass shell. In particular the senstivity of this off-mass-shell extrapolution to details of the N-N interaction is studied. (author)

  12. The mean mass of the abundant cosmic-ray nuclei from boron to silicon at 1.2 GeV per atomic mass unit

    Science.gov (United States)

    Dwyer, R.

    1978-01-01

    Results are presented for an investigation of cosmic-ray isotopic composition in which a balloon-borne instrument was used to perform an isotopic analysis of the abundant elements from B through Si in the energy range from 1.0 to 1.6 GeV/amu. The technique employed, which depends on the effect of earth's magnetic field on incoming cosmic rays, and reduction of the observational data are described in detail. Mean masses of the elements B, C, N, O, Ne, Mg, and Si are extracted from normalized Cerenkov spectra and evaluated in terms of the 'leaky box' model of galactic propagation and confinement. The implications of the results for cosmic-ray sources are shown to be consistent with the nucleosynthesis of certain isotopes in the cosmic rays in explosive carbon burning under the conditions of peak temperature, density, and neutronization expected in an explosion of a massive highly evolved star. The possibility of alternate interpretations is noted.

  13. Neutrino interactions with nuclei

    International Nuclear Information System (INIS)

    Walecka, J.D.

    1983-01-01

    We examine tests of the Glashow-Weinberg-Salam (GWS) Standard Theory of Electroweak Interactions. The tests are model-independent in the sense that they are relations between experimental quantities that are direct consequences of the GWS theory, but they are independent of the detailed structure of the nucleus. Such relationships were anticipated by Weinberg. Neutrino reactions with nuclei are considered, focusing largely on charged-lepton production, and it is demonstrated that intermediate-energy neutrino reactions have a central and unique role to play in our understanding of semileptonic weak interactions. This point is illustrated by discussing a complete kinematic experiment on the nucleon. A discussion of what neutrino reactions could teach us about nuclear structure is also given

  14. Evolution of the shell structure in medium-mass nuclei: search for the 2d5/2 neutron orbital in 69Ni

    International Nuclear Information System (INIS)

    Moukaddam, M.

    2012-01-01

    The harmonic oscillator shell closure at N=40 in 68 Ni is weak and loses its strength when removing (or adding) pair of protons. Calculations performed in this mass region predict a new island of inversion at N=40 similar to the one at N=20. Using a large valence space, the neutron orbital 2d(5/2) is shown to be a crucial ingredient for the interpretation of the nuclear structure at N ∼40. The neutron 1g(9/2) -2d(5/2) energy difference has been determined in 69 Ni beam at 25.14 MeV/u separated by the LISE3 spectrometer was impinging a CD 2 target of 2.6 mg/cm 2 thickness. The experimental setup consisted of CATS/MUST2-S1/EXOGAM detectors coupled to an ionization chamber and a plastic scintillator. The angular moment and spectroscopic factors of the ground state (J π =9/2 + ) and a doublet of states (J π =5/2 + ) around 2.48 MeV corresponding to the population of the 1g(9/2) and the 2d(5/2) orbitals, were obtained from the comparison between the experimental cross-sections as a function of the proton detection angle and ADWA calculations. The spins of the observed states were assigned by comparison to large scale Shell-Model calculations. The position of the 2d(5/2) orbital in 69 Ni has been established for the first time. Our measurements support the hypothesis of a low-lying 2d(5/2) orbital (∼2.5 MeV) with respect to the 1g(9/2) neutron orbital and thus its major role in the structure of the nuclei around N=40. (author)

  15. Efficiency and rate capability studies of the time-of-flight detector for isochronous mass measurements of stored short-lived nuclei with the FRS-ESR facility

    International Nuclear Information System (INIS)

    Kuzminchuk-Feuerstein, Natalia; Fabian, Benjamin; Diwisch, Marcel; Plaß, Wolfgang R.; Geissel, Hans; Ayet San Andrés, Samuel; Dickel, Timo; Knöbel, Ronja; Scheidenberger, Christoph; Sun, Baohua; Weick, Helmut

    2016-01-01

    A time-of-flight (TOF) detector is used for Isochronous Mass Spectrometry (IMS) with the projectile fragment separator FRS and the heavy-ion storage ring ESR. Exotic nuclei are spatially separated in flight with the FRS at about 70% of the speed of light and are injected into the ESR. The revolution times of the stored ions circulating in the ESR are measured with a thin transmission foil detector. When the ions penetrate the thin detector foil, secondary electrons (SEs) are emitted from the surface and provide the timing information in combination with microchannel plate (MCP) detectors. The isochronous transport of the SEs is performed by perpendicular superimposed electric and magnetic fields. The detection efficiency and the rate capability of the TOF detector have been studied in simulations and experiments. As a result the performance of the TOF detector has been improved substantially: (i) The SE collection efficiency was doubled by use of an optimized set of electric and magnetic field values; now SEs from almost the full area of the foil are transmitted to the MCP detectors. (ii) The rate capability of the TOF detector was improved by a factor of four by the use of MCPs with 5 μm pore size. (iii) With these MCPs and a carbon foil with a reduced thickness of 10 μg/cm 2 the number of recorded revolutions in the ESR has been increased by nearly a factor of 10. The number of recorded revolutions determine the precision of the IMS experiments. Heavy-ion measurements were performed with neon ions at 322 MeV/u and uranium fission fragments at about 370 MeV/u. In addition, measurements with an alpha source were performed in the laboratory with a duplicate of the TOF detector.

  16. Hot nuclei, limiting temperatures and excitation energies

    International Nuclear Information System (INIS)

    Peter, J.

    1986-09-01

    Hot fusion nuclei are produced in heavy ion collisions at intermediate energies (20-100 MeV/U). Information on the maximum excitation energy per nucleon -and temperatures- indicated by the experimental data is compared to the predictions of static and dynamical calculations. Temperatures around 5-6 MeV are reached and seem to be the limit of formation of thermally equilibrated fusion nuclei

  17. Impact of electron-captures on nuclei near N = 50 on core-collapse supernovae

    Science.gov (United States)

    Titus, R.; Sullivan, C.; Zegers, R. G. T.; Brown, B. A.; Gao, B.

    2018-01-01

    The sensitivity of the late stages of stellar core collapse to electron-capture rates on nuclei is investigated, with a focus on electron-capture rates on 74 nuclei with neutron number close to 50, just above doubly magic 78Ni. It is demonstrated that variations in key characteristics of the evolution, such as the lepton fraction, electron fraction, entropy, stellar density, and in-fall velocity are about 50% due to uncertainties in the electron-capture rates on nuclei in this region, although thousands of nuclei are included in the simulations. The present electron-capture rate estimates used for the nuclei in this high-sensitivity region of the chart of isotopes are primarily based on a simple approximation, and it is shown that the estimated rates are likely too high, by an order of magnitude or more. Electron-capture rates based on Gamow–Teller strength distributions calculated in microscopic theoretical models will be required to obtain better estimates. Gamow–Teller distributions extracted from charge-exchange experiments performed at intermediate energies serve to guide the development and benchmark the models. A previously compiled weak-rate library that is used in the astrophysical simulations was updated as part of the work presented here, by adding additional rate tables for nuclei near stability for mass numbers between 60 and 110.

  18. Nuclear sub-structure in 112–122Ba nuclei within relativistic mean field theory

    International Nuclear Information System (INIS)

    Bhuyan, M.; Patra, S.K.; Arumugam, P.; Gupta, Raj K.

    2011-01-01

    Working within the framework of relativistic mean field theory, we study for the first time the clustering structure (nuclear sub-structure) of 112–122 Ba nuclei in an axially deformed cylindrical coordinate. We calculate the individual neutrons and protons density distributions for Ba-isotopes. From the analysis of the clustering configurations in total (neutrons-plus-protons) density distributions for various shapes of both the ground and excited states, we find different sub-structures inside the Ba nuclei considered here. The important step, carried out here for the first time, is the counting of number of protons and neutrons present in the clustering region(s). 12 C is shown to constitute the cluster configuration in prolate-deformed ground-states of 112–116 Ba and oblate-deformed first excited states of 118–122 Ba nuclei. Presence of other lighter clusters such as 2 H, 3 H and nuclei in the neighborhood of N = Z, 14 N, 34–36 Cl, 36 Ar and 42 Ca are also indicated in the ground and excited states of these nuclei. Cases with no cluster configuration are shown for 112–116 Ba in their first and second excited states. All these results are of interest for the observed intermediate-mass-fragments and fusion–fission processes, and the so far unobserved evaporation residues from the decaying Ba* compound nuclei formed in heavy ion reactions. (author)

  19. Particles and nuclei, letters

    International Nuclear Information System (INIS)

    2001-01-01

    The present collection of letters from JINR, Dubna, contains eight separate records on the interaction of high energy Λ 6 He hypernuclear beams with atomic nuclei, the position-sensitive detector of a high spatial resolution on the basis of a multiwire gas electron multiplier, pseudorapidity hadron density at the LHC energy, high precision laser control of the ATLAS tile-calorimeter module mass production at JINR, a new approach to ECG's features recognition involving neural network, subcriticity of a uranium target enriched in 235 U, beam space charge effects in high-current cyclotron injector CI-5, a homogeneous static gravitational field and the principle of equivalence

  20. LIMES: A computer program for analyses of light and intermediate-mass fragment emission in heavy ion reactions by an extended sum-rule model

    International Nuclear Information System (INIS)

    Brancus, I.M.; Wentz, J.; Hohn, H.U.

    1989-10-01

    The computer program LIMES is based on an improved version of the extended sum-rule model for light and intermediate-mass fragment emission in heavy ion reactions. It includes a code for dynamical calculations of the critical angular momentum for fusion following the suggestions. The report briefly describes the use of this program, the necessary input for the calculations of the element distribution and partial cross sections and gives a Fortran listing. Using the fitting routine FITEX the program provides an option for fast parameter adjustments. The use is demonstrated by an application to a specific example. (orig.) [de

  1. Band-head spectra of low-energy single-particle excitations in some well-deformed, odd-mass heavy nuclei within a microscopic approach

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Meng-Hock [Universiti Teknologi Malaysia, Skudai, Johor (Malaysia); Univ. Bordeaux, CENBG, UMR5797, Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, Gradignan (France); Duc, Dao Duy [Ton Duc Thang University, Division of Nuclear Physics, Ho Chi Minh City (Viet Nam); Ton Duc Thang University, Faculty of Applied Sciences, Ho Chi Minh City (Viet Nam); Nhan Hao, T.V. [Duy Tan University, Center of Research and Development, Danang (Viet Nam); Hue University, Center for Theoretical and Computational Physics, College of Education, Hue City (Viet Nam); Long, Ha Thuy [Hanoi University of Sciences, Vietnam National University, Hanoi (Viet Nam); Quentin, P. [Universiti Teknologi Malaysia, Skudai, Johor (Malaysia); Univ. Bordeaux, CENBG, UMR5797, Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, Gradignan (France); Ton Duc Thang University, Division of Nuclear Physics, Ho Chi Minh City (Viet Nam); Bonneau, L. [Univ. Bordeaux, CENBG, UMR5797, Gradignan (France); CNRS, IN2P3, CENBG, UMR5797, Gradignan (France)

    2016-01-15

    In four well-deformed heavy odd nuclei, the energies of low-lying rotational band heads have been determined microscopically within a self-consistent Hartree-Fock-plus-BCS approach with blocking. A Skyrme nucleon-nucleon effective interaction has been used together with a seniority force to describe pairing correlations. Only such states which are phenomenologically deemed to be related to single-particle excitations have been considered. The polarization effects, including those associated with the genuine time-reversal symmetry breaking have been fully taken into account within our model assumptions. The calculated spectra are in reasonably good qualitative agreement with available data for the considered odd-neutron nuclei. This is not so much the case for the odd-proton nuclei. A potential explanation for such a difference in behavior is proposed. (orig.)

  2. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    collaborators [1,2]. The importance of deformed valleys in the potential energy surfaces. (PES) is that they provide the most favoured fission channels for the decay of superheavy nuclei. For the dynamics study, one has to introduce the influence of mass tensor. We use the results from pairing calculations for the occupation ...

  3. Deformation effect on spectral statistics of nuclei

    Science.gov (United States)

    Sabri, H.; Jalili Majarshin, A.

    2018-02-01

    In this study, we tried to get significant relations between the spectral statistics of atomic nuclei and their different degrees of deformations. To this aim, the empirical energy levels of 109 even-even nuclei in the 22 ≤ A ≤ 196 mass region are classified as their experimental and calculated quadrupole, octupole, hexadecapole and hexacontatetrapole deformations values and analyzed by random matrix theory. Our results show an obvious relation between the regularity of nuclei and strong quadrupole, hexadecapole and hexacontatetrapole deformations and but for nuclei that their octupole deformations are nonzero, we have observed a GOE-like statistics.

  4. Comprehensive determination of macrolide antibiotics, their synthesis intermediates and transformation products in wastewater effluents and ambient waters by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Senta, Ivan; Krizman-Matasic, Ivona; Terzic, Senka; Ahel, Marijan

    2017-08-04

    Macrolide antibiotics are a prominent group of emerging contaminants frequently found in wastewater effluents and wastewater-impacted aquatic environments. In this work, a novel analytical method for simultaneous determination of parent macrolide antibiotics (azithromycin, erythromycin, clarithromycin and roxithromycin), along with their synthesis intermediates, byproducts, metabolites and transformation products in wastewater and surface water was developed and validated. Samples were enriched using solid-phase extraction on Oasis HLB cartridges and analyzed by reversed-phase liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The target macrolide compounds were separated on an ACE C18 PFP column and detected using multiple reaction monitoring in positive ionization polarity. The optimized method, which included an additional extract clean-up on strong anion-exchange cartridges (SAX), resulted in high recoveries and accuracies, low matrix effects and improved chromatographic separation of the target compounds, even in highly complex matrices, such as raw wastewater. The developed method was applied to the analysis of macrolide compounds in wastewater and river water samples from Croatia. In addition to parent antibiotics, several previously unreported macrolide transformation products and/or synthesis intermediates were detected in municipal wastewater, some of them reaching μg/L levels. Moreover, extremely high concentrations of macrolides up to mg/L level were found in pharmaceutical industry effluents, indicating possible importance of this source to the total loads into ambient waters. The results revealed a significant contribution of synthesis intermediates and transformation products to the overall mass balance of macrolides in the aquatic environment. Copyright © 2017. Published by Elsevier B.V.

  5. Event Rates of Gravitational Waves from merging Intermediate mass Black Holes: based on a Runaway Path to a SMBH

    Science.gov (United States)

    Shinkai, Hisaaki

    2018-01-01

    Based on a dynamical formation model of a supermassive black hole (SMBH), we estimate the expected observational profile of gravitational wave at ground-based detectors, such as KAGRA or advanced LIGO/VIRGO. Noting that the second generation of detectors have enough sensitivity from 10 Hz and up, we are able to detect the ring-down gravitational wave of a BH with the mass M LIGO/VIRGO), we find that the BH merger of its total mass M ˜ 60M⊙ is at the peak of the expected mass distribution. With its signal-to-noise ratio ρ = 10(30), we estimate the event rate R ˜ 200(20) per year in the most optimistic case, and we also find that BH mergers in the range M 1 per year for ρ = 10. Thus, if we observe a BH with more than 100M⊙ in future gravitational-wave observations, our model naturally explains its source.

  6. BLAST: THE MASS FUNCTION, LIFETIMES, AND PROPERTIES OF INTERMEDIATE MASS CORES FROM A 50 deg2 SUBMILLIMETER GALACTIC SURVEY IN VELA (l ∼ 2650)

    International Nuclear Information System (INIS)

    Netterfield, Calvin B.; Martin, Peter G.; Roy, Arabindo; Ade, Peter A. R.; Griffin, Matthew; Hargrave, Peter C.; Mauskopf, Phillip; Pascale, Enzo; Bock, James J.; Chapin, Edward L.; Halpern, Mark; Marsden, Gaelen; Scott, Douglas; Devlin, Mark J.; Klein, Jeff; Rex, Marie; Gundersen, Joshua O.; Hughes, David H.; Olmi, Luca; Patanchon, Guillaume

    2009-01-01

    We present first results from an unbiased 50 deg 2 submillimeter Galactic survey at 250, 350, and 500 μm from the 2006 flight of the Balloon-borne Large Aperture Submillimeter Telescope. The map has resolution ranging from 36'' to 60'' in the three submillimeter bands spanning the thermal emission peak of cold starless cores. We determine the temperature, luminosity, and mass of more than 1000 compact sources in a range of evolutionary stages and an unbiased statistical characterization of the population. From comparison with C 18 O data, we find the dust opacity per gas mass, κr= 0.16 cm 2 g -1 at 250 μm, for cold clumps. We find that 2% of the mass of the molecular gas over this diverse region is in cores colder than 14 K, and that the mass function for these cold cores is consistent with a power law with index α = -3.22 ± 0.14 over the mass range 14 M sun sun . Additionally, we infer a mass-dependent cold core lifetime of t c (M) = 4 x 10 6 (M/20 M sun ) -0.9 yr-longer than what has been found in previous surveys of either low or high-mass cores, and significantly longer than free fall or likely turbulent decay times. This implies some form of non-thermal support for cold cores during this early stage of star formation.

  7. ON THE INTERMEDIATE-REDSHIFT CENTRAL STELLAR MASS-HALO MASS RELATION, AND IMPLICATIONS FOR THE EVOLUTION OF THE MOST MASSIVE GALAXIES SINCE z ∼ 1

    Energy Technology Data Exchange (ETDEWEB)

    Shankar, Francesco; Buchan, Stewart [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Guo, Hong; Zheng, Zheng [Department of Physics and Astronomy, University of Utah, UT 84112 (United States); Bouillot, Vincent [Centre for Astrophysics, Cosmology and Gravitation, Department of Mathematics and Applied Mathematics, University of Cape Town, Cape Town 7701 (South Africa); Rettura, Alessandro [Jet Propulsion Laboratory, California Institute of Technology, MS 169-234, Pasadena, CA 91109 (United States); Meert, Alan; Bernardi, Mariangela; Sheth, Ravi; Vikram, Vinu [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Kravtsov, Andrey [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States); Marchesini, Danilo [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Behroozi, Peter [Kavli Institute for Particle Astrophysics and Cosmology, Stanford, CA 94305 (United States); Maraston, Claudia; Capozzi, Diego [Institute of Cosmology and Gravitation, Dennis Sciama Building, Burnaby Road, Portsmouth PO1 3FX (United Kingdom); Ascaso, Begoña; Huertas-Company, Marc [GEPI, Observatoire de Paris, CNRS, Univ. Paris Diderot, 5 Place Jules Janssen, F-92195 Meudon (France); Lemaux, Brian C. [Aix Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Gal, Roy R. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Lubin, Lori M., E-mail: F.Shankar@soton.ac.uk [University of California, One Shields Avenue, Davis, CA 95616 (United States); and others

    2014-12-20

    The stellar mass-halo mass relation is a key constraint in all semi-analytic, numerical, and semi-empirical models of galaxy formation and evolution. However, its exact shape and redshift dependence remain under debate. Several recent works support a relation in the local universe steeper than previously thought. Based on comparisons with a variety of data on massive central galaxies, we show that this steepening holds up to z ∼ 1 for stellar masses M {sub star} ≳ 2 × 10{sup 11} M {sub ☉}. Specifically, we find significant evidence for a high-mass end slope of β ≳ 0.35-0.70 instead of the usual β ≲ 0.20-0.30 reported by a number of previous results. When including the independent constraints from the recent Baryon Oscillation Spectroscopic Survey clustering measurements, the data, independent of any systematic errors in stellar masses, tend to favor a model with a very small scatter (≲ 0.15 dex) in stellar mass at fixed halo mass, in the redshift range z < 0.8 and for M {sub star} > 3 × 10{sup 11} M {sub ☉}, suggesting a close connection between massive galaxies and host halos even at relatively recent epochs. We discuss the implications of our results with respect to the evolution of the most massive galaxies since z ∼ 1.

  8. Barriers in the energy of deformed nuclei

    Directory of Open Access Journals (Sweden)

    V. Yu. Denisov

    2014-06-01

    Full Text Available Interaction energy between two nuclei considering to their deformations is studied. Coulomb and nuclear in-teraction energies, as well as the deformation energies of both nuclei, are taken into account at evaluation of the interaction energy. It is shown that the barrier related to the interaction energy of two nuclei depends on the de-formations and the height of the minimal barrier is evaluated. It is obtained that the heavier nucleus-nucleus sys-tems have large deformation values at the lowest barrier. The difference between the barrier between spherical nuclei and the lowest barrier between deformed nuclei increases with the mass and the charge of the interacting nuclei.

  9. OH far-infrared emission from low- and intermediate-mass protostars surveyed with Herschel-PACS

    DEFF Research Database (Denmark)

    Wampfler, Susanne Franziska; Bruderer, S.; Karska, A.

    2013-01-01

    are sufficiently high. Using realistic source parameters and radiation fields, it is shown for the case of Ser SMM1 that radiative pumping plays an important role in transitions arising from upper level energies higher than 300 K. The compact emission in the low-mass sources and the required presence of a strong...

  10. THE LEECH EXOPLANET IMAGING SURVEY: ORBIT AND COMPONENT MASSES OF THE INTERMEDIATE-AGE, LATE-TYPE BINARY NO UMa

    Energy Technology Data Exchange (ETDEWEB)

    Schlieder, Joshua E. [NASA Ames Research Center, Space Science and Astrobiology Division, MS 245-6, Moffett Field, CA 94035 (United States); Skemer, Andrew J.; Hinz, Philip; Leisenring, Jarron; Defrère, Denis; Close, Laird M.; Eisner, Josh A. [Steward Observatory, Department of Astronomy, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Maire, Anne-Lise; Desidera, Silvano [INAF—Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122, Padova (Italy); Skrutskie, Michael F. [Department of Astronomy, University of Virginia, Charlottesville, VA, 22904 (United States); Bailey, Vanessa [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Esposito, Simone [INAF—Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze (Italy); Strassmeier, Klaus G.; Weber, Michael [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482, Potsdam (Germany); Biller, Beth A.; Bonnefoy, Mickaël; Buenzli, Esther; Henning, Thomas [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Crepp, Justin R. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN, 46556 (United States); Hofmann, Karl-Heinz, E-mail: joshua.e.schlieder@nasa.gov [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn (Germany); and others

    2016-02-10

    We present high-resolution Large Binocular Telescope LBTI/LMIRcam images of the spectroscopic and astrometric binary NO UMa obtained as part of the LBT Interferometer Exozodi Exoplanet Common Hunt exoplanet imaging survey. Our H-, K{sub s}-, and L′-band observations resolve the system at angular separations <0.″09. The components exhibit significant orbital motion over a span of ∼7 months. We combine our imaging data with archival images, published speckle interferometry measurements, and existing spectroscopic velocity data to solve the full orbital solution and estimate component masses. The masses of the K2.0 ± 0.5 primary and K6.5 ± 0.5 secondary are 0.83 ± 0.02 M{sub ⊙} and 0.64 ± 0.02 M{sub ⊙}, respectively. We also derive a system distance of d = 25.87 ± 0.02 pc and revise the Galactic kinematics of NO UMa. Our revised Galactic kinematics confirm NO UMa as a nuclear member of the ∼500 Myr old Ursa Major moving group, and it is thus a mass and age benchmark. We compare the masses of the NO UMa binary components to those predicted by five sets of stellar evolution models at the age of the Ursa Major group. We find excellent agreement between our measured masses and model predictions with little systematic scatter between the models. NO UMa joins the short list of nearby, bright, late-type binaries having known ages and fully characterized orbits.

  11. Thermohaline instability and rotation-induced mixing in low and intermediate mass stars: Consequences on global asteroseismic quantities

    Directory of Open Access Journals (Sweden)

    Ekström S.

    2013-03-01

    Full Text Available Thermohaline mixing has been recently identified as the probable dominating process that governs the photospheric composition of low-mass bright red giant stars. Here, we present the predictions of stellar models computed with the code STAREVOL including this process together with rotational mixing. We compare our theoretical predictions with recent observations, and discuss the effects of both mechanisms on asteroseismic diagnostics.

  12. Herschel/PACS far-IR spectral imaging of a jet from an intermediate mass protostar in the OMC-2 region

    Science.gov (United States)

    González-García, B.; Manoj, P.; Watson, D. M.; Vavrek, R.; Megeath, S. T.; Stutz, A. M.; Osorio, M.; Wyrowski, F.; Fischer, W.; Tobin, J. J.; Sánchez-Portal, M.; Diaz Rodriguez, A. K.; Wilson, T. L.

    2016-11-01

    We present the first detection of a jet in the far-IR [O I] lines from an intermediate mass protostar. This jet was detected in a Herschel/PACS spectral mapping study in the [O I] lines of OMC-2 FIR 3 and FIR 4, two of the most luminous protostars in Orion outside of the Orion Nebula. The spatial morphology of the fine structure line emission reveals the presence of an extended photodissociation region (PDR) and a narrow, but intense jet connecting the two protostars. The jet seen in [O I] emission is spatially aligned with the Spitzer/IRAC 4.5 μm jet and the CO (6-5) molecular outflow centered on FIR 3. The mass-loss rate derived from the total [O I] 63 μm line luminosity of the jet is 7.7 × 10-6M⊙ yr-1, more than an order of magnitude higher than that measured for typical low-mass class 0 protostars. The implied accretion luminosity is significantly higher than the observed bolometric luminosity of FIR 4, indicating that the [O I] jet is unlikely to be associated with FIR 4. We argue that the peak line emission seen toward FIR 4 originates in the terminal shock produced by the jet driven by FIR 3. The higher mass-loss rate that we find for FIR 3 is consistent with the idea that intermediate-mass protostars drive more powerful jets than their low-mass counterparts. Our results also call into question the nature of FIR 4. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.The final reduced Herschel data used in this paper (FITS) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/596/A26

  13. Infrared Observations of Cometary Dust and Nuclei

    Science.gov (United States)

    Lisse, Carey

    2004-01-01

    This bibliography lists citations for publications published under the grant. Subjects of the publications include cometary dust, instellar and interplanetary dust, comet nuclei and comae, Comet Hale-Bopp, infrared observations of comets, mass loss, and comet break-up.

  14. Nuclei in a neutron star

    International Nuclear Information System (INIS)

    Oyamatsu, K.; Yamada, M.

    1994-01-01

    We report on the recent progress in understanding the matter in the crust of a neutron star. For nuclides in the outer crust, recently measured masses of neutron-rich nuclei enable us to determine more accurately the stable nuclide as a function of the matter density. In the inner crust, the compressible liquid-drop model predicts successive change of the nuclear shape, from sphere to cylinder, slab, cylindrical hole and spherical hole at densities just before the transition to uniform matter. In order to go beyond the liquiddrop model, we performed the Thomas-Fermi calculation paying special attention to the surface diffuseness, and have recently calculated the shell energies of the non-spherical nuclei. We have found from these studies that all these non-spherical nuclei exist stably in the above order even if we include the surface diffuseness and shell energies. (author)

  15. Event Rates of Gravitational Waves from merging Intermediate mass Black Holes: based on a Runaway Path to a SMBH

    Directory of Open Access Journals (Sweden)

    Shinkai Hisaaki

    2018-01-01

    Full Text Available Based on a dynamical formation model of a supermassive black hole (SMBH, we estimate the expected observational profile of gravitational wave at ground-based detectors, such as KAGRA or advanced LIGO/VIRGO. Noting that the second generation of detectors have enough sensitivity from 10 Hz and up, we are able to detect the ring-down gravitational wave of a BH with the mass M 1 per year for ρ = 10. Thus, if we observe a BH with more than 100M⊙ in future gravitational-wave observations, our model naturally explains its source.

  16. Probing the density tail of radioactive nuclei with antiprotons

    CERN Document Server

    Obertelli, Alexandre; Uesaka, Tomohiro; Corsi, Anna; Pollacco, Emmanuel; Flavigny, Freddy

    2017-01-01

    We propose an experiment to determine the proton and neutron content of the radial density tail in short-lived nuclei. The objectives are to (i) to evidence new proton and neutron halos, (ii) to understand the development of neutron skins in medium-mass nuclei, (iii) to provide a new observable that characterises the density tail of short-lived nuclei.

  17. The Role of Broken Cooper Pairs in Warm Nuclei

    International Nuclear Information System (INIS)

    Guttormsen, M.; Chankova, R.; Larsen, A.C.; Rekstad, J.; Siem, S.; Syed, N.U.H.; Agvaanluvsan, U.; Schiller, A.; Voinov, A.

    2007-01-01

    In order to understand warm nuclei and describe the underlying microscopic structure, entropy is measured for several even-even and odd-mass nuclei. Mid-shell nuclei show significant odd-even entropy differences interpreted as the single-particle entropy introduced by the valence nucleon. A method to extract critical temperatures for the pair breaking process is demonstrated. (author)

  18. Theory of magic nuclei

    International Nuclear Information System (INIS)

    Nosov, V.G.; Kamchatnov, A.M.

    A consistent theory of the shell and magic oscillations of the masses of spherical nuclei is developed on the basis of the Fermi liquid concept of the energy spectrum of nuclear matter. A ''magic'' relationship between the system's dimensions and the limiting momentum of the quasi-particle distribution is derived; an integer number of the de Broglie half-waves falls on the nuclear diameter. An expression for the discontinuity in the nucleon binding energy in the vicinity of a magic nucleus is obtained. The role of the residual interaction is analyzed. It is shown that the width of the Fermi-surface diffuseness due to the residual interaction is proportional to the squared vector of the quasi-particle orbital angular momentum. The values of the corresponding proportionality factors (the coupling constant for quasi particles) are determined from the experimental data for 52 magic nuclei. The rapid drop of the residual interaction with increasing nuclear size is demonstrated. (7 figures, 3 tables) (U.S.)

  19. An Asymmetric Runaway Domain Swap Antithrombin Dimer as a Key Intermediate for Polymerization Revealed by Hydrogen/Deuterium-Exchange Mass Spectrometry.

    Science.gov (United States)

    Trelle, Morten Beck; Pedersen, Shona; Østerlund, Eva Christina; Madsen, Jeppe Buur; Kristensen, Søren Risom; Jørgensen, Thomas J D

    2017-01-03

    Antithrombin deficiency is associated with increased risk of venous thrombosis. In certain families, this condition is caused by pathogenic polymerization of mutated antithrombin in the blood. To facilitate future development of pharmaceuticals against antithrombin polymerization, an improved understanding of the polymerogenic intermediates is crucial. However, X-ray crystallography of these intermediates is severely hampered by the difficulty in obtaining well-diffracting crystals of transient and heterogeneous noncovalent protein assemblies. Furthermore, their large size prohibits structural analysis by NMR spectroscopy. Here, we show how hydrogen/deuterium-exchange mass spectrometry (HDX-MS) provides detailed insight into the structural dynamics of each subunit in a polymerization-competent antithrombin dimer. Upon deuteration, this dimer surprisingly yields bimodal isotope distributions for the majority of peptides, demonstrating an asymmetric configuration of the two subunits. The data reveal that one subunit is very dynamic, potentially intrinsically disordered, whereas the other is considerably less dynamic. The local subunit-specific deuterium uptake of this polymerization-competent dimer strongly supports a β4A-β5A β-hairpin runaway domain swap mechanism for antithrombin polymerization. HDX-MS thus holds exceptional promise as an enabling analytical technique in the efforts toward future pharmacological intervention with protein polymerization and associated diseases.

  20. Measurement of Fragment Mass Distributions in Neutron-induced Fission of {sup 238}U and {sup 232}Th at Intermediate Energies

    Energy Technology Data Exchange (ETDEWEB)

    Simutkin, V.D. [Uppsala University, P.O Box 525, SE-751 20 Uppsala (Sweden)

    2008-07-01

    Conceptual analysis of accelerator-driven systems assumes extensive use of nuclear data on neutron-induced reactions at intermediate energies. In particular, information about the fission fragment yields from the {sup 238}U(n,f) and {sup 232}Th(n,f) reactions is of particular interest at neutron energies from 10 to 200 MeV. However, there is a lack of such data for both {sup 238}U and {sup 232}Th. Up to now, the intermediate energy measurements have been performed for {sup 238}U only, and there are no data for the {sup 232}Th(n,f) reaction. The aim of the work is to provide such data. Fission fragment mass distributions for the {sup 232}Th(n,f) and {sup 238}U(n,f) reactions have been measured for the incident neutron energies 32.8 MeV, 45.3 MeV and 59.9 MeV. The experiments have been performed at the neutron beam facility of the Universite Catholique de Louvain, Belgium. A multi-section Frisch-gridded ionization chamber has been used as a fission fragment detector. The data obtained have been interpreted in terms of the multimodal random neck-rupture model (MMRNRM). (authors)

  1. Isobaric yield curves at A=72 from the spallation of medium mass isotopes by intermediate energy protons

    International Nuclear Information System (INIS)

    Tobin, M.J.; Karol, P.J.; Department of Chemistry, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213)

    1989-01-01

    Cross sections of radionuclides in the A∼72 mass region produced by the interaction 800 MeV protons with 89 Y, /sup 92,96,100/Mo, and 130 Te were measured. Particular emphasis was paid to the measurement of short-lived products far from β stability. The cross sections were used to generate isobaric yield curves at A=72. Precise characterization of these curves showed that the distribution parameters (mean, standard deviation, skewness) vary in a regular fashion with target N/Z. For 89 Y, relative isobaric curves produced by 500 and 800 MeV protons were found to be identical within experimental error. The yield distributions for the /sup 92,96,100/Mo targets also scaled with those from an earlier alpha-induced spallation study. These findings lend strong support to the argument that the spallation mechanism is independent of projectile energy and target composition

  2. Observing the linked depletion of dust and CO gas at 0.1–10 au in disks of intermediate-mass stars

    Science.gov (United States)

    Banzatti, A.; Garufi, A.; Kama, M.; Benisty, M.; Brittain, S.; Pontoppidan, K. M.; Rayner, J.

    2018-02-01

    We report on the discovery of correlations between dust and CO gas tracers of the 0.1–10 au region in planet-forming disks around young intermediate-mass stars. The abundance of refractory elements on stellar photospheres decreases as the location of hot CO gas emission recedes to larger disk radii, and as the near-infrared excess emission from hot dust in the inner disk decreases. The linked behavior between these observables demonstrates that the recession of infrared CO emission to larger disk radii traces an inner disk region where dust is being depleted. We also find that Herbig disk cavities have either low ( 5–10%) or high ( 20–35%) near-infrared excess, a dichotomy that has not been captured by the classic definition of “pre-transitional” disks.

  3. An integrated metabolomics workflow for the quantification of sulfur pathway intermediates employing thiol protection with N-ethyl maleimide and hydrophilic interaction liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Ortmayr, Karin; Schwaiger, Michaela; Hann, Stephan; Koellensperger, Gunda

    2015-11-21

    The sulfur metabolic pathway is involved in basic modes of cellular metabolism, including methylation, cell division, respiratory oscillations and stress responses. Hence, the implicated high reactivity of the sulfur pathway intermediates entails challenges for their quantitative analysis. In particular the unwanted oxidation of the thiol group-containing metabolites glutathione, cysteine, homocysteine, γ-glutamyl cysteine and cysteinyl glycine must be prevented in order to obtain accurate snapshots of this important part of cellular metabolism. Suitable analytical methodologies are therefore needed to support studies of drug metabolism and metabolic engineering. In this work, a novel sample preparation strategy targeting thiolic metabolites was established by implementing thiol group protection with N-ethyl maleimide using a cold methanol metabolite extraction procedure. It was shown that N-ethyl maleimide derivatization is compatible with typical metabolite extraction procedures and also allowed for the stabilization of the instable thiolic metabolites in a fully (13)C-labeled yeast cell extract. The stable isotope labeled metabolite analogs could be used for internal standardization to achieve metabolite quantification with high precision. Furthermore, a dedicated hydrophilic interaction liquid chromatography tandem mass spectrometry method for the separation of sulfur metabolic pathway intermediates using a sub-2 μm particle size stationary phase was developed. Coupled with tandem mass spectrometry, the presented methodology proved to be robust, and sensitive (absolute detection limits in the low femtomole range), and allowed for the quantification of cysteine, cysteinyl glycine, cystathionine, cystine, glutamic acid, glutamyl cysteine, reduced glutathione, glutathione disulfide, homocysteine, methionine, S-adenosyl homocysteine and serine in a human ovarian carcinoma cell model.

  4. Particles and nuclei, letters

    International Nuclear Information System (INIS)

    2000-01-01

    The present collection of letters from JINR, Dubna, contains eight separate records on liquid argon pollution tests of the ATLAS detector materials at IBR-2 reactor in Dubna, irradiation tests of readout chain components of the ATLAS liquid argon calorimeters, study of neutron induced outgassing from tungsten alloy for ATLAS FCAL, yields of nuclear reaction products from a thick beryllium target bombarded by beams of 7 Li, 11 B and 15 N ions as well as on the mass surface and the properties of nuclides close to hypothetic doubly magic lead-164, the Web-site of information-diagnostic system of IBR-2 pulsed neutron source state, discovery of η-mesic nuclei and calculation of the ion angular distributions after the ionization in ion-atom collisions

  5. Evolution of Thermally Pulsing Asymptotic Giant Branch Stars. V. Constraining the Mass Loss and Lifetimes of Intermediate-mass, Low-metallicity AGB Stars

    Science.gov (United States)

    Rosenfield, Philip; Marigo, Paola; Girardi, Léo; Dalcanton, Julianne J.; Bressan, Alessandro; Williams, Benjamin F.; Dolphin, Andrew

    2016-05-01

    Thermally pulsing asymptotic giant branch (TP-AGB) stars are relatively short lived (less than a few Myr), yet their cool effective temperatures, high luminosities, efficient mass loss, and dust production can dramatically affect the chemical enrichment histories and the spectral energy distributions of their host galaxies. The ability to accurately model TP-AGB stars is critical to the interpretation of the integrated light of distant galaxies, especially in redder wavelengths. We continue previous efforts to constrain the evolution and lifetimes of TP-AGB stars by modeling their underlying stellar populations. Using Hubble Space Telescope (HST) optical and near-infrared photometry taken of 12 fields of 10 nearby galaxies imaged via the Advanced Camera for Surveys Nearby Galaxy Survey Treasury and the near-infrared HST/SNAP follow-up campaign, we compare the model and observed TP-AGB luminosity functions as well as the ratio of TP-AGB to red giant branch stars. We confirm the best-fitting mass-loss prescription, introduced by Rosenfield et al., in which two different wind regimes are active during the TP-AGB, significantly improves models of many galaxies that show evidence of recent star formation. This study extends previous efforts to constrain TP-AGB lifetimes to metallicities ranging -1.59 ≲ {{[Fe/H]}} ≲ -0.56 and initial TP-AGB masses up to ˜4 M ⊙, which include TP-AGB stars that undergo hot-bottom burning. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  6. New probe of dark-matter properties: gravitational waves from an intermediate-mass black hole embedded in a dark-matter minispike.

    Science.gov (United States)

    Eda, Kazunari; Itoh, Yousuke; Kuroyanagi, Sachiko; Silk, Joseph

    2013-05-31

    An intermediate-mass black hole (IMBH) may have a dark-matter (DM) minihalo around it and develop a spiky structure within less than a parsec from the IMBH. When a stellar mass object is captured by the minihalo, it eventually infalls into such an IMBH due to gravitational wave backreaction which in turn could be observed directly by future space-borne gravitational wave experiments such as eLISA and NGO. In this Letter, we show that the gravitational wave (GW) detectability strongly depends on the radial profile of the DM distribution. So if the GW is detected, the power index, that is, the DM density distribution, would be determined very accurately. The DM density distribution obtained would make it clear how the IMBH has evolved from a seed black hole and whether the IMBH has experienced major mergers in the past. Unlike the γ-ray observations of DM annihilation, GW is just sensitive to the radial profile of the DM distribution and even to noninteracting DM. Hence, the effect we demonstrate here can be used as a new and powerful probe into DM properties.

  7. N-body modeling of globular clusters: detecting intermediate-mass black holes by non-equipartition in HST proper motions

    Science.gov (United States)

    Trenti, Michele

    2010-09-01

    Intermediate Mass Black Holes {IMBHs} are objects of considerable astrophysical significance. They have been invoked as possible remnants of Population III stars, precursors of supermassive black holes, sources of ultra-luminous X-ray emission, and emitters of gravitational waves. The centers of globular clusters, where they may have formed through runaway collapse of massive stars, may be our best chance of detecting them. HST studies of velocity dispersions have provided tentative evidence, but the measurements are difficult and the results have been disputed. It is thus important to explore and develop additional indicators of the presence of an IMBH in these systems. In a Cycle 16 theory project we focused on the fingerprints of an IMBH derived from HST photometry. We showed that an IMBH leads to a detectable quenching of mass segregation. Analysis of HST-ACS data for NGC 2298 validated the method, and ruled out an IMBH of more than 300 solar masses. We propose here to extend the search for IMBH signatures from photometry to kinematics. The velocity dispersion of stars in collisionally relaxed stellar systems such as globular clusters scales with main sequence mass as sigma m^alpha. A value alpha = -0.5 corresponds to equipartition. Mass-dependent kinematics can now be measured from HST proper motion studies {e.g., alpha = -0.21 for Omega Cen}. Preliminary analysis shows that the value of alpha can be used as indicator of the presence of an IMBH. In fact, the quenching of mass segregation is a result of the degree of equipartition that the system attains. However, detailed numerical simulations are required to quantify this. Therefore we propose {a} to carry out a new, larger set of realistic N-body simulations of star clusters with IMBHs, primordial binaries and stellar evolution to predict in detail the expected kinematic signatures and {b} to compare these predictions to datasets that are {becoming} available. Considerable HST resources have been invested in

  8. Interannual thermohaline (1979-2014) and nutrient (2002-2014) dynamics in the Levantine surface and intermediate water masses, SE Mediterranean Sea

    Science.gov (United States)

    Ozer, Tal; Gertman, Isaac; Kress, Nurit; Silverman, Jacob; Herut, Barak

    2017-04-01

    In this study a > 30 years dataset of 1382 CTD casts in the Levantine Basin (LB) was analyzed to examine the thermohaline trends of the Surface ( 0-50 m) and Intermediate ( 150-350 m) Water masses (LSW, LIW). In addition, a 13 years (2002-2014) dataset of 3 deep water stations (> 1000 m) in the eastern Levantine Basin (Haifa Section cruises) that were visited 2-3 times annually was used to explore the relations between the physical and nutrient properties in the LIW. Over the past 30 years the LSW and LIW masses displayed positive long-term trends in salinity of + 0.008 ± 0.006 and + 0.005 ± 0.003 year- 1, respectively, and temperature of + 0.12 ± 0.07 and + 0.03 ± 0.02 °C year- 1, respectively. Decadal variations in salinity and temperature were superimposed on all long-term trends. Throughout the period 2002-2014 nutrient levels in the LIW core and corresponding integrated values of chlorophyll a also varied in nearly opposite phase with temperature and salinity. Furthermore, these variations occurred with a similar decadal periodicity, but with shifted phase with those observed in the Southern Adriatic and North Ionian Seas in the same water mass. The latter were considered to be caused by decadal reversals in the North Ionian Gyre, i.e. Bimodal Oscillation System (BiOS). These results indicate that the thermohaline flux variations attributed to the BiOS mechanism have a significant impact in magnitude on the available nutrients and the dynamics of the eastern basin primary productivity. These results should be taken into consideration in assessing the relative contribution of external nutrient loads in comparison to those attributed to variations in thermohaline fluxes and in the assessment of long-term and interannual primary productivity (chlorophyll a and nutrients) trends in the LB.

  9. Experimental and theoretical study of several nuclei from the 1f(7/2) region for mass number 47, 48, 49

    International Nuclear Information System (INIS)

    Haas, Bernard.

    1974-01-01

    The experimental study of the following nuclei 48 V, 49 V and 48 Cr has been undertaken by in-beam γ-ray spectroscopy. The nuclear structure has been deduced from angular distribution and particle-γ angular correlation measurements as well as lifetime measurements with the Doppler shift technique. Most of the energy levels could be classified in rotational bands followings quite well the low I(I+1):K(π)=1 - ( 48 V), K(π)=3/2 + and 1/2 + ( 49 V) and K(π)=0 + ( 48 Cr). The properties of these bands, as for example the B(E2) reduced matrix elements and the intrinsic quadrupole moments Q 0 have been described in the framework of the Nilsson model using a deformation parameter β approximately 0.3. The negative parity levels of the cross-conjugate nuclei 47 V- 49 Cr and 49 V- 47 Ti have also been explained by a collective model, however a strong configuration mixing in their wave function, due to the Coriolis interaction, destroys the energy dependence in I(I+1) [fr

  10. Nuclear structure studies on medium-heavy mass nuclei using the method of nuclear resonance fluorescence; Kernstrukturuntersuchungen in mittelschweren Atomkernen mit der Methode der Kernresonanzfluoreszenz

    Energy Technology Data Exchange (ETDEWEB)

    Zweidinger, Markus

    2016-06-22

    In the present work the dipole strength distribution in the stable even-even isotopes {sup 92}Zr and {sup 94}Zr is investigated. To excite the nuclei from the ground state to an excited state, real photons are used. This method is called Nuclear Resonance Fluorescence. The measurements were performed at two different setups. The first one is the Darmstadt High Intensity Photon Setup (DHIPS). At DHIPS the measurements yield information about the spin quantum number and the integrated cross section. The second part of the experiments took place at the High Intensity γ-ray Source (HIγS). Here, information about the parity quantum number and the averaged branching ratio of the excited state is accessible. In total, 105 dipole excited states in the nucleus {sup 92}Zr and 124 in the isotope {sup 94}Zr are observed, most of them for the first time. The extracted dipole strength distribution is investigated for the existence of the pygmy dipole resonance that was observed in neighboring nuclei. Furthermore, in previously performed experiments on the isotope {sup 90}Zr, the spin-flip M1 resonance was observed as well. Therefore, also the magnetic dipole strength is investigated. Further, by comparison with global systematics, the two-phonon state is identified. Additionally, the averaged branching ratio is compared to the results of theoretical calculations in the framework of the statistical model.

  11. Medium energy hadron scattering from nuclei

    International Nuclear Information System (INIS)

    Ginocchio, J.N.; Wenes, G.

    1986-01-01

    The Glauber approximation for medium energy scattering of hadronic projectiles from nuclei is combined with the interacting boson model of nuclei to produce a transition matrix for elastic and inelastic scattering in algebraic form which includes coupling to all the intermediate states. We present closed form analytic expresions for the transition matrix elements for the three dynamical symmetries of the interacting boson model; that is for, a spherical quadrupole vibrator, a γ unstable rotor, and both prolate and oblate axially symmetric rotors. We give examples of application of this formalism to proton scattering from 154 Sm and 154 Gd. 27 refs., 5 figs., 1 tab

  12. Coupled-cluster computations of atomic nuclei.

    Science.gov (United States)

    Hagen, G; Papenbrock, T; Hjorth-Jensen, M; Dean, D J

    2014-09-01

    In the past decade, coupled-cluster theory has seen a renaissance in nuclear physics, with computations of neutron-rich and medium-mass nuclei. The method is efficient for nuclei with product-state references, and it describes many aspects of weakly bound and unbound nuclei. This report reviews the technical and conceptual developments of this method in nuclear physics, and the results of coupled-cluster calculations for nucleonic matter, and for exotic isotopes of helium, oxygen, calcium, and some of their neighbors.

  13. THE ACS FORNAX CLUSTER SURVEY. VI. THE NUCLEI OF EARLY-TYPE GALAXIES IN THE FORNAX CLUSTER

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Monica L. [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 3P6 (Canada); Cote, Patrick; Ferrarese, Laura; Blakeslee, John P. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Jordan, Andres [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Av. Vicuna Mackenna 4860, Macul 7820436, Santiago (Chile); Mei, Simona [Department of Physics University of Paris Denis Diderot, F-75205 Paris Cedex 13 (France); Peng, Eric W. [Department of Astronomy, Peking University, Beijing 100871 (China); West, Michael J., E-mail: turnerm@uvic.ca [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile)

    2012-11-15

    The Advanced Camera for Surveys (ACS) Fornax Cluster Survey is a Hubble Space Telescope program to image 43 early-type galaxies in the Fornax cluster, using the F475W and F850LP bandpasses of the ACS. We employ both one-dimensional and two-dimensional techniques to characterize the properties of the stellar nuclei in these galaxies, defined as the central 'luminosity excesses', relative to a Sersic model fitted to the underlying host. We find 72% {+-} 13% of our sample (31 galaxies) to be nucleated, with only three of the nuclei offset by more than 0.''5 from their galaxy photocenter, and with the majority of nuclei having colors bluer than their hosts. The nuclei are observed to be larger, and brighter, than typical Fornax globular clusters and to follow different structural scaling relations. A comparison of our results to those from the ACS Virgo Cluster Survey reveals striking similarities in the properties of the nuclei belonging to these different environments. We briefly review a variety of proposed formation models and conclude that, for the low-mass galaxies in our sample, the most important mechanism for nucleus growth is probably infall of star clusters through dynamical friction, while for higher mass galaxies, gas accretion triggered by mergers, accretions, and tidal torques is likely to dominate, with the relative importance of these two processes varying smoothly as a function of galaxy mass. Some intermediate-mass galaxies in our sample show a complexity in their inner structure that may be the signature of the 'hybrid nuclei' that arose through parallel formation channels.

  14. Nuclei far off the stability line

    International Nuclear Information System (INIS)

    Fenyes, T.

    1978-01-01

    Theoretical and experimental aspects of the formation of some ''exotic'' nuclei far off the stability line were reviewed in addition to the relevant results of research in this field. Results in beta- and gamma-ray spectroscopy, heavy-ion-spectroscopy, achievements in the fields of measuring the atomic mass, the moment, and the radius of the nuclei as well as some astronomical aspects were described. (Z.P.)

  15. Studies of heavy-ion reactions and transuranic nuclei

    International Nuclear Information System (INIS)

    Schroeder, W.U.

    1993-08-01

    This report contain papers on the following topics: The Cold-Fusion Saga; Decay Patterns of Dysprosium Nuclei Produced in 32 S + 118,124 Sn Fusion Reactions; Unexpected Features of Reactions Between Very Heavy Ions at Intermediate Bombarding Energies; Correlations Between Neutrons and Charged Products from the Dissipative Reaction 197 Au+ 208 Pb at E/A = 29 MeV; Dissipative Dynamics of Projectile-Like Fragment Production in the Reaction 209 Bi+ 136 Xe at E/A = 28.2 MeV; Dynamical Production of Intermediate-Mass Fragments in Peripheral 209 Bi+ 136 Xe Collisions at E lab /A = 28.2 MeV; The Rochester 960-Liter Neutron Multiplicity Meter; A Simple Pulse Processing Concept for a Low-Cost Pulse-Shape-Based Particle Identification; A One-Transistor Preamplifier for PMT Anode Signals; A Five-Channel Multistop TDC/Event Handler for the SuperBall Neutron Multiplicity Meter; Construction of the SuperBall -- a 16,000-Liter Neutron Detector for Calorimetric Studies of Intermediate-Energy Heavy-Ion Reactions; A Computer Code for Light Detection Efficiency Calculations for Photo-multipliers of a Neutron Detector; Evaluation of Gd-Loaded Liquid Scintillators for the SuperBall Neutron Calorimeter; and Measurement of the Interaction of Cosmic-Ray μ - with a Muon Telescope

  16. Hot nuclei studied with high efficiency neutron detectors

    International Nuclear Information System (INIS)

    Galin, J.

    1990-01-01

    We have shown the invaluable benefit that a high efficiency 4π neutron detector can bring to the study of reaction mechanisms following collisions of heavy nuclei at intermediate energy. Analysis requires Monte-Carlo simulations for comparison between experimental data and any emission model. In systematic measurements with projectiles of velocity corresponding to energies between 27 and 77 MeV/u, where both the influence of beam velocity and mass have been investigated separately, it has been shown that the projectile-target mass asymmetry, much more than velocity, has a decisive influence on energy dissipation. The closer the projectile mass to the target mass, the more energy is dissipated per unit mass of the considered projectile plus target system. The latter presents all the characteristics of a thermalized system, evaporating a copious number of light particles: up to about 40 neutrons (after efficiency correction) and 11 light charged particles in the most dissipative collisions between Kr+Au, and 90 neutrons for Pb+U with a yet unknown number of l.c.p. In the Kr experiment, these particles are isotropically emitted in the frame of a fused system, excited with 1.2 GeV. Moreover, l.c.p. exhibit Maxwellian energy distributions as in any standard evaporation process. We are now eager to better characterize the properties of the Pb+Au (U) systems for which about 1/3 of the neutrons are freed in a rather large fraction of all collisions. The thermalized energy should then approach very closely the total binding energy of the two interacting nuclei

  17. Nuclei and quantum worlds

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    2000-01-01

    This document gathers the slides and their commentaries that have been presented at the conference 'physics and fundamental questions' by P. Chomaz. The author reviews the different quantum aspects of nuclei: tunnel effect, symmetries, magic numbers, wave functions, size, shapes and deformations. The author shows that nuclei are quantum objects of great complexity, their structures are not yet well understood and the study of exotic nuclei will continue bringing valuable information

  18. Production of intermediate vector bosons W and Z in proton and anti-protons interactions at 540 GeV in the center of mass

    International Nuclear Information System (INIS)

    Locci, E.

    1984-06-01

    The most important and the most expected result of the s = 540 GeV pantip collider at CERN is the proof of the existence of the weak intermediate bosons W +- and Z 0 , and the study of their properties. This study in the UA1 experiment is presented. 52W + (W - )→e + (e - )νsub(e)(antiνsub(e)) and 4 Z 0 → e + e - have been produced. Their measured masses are Msub(W) = 80.9sub(-1.4)sup(+0.6) GeV/c 2 et Msub(Z) = 95.6 +- 1.4 GeV/c 2 . Their properties are entirely consistent with the ''standard model'' and their characteristics of production are consistent with QCD expectations. The relative numbers of W → eνsub(e) and Z → e + e - , as well as the width of the Z, give an upper limit of the number of ''generations'' [fr

  19. Mass spectrometric identification of intermediates in the O2-driven [4Fe-4S] to [2Fe-2S] cluster conversion in FNR.

    Science.gov (United States)

    Crack, Jason C; Thomson, Andrew J; Le Brun, Nick E

    2017-04-18

    The iron-sulfur cluster containing protein Fumarate and Nitrate Reduction (FNR) is the master regulator for the switch between anaerobic and aerobic respiration in Escherichia coli and many other bacteria. The [4Fe-4S] cluster functions as the sensory module, undergoing reaction with O 2 that leads to conversion to a [2Fe-2S] form with loss of high-affinity DNA binding. Here, we report studies of the FNR cluster conversion reaction using time-resolved electrospray ionization mass spectrometry. The data provide insight into the reaction, permitting the detection of cluster conversion intermediates and products, including a [3Fe-3S] cluster and persulfide-coordinated [2Fe-2S] clusters [[2Fe-2S](S) n , where n = 1 or 2]. Analysis of kinetic data revealed a branched mechanism in which cluster sulfide oxidation occurs in parallel with cluster conversion and not as a subsequent, secondary reaction to generate [2Fe-2S](S) n species. This methodology shows great potential for broad application to studies of protein cofactor-small molecule interactions.

  20. Nuclear treasure island [superheavy nuclei

    CERN Document Server

    CERN. Geneva

    1999-01-01

    Summary form only given. Soon after the experiments at Dubna, which synthesized element 114 and made the first footprints on the beach of the "island of nuclear stability", two new superheavy elements have been discovered at the Lawrence Berkeley National Laboratory. Element 118 and its immediate decay product, element 116, were manufactured at Berkeley's 88 inch cyclotron by fusing targets of lead-208 with an intense beam of 449 MeV krypton-86 ions. Although both new nuclei almost instantly decay into lighter ones, the decay sequence is consistent with theories that have long predicted the island of stability for nuclei with approximately 114 protons and 184 neutrons. Theorist Robert Smolanczuk, visiting from the Soltan Institute for Nuclear Studies in Poland, had calculated that this reaction should have particularly favourable production rates. Now that this route has been signposted, similar reactions could be possible: new elements and isotopes, tests of nuclear stability and mass models, and a new under...

  1. Isobars in nuclei

    International Nuclear Information System (INIS)

    Beurtey, R.

    1975-01-01

    The present situation of the theoretical studies and experimental material concerning the potential presence of virtual nucleon excited states (isobars) in nuclei is reported. Three particular aspects are examined: the theoretical work devoted to the isobar content of nuclei (especially deuteron), the experimental material concerning isobar exchange and the attempts to obtain a direct evidence for such objects in the deuteron (spectator method) [fr

  2. Neutron rich nuclei

    International Nuclear Information System (INIS)

    Foucher, R.

    1979-01-01

    If some β - emitters are particularly interesting to study in light, medium, and heavy nuclei, another (and also) difficult problem is to know systematically the properties of these neutron rich nuclei far from the stability line. A review of some of their characteristics is presented. How far is it possible to be objective in the interpretation of data is questioned and implications are discussed

  3. Nuclei in high forms

    International Nuclear Information System (INIS)

    Szymanski, Z.; Berger, J.F.; Heenen, P.H.; Heyde, K.; Haas, B.; Janssens, R.; Paya, D.; Gogny, D.; Huber, G.; Bjoernholm, S.; Brack, M.

    1991-01-01

    The purpose of 1991 Joliot-Curie Summer School is to review the most advances in the understanding of the nuclei physics after the considerable progress in gamma spectroscopy. It covers the following topics: Highly and super-deformed nuclei, nuclear structures, mean-field approach and beyond, fission isomers, nuclear excitations with long lifetime and metal clusters

  4. Eta mesons in nuclei

    International Nuclear Information System (INIS)

    Liu, L.C.

    1987-01-01

    The possibility of producing eta-mesic nuclei by the use of pions is discussed. If these nuclei are observed experimentally, then the binding energies of the eta in this new nuclear matter can be used to extract accurately the eta-N-N* coupling constant in a nucleus. The framework for these calculations is the coupled channel isobar model

  5. Identical Bands and ΔI=2 Staggering in Superdeformed Nuclei in A~150 Mass Region Using Three Parameters Rotational Model

    Directory of Open Access Journals (Sweden)

    Khalaf A. M.

    2012-10-01

    Full Text Available By using a computer simulated search program, the experimental gamma transition en- ergies for superdeformed rotational bands (SDRB’s in A 150 region are fitted to proposed three-parameters model. The model parameters and the spin of the bandhead were obtained for the selected ten SDRB’s namely: 150 Gd (yrast and excited SD bands, 151 Tb (yrast and excited SD bands, 152 Dy (yrast SD bands, 148 Gd (SD-1,SD-6, 149 Gd (SD-1, 153 Dy (SD-1 and 148 Eu (SD-1. The Kinematic J (1 and dynamic J (2 moments of inertia are studied as a function of the rotational frequency ~ ω . From the calculated results, we notic that the excited SD bands have identical energies to their Z + 1 neigh- bours for the twinned SD bands in N = 86 nuclei. Also the analysis done allows us to confirm Δ I = 2 staggering in the yrast SD bands of 148 Gd, 149 Gd, 153 Dy, and 148 Eu and in the excited SD bands of 148 Gd, by performing a staggering parameter analysis. For each band, we calculated the deviation of the gamma ray energies from smooth ref- erence representing the finite di ff erence approximation to the fourth derivative of the gamma ray transition energies at a given spin.

  6. Masses of T/sub z/ = +5/2 nuclei in the s--d shell from β--decay measurements

    International Nuclear Information System (INIS)

    Alburger, D.E.; Goosman, D.R.; Davids, C.N.; Hardy, J.C.

    1975-01-01

    In this work the existence of five new T/sub z/ = + 5 / 2 nuclides, 23 F, 29 Mg, 31 Al, 33 Si, and 35 P, was established; their properties, including mass values, were determined, along with those of 25 Ne and 27 Na. Two experimental techniques were used, the ''rabbit'' transfer of a solid target and the gas transfer system; some novel features of these are described. A β spectrum of 33 Si observed in coincidence with 1848-keV γ rays is shown; a mass excess of -20569 +- 50 keV was derived for 33 Si. Attempts to produce 21 O were unsuccessful. Comparisons of the measured masses of the T/sub z/ = + 5 / 2 nuclides in the 2s--1d shell with predictions of the Garvey--Kelson mass formulation and with shell-model calculations are shown. The latter produce considerably better agreement with experiment. (3 figures, 1 table) (U.S.)

  7. Production and identification of very exotic nuclei

    International Nuclear Information System (INIS)

    Pougheon, F.

    1986-01-01

    New very exotic nuclei have been produced by fragmentation of the projectile at intermediate energy at GANIL. They have been identified through time of flight and ΔE-E measurements after a magnetic separation with the 0 0 LISE spectrometer. New neutron rich isotopes have been identified up to Z = 26 and evidence for the stability of the new series Tz = -5/2 has been shown. These results improve the knowledge of the neutron and proton drip lines

  8. New vistas of exotic heavy nuclei

    International Nuclear Information System (INIS)

    Cocks, J.F.C.; Butler, P.A.

    1997-01-01

    We report studies of examples of reflection-asymmetric nuclei which are difficult to access using compound nucleus reactions. The most octupole deformed nuclei should be uranium isotopes with N ∼ 132; preliminary measurements of these very fissile nuclei suggest that they are within reach of current spectroscopic techniques. The octupole radium isotopes with N > 132 and radon isotopes are not accessible by reactions employing stable targets and beams; we have shown that multinucleon transfer reactions can populate these nuclei with sufficient yield for their structure to be determined. We report high spin studies in 218,220,222 Rn and 222,224,226 Ra which reveal upbending effects in this mass region for the first time and show that the electric dipole moment is constant with spin. (author)

  9. Electric monopole transitions from low energy excitations in nuclei

    CERN Document Server

    Wood, J L; De Coster, C; Heyde, Kris L G

    1999-01-01

    Electric monopole (E0) properties are studied across the entire nuclear mass surface. Besides an introductory discussion of various model results (shell model, geometric vibrational and rotational models, algebraic models), we point out that many of the largest E0 transition strengths, $\\rho^2$(E0), are associated with shape mixing. We discuss in detail the manifestation of E0 transitions and present extensive data for~: single-closed shell nuclei, vibrational nuclei, well-deformed nuclei, nuclei that exhibit sudden ground-state changes, and nuclei that exhibit shape coexistence and intruder states. We also give attention to light nuclei, odd-A nuclei, and illustrate a suggested relation between $\\rho^2$(E0) and isotopic shifts.

  10. Spectroscopy of exotic nuclei with A {approx} 190: single particle states and collective properties of {sup 187,189}Bi and {sup 188}Pb; Spectroscopie de noyaux exotiques dans la region de masse A {approx} 190: la structure des isotopes {sup 187,189}Bi et {sup 188}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Huerstel, A

    2002-11-01

    This thesis is devoted to the study of very neutron deficient nuclei in the lead region of the nuclear chart and more precisely to the investigation of the single particle states and collective properties of the {sup 187,189}Bi isotopes by gamma-ray spectroscopy. These nuclei were produced via fusion-evaporation reaction induced by a krypton beam on a silver target. In this mass region, the cross section for producing these nuclei are very low, of the order of a few micro-barns, making experimental studies very difficult. The identification of the nuclei was done using the very powerful RDT (Recoil Decay Tagging) technique, based on the selection of the isotopes through their characteristic alpha-particle decays. The experiments were performed at the university of Jyvdskyla (Finland) with the facility combining the gamma-ray spectrometer JUROSPHERE and the magnetic gas-filled separator RITU. Isomeric states were observed in both nuclei and their life-times measured. The systematics of individual proton states in odd-mass bismuth isotopes have been reproduced with a shell model up to 20 neutrons away from the valley of stability. Furthermore, rotational bands, a signature of collective nuclear motion, have been established for the first time in these nuclei. The interpretation of these results led to the conclusion that {sup 187,189}Bi have a prolate shape at low excitation energy, unlike the heavier bismuth isotopes which have been interpreted to have oblate deformation, implying a shape transition in this mass region. Hartree-Fock-Bogolyubov calculations are consistent with the experimental indication of shape coexistence, as seen in the neighbouring even-even lead nuclei. (author)

  11. Dissipation and the population of compound nuclei

    International Nuclear Information System (INIS)

    Thoennessen, M.; Beene, J.R.

    1992-01-01

    The importance of nuclear dissipative efforts on the formation of compound nuclei is studied with the γ-ray decay of the giant dipole resonance (GDR) built on highly excited states. The compound nuclei 164 Yb, 160 Er, and 110 Sn were produced with very mass-asymmetric and with more mass-symmetric target/projectile combinations. The large deviation from statistical model prediction observed in the γ-ray spectra from the more symmetrically formed 160 Er and 164 Yb can be qualitatively explained within the particle exchange model

  12. Systematics of light nuclei in a relativistic model

    International Nuclear Information System (INIS)

    Price, C.E.

    1988-01-01

    The results of relativistic mean field calculations for non-spherical nuclei are presented and discussed. The need for non-linear scalar meson self-couplings in order to describe the properties of s-d shell nuclei is emphasized along with the importance of self-consistency in calculations of magnetic moments of odd-mass nuclei. 16 refs., 3 figs., 2 tabs

  13. Interactions of quarks and gluons with nuclei at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, A.H. [Columbia Univ., New York, NY (United States)

    1994-04-01

    Some processes involving the interaction of medium energy quarks and gluons with nuclear matter are described. Possible mechanisms for the A-dependence of the energy loss of leading protons produced in proton-nucleus collisions are given, and an experiment which may help to distinguish these mechanisms is described. A possible color transparency experiment at CEBAF is described. Experiments to measure energy loss of quarks in nuclear matter and the formation time of hadrons are discussed along with the possibilities of measuring {sigma}{sub J}/{psi} and {sigma}{sub {psi}{prime}} at CEBAF.

  14. Stability of the spherical form of nuclei

    International Nuclear Information System (INIS)

    Sabry, A.A.

    1976-08-01

    An extension of the mass formula for a spherical nucleus in the drop model to include a largely deformed nucleus of different forms is investigated. It is found that although the spherical form is stable under small deformations from equilibrium, there exists for heavier nuclei another more favourable stable form, which can be approximated by two, or three touching prolate ellipsoids of revolution

  15. Deformed shapes in odd-odd nuclei near Z = 82

    International Nuclear Information System (INIS)

    Mukherjee, G.; Pai, H.; Bhattacharya, S.; Bhattacharya, C.; Bhattacharyya, S.; Bhattacharjee, T.; Basu, S.K.; Kundu, S.; Ghosh, T.K.; Bannerjee, K.; Rana, T.K.; Meena, J.K.; Chanda, S.; Bhowmik, R.K.; Singh, R.P.; Muralithar, S.; Garg, R.

    2009-01-01

    The neutron deficient nuclei in the vicinity of the Z = 82 region are known for interesting structural phenomena arising due to different shape driving effects of the proton and neutron orbitals near the Fermi surface. It has been found that the heavier bismuth and thallium nuclei with A > 200 are spherical and the lighter nuclei with A < 194 have rotational bands indicating deformation. We report here our recent experimental investigation of γ-ray spectroscopy of odd-odd Bi and Tl nuclei in mass region A = 190

  16. Study of nuclear level densities for exotic nuclei

    International Nuclear Information System (INIS)

    Nasrabadi, M. N.; Sepiani, M.

    2012-01-01

    Nuclear level density is one of the properties of nuclei with widespread applications in astrophysics and nuclear medicine. Since there has been little experimental and theoretical research on the study of nuclei which are far from stability line, studying nuclear level density for these nuclei is of crucial importance. Also, as nuclear level density is an important input for nuclear research codes, hence studying the methods for calculation of this parameter is essential. Besides introducing various methods and models for calculating nuclear level density for practical applications, we used exact spectra distribution (SPDM) for determining nuclear level density of two neutron and proton enriched exotic nuclei with the same mass number.

  17. Investigation of mass and nuclear charge distributions in a fission induced by 3 MeV neutrons for some fissile nuclei

    International Nuclear Information System (INIS)

    Hamelin, Christiane

    1983-01-01

    After a presentation of the phenomenon of fission (liquid droplet model, microscopic model, Strutinski model, static approach to the scission point with the Fong statistical model and with the Wilkins thermodynamic model), this research thesis presents an experimental installation with its irradiation systems, its measurement assembly, its measurement process (rare gas emission). The author then describes the methods used to determine efficiencies: charge distributions within an isobaric chain, efficiency determination principle, choice of experimental parameters, test with Uranium 235. Experimental results are then presented and discussed in terms of mass distribution and of charge distribution for various uranium isotopes (235, 238 and 232). They are discussed with respect to the Wilkins model, to the pair breakage model, and to the calculation of the average number of neutrons emitted by different fissile systems

  18. Intermediate mass fragment production from neck-like structures in peripheral 58Ni + 58Ni collisions at E/A = 30 MeV

    International Nuclear Information System (INIS)

    Milazzo, P.M.; Sisto, M.; Vannini, G.; Agodi, C.; Alba, R.; Bellia, G.; Coniglione, R.; Del Zoppo, A.; Colonna, N.; Fabbietti, L.

    2000-01-01

    An experiment to investigate the 58 Ni + 58 Ni reaction at E/A = 30 MeV was performed at the Superconducting Cyclotron of the INFN Laboratorio Nazionale del Sud. In peripheral collisions massive fragments (4 ≤ Z ≤ 12) emission from neck-like structures joining projectile-like and target-like residues has been observed in coincidence with other reaction products. Their emission patterns exhibit features consistent with dynamical fragmentation of a neck zone between the interacting nuclei. In addition, at the same time the projectile-like and target-like residues are subject to statistical decay. (author)

  19. An Effective Method to Detect Volatile Intermediates Generated in the Bioconversion of Coal to Methane by Gas Chromatography-Mass Spectrometry after In-Situ Extraction Using Headspace Solid-Phase Micro-Extraction under Strict Anaerobic Conditions.

    Science.gov (United States)

    Liu, Jianmin; Wang, Baoyu; Tai, Chao; Wu, Li; Zhao, Han; Guan, Jiadong; Chen, Linyong

    2016-01-01

    Bioconversion of coal to methane has gained increased attention in recent decades because of its economic and environmental advantages. However, the mechanism of this process is difficult to study in depth, partly because of difficulties associated with the analysis of intermediates generated in coal bioconversion. In this investigation, we report on an effective method to analyze volatile intermediates generated in the bioconversion of coal under strict anaerobic conditions. We conduct in-situ extraction of intermediates using headspace solid-phase micro-extraction followed by detection by gas chromatography-mass spectrometry. Bioconversion simulation equipment was modified and combined with a solid-phase micro-extraction device. In-situ extraction could be achieved by using the combined units, to avoid a breakdown in anaerobic conditions and to maintain the experiment continuity. More than 30 intermediates were identified qualitatively in the conversion process, and the variation in trends of some typical intermediates has been discussed. Volatile organic acids (C2-C7) were chosen for a quantitative study of the intermediates because of their importance during coal bioconversion to methane. Fiber coating, extraction time, and solution acidity were optimized in the solid-phase micro-extraction procedure. The pressure was enhanced during the bioconversion process to investigate the influence of headspace pressure on analyte extraction. The detection limits of the method ranged from 0.0006 to 0.02 mmol/L for the volatile organic acids and the relative standard deviations were between 4.6% and 11.5%. The volatile organic acids (C2-C7) generated in the bioconversion process were 0.01-1.15 mmol/L with a recovery range from 80% to 105%. The developed method is useful for further in-depth research on the bioconversion of coal to methane.

  20. How atomic nuclei cluster.

    Science.gov (United States)

    Ebran, J-P; Khan, E; Nikšić, T; Vretenar, D

    2012-07-18

    Nucleonic matter displays a quantum-liquid structure, but in some cases finite nuclei behave like molecules composed of clusters of protons and neutrons. Clustering is a recurrent feature in light nuclei, from beryllium to nickel. Cluster structures are typically observed as excited states close to the corresponding decay threshold; the origin of this phenomenon lies in the effective nuclear interaction, but the detailed mechanism of clustering in nuclei has not yet been fully understood. Here we use the theoretical framework of energy-density functionals, encompassing both cluster and quantum liquid-drop aspects of nuclei, to show that conditions for cluster formation can in part be traced back to the depth of the confining nuclear potential. For the illustrative example of neon-20, we show that the depth of the potential determines the energy spacings between single-nucleon orbitals in deformed nuclei, the localization of the corresponding wavefunctions and, therefore, the degree of nucleonic density clustering. Relativistic functionals, in particular, are characterized by deep single-nucleon potentials. When compared to non-relativistic functionals that yield similar ground-state properties (binding energy, deformation, radii), they predict the occurrence of much more pronounced cluster structures. More generally, clustering is considered as a transitional phenomenon between crystalline and quantum-liquid phases of fermionic systems.

  1. The Sloan Lens ACS Survey. XI. Beyond Hubble Resolution : Size, Luminosity, and Stellar Mass of Compact Lensed Galaxies at Intermediate Redshift

    NARCIS (Netherlands)

    Newton, Elisabeth R.; Marshall, Philip J.; Treu, Tommaso; Auger, Matthew W.; Gavazzi, Raphaeel; Bolton, Adam S.; Koopmans, Leon V. E.; Moustakas, Leonidas A.

    We exploit the strong lensing effect to explore the properties of intrinsically faint and compact galaxies at intermediate redshift (z(s) similar or equal to 0.4-0.8) at the highest possible resolution at optical wavelengths. Our sample consists of 46 strongly lensed emission line galaxies (ELGs)

  2. Selfconsistent theory of Coulomb mixing in nuclei

    International Nuclear Information System (INIS)

    Pyatov, N.I.

    1978-01-01

    The theory of isobaric states is considered according to the Coulomb mixing in nuclei. For a given form of the isovestor potential the separable residual interactions are constructed by means of the isotopic invariance principle. The strength parameter of the force is found from a selfconsistency condition. The charge dependent force is represented by the Coulomb effective potential. The theory of the isobaric states is developed using the random phase approximation. The Coulomb mixing effects in the ground and isobaric 0 + states of even-mass nuclei are investigated

  3. Weak and electromagnetic interactions in nuclei

    International Nuclear Information System (INIS)

    Klapdor, H.V.

    1986-01-01

    The International Symposium W.E.I.N. 1986 brought together leading experts in the fields of nuclear and elementary particle physics, astrophysics and cosmology. In addition to current problems in nuclear physics (weak and electromagnetic nuclear properties, electroweak interactions in nuclei, exotic nuclei) this book presents fascinating contributions that arise from the interaction among these fields: lepton number violation and neutrino mass; muon physics; weak interactions and fundamental symmetries; fundamental decays; basic experiments for GUTs; weak interactions and astrophysics; GUTs, SUSYs and the early Universe. The book demonstrates that in this context nuclear physics promises exciting future developments. (orig.)

  4. Structure of neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, W. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics]|[Oak Ridge National Lab., TN (United States). Physics Div.]|[Warsaw Univ. (Poland). Inst. of Theoretical Physics

    1997-11-01

    One of the frontiers of today`s nuclear science is the ``journey to the limits``: of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The new data on exotic nuclei are expected to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this talk, current developments in nuclear structure of neutron-rich nuclei are discussed from a theoretical perspective.

  5. Structure of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Nazarewicz, W.; Oak Ridge National Lab., TN; Warsaw Univ.

    1997-11-01

    One of the frontiers of today's nuclear science is the ''journey to the limits'': of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The new data on exotic nuclei are expected to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this talk, current developments in nuclear structure of neutron-rich nuclei are discussed from a theoretical perspective

  6. Vibrations in deformed nuclei

    International Nuclear Information System (INIS)

    Aprahamian, A.

    1992-01-01

    Quadrupole oscillations around a deformed shape give rise to vibrations in deformed nuclei. Single phonon vibrations of K = 0 (β) and K = 2 (γ) are a systematic feature in deformed nuclei, but the existence of multi-phonon vibrations had remained an open question until the recently reported results in 168 Er. In this nucleus, a two-phonon K = 4(γγ) band was observed at approximately 2.5 times the energy of the single γ vibration. The authors have studied several deformed rare-earth nuclei using the ( 4 He,2n) reaction in order to map out the systematic behavior of these multi-phonon vibrations. Recently, they have identified a similar K = 4 band in 154 Gd

  7. Evolution of planetary nebula nuclei

    International Nuclear Information System (INIS)

    Shaw, R.A.

    1985-01-01

    The evolution of planetary nebula nuclei (PNNs) is examined with the aid of the most recent available stellar evolution calculations and new observations of these objects. Their expected distribution in the log L-log T plane is calculated based upon the stellar evolutionary models of Paczynski, Schoenberner and Iben, the initial mass function derived by Miller and Scalo, and various assumptions concerning mass loss during post-main sequence evolution. The distribution is found to be insensitive both to the assumed range of main-sequence progenitor mass and to reasonable variations in the age and the star forming history of the galactic disk. Rather, the distribution is determined by the strong dependence of the rate of stellar evolution upon core mass, the steepness of the initial mass function, and to a lesser extent the finite lifetime of an observable planetary nebula. The theoretical distributions are rather different than any of those inferred from earlier observations. Possible observational selection effects that may be responsible are examined, as well as the intrinsic uncertainties associated with the theoretical model predictions. An extensive photometric and smaller photographic survey of southern hemisphere planetary nebulae (PNs) is presented

  8. Mass

    International Nuclear Information System (INIS)

    Quigg, Chris

    2007-01-01

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  9. Weak interactions with nuclei

    International Nuclear Information System (INIS)

    Walecka, J.D.

    1983-01-01

    Nuclei provide systems where the strong, electomagnetic, and weak interactions are all present. The current picture of the strong interactions is based on quarks and quantum chromodynamics (QCD). The symmetry structure of this theory is SU(3)/sub C/ x SU(2)/sub W/ x U(1)/sub W/. The electroweak interactions in nuclei can be used to probe this structure. Semileptonic weak interactions are considered. The processes under consideration include beta decay, neutrino scattering and weak neutral-current interactions. The starting point in the analysis is the effective Lagrangian of the Standard Model

  10. Disintegration of comet nuclei

    Science.gov (United States)

    Ksanfomality, Leonid V.

    2012-02-01

    The breaking up of comets into separate pieces, each with its own tail, was seen many times by astronomers of the past. The phenomenon was in sharp contrast to the idea of the eternal and unchangeable celestial firmament and was commonly believed to be an omen of impending disaster, especially for comets with tails stretching across half the sky. It is only now that we have efficient enough space exploration tools to see comet nuclei and even - in the particular case of small comet Hartley-2 in 2010 - to watch their disintegration stage. There are also other suspected candidates for disintegration in the vast family of comet nuclei and other Solar System bodies.

  11. Light (Hyper-)Nuclei production at the LHC measured with ALICE

    CERN Document Server

    Barile, Francesco

    2015-05-29

    The high center-of-mass energies delivered by the LHC during the last three years of operation led to accumulate a significant statistics of light (hyper-)nuclei in pp, p--Pb and Pb--Pb collisions. The ALICE apparatus allows for the detection of these rarely produced particles over a wide momentum range thanks to its excellent vertexing, tracking and particle identification capabilities. The last is based on the specific energy loss in the Time Projection Chamber and the velocity measurement with the Time-Of-Flight detector. The Cherenkov technique, exploited by a small acceptance detector (HMPID), has also been used for the most central Pb--Pb collisions to identify (anti-)deuterons at intermediate transverse momentum.\\\\ Results on the production of stable nuclei and anti-nuclei in pp, p--Pb and Pb--Pb collisions are presented. Hypernuclei production rates in Pb--Pb are also described, together with a measurement of the hypertriton lifetime. The results are compared with the predictions from thermal and coal...

  12. Electromagnetic structure of nuclei

    International Nuclear Information System (INIS)

    Arnold, R.G.

    1986-07-01

    A brief review is given of selected topics in the electromagnetic structure of nucleons and nuclei, including nucleon form factors from both quantum chromodynamics and electron scattering data, measurements of the deuteron and triton form factors, quasi-elastic scattering, and the EMC effect. 47 refs., 13 figs

  13. Mesons and light nuclei

    International Nuclear Information System (INIS)

    Truhlik, E.; Mach, R.

    1992-01-01

    62 papers and one summary talk were presented at the conference, on subject matters in between nuclear physics (mainly light nuclei) and elementary particle physics, as indicated by the session headings (1) Electroweak nuclear interaction (2) Nuclear physics with pions and antiprotons (3) Nuclear physics with strange particles (4) Relativistic nuclear physics (5) Quark degrees of freedom. (Quittner)

  14. Nucleons in nuclei (II)

    International Nuclear Information System (INIS)

    Laget, J.M.

    1988-01-01

    This summary is a review of our understanding of nuclei in terms of hadrons exchanging mesons. The open problems are: the determination of the high momentum components of nuclear systems, the role of the three-body forces and the nature of the short range correlations. The ways of studying these problems are discussed

  15. Alpha clustering in nuclei

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1990-01-01

    The effects of nucleon clustering in nuclei are described, with reference to both nuclear structure and nuclear reactions, and the advantages of using the cluster formalism to describe a range of phenomena are discussed. It is shown that bound and scattering alpha-particle states can be described in a unified way using an energy-dependent alpha-nucleus potential. (author)

  16. Microscopic properties of superdeformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Lennart B

    1999-04-01

    Many high spin rotational bands in superdeformed nuclei have been found in the A 140 - 150 region, but so far no linking transitions to known normal-deformed states have been found in these nuclei. Therefore, configuration and spin assignments have to be based on indirect spectroscopic information. Identical bands were first discovered in this region of superdeformed states. At present, some identical bands have also been found at normal deformation, but such bands are more common at superdeformation. Recently lifetime measurements have given relative quadrupole moments with high accuracy. Spectroscopic quantities are calculated using the configuration constrained cranked Nilsson-Strutinsky model with the modified oscillator potential. In a statistical study the occurrence of identical bands is tested. Comparing superdeformed and normal deformed nuclei, the higher possibility for identical bands at superdeformation is understood from calculated reduced widths of the E{sub {gamma}} and J{sup (2)} distributions. The importance of high-N orbitals for identical bands is also discussed. Additivity of electric quadrupole moment contributions in the superdeformed A - 150 region is discussed with the nucleus {sup 152}Dy as a `core`. In analytic harmonic oscillator calculations, the effective electric quadrupole moment q{sub eff}, i.e. the change in the total quadrupole moment caused by the added particle, is expressed as a simple function of the single-particle mass, quadrupole moment q{sub {nu}}. Also in realistic calculations, simple relations between q{sub eff} and q{sub {nu}} can be used to estimate the total electric quadrupole moment, e.g. for the nucleus {sup 142}Sm, by adding the effect of 10 holes, to the total electric quadrupole moment of {sup 152}Dy. Furthermore, tools are given for estimating the quadrupole moment for possible configurations in the superdeformed A - 150 region. For the superdeformed region around {sup 143}Eu, configuration and spin assignments

  17. Shape Deformations in Atomic Nuclei

    OpenAIRE

    Hamamoto, Ikuko; Mottelson, Ben R.

    2011-01-01

    The ground states of some nuclei are described by densities and mean fields that are spherical, while others are deformed. The existence of non-spherical shape in nuclei represents a spontaneous symmetry breaking.

  18. Rotating bubble and toroidal nuclei and fragmentation

    International Nuclear Information System (INIS)

    Royer, G.; Haddad, F.; Jouault, B.

    1995-01-01

    The energy of rotating bubble and toroidal nuclei predicted to be formed in central heavy-ion collisions at intermediate energies is calculated within the generalized rotating liquid drop model. The potential barriers standing in these exotic deformation paths are compared with the three dimensional and plane fragmentation barriers. In the toroidal deformation path of the heaviest systems exists a large potential pocket localised below the plane fragmentation barriers. This might allow the temporary survival of heavy nuclear toroids before the final clusterization induced by the surface and proximity tension. (author)

  19. Planck Intermediate Results. XI: The gas content of dark matter halos: the Sunyaev-Zeldovich-stellar mass relation for locally brightest galaxies

    DEFF Research Database (Denmark)

    Planck Collaboration,; Ade, P. A. R.; Aghanim, N.

    2013-01-01

    gas, and that this gas must be less concentrated than the dark matter in such halos in order to remain consistent with X-ray observations. At the high-mass end, the measured SZ signal is 20% lower than found from observations of X-ray clusters, a difference consistent with Malmquist bias effects......We present the scaling relation between Sunyaev-Zeldovich (SZ) signal and stellar mass for almost 260,000 locally brightest galaxies (LBGs) selected from the Sloan Digital Sky Survey (SDSS). These are predominantly the central galaxies of their dark matter halos. We calibrate the stellar-to-halo...... indication of signal at even lower stellar mass. We derive the scaling relation between SZ signal and halo mass by assigning halo properties from our mock catalogues to the real LBGs and simulating the Planck observation process. This relation shows no evidence for deviation from a power law over a halo mass...

  20. Recoil studies of photonuclear reactions at intermediate energies

    CERN Document Server

    Haba, H

    2002-01-01

    A review is given on the recoil studies of photonuclear reactions on complex nuclei at intermediate energies. Recoils of 167 radionuclides formed in the photonuclear reactions of sup 2 sup 7 Al, sup n sup a sup t V, sup n sup a sup t Cu, sup 9 sup 3 Nb, sup n sup a sup t Ag, sup n sup a sup t Ta, and sup 1 sup 9 sup 7 Au, induced by bremsstrahlung of end-point energies (E sub 0) from 600 to 1100 MeV, have been investigated by the thick-target thick-catcher method. The recoil velocity from the first step and the mean kinetic energy of the residual nuclei in the second step were deduced based on the two-step vector velocity model and discussed by comparing with the reported results on proton-induced reactions. Recoils of sup 2 sup 4 Na produced from sup 2 sup 7 Al, sup n sup a sup t V, sup n sup a sup t Cu, sup n sup a sup t Ag, and sup 1 sup 9 sup 7 Au are of special interest from a viewpoint of a change in the production mechanism with respect to target mass. Reaction yields of 58 and 63 radionuclides produce...

  1. Nuclei in Astrophysics

    Science.gov (United States)

    Penionzhkevich, Yu. E.

    2016-06-01

    This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclearphysics methods for studying cosmic objects and properties of the Universe. The results of investigations in nuclear reactions, induced by radioactive nuclear beams, make it possible to analyze the nucleosynthesis scenario in the region of light elements in a new manner.

  2. Intermediate-energy nuclear chemistry workshop

    Energy Technology Data Exchange (ETDEWEB)

    Butler, G.W.; Giesler, G.C.; Liu, L.C.; Dropesky, B.J.; Knight, J.D.; Lucero, F.; Orth, C.J.

    1981-05-01

    This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities.

  3. Intermediate-energy nuclear chemistry workshop

    International Nuclear Information System (INIS)

    Butler, G.W.; Giesler, G.C.; Liu, L.C.; Dropesky, B.J.; Knight, J.D.; Lucero, F.; Orth, C.J.

    1981-05-01

    This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities

  4. Pion coupling to nuclei

    International Nuclear Information System (INIS)

    Dumbrajs, O.

    1981-01-01

    The concept of the pion-nucleus coupling constants is discussed. Methods of their determination are reviewed. These include: forward dispersion relations, extrapolation of differential cross sections to the poles in the angular variable, analysis of data on electromagnetic form factors with the use of the PCAC and CVC hypotheses, pion photoproduction at threshold and low-energy theorems. Our present knowledge of the pion coupling to the He, Li, Be, C, N and O nuclei is summarized. (author)

  5. Chaotic behavior in nuclei

    International Nuclear Information System (INIS)

    Mitchel, G.; Shriner, J.

    2005-01-01

    Although the predictions of Random Matrix Theory (RMT) were available by the early 1960s, data of sufficiently high quality to adequately test the theory were only obtained a decade later by Rainwater. It was another decade later that Bohigas, Haq and Pandey combined the best available nuclear resonance data - the Columbia neutron resonances in heavy nuclei and the TUNL proton resonances in lighter nuclei - to form the Nuclear Data Ensemble. They obtained excellent agreement for the level statistics with the RMT predictions. The expected Porter-Thomas (PT) distribution was considered very early. However, since the widths (amplitudes squared) are measured, the predicted Gaussian distribution for the amplitudes was only qualitatively confirmed. A much more sensitive test was performed by measuring two widths and the relative phase between the two amplitudes. By comparison of the width and amplitude correlations, the Gaussian distribution was confirmed at the 1% level. Following the Bohigas conjecture - that quantum analogs of classically chaotic systems obey RMT - there was an explosion of activity utilizing level statistics in many different quantum systems. In nuclei the focus was verifying the range of applicability of RMT. Of particular interest was the effect of collectivity and of excitation energy on statistical properties. The effect of symmetry breaking on level statistics was examined and early predictions by Dyson were confirmed. The effect of symmetry breaking on the width distribution was also measured for the first time. Although heuristic arguments predicted no change from the PT distribution, experimentally there was a large deviation from the PT prediction. Later theoretical efforts were consistent with this result. The stringent conditions placed on the experiments - for eigenvalue tests the data need to be essentially perfect (few or no missing levels or mis assigned quantum numbers) - has limited the amount of suitable experimental data. The

  6. Far from the intermediate nuclear field

    International Nuclear Information System (INIS)

    Dietrich, K.; Wagner, G.J.; Gregoire, C.; Campi, X.; Silvestre-Brac, B.; Platchkov, S.; Mayer, B.; Abgrall, Y.; Bohigas, O.; Grange, P.; Signarbieux, C.

    1988-01-01

    Pairing correlations in nuclear physics; the BCS state and quasi-particles; the layer model; collision effects on nuclear dynamics; the theory of cluster formation (application to nucleus fragmentation); short range correlations (few-particle systems); deuterium electron scattering; dibaryonic resonances; traditional and exotic hadron probes of nuclear structure; spectral fluctuations and chaotic motion; corrections to the intermediate nuclear field (nonrelativistic and other effects); and heavy nuclei splitting and nuclear superfluidity are introduced [fr

  7. Double charge exchange of pions on nuclei

    International Nuclear Information System (INIS)

    Dzhibuti, R.I.; Kezerashvili, R.Y.

    1985-01-01

    An analysis is made of the results of experimental and theoretical studies during the last ten years of a unique process: double charge exchange of pions on nuclei. On the one hand, the commissioning of meson factories and the use of new and more accurate experimental methods have led to the accumulation of rich and reliable material for not only light but also medium and heavy nuclei. On the other hand, the development and application of new microscopic theoretical approaches have led to a deepening of our ideas about the mechanism of these exotic reactions at low, intermediate, and high energies. The currently existing methods of theoretical investigation and all possible reaction mechanisms are considered. Particular attention is devoted to double charge exchange of pions on the lightest nuclei, for the theoretical description of which it is possible to use the well-developed methods for investigating few-particle systems. The experimental investigations of double-isobar analog and nonanalog transitions in the reaction of double charge exchange are systematized

  8. Decay of heavy and superheavy nuclei

    Indian Academy of Sciences (India)

    study on the feasibility of observing α decay chains from the isotopes of the superheavy nuclei. Z = 115 in the range 271 ≤ A ≤ 294 and the isotopes of Z = 117 in the range 270 ≤ A ≤ 301, within the Coulomb and .... For Ri we use semiempirical formula in terms of mass number Ai as [3]. Ri = 1.28A. 1/3 i. − 0.76 + 0.8A.

  9. ''Identical'' bands in normally-deformed nuclei

    International Nuclear Information System (INIS)

    Garrett, J.D.; Baktash, C.; Yu, C.H.

    1990-01-01

    Gamma-ray transitions energies in neighboring odd- and even-mass nuclei for normally-deformed nuclear configurations are analyzed in a manner similar to recent analyses for superdeformed states. The moment of inertia is shown to depend on pair correlations and the aligned angular momentum of the odd nucleon. The implications of this analysis for ''identical'' super-deformed bands are discussed. 26 refs., 9 figs

  10. Mass-independent isotope effects.

    Science.gov (United States)

    Buchachenko, Anatoly L

    2013-02-28

    Three fundamental properties of atomic nuclei-mass, spin (and related magnetic moment), and volume-are the source of isotope effects. The mostly deserved and popular, with almost hundred-year history, is the mass-dependent isotope effect. The first mass-independent isotope effect which chemically discriminates isotopes by their nuclear spins and nuclear magnetic moments rather than by their masses was detected in 1976. It was named as the magnetic isotope effect because it is controlled by magnetic interaction, i.e., electron-nuclear hyperfine coupling in the paramagnetic species, the reaction intermediates. The effect follows from the universal physical property of chemical reactions to conserve angular momentum (spin) of electrons and nuclei. It is now detected for oxygen, silicon, sulfur, germanium, tin, mercury, magnesium, calcium, zinc, and uranium in a great variety of chemical and biochemical reactions including those of medical and ecological importance. Another mass-independent isotope effect was detected in 1983 as a deviation of isotopic distribution in reaction products from that which would be expected from the mass-dependent isotope effect. On the physical basis, it is in fact a mass-dependent effect, but it surprisingly results in isotope fractionation which is incompatible with that predicted by traditional mass-dependent effects. It is supposed to be a function of dynamic parameters of reaction and energy relaxation in excited states of products. The third, nuclear volume mass-independent isotope effect is detected in the high-resolution atomic and molecular spectra and in the extraction processes, but there are no unambiguous indications of its importance as an isotope fractionation factor in chemical reactions.

  11. Initial temperature and extent of chemical equilibration of partons in relativistic collisions of heavy nuclei

    Science.gov (United States)

    Srivastava, Dinesh K.; Chatterjee, Rupa; Mustafa, Munshi G.

    2018-01-01

    We study the consequences of a premise that, if a thermalized and chemically equilibrating quark gluon plasma is formed in relativistic collisions of heavy nuclei, then a knowledge of energy and entropy densities of the plasma fixes the initial temperature and the product of gluon fugacity and formation time uniquely, provided we know the relative fugacities of quarks and gluons. Thus, a smaller formation time would imply a larger fugacity, independent of the initial temperature. Next, we explore the limits of chemical equilibration of partons during the initial stages in relativistic collisions of heavy nuclei. Experimentally measured rapidity densities of transverse energy and charged particle multiplicities at RHIC and LHC energies are used to estimate energy and number densities with the assumption of the formation of a kinetically equilibrated plasma that may not be chemically equilibrated for quarks and gluons. The estimates are found to be very sensitive to the correction factor used to multiply the Bjorken energy density to get the initial energy density. The evolution of the chemical equilibration during the quark gluon plasma phase is inferred by solving master equations, including the processes {gg}≤ftrightarrow {ggg} and {gg}≤ftrightarrow q\\overline{q} along with expansion and cooling of the plasma. Possible consequences for the invariant mass distribution of intermediate mass dileptons radiated from the plasma are discussed.

  12. Exotic nuclei: α-decay, direct reactions and structure

    International Nuclear Information System (INIS)

    Jain, Arun K.

    2003-01-01

    With input parameters from the microscopic studies of stable nuclei and their variations with respect to energy, density, asymmetry etc. one expects to describe the decay of unstable nuclei, their microscopic structure and various scattering and reaction cross sections. The exotic nuclei, both in the lower-mass region as well as in the super-heavy region also should be accessible for predictions and verification. Somehow the direct nuclear reactions of the transfer and knockout type, employed to investigate quantitatively the microscopic behaviour of nuclei, have been only marginally successful. Successful resolution of some of the striking gross disagreements between theory and observations has been achieved now. The manner in which information of the microscopic structure and the effective nuclear interaction affect the predictive power of the direct reactions is found to be remarkable. In the α-decay of heavy nuclei also the microscopic structure information of the target and residual nuclei play decisive role in the values of decay energy and half-life. The interior and surface parts of the α-particle residual nucleus effective interaction, control the energy and decay rates. Fitting the observations with microscopic model values lead to the required predictive power for decay properties of super-heavy nuclei. In a similar manner the analysis of scattering and reactions involving light exotic-nuclei gives information about their microscopic structure. (author)

  13. Growth and Interaction of Colloid Nuclei

    Science.gov (United States)

    Lam, Michael-Angelo; Khusid, Boris; Meyer, William; Kondic, Lou

    2017-11-01

    We study evolution of colloid systems under zero-gravity conditions. In particular, we focus on the regime where there is a coexistence between a liquid and a solid state. Under zero gravity, the dominating process in the bulk of the fluid phase and the solid phase is diffusion. At the moving solid/liquid interface, osmotic pressure is balanced by surface tension, as well as balancing fluxes (conservation of mass) with the kinematics of nuclei growth (Wilson-Frenkel law). Due to the highly nonlinear boundary condition at the moving boundary, care has to be taken when performing numerical simulations. In this work, we present a nonlinear model for colloid nuclei growth. Numerical simulations using a finite volume method are compared with asymptotic analysis of the governing equation and experimental results for nuclei growth. Novel component in our numerical simulations is the inclusion of nonlinear (collective) diffusion terms that depend on the chemical potentials of the colloid in the solid and fluid phase. The results include growth and dissolution of a single colloidal nucleus, as well as evolution of multiple interacting nuclei. Supported by NASA Grant No. NNX16AQ79G.

  14. Shell and pairing effects in spherical nuclei close to the nucleon drip lines

    International Nuclear Information System (INIS)

    Beiner, M.; Lombard, R.J.

    1975-01-01

    The unstability against nucleon emission of light and medium exotic spherical nuclei is investigated systematically using an extended version of the energy density formalism which reproduces correctly shell and pairing effects in stable nuclei. The reliability of the predictions of this microscopic, self-consistent and weakly parametrized model should not decrease significantly with the distance of the nuclei from the β-stability line, what is not the case for conventional mass formulae or mass tables [fr

  15. Deexcitation of nuclei formed near the instability temperature

    International Nuclear Information System (INIS)

    Rivet, M.F.; Borderie, B.; Gauvin, H.; Gardes, D.; Cabot, C.; Hanappe, F.; Peter, J.

    1986-01-01

    Fusion-like reactions induced on medium mass targets by 27 MeV per nucleon argon projectiles were studied. The properties of evaporation residues and binary fission fragments, both cold remnants of fusion nuclei, show that highly excited nuclei were produced, near the temperature of instability of nuclear matter. Fission-evaporation competition in the deexcitation of these nuclei is reflected in the ratio of fission and residue cross sections, which provides a way of studying the role of prefission evaporation and fission barriers in the deexcitation process

  16. Universality and Halo Nuclei

    Directory of Open Access Journals (Sweden)

    Tomio L.

    2010-04-01

    Full Text Available Universal aspects of few-body systems will be reviewed motivated by recent interest in atomic and nuclear physics. The critical conditions for the existence of excited states in three-body systems with two-identical particles will be explored. In particular, we consider halo nuclei that can be modeled as three-body nuclear systems, with two halo neutrons and a core. In this context, we also discuss the low-energy neutron−19C elastic scattering, near the conditions for the app earance of an Efimov state.

  17. Anomalous carbon nuclei

    International Nuclear Information System (INIS)

    Gasparian, A.P.

    1984-01-01

    Results are presented from a bubble chamber experiment to search for anomalous mean free path (MFP) phenomena for secondary multicharged fragments (Zsub(f)=5 and 6) of the beam carbon nucleus at 4.2 GeV/c per nucleon. A total of 50000 primary interactions of carbon with propane (C 3 H 8 ) were created. Approximately 6000 beam tragments with charges Zsub(f)=5 and 6 were analyzed in detail to find out an anomalous decrease of MFP. The anomaly is observed only for secondary 12 C nuclei

  18. Active galactic nuclei

    CERN Document Server

    Blandford, RD; Woltjer, L

    1990-01-01

    Starting with this volume, the Lecture Notes of the renowned Advanced Courses of the Swiss Society for Astrophysics and Astronomy will be published annually. In each course, three extensive lectures given by leading experts in their respective fields cover different and essential aspects of the subject. The 20th course, held at Les Diablerets in April 1990, dealt with current research on active galactic nuclei; it represents the most up-to-date views on the subject, presented with particular regard for clarity. The previous courses considered a wide variety of subjects, beginning with ""Theory

  19. Active galactic nuclei

    CERN Document Server

    Beckmann, Volker

    2012-01-01

    This AGN textbook includes phenomena based on new results in the X-Ray domain from new telescopes such as Chandra and XMM Newton not mentioned in any other book. Furthermore, it considers also the Fermi Gamma Ray Space Telescope with its revolutionary advances of unprecedented sensitivity, field of view and all-sky monitoring. Those and other new developments as well as simulations of AGN merging events and formations, enabled through latest super-computing capabilities. The book gives an overview on the current knowledge of the Active Galacitc Nuclei phenomenon. The spectral energy d

  20. Study of Triaxial deformation variable γ in even - even nuclei

    International Nuclear Information System (INIS)

    Singh, Yuvraj; Gupta, K.K.; Bihari, Chhail; Sharma, Aparna; Varshney, A.K.; Singh, M.; Gupta, D.K.; Varshney, Mani; Dhiman, S.K.

    2011-01-01

    The deformation parameters β and γ of the collective model are basic description of the nuclear equilibrium shape and structure, while values for these variables have been discussed for many nuclei. A systematic study in mass region A = 120-140 and A = 150 -180 can never be less revealing, such study has been presented, in A = 90 -120 for Mo, Ru and Pd nuclei where β and γ both vary strongly

  1. Millimeter- and Submillimeter-Wave Observations of the OMC-2/3 Region. I. Dispersing and Rotating Core around the Intermediate-Mass Protostar MMS 7

    Science.gov (United States)

    Takahashi, Satoko; Saito, Masao; Takakuwa, Shigehisa; Kawabe, Ryohei

    2006-11-01

    We report the results of H13CO+ (1-0), CO (1-0), and 3.3 mm dust continuum observations toward MMS 7, one of the strongest millimeter-wave sources in OMC-3, with the Nobeyama Millimeter Array (NMA) and the Nobeyama 45 m telescope. With the NMA, we detected centrally condensed 3.3 mm dust continuum emission, which coincides with the mid-infrared (MIR) source and the free-free jet. Our H13CO+ observations revealed a disklike envelope around MMS 7, whose size and mass are 0.15×0.11 pc and 5.1 Msolar, respectively. The outer portion of the disklike envelope has a fan-shaped structure, which delineates the rim of the observed CO outflow. The position-velocity diagrams in the H13CO+ (1-0) emission show that the velocity field in the disklike envelope is composed of a dispersing gas motion and a possible rigid-like rotation. The mass-dispersing rate is estimated to be 3.4×10-5 Msolar yr-1, which implies that MMS 7 has an ability to disperse ~10 Msolar during the protostellar evolutional time. The specific angular momentum in the disklike envelope is nearly 2 orders of magnitude larger than that in low-mass cores. The turnover point of the power law of the angular momentum distribution in the disklike envelope (Sports, Science, and Technology of Japan.

  2. Shell effects and nucleosynthesis of heavy nuclei

    International Nuclear Information System (INIS)

    Farhan, A.R.; Sharma, M.M.

    2005-01-01

    The nuclear shell effects across the magic numbers N = 50, 82 and 126 near the r-process path are crucial to understanding the nucleosynthesis of heavy nuclei. Since nuclei near the r-process path are extremely neutron rich and are not accessible in the laboratory, the current understanding of the nuclear abundances is based much upon extrapolations of various mass formulae. In this talk, we will discuss as to how the shell effects evolve in going from the stability line to the r-process path and towards drip line in the heavy mass region. Within the framework of to the relativistic Hartree-Bogoliubov (RHB) theory with the vector self-coupling of omega meson, it will be shown that the shell effects across N = 82 show a significant decline in going from the r-process path to the drip line, whereas those at N = 126 remain resilient to the change in isospin in going from the r-process path to the neutron drip line. This behaviour of the microscopic RHB calculations is consistent with the recent r-process calculations suggesting that a shell quenching at N = 82 would be useful, however, a quenching is not necessary for reproducing r-process abundances near the peak at A ∼ 190. We will also show that due to an onset of deformation for nuclei above N = 126, an additional stability in some nuclei beyond the neutron drip line is provided. Consequently, this would contribute to r-process nuclear abundances in the third peak. A comparative analysis of shell effects with the microscopic RMF theory and with the macroscopic-microscopic mass formulae shows that the microscopic RMF theory possesses the potential of describing nuclear abundances in the peaks about A ∼ 130 and A ∼ 190. (author)

  3. Stability of superheavy nuclei

    Science.gov (United States)

    Pomorski, K.; Nerlo-Pomorska, B.; Bartel, J.; Schmitt, C.

    2018-03-01

    The potential-energy surfaces of an extended set of heavy and superheavy even-even nuclei with 92 ≤Z ≤126 and isospins 40 ≤N -Z ≤74 are evaluated within the recently developed Fourier shape parametrization. Ground-state and decay properties are studied for 324 different even-even isotopes in a four-dimensional deformation space, defined by nonaxiality, quadrupole, octupole, and hexadecapole degrees of freedom. Nuclear deformation energies are evaluated in the framework of the macroscopic-microscopic approach, with the Lublin-Strasbourg drop model and a Yukawa-folded mean-field potential. The evolution of the ground-state equilibrium shape (and possible isomeric, metastable states) is studied as a function of Z and N . α -decay Q values and half-lives, as well as fission-barrier heights, are deduced. In order to understand the transition from asymmetric to symmetric fission along the Fm isotopic chain, the properties of all identified fission paths are investigated. Good agreement is found with experimental data wherever available. New interesting features about the population of different fission modes for nuclei beyond Fm are predicted.

  4. Rotating clusters in nuclei

    International Nuclear Information System (INIS)

    Pauling, L.; Robinson, A.B.

    1975-01-01

    Values of R, the radius of rotation of the rotating cluster, are calculated from the energy of the lowest 2 + level of even-even nuclei with the assumption that the cluster consists of p 2 or n 2 respectively, for N or P magic, and of a helion (α) for N or P differing from a magic number by +-2. The values as a function of A show a zigzag course, which is correlated with the polyspheron structure of the nuclei. If the mantle is not overcrowded the cluster glides over the surface of the mantle and the value of R increases by one spheron diameter, about 3.2 fm. At certain values of N a change in structure of the nucleus occurs, with increase in radius of the core by half a spheron diameter, permitting the cluster to drop back into the mantle, with decrease in R by half a spheron diameter. In the lanthanon region of permanent prolate deformation the rotating cluster is a polyhelion, containing the number of helions permitted by the difference between Z or N and the nearest magic number, and in the actinon region it contains all the nucleons beyond 208 Pb, with maximum p 10 n 16 . An explanation is given of the difference between these regions. (author)

  5. Exotic nuclei and radioactive beams

    International Nuclear Information System (INIS)

    Chomaz, P.

    1996-01-01

    The Nuclei called exotic are all the nuclei that it is necessary to recreate in laboratory to study them. Their life time is too short -in relation to earth age- for it remains enough on earth. The researchers are going to have at their s disposal at GANIL (Caen) with the S.P.I.R.A.L. project, exotic nuclei beams and will study new kinds of nuclear reactions to better understand the atom nucleus. (N.C.). 2 refs., 9 figs

  6. Translationally invariant treatment of pair correlations in nuclei: I. Spin and isospin dependent correlations

    Energy Technology Data Exchange (ETDEWEB)

    Guardiola, R. [Valencia Univ., Burjassot (Spain). Dept. de Fisica Atomica, Molecular y Nucl.; Moliner, P.I. [Valencia Univ., Burjassot (Spain). Dept. de Fisica Atomica, Molecular y Nucl.; Navarro, J. [IFIC (Centre Mixt CSIC -Universitat de Valencia), Avda. Dr. Moliner 50, E-46100 Burjassot (Spain); Bishop, R.F. [Department of Physics, UMIST, P.O. Box 88, Manchester M60 1QD (United Kingdom); Puente, A. [Department of Physics, UMIST, P.O. Box 88, Manchester M60 1QD (United Kingdom); Walet, N.R. [Department of Physics, UMIST, P.O. Box 88, Manchester M60 1QD (United Kingdom)

    1996-11-11

    We study the extension of our translationally invariant treatment of few-body nuclear systems to heavier nuclei. At the same time we also introduce state-dependent correlation operators. Our techniques are tailored to those nuclei that can be dealt with in LS coupling, which includes all nuclei up to the shell closure at A=40. We study mainly p-shell nuclei in this paper. A detailed comparison with other microscopic many-body approaches is made, using a variety of schematic nuclear interactions. It is shown that our methodology produces very good energies, and presumably also wave functions, for medium mass nuclei. (orig.).

  7. On the production of He, C, and N by low- and intermediate-mass stars: a comparison of observed and model-predicted planetary nebula abundances

    Science.gov (United States)

    Henry, R. B. C.; Stephenson, B. G.; Miller Bertolami, M. M.; Kwitter, K. B.; Balick, B.

    2018-01-01

    The primary goal of this paper is to make a direct comparison between the measured and model-predicted abundances of He, C, and N in a sample of 35 well-observed Galactic planetary nebulae (PNe). All observations, data reductions, and abundance determinations were performed in house to ensure maximum homogeneity. Progenitor star masses (M ≤ 4 M⊙) were inferred using two published sets of post-asymptotic giant branch model tracks and L and Teff values. We conclude the following: (1) the mean values of N/O across the progenitor mass range exceeds the solar value, indicating significant N enrichment in the majority of our objects; (2) the onset of hot bottom burning appears to begin around 2 M⊙, i.e. lower than ∼5 M⊙ implied by theory; (3) most of our objects show a clear He enrichment, as expected from dredge-up episodes; (4) the average sample C/O value is 1.23, consistent with the effects of third dredge up; and (5) model grids used to compare to observations successfully span the distribution over metallicity space of all C/O and many He/H data points but mostly fail to do so in the case of N/O. The evident enrichment of N in PN and the general discrepancy between the observed and model-predicted N/O abundance ratios signal the need for extra mixing as an effect of rotation and/or thermohaline mixing in the models. The unexpectedly high N enrichment that is implied here for low-mass stars, if confirmed, will likely impact our conclusions about the source of N in the Universe.

  8. Experiments with stored relativistic exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Geissel, H.; Radon, T.; Attallah, F. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)] [and others

    1998-07-01

    Beams of relativistic exotic nuclei were produced, separated and investigated with the combination of the fragment separator FRS and the storage ring ESR. The following experiments are presented: (1) Direct mass measurements of relativistic nickel and bismuth projectile fragments were performed using Schottky spectrometry. Applying electron cooling, the relative velocity spread of the circulating secondary nuclear beams of low intensity was reduced to below 10{sup -6}. The achieved mass resolving power of m/{Delta}m = 6.5 . 10{sup 5} (FWHM) in recent measurements represents an improvement by a factor of two compared to our previous experiments. The previously unknown masses of more than 100 proton-rich isotopes have been measured in the range of 54 {<=} Z {<=} 84. The results are compared with mass models and estimated values based on extrapolations of experimental values. (2) Exotic nuclei with half-lives shorter than the time required for electron cooling can be investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique has been successfully applied in a first measurement with nickel fragments. A mass resolving power of m/{Delta}m = 1.5 . 10{sup 5} (FWHM) was achieved in this mode of operation. (3) Nuclear half-lives of stored and cooled bare projectile fragments have been measured to study the influence of the ionic charge state on the beta-decay probability. (orig.)

  9. Experiments with stored relativistic exotic nuclei

    International Nuclear Information System (INIS)

    Klepper, O.; Attallah, F.; Beckert, K.; Bosch, F.; Dolinskiy, A.; Eickhoff, H.; Franczak, B.; Franzke, B.; Geissel, H.; Hausmann, M.; Hellstroem, M.; Herfurth, F.; Kluge, H.-J.; Kozhuharov, C.; Muenzenberg, G.; Nolden, F.; Quint, W.; Tradon, T.; Reich, H.; Scheidenberger, C.; Schlitt, B.; Steck, M.; Suemmerer, K.; Vermeeren, L.; Winkler, M.; Winkler, Th.; Falch, M.; Kerscher, Th.; Loebner, K.E.G.; Fujita, Y.; Novikov, Yu.; Patyk, Z.; Stadlmann, J.; Wollnik, H.

    1999-01-01

    Beams of relativistic exotic nuclei were produced, separated and investigated with the combination of the fragment separator FRS and the storage ring ESR. The following experiments are presented: 1) Direct mass measurements of relativistic nickel and bismuth projectile fragments were performed using Schottky spectrometry. Applying electron cooling, the relative velocity spread of the circulating secondary nuclear beams of low intensity was reduced to below 10 -6 . The achieved mass resolving power of m/Δm = 6.5·10 5 (FWHM) in recent measurements represents an improvement by a factor of two compared to authors' previous experiments. The previously unknown masses of more than 100 proton-rich isotopes have been measured in the range of 54≤Z≤84. The results are compared with mass models and estimated values based on extrapolations of experimental values. 2) Exotic nuclei with half-lives shorter than the time required for electron cooling can be investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique has been successfully applied in a first measurement with nickel fragments. A mass resolving power of m/Δm = 1.5·10 5 (FWHM) was achieved in this mode of operation. 3) Nuclear half-lives of stored and cooled bare projectile fragments have been measured to study the influence of the ionic charge state on the beta-decay probability

  10. Fission Fragment Mass Distributions and Total Kinetic Energy Release of 235-Uranium and 238-Uranium in Neutron-Induced Fission at Intermediate and Fast Neutron Energies

    Energy Technology Data Exchange (ETDEWEB)

    Duke, Dana Lynn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-12

    This Ph.D. dissertation describes a measurement of the change in mass distributions and average total kinetic energy (TKE) release with increasing incident neutron energy for fission of 235U and 238U. Although fission was discovered over seventy-five years ago, open questions remain about the physics of the fission process. The energy of the incident neutron, En, changes the division of energy release in the resulting fission fragments, however, the details of energy partitioning remain ambiguous because the nucleus is a many-body quantum system. Creating a full theoretical model is difficult and experimental data to validate existing models are lacking. Additional fission measurements will lead to higher-quality models of the fission process, therefore improving applications such as the development of next-generation nuclear reactors and defense. This work also paves the way for precision experiments such as the Time Projection Chamber (TPC) for fission cross section measurements and the Spectrometer for Ion Determination in Fission (SPIDER) for precision mass yields.

  11. Intermediate energy proton and light-ion scattering

    International Nuclear Information System (INIS)

    Moss, J.M.

    1981-01-01

    A review is presented of recent (1979-81) developments in the field of intermediate-energy proton and light-ion scattering from nuclei. New theoretical and calculational techniques of particular interest to experimentalists are discussed. Emphasis is placed on topics in nuclear structure physics - giant resonances, pion-condensation precursor phenomena, and polarization transfer (spin-flip) experiments - where intermediate energy proton and light-ion scattering has made new and unique contributions

  12. Disappearance of collective motion in hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Santonocito, D.; Piattelli, P.; Agodi, C.; Alba, R.; Bellia, G.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Hongmei, F.; Maiolino, C.; Migneco, E.; Sapienza, P. [INFN-LNS, Laboratori Nazionali del Sud, Catania (Italy); Blumenfeld, Y.; Delaunay, F.; Frascaria, N.; Lima, V.; Scarpaci, J. [Institut de Physique Nucleaire, IN2P3-CNRS, 91 - Orsay (France); Migneco, E. [Catania Univ., Dipartimento di Fisica (Italy)

    2003-07-01

    The evolution of the GDR {gamma} yield for excitation energies between 160 and 300 MeV has been investigated in nuclei of mass A {approx} 126 through the reactions {sup 116}Sn + {sup 12}C and {sup 24}Mg at 17 and 23 A*MeV. Gamma-rays were detected with MEDEA array in coincidence with residues detected in MACISTE. The evolution of the GDR parameters has been investigated as a function of the linear momentum transferred to the fused system. This procedure allowed us to select hot nuclei produced in incomplete fusion reactions with different excitation energies. The analysis of the {gamma} spectra and their comparison with CASCADE calculations is presented. Results suggest a saturation of the GDR yield between 200 and 300 MeV excitation energy. (authors)

  13. The structure of nuclei far from stability

    International Nuclear Information System (INIS)

    Zganjar, E.F.

    1993-01-01

    Studies on nuclei near Z=82 contributed to the establishment of a new region of nuclear deformation and a new class of nuclear structure at closed shells. A important aspect of this work is the establishment of the connection between low-lying 0 + states in even endash even nuclei and the occurrence of shape coexistence in the odd-mass neighbors (E0 transitions in 185 Pt, shape coexistence in 184 Pt and 187 Au). A new type of picosecond lifetime measurement system capable of measuring the lifetime of states that decay only by internal conversion was developed and applied to the 186,188 Tl decay to determine the lifetime of the 0 2 + and 2 2 + deformed states in 186,188 Hg. A search for the population of superdeformed states in 192 Hg by the radioactive decay of 192 Tl was accomplished by using a prototype internal pair formation spectrometer

  14. An Asymmetric Runaway Domain Swap Antithrombin Dimer as a Key Intermediate for Polymerization Revealed by Hydrogen/Deuterium-Exchange Mass Spectrometry

    DEFF Research Database (Denmark)

    Trelle, Morten Beck; Pedersen, Shona; Østerlund, Eva Christina

    2017-01-01

    analysis by NMR spectroscopy. Here, we show how hydrogen/deuterium-exchange mass spectrometry (HDX-MS) provides detailed insight into the structural dynamics of each subunit in a polymerization-competent antithrombin dimer. Upon deuteration, this dimer surprisingly yields bimodal isotope distributions...... for the majority of peptides, demonstrating an asymmetric configuration of the two subunits. The data reveal that one subunit is very dynamic, potentially intrinsically disordered, whereas the other is considerably less dynamic. The local subunit-specific deuterium uptake of this polymerization-competent dimer...... strongly supports a β4A-β5A β-hairpin runaway domain swap mechanism for antithrombin polymerization. HDX-MS thus holds exceptional promise as an enabling analytical technique in the efforts toward future pharmacological intervention with protein polymerization and associated diseases....

  15. Electron scattering off nuclei

    International Nuclear Information System (INIS)

    Gattone, A.O.

    1989-01-01

    Two recently developed aspects related to the scattering of electrons off nuclei are presented. On the one hand, a model is introduced which emphasizes the relativistic aspects of the problem in the impulse approximation, by demanding strict maintenance of the algebra of the Poincare group. On the other hand, the second model aims at a more sophisticated description of the nuclear response in the case of collective excitations. Basically, it utilizes the RPA formalism with a new development which enables a more careful treatment of the states in the continuum as is the case for the giant resonances. Applications of both models to the description of elastic scattering, inelastic scattering to discrete levels, giant resonances and the quasi-elastic region are discussed. (Author) [es

  16. Clusters in nuclei

    CERN Document Server

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This third volume follows the successful Lect. Notes Phys. 818 (Vol. 1) and 848 (Vol. 2), and comprises six extensive lectures covering the following topics:  - Gamma Rays and Molecular Structure - Faddeev Equation Approach for Three Cluster Nuclear Reactions - Tomography of the Cluster Structure of Light Nuclei Via Relativistic Dissociation - Clustering Effects Within the Dinuclear Model : From Light to Hyper-heavy Molecules in Dynamical Mean-field Approach - Clusterization in Ternary Fission - Clusters in Light N...

  17. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors) 304 refs., 53 figs., 5 tabs.

  18. Collective excitations in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    1998-01-01

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors)

  19. Three-body forces in p-shell nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hees, A.G.M. van; Booten, J.G.L.; Glaudemans, P.W.M. (Rijksuniversiteit Utrecht (Netherlands). Dept. of Physics and Astronomy)

    1990-01-29

    Within the (0 + 1){Dirac h}{omega} shell-model space for p-shell nuclei we found that a schematic three-body interaction in addition to a translationally invariant two-body interaction leads to a strongly improved description of energy levels. The present three-body interaction is related to the {Delta}-isobar intermediate-state model of the two-pion exchange three-nucleon interaction. (orig.).

  20. Dynamics of light, intermediate, heavy and superheavy nuclear ...

    Indian Academy of Sciences (India)

    2014-05-01

    May 1, 2014 ... Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 5 ... The dynamical description of light, intermediate, heavy and superheavy nuclei formed in heavy-ion collisions is worked out using the dynamical cluster ... School of Physics and Materials Science, Thapar University, Patiala 147 004, India ...

  1. Dynamics of light, intermediate, heavy and superheavy nuclear ...

    Indian Academy of Sciences (India)

    2014-05-01

    May 1, 2014 ... Abstract. The dynamical description of light, intermediate, heavy and superheavy nuclei formed in heavy-ion collisions is worked out using the dynamical cluster decay model (DCM), with refer- ence to various effects such as deformation and orientation, temperature, angular momentum etc. Based on the ...

  2. A new spin on nuclei

    International Nuclear Information System (INIS)

    Clark, R.; Wadsworth, B.

    1998-01-01

    Magnetic rotation is a new phenomenon that is forcing physicists to rethink their understanding of what goes on inside the nucleus The rotation of quantum objects has a long and distinguished history in physics. In 1912 the Danish scientist Niels Bjerrum was the first to recognize that the rotation of molecules is quantized. In 1938 Edward Teller and John Wheeler observed similar features in the spectra of excited nuclei, and suggested that this was caused by the nucleus rotating. But a more complete explanation had to wait until 1951, when Aage Bohr (the son of Niels) pointed out that rotation was a consequence of the nucleus deforming from its spherical shape. We owe much of our current understanding of nuclear rotation to the work of Bohr and Ben Mottelson, who shared the 1975 Nobel Prize for Physics with James Rainwater for developing a model of the nucleus that combined the individual and collective motions of the neutrons and protons inside the nucleus. What makes it possible for a nucleus to rotate? Quantum mechanically, a perfect sphere cannot rotate because it appears the same when viewed from any direction and there is no point of reference against which its change in position can be detected. To see the rotation the spherical symmetry must be broken to allow an orientation in space to be defined. For example, a diatomic molecule, which has a dumbbell shape, can rotate about the two axes perpendicular to its axis of symmetry. A quantum mechanical treatment of a diatomic molecule leads to a very simple relationship between rotational energy, E, and angular momentum. This energy is found to be proportional to J(J + 1), where J is the angular momentum quantum number. The molecule also has a magnetic moment that is proportional to J. These concepts can be applied to the atomic nucleus. If the distribution of mass and/or charge inside the nucleus becomes non-spherical then the nucleus will be able to rotate. The rotation is termed ''collective'' because many

  3. The cochlear nuclei of snakes.

    Science.gov (United States)

    Miller, M R

    1980-08-15

    The cochlear nuclei of three burrowing snakes (Xenopeltis unicolor, Cylindrophis rufus, and Eryx johni) and three non-burrowing snakes (Epicrates cenchris, Natrix sipedon, and Pituophis catenifer) were studied. The posterior branch of the statoacoustic nerve and its posterior ganglion were destroyed and the degenerated nerve fibers and terminals traced to primary cochlear nuclei in 13 specimens of Pituophis catenifer. All these snake species possess three primary and one secondary cochlear nuclei. The primary cochlear nuclei consist of a small nucleus angularis located at the cerebello-medullary junction and a fairly large nucleus magnocellularis forming a dorsal cap over the cephalic end of the alar eminence. Nucleus magnocellularis may be subdivided into a medially placed group of rounder cells, nucleus magnocellularis medialis, and a laterally placed group of more ovate and paler-staining cells, nucleus magnocellularis lateralis. A small but well-defined secondary nucleus which showed no degenerated nerve terminals after nerve root section, nucleus laminaris, underlies the cephalic part of both nucleus magnocellularis medialis and nucleus magnocellularis lateralis. Larger and better-developed cochlear nuclei were found in burrowing species than in non-burrowing species of snakes. Of the three burrowing species studied, Xenopeltis showed the greatest development of cochlear nuclei; Eryx cochlear nuclei were not quite as large but were better differentiated than in Xenopeltis; and Cylindrophis cochlear nuclei were fairly large but not as well developed nor as well differentiated as in either Xenopeltis or Eryx. The cochlear nuclei of the three non-burrowing snakes, Epicrates, Natrix, and Pituophis, were not as large nor as well developed as those of the burrowing snakes. There is some, but not complete, correlation between cochlear development and papilla basilaris length and number of hair cells. Thus, Xenopeltis and Eryx, with well-developed cochlear nuclei

  4. Birth, life and death of hot nuclei

    International Nuclear Information System (INIS)

    Suraud, E.; Tamain, B.; Gregoire, C.

    1989-01-01

    Intermediate energy heavy-ions (10-100 MeV/u) are the most powerful tool to study hot nuclear matter properties. In this paper we give a review of experimental and theoretical works which support this statement. The first challenge is to achieve hot nuclei formation. The second one is to study their properties. The formation step is governed by the relative influence of nucleon-nucleon collisions and mean field effects. Fundamental quantities such as excited matter decay time, thermalization time, relaxation time for collective modes are of major importance and are compared with typical collision times. It appears that semi-classical theories are able to give a reasonable description of the collision and that they are a good guide for defining further experiments. We show how it has been possible to experimentally establish that very hot equilibrated nuclei are really formed. Their decay properties are not basically different from decay properties at lower bombarding energy. However specific channels are open: in that sense, we take stock of the multifragmentation process. Moreover, compression effects may be an important feature of this energy range. Future studies will involve heavier projectiles around 30-50 MeV/u. They will be the best probe for hot and compressed nuclear matter studies

  5. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph

    1997-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author) 270 refs.

  6. Photon interactions with nuclei

    International Nuclear Information System (INIS)

    Thornton, S.T.; Sealock, R.M.

    1989-01-01

    This document is a progress report for DOE Grant No. FG05-89ER40501, A000. The grant began March, 1989. Our primary research effort has been expended at the LEGS project at Brookhaven National Laboratory. This report will summarize our present research effort at LEGS as well as data analysis and publications from previous experiments performed at SLAC. In addition the principal investigators are heavily involved in the CLAS collaboration in Hall B at CEBAF. We have submitted several letters of intent and proposals and have made commitments to construct experimental equipment for CEBAF. We expect our primary experimental effort to continue at LEGS until CEBAF becomes operational. This report will be divided into separate sections describing our progress at LEGS, SLAC, and CEBAF. We will also discuss our significant efforts in the education and training of both undergraduate and graduate students. Photon detectors are described as well as experiments on delta deformation in nuclei of quasielastic scattering and excitation of the delta by 4 He(e,e')

  7. Supersymmetry in nuclei

    CERN Document Server

    Jolie, J

    2002-01-01

    All the elementary particles that make up matter (as do quarks, electrons, neutrinos....) are fermions, the particles that convey the fundamental interactions (as do photons, gluons, W, Z...) are bosons. Composite particles are either bosons, or fermions according to the number of fermions they contain: if this number is even the particle is a boson, otherwise it is a fermion. According to this rule a proton is a fermion and the He sup 4 atom is a boson. Symmetry plays an important role in the standard model, a symmetry is a transformation that connect bosons with other bosons or fermions with other fermions. Supersymmetry associates a boson with a fermion or a fermion with a boson, in fact supersymmetry connects nuclei that are not generally considered as akin. Supersymmetry has just been observed in low energy levels of Gold sup 1 sup 9 sup 5 sup - sup 1 sup 9 sup 6 and Platinum sup 1 sup 9 sup 4 - sup 1 sup 9 sup 5 , it means that the description of these energy levels is simplified and can be made by a co...

  8. Collective excitations in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    1997-01-01

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author)

  9. Gluon density in nuclei

    International Nuclear Information System (INIS)

    Ayala, A.L.

    1996-01-01

    In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab

  10. Electron scattering for exotic nuclei

    International Nuclear Information System (INIS)

    Suda, T.

    2013-01-01

    An electron scattering facility is under construction in RIKEN RI Beam Factory, Japan, which is dedicated to the structure studies of short-lived nuclei. This is the world's first and currently only facility of its type. The construction is nearly completed, and the first electron scattering experiment off short-lived nuclei will be carried out in the beginning of next year. The charge density distributions of short-lived nuclei will be precisely determined by elastic electron scattering for the first time. Physics pursued at this facility including future perspectives are explained

  11. Monopole transitions in hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Sujkowski, Z. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

    1994-12-31

    Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs.

  12. 3rd International conference on nuclei far from stability, Cargese, Corsica, 19-26 May 1976

    International Nuclear Information System (INIS)

    1976-01-01

    These conference proceedings contain 103 contributions which are grouped under the following headings: Experimental methods and techniques; Perspectives in research on exotic nuclei; Nuclear masses - experiment and theory; Nuclear spins, moments, and radii; Light nuclei; Delayed particle emission and statistical aspects; Excited states of neutron-deficient nuclei; Excited states of fission products and other neutron-rich isotopes; Heavy elements and astrophysical aspects. Also included are the Scientific programme and a List of participants. (AJ)

  13. STELLAR TRANSITS IN ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Béky, Bence; Kocsis, Bence

    2013-01-01

    Supermassive black holes (SMBHs) are typically surrounded by a dense stellar population in galactic nuclei. Stars crossing the line of site in active galactic nuclei (AGNs) produce a characteristic transit light curve, just like extrasolar planets do when they transit their host star. We examine the possibility of finding such AGN transits in deep optical, UV, and X-ray surveys. We calculate transit light curves using the Novikov-Thorne thin accretion disk model, including general relativistic effects. Based on the expected properties of stellar cusps, we find that around 10 6 solar mass SMBHs, transits of red giants are most common for stars on close orbits with transit durations of a few weeks and orbital periods of a few years. We find that detecting AGN transits requires repeated observations of thousands of low-mass AGNs to 1% photometric accuracy in optical, or ∼10% in UV bands or soft X-ray. It may be possible to identify stellar transits in the Pan-STARRS and LSST optical and the eROSITA X-ray surveys. Such observations could be used to constrain black hole mass, spin, inclination, and accretion rate. Transit rates and durations could give valuable information on the circumnuclear stellar clusters as well. Transit light curves could be used to image accretion disks with unprecedented resolution, allowing us to resolve the SMBH silhouette in distant AGNs.

  14. Cluster and alpha decay of superheavy nuclei

    Science.gov (United States)

    Poenaru, D. N.; Stöcker, H.; Gherghescu, R. A.

    2018-02-01

    We investigated cluster radioactivity and alpha decay of some superheavy nuclei with atomic numbers Z = 119, 120 , which may be produced in the future. Two models are used to calculate the half-lives against cluster radioactivity: ASAF (Analytical Super-Asymmetric Fission) and UNIV (Universal Formula). For α decay half-lives we are based on four models: ASAF, UNIV, semFIS (semi-empirical formula based on Fission Theory) and AKRA (first author Akrawy). The Q -values are calculated using the theoretical model of atomic masses WS10, which sometimes is called W4.

  15. Inclusive charge longitudinal response in finite nuclei

    International Nuclear Information System (INIS)

    Alberico, W.M.; Molinari, A.; Czerski, P.; Czerski, P.; Ericson, M.

    1986-03-01

    The experimental dynamic and static longitudinal structure factors of 12 C, 40 Ca and 56 Fe are investigated with a semiclassical RPA theory. The parameters entering into the nuclear mean field (including the nucleon effective mass) and in the isoscalar and isovector particle-hole forces are set by best fitting procedures. Quite reasonable values of these quantities allow a satisfactory account of the experimental data over a wide range of momentum transfers in all the three nuclei. However, to achieve this result, the proton root mean square radius has to be increased over the conventional value of about 13% in 12 C and 22% in 40 Ca and 56 Fe

  16. Experimental level densities of atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Guttormsen, M.; Bello Garrote, F.L.; Eriksen, T.K.; Giacoppo, F.; Goergen, A.; Hagen, T.W.; Klintefjord, M.; Larsen, A.C.; Nyhus, H.T.; Renstroem, T.; Rose, S.J.; Sahin, E.; Siem, S.; Tornyi, T.G.; Tveten, G.M. [University of Oslo, Department of Physics, Oslo (Norway); Aiche, M.; Ducasse, Q.; Jurado, B. [University of Bordeaux, CENBG, CNRS/IN2P3, B.P. 120, Gradignan (France); Bernstein, L.A.; Bleuel, D.L. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Byun, Y.; Voinov, A. [Ohio University, Department of Physics and Astronomy, Athens, Ohio (United States); Gunsing, F. [CEA Saclay, DSM/Irfu/SPhN, Cedex (France); Lebois, L.; Leniau, B.; Wilson, J. [Institut de Physique Nucleaire d' Orsay, Orsay Cedex (France); Wiedeking, M. [iThemba LABS, P.O. Box 722, Somerset West (South Africa)

    2015-12-15

    It is almost 80 years since Hans Bethe described the level density as a non-interacting gas of protons and neutrons. In all these years, experimental data were interpreted within this picture of a fermionic gas. However, the renewed interest of measuring level density using various techniques calls for a revision of this description. In particular, the wealth of nuclear level densities measured with the Oslo method favors the constant-temperature level density over the Fermi-gas picture. From the basis of experimental data, we demonstrate that nuclei exhibit a constant-temperature level density behavior for all mass regions and at least up to the neutron threshold. (orig.)

  17. Cavitation inception from bubble nuclei

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2015-01-01

    The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years....... The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure-time history of the water. A recent model...... and associated experiments throw new light on the effects of transient pressures on the tensile strength of water, which may be notably reduced or increased by such pressure changes....

  18. The delta in nuclei. Experiments

    International Nuclear Information System (INIS)

    Roy-Stephan, M.

    1989-01-01

    Experimental aspects of the Δ excitation will be presented. The Δ excitation in nuclei will be compared to the free Δ excitation. Various probes will be reviewed and their specific features will be underlined [fr

  19. Intermediate Energy Activation File (IEAF-99)

    International Nuclear Information System (INIS)

    Korovin, Yu.; Konobeev, A.; Pereslavtsev, P.; Stankovskij, A.; Fischer, U.; Moellendorff, U. von

    1999-01-01

    Nuclear data library IEAF-99, elaborated to study processes of interactions of intermediate energy neutrons with materials in accelerator driven systems, is described. The library is intended for activation and transmutation studies for materials irradiated by neutrons. IEAF-99 contains evaluated neutron induced reaction cross sections at the energies 0-150 MeV for 665 stable and unstable nuclei from C to Po. Approximately 50,000 excitation functions are included in the library. The IEAF-99 data are written in the ENDF-6 format combining MF = 3,6 MT = 5 data recording. (author)

  20. Identification of near-drip line Pm nuclei

    Science.gov (United States)

    Padilla, E.; Galindo-Uribarri, A.; Gross, C. J.; Batchelder, J. C.; Baktash, C.; Radford, D. C.; Yu, C.-H.; Fuentes, B.; Hartley, D. J.; Riedinger, L.; Zeidan, O.

    2001-04-01

    Motivated by the recent identification of ^126Pr (D.J. Hartley et al., submitted to Phys. Rev. C. (Rap. Comm.)), the combination of the CLARION Ge array, the HyBall charged-particle array, and the RMS at the HRIBF facility has been used to extend our study of nuclei near the proton drip line towards heavier masses. The reaction ^40Ca + ^96Ru at a beam energy of 193 MeV was used to populate excited states in neutron-deficient Pm and Sm nuclei. Positive identification of the nuclei ^132Sm and ^132Pm, has been accomplished and a search for the first observation of ^130Pm is ongoing. Results will be discussed in the framework of systematic behavior in the mass 130 region.

  1. Proton elastic scattering from stable and unstable nuclei - Extraction of nuclear densities

    Science.gov (United States)

    Sakaguchi, H.; Zenihiro, J.

    2017-11-01

    Progress in proton elastic scattering at intermediate energies to determine nuclear density distributions is reviewed. After challenges of about 15 years to explain proton elastic scattering and associated polarization phenomena at intermediate energies, we have reached to some conclusions regarding proton elastic scattering as a means of obtaining nuclear densities. During this same period, physics of unstable nuclei has become of interest, and the density distributions of protons and neutrons play more important roles in unstable nuclei, since the differences in proton and neutron numbers and densities are expected to be significant. As such, proton elastic scattering experiments at intermediate energies using the inverse kinematic method have started to determine density distributions of unstable nuclei. In the region of unstable nuclei, we are confronted with a new problem when attempting to find proton and neutron densities separately from elastic proton scattering data, since electron scattering data for unstable nuclei are not presently available. We introduce a new means of determining proton and neutron densities separately by double-energy proton elastic scattering at intermediate energies.

  2. New possible properties of atomic nuclei investigated by non linear methods: Fractal and recurrence quantification analysis

    OpenAIRE

    Conte, Elio; Khrennikov, Andrei Yu.; Zbilut, Joseph P.

    2007-01-01

    For the first time we apply the methodologies of nonlinear analysis to investigate atomic matter. We use these methods in the analysis of Atomic Weights and of Mass Number of atomic nuclei. Using the AutoCorrelation Function and Mutual Information we establish the presence of nonlinear effects in the mechanism of increasing mass of atomic nuclei considered as a function of the atomic number. We find that increasing mass is divergent, possibly chaotic. We also investigate the possible existenc...

  3. Nuclei Isolation from Nematode Ascaris

    Science.gov (United States)

    Kang, Yuanyuan; Wang, Jianbin; Davis, Richard E.

    2017-01-01

    Preparing nuclei is necessary in a variety of experimental paradigms to study nuclear processes. In this protocol, we describe a method for rapid preparation of large number of relatively pure nuclei from Ascaris embryos or tissues that are ready to be used for further experiments such as chromatin isolation and ChIP-seq, nuclear RNA analyses, or preparation of nuclear extracts (Kang et al., 2016; Wang et al., 2016). PMID:29082294

  4. The magnetic strip(s) in the advanced phases of stellar evolution. Theoretical convective turnover timescale and Rossby number for low- and intermediate-mass stars up to the AGB at various metallicities

    Science.gov (United States)

    Charbonnel, C.; Decressin, T.; Lagarde, N.; Gallet, F.; Palacios, A.; Aurière, M.; Konstantinova-Antova, R.; Mathis, S.; Anderson, R. I.; Dintrans, B.

    2017-09-01

    Context. Recent spectropolarimetric observations of otherwise ordinary (in terms e.g. of surface rotation and chemical properties) G, K, and M giants have revealed localized magnetic strips in the Hertzsprung-Russell diagram coincident with the regions where the first dredge-up and core helium burning occur. Aims: We seek to understand the origin of magnetic fields in such late-type giant stars, which is currently unexplained. In analogy with late-type dwarf stars, we focus primarily on parameters known to influence the generation of magnetic fields in the outer convective envelope. Methods: We compute the classical dynamo parameters along the evolutionary tracks of low- and intermediate-mass stars at various metallicities using stellar models that have been extensively tested by spectroscopic and asteroseismic observations. Specifically, these include convective turnover timescales and convective Rossby numbers, computed from the pre-main sequence (PMS) to the tip of the red giant branch (RGB) or the early asymptotic giant branch (AGB) phase. To investigate the effects of the very extended outer convective envelope, we compute these parameters both for the entire convective envelope and locally, that is, at different depths within the envelope. We also compute the turnover timescales and corresponding Rossby numbers for the convective cores of intermediate-mass stars on the main sequence. Results: Our models show that the Rossby number of the convective envelope becomes lower than unity in the well-delimited locations of the Hertzsprung-Russell diagram where magnetic fields have indeed been detected. Conclusions: We show that α - Ω dynamo processes might not be continuously operating, but that they are favored in the stellar convective envelope at two specific moments along the evolution tracks, that is, during the first dredge-up at the base of the RGB and during central helium burning in the helium-burning phase and early-AGB. This general behavior can explain

  5. Rotation and magnetism in intermediate mass stars

    Science.gov (United States)

    Quentin, Léo G.; Tout, Christopher A.

    2018-03-01

    Rotation and magnetism are increasingly recognized as important phenomena in stellar evolution. Surface magnetic fields from a few to 20, 000 G have been observed and models have suggested that magnetohydrodynamic transport of angular momentum and chemical composition could explain the peculiar composition of some stars. Stellar remnants such as white dwarfs have been observed with fields from a few to more than 109 G. We investigate the origin of and the evolution, on thermal and nuclear rather than dynamical time-scales, of an averaged large-scale magnetic field throughout a star's life and its coupling to stellar rotation. Large-scale magnetic fields sustained until late stages of stellar evolution with conservation of magnetic flux could explain the very high fields observed in white dwarfs. We include these effects in the Cambridge stellar evolution code using three time-dependant advection-diffusion equations coupled to the structural and composition equations of stars to model the evolution of angular momentum and the two components of the magnetic field. We present the evolution in various cases for a 3 M_{⊙} star from the beginning to the late stages of its life. Our particular model assumes that turbulent motions, including convection, favour small-scale field at the expense of large-scale field. As a result the large-scale field concentrates in radiative zones of the star and so is exchanged between the core and the envelope of the star as it evolves. The field is sustained until the end of the asymptotic giant branch, when it concentrates in the degenerate core.

  6. Beta decay rates of nuclei with 65

    Indian Academy of Sciences (India)

    The half-lives are calculated for the β− decay process for nuclei in the mass range ∼65–75 relevant for the ... method, termed as moment method, is a convenient way for rapid construction of. NIP strength densities. ... decay processes at finite temperature relevant for pre-supernova environment are calculated for the nuclei ...

  7. Present and Future Experiments with Stored Exotic Nuclei at GSI

    International Nuclear Information System (INIS)

    Geissel, H.

    2009-01-01

    Recent results and perspectives of experiments with stored exotic nuclei at GSI-FAIR will presented. An overview on the planned NUSTAR experiments will also presented. Relativistic exotic nuclei produced via projectile fragmentation and fission were separated in flight by the fragment separator FRS and injected into the storage-cooler ring ESR for accurate mass- and lifetime measurements. Direct mass measurements of electron-cooled exotic nuclei were performed using time-resolved Schottky spectrometry. Fragments with half-lives shorter than the time required for electron cooling have been investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique gives access to all nuclei with half-lives down to the microsecond range and has been successfully applied. Lifetimes of stored bare and few-electron ions have been measured with the goal to study the beta-decay under ionization conditions prevailing in stellar plasma. For the first time the direct observation of bound-state beta decay has been achieved with 2 07T l fragments. The future project FAIR includes a new large-acceptance in-flight separator (Super-FRS) in combination with a new storage ring system (CR, NESR) which will be ideal tools to study exotic nuclei far from stability.(author)

  8. On the Formation Mechanism of the Atomcule of Light Nuclei

    CERN Document Server

    Dineykhan, M D; Sakhyev, S K

    2002-01-01

    In the framework of the oscillator representation method the interaction potential between the antiproton and the nucleus is analytically derived. This potential is antisymmetrical with respect to the charge and masses of the constituent particles. It is shown that the antisymmetry of the potential determines the stability of the atomcule of light nuclei.

  9. Studies of nuclei using radioactive beams

    International Nuclear Information System (INIS)

    Piercey, R.B.

    1989-07-01

    The 12 month period from May 1988 to July 1989 represents the first full year of our 18 month pilot program in nuclear structure research. In this period, research was initiated to develop a capability for radioactive secondary beams at Argonne National Laboratory using the Atlas and the new Fragment Mass Analyzer (FMA), which is currently under construction. Two major new detector facilities are currently in the final stages of design and testing. The Large-Area, Scintillator Telescope (LAST) detector is fully operational and will be shipped to Argonne National Laboratory in August for fit-tests and in-beam calibrations. The first segments of a new sixteen-segment neutron multiplicity detector have been built and tested. The remaining segments are currently being constructed. Research was continued in the areas of (1) Coulomb excitation studies of rare earth and actinide nuclei; (2) In-beam, gamma-ray spectroscopy of nuclei in the mass 100 region, and (3) Advanced detector design. Several journal articles and abstracts were published or submitted for publication in the reporting period, and others are currently in preparation. Three graduate students participated in the program, one from the University of Florida and two from the Royal Institute of Technology, Stockholm, Sweden

  10. Intermediate processes in nuclear reactions

    International Nuclear Information System (INIS)

    Petrovici, M.

    1983-01-01

    The main results presented here cannot be interpreted in terms of the direct reaction model or the statistical models and one can more or less explicitely use some nuclear configurations for their interpretation. The first chapter deals with the so-called second order intermediate structures observed in the elastic and inelastic proton scattering on 66 Zn and 70 Ge targets in the energetic regions of some isobaric analog resonances. A formal theory for their interpretation is developed and the comparison with the experimental data is presented. New experimental results on the resonant structures observed in the elastic and inelastic scattering of 12 C on 24 Mg are presented in the second chapter. Detailed statistical analysis and their interpretation is presented too. Charge equilibration in deep inelastic collisions is the main subject of the third chapter. The experimental results obtained by the 98 Mo + 154 Sm collision at 12 MeV/n, a quantum treatment of a damped harmonic oscillator and the comparison with the experimental data are given. In the last chapter, some results on the existence of two other processes which could candidate to be involved in the main topic are presented. Those processes are: the fast fragmentation and preequilibrium charged particles emission. All these processes originate in the excitation of some simple configurations which can be seen on ''doorway'' states (''Hallway'' in the case of the second intermediate structures). The coupling of these states to other more complicated excitation modes of the nuclei and to outgoing channel=gives the possibility to study the nuclear dynamics. This justifies the interest for their detailed theoretical and experimental investigations. (author)

  11. Intrinsic excitations in deformed nuclei: characteristic predictions of the IBA

    International Nuclear Information System (INIS)

    Casten, R.F.

    1982-01-01

    Deformed nuclei represent perhaps the largest and best studied class of nuclear level schemes. The Interacting Boson Approximation (IBA) model is devised so as to provide a general framework for the description of low lying collective states in nuclei spanning vibrational, rotational (i.e., deformed) and axially asymmetric types as well as the transitional species intermediate between these limiting cases. The juxtaposition of these two statements makes it all the more surprising that until recently there had been no thorough test of the model in such nuclei. Partly, the explanation for this lies in the type of data required for an adequate test. Since the IBA predicts a broad range of collective states it requires a correspondingly thorough empirical test. Moreover, in deformed nuclei, though the characteristic predictions that distinguish the IBA from the traditional, familiar collective model of harmonic β and γ vibrations are important, their clearest manifestation occurs in very weak, hard-to-detect low energy transitions between excited vibrational bands (in particular between β and γ bands), that had not heretofore been systematically observed. The present brief summary will begin with a review of the properties of the (n,γ) reaction that render it a useful empirical tool for such studies, and follow this with a description of the results of the 168 Er study and the application of the IBA model to the resultant level scheme. The discussion will then be generalized to other deformed nuclei and to the inherent systematic predictions that must characterize the IBA for such nuclei. Many of these ideas will be related to the role of finite boson number in the IBA

  12. From heavy nuclei to super-heavy nuclei

    International Nuclear Information System (INIS)

    Theisen, Ch.

    2003-01-01

    The existence of super-heavy nuclei has been predicted nearly fifty years ago. Due to the strong coulomb repulsion, the stabilisation of these nuclei is possible only through shell effects. The reasons for this fragile stability, as well as the theoretical predictions concerning the position of the island of stability are presented in the first part of this lecture. In the second part, experiments and experimental techniques which have been used to synthesize or search for super-heavy elements are described. Spectroscopic studies performed in very heavy elements are presented in the following section. We close this lecture with techniques that are currently being developed in order to reach the superheavy island and to study the structure of very-heavy nuclei. (author)

  13. Studies of heavy-ion reactions and transuranic nuclei. Progress report, September 1, 1992--August 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, W.U.

    1993-08-01

    This report contain papers on the following topics: The Cold-Fusion Saga; Decay Patterns of Dysprosium Nuclei Produced in {sup 32}S + {sup 118,124}Sn Fusion Reactions; Unexpected Features of Reactions Between Very Heavy Ions at Intermediate Bombarding Energies; Correlations Between Neutrons and Charged Products from the Dissipative Reaction {sup 197}Au+{sup 208}Pb at E/A = 29 MeV; Dissipative Dynamics of Projectile-Like Fragment Production in the Reaction {sup 209}Bi+{sup 136}Xe at E/A = 28.2 MeV; Dynamical Production of Intermediate-Mass Fragments in Peripheral {sup 209}Bi+{sup 136}Xe Collisions at E{sub lab}/A = 28.2 MeV; The Rochester 960-Liter Neutron Multiplicity Meter; A Simple Pulse Processing Concept for a Low-Cost Pulse-Shape-Based Particle Identification; A One-Transistor Preamplifier for PMT Anode Signals; A Five-Channel Multistop TDC/Event Handler for the SuperBall Neutron Multiplicity Meter; Construction of the SuperBall -- a 16,000-Liter Neutron Detector for Calorimetric Studies of Intermediate-Energy Heavy-Ion Reactions; A Computer Code for Light Detection Efficiency Calculations for Photo-multipliers of a Neutron Detector; Evaluation of Gd-Loaded Liquid Scintillators for the SuperBall Neutron Calorimeter; and Measurement of the Interaction of Cosmic-Ray {mu}{sup {minus}} with a Muon Telescope.

  14. Experiments in intermediate energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Dehnhard, D.

    2003-02-28

    Research in experimental nuclear physics was done from 1979 to 2002 primarily at intermediate energy facilities that provide pion, proton, and kaon beams. Particularly successful has been the work at the Los Alamos Meson Physics Facility (LAMPF) on unraveling the neutron and proton contributions to nuclear ground state and transition densities. This work was done on a wide variety of nuclei and with great detail on the carbon, oxygen, and helium isotopes. Some of the investigations involved the use of polarized targets which allowed the extraction of information on the spin-dependent part of the triangle-nucleon interaction. At the Indiana University Cyclotron Facility (IUCF) we studied proton-induced charge exchange reactions with results of importance to astrophysics and the nuclear few-body problem. During the first few years, the analysis of heavy-ion nucleus scattering data that had been taken prior to 1979 was completed. During the last few years we created hypernuclei by use of a kaon beam at Brookhaven National Laboratory (BNL) and an electron beam at Jefferson Laboratory (JLab). The data taken at BNL for a study of the non-mesonic weak decay of the A particle in a nucleus are still under analysis by our collaborators. The work at JLab resulted in the best resolution hypernuclear spectra measured thus far with magnetic spectrometers.

  15. Pairing field and moments of inertia of superdeformed nuclei

    CERN Document Server

    Chen Yong; Xu Fu Xin

    2002-01-01

    The authors have systematically analysed the dynamic moments of inertia of the experimental superdeformed (SD) bands observed in the A = 190, 150 and 60-80 mass regions as functions of rotational frequency. By combining the different mass regions, the dramatic features of the dynamic moments of inertia were found and explained based on the calculations of the pairing fields of SD nuclei with the anisotropic harmonic oscillator quadrupole pairing Hartree-Fock-Bogoliubov model

  16. Increased ionization supports growth of aerosols into cloud condensation nuclei

    DEFF Research Database (Denmark)

    Svensmark, H.; Enghoff, M. B.; Shaviv, N. J.

    2017-01-01

    Ions produced by cosmic rays have been thought to influence aerosols and clouds. In this study, the effect of ionization on the growth of aerosols into cloud condensation nuclei is investigated theoretically and experimentally. We show that the mass-flux of small ions can constitute an important...... and find good agreement with theory. Ion-induced condensation should be of importance not just in Earth’s present day atmosphere for the growth of aerosols into cloud condensation nuclei under pristine marine conditions, but also under elevated atmospheric ionization caused by increased supernova activity....

  17. General Relativistic Mean Field Theory for rotating nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Madokoro, Hideki [Kyushu Univ., Fukuoka (Japan). Dept. of Physics; Matsuzaki, Masayuki

    1998-03-01

    The {sigma}-{omega} model Lagrangian is generalized to an accelerated frame by using the technique of general relativity which is known as tetrad formalism. We apply this model to the description of rotating nuclei within the mean field approximation, which we call General Relativistic Mean Field Theory (GRMFT) for rotating nuclei. The resulting equations of motion coincide with those of Munich group whose formulation was not based on the general relativistic transformation property of the spinor fields. Some numerical results are shown for the yrast states of the Mg isotopes and the superdeformed rotational bands in the A {approx} 60 mass region. (author)

  18. A quasi-particle model for computational nuclei

    International Nuclear Information System (INIS)

    Boal, D.H.; Glosli, J.N.

    1988-03-01

    A model Hamiltonian is derived which provides a computationally efficient means of representing nuclei. The Hamiltonian includes both coulomb and isospin dependent terms, and incorporates antisymmetrization effects through a momentum dependent potential. Unlike many other classical or semiclassical models, the nuclei of this simulation have a well-defined ground state with a a non-vanishing 2 >. It is shown that the binding energies per nucleon and r.m.s. radii of these ground states are close to the measured values over a wide mass range

  19. Study on decay of rare earth nuclei produced by fission

    Energy Technology Data Exchange (ETDEWEB)

    Kawade, Kiyoshi; Yamamoto, Hiroshi; Shibata, Michihiro; Asai, Masato [Nagoya Univ. (Japan); Tsukada, Kazuaki; Osa, Akihiko; Shinohara, Nobuo; Iimura, Hideki

    1996-01-01

    JAERI-ISOL utilizes charge particle induced fission by proton and heavy proton produced by the tandem type accelerator (JAERI). To study the decay mechanism and nuclei structure of neutron and excess nuclei produced by actinoid fission, JAERI-ISOL was improved by developing the multilayer target tank. So that, the intensity of mass separated ion beam increased enough to use. New 76.6 KeV {gamma}-ray with about 10s of half life was found in the preliminary experiment. (S.Y.)

  20. Heavy ions as probes of nuclei far from stability

    International Nuclear Information System (INIS)

    Moltz, D.M.; Nitschke, J.M.; Wilmarth, P.A.; Toth, K.S.

    1989-01-01

    Nuclei located far from stability provide us with an opportunity for studying nuclear matter existing under unusual conditions. In these regions of instability, radioactive decay becomes the predominant technique by which one can obtain structure information. We have been involved in the investigation of nuclear properties of nuclei close to the proton drip line. In our explorations we have utilized heavy-ion fusion, followed by particle evaporation, to produce the extremely neutron-deficient nuclei of interest. In our studies, single-particle states near the 82-neutron shell, populated in the β decay of short-lived nuclides, have been examined and their excitation energies determined. Numerous new isotopes, isomers, and β-delayed-proton and α-particle emitters have been discovered. This contribution will discuss our particle-decay investigations. These decay modes provide us with a convenient means of discovering new isotopes whose identification opens the way for further, more extensive explorations. Also, particle-decay energies in many instances can be used to determine mass differences between parent and daughter ground states. Such measurements are therefore used to test mass formulae and to obtain estimates of masses for proton rich nuclei. 19 refs., 13 figs

  1. Spinodal decomposition of atomic nuclei

    International Nuclear Information System (INIS)

    Chomaz, P.; Colonna, M.; Guarnera, A.

    1996-01-01

    Multifragmentation of atomic nuclei is discussed. It is shown that this description of the dynamics of first order phase transitions in infinite and finite system is now partially achieved. An important conclusion is that in some specific cases well-defined collective motions were initiating the self-organisation of the unstable matter in fragments. In the case of finite systems the possible signals kept from this early fragmentation stage can inform on the possible occurrence of a liquid-gas phase transition in nuclei. (K.A.)

  2. [Intermediate/high energy nuclear physics

    International Nuclear Information System (INIS)

    1989-01-01

    We have continued to develop a theoretical framework for the quark and gluon structure of nuclei. Our approach features a successful phenomenological model, the quark cluster model (QCM), and an ambitious program in the non-perturbative solution of quantum field theories. The effort in quantum field theory provides theoretical results to test or replace assumed ingredients of the QCM. By the explicit example of a scalar field theory in 2D we have solved the long-standing problem of how to treat the dynamics of the vacuum in light-front quantization. We now propose to solve the same problem for simple Fermion field theories in 2D such as the Gross-Neveu model. We propose in subsequent years to address QCD in low dimensionality with the purpose of extracting non-perturbative predictions for quark and gluon amplitudes in few baryon systems. Simultaneously with this new effort we will continue to develop extensions and applications of the QCM. We propose to continue predicting phenomena to be observed in high energy particle-nucleus collisions that reflect the rearrangement of quarks and gluons in nuclei. We have completed our analysis of the SLAC E101 and E133 experiments on Deuterium to elucidate the degree to which a six-quark cluster contribution is admissable in the Bjorken x > 1 data. We have completed our development of a parameterized thermal liquid drop model for light nuclei. In addition we have completed a set of predictions for the formation of a ''nuclear stratosphere'' in nuclei created by intermediate energy heavy ion interactions. These results motivate a new investigation of the temperature dependence of the ion-ion potential with particular emphasis on the thermal dependence of the barrier height and radius. We have also shown that a consistent treatment of relativistic effects is important for a theoretical description of the elastic magnetic form factor of 17 O. 85 refs

  3. Neutron skin studies of medium and heavy nuclei

    Directory of Open Access Journals (Sweden)

    Thiel M.

    2014-06-01

    Full Text Available The recent PREX experiment at JLab has demonstrated the sensitivity of parity violating electron scattering to the neutron density, meanwhile outlining its major experimental challenges. On the other side, intermediate energy photons are an ideal probe for studying the properties of strongly interacting matter from the nuclear scale down to the sub-nuclear components of the nucleus. Among others coherent pion photoproduction can provide information on the existence and nature of neutron skins in nuclei. The simultaneous combination of different techniques allows a systematic determination across the periodic table thus benchmarking modern calculation. Recently a systematic investigation of the latter method has been exploited at MAMI (Mainz. At MESA the same setup as in the measurement of the weak mixing angle can be used to determine the parity-violating asymmetry for polarized electrons scattered on heavy nuclei with a 1% resolution. Status and prospects of the projects are presented.

  4. Detection system with a large angular acceptance and an energy high dynamics, for heavy ion physics at intermediate energies: M.E.ω. detector

    International Nuclear Information System (INIS)

    Monnet, F.

    1985-01-01

    Built for intermediate energy heavy ions nuclear physics, the M.E.ω. detector uses various and complementary detection methods: ionization chamber, parallel plate avalanche counter, plastic scintillators. With these techniques, velocity, energy, mass and charge of nuclei were measured over wide range. From the detailed theoretical study of each method, limitations and perturbation causes are deduced. The solutions used for optimizing the detector, and the main results are exposed. The internal sectorisation of the detector, which permits a modulation in counting rate and electronical adjustments, has been revealed to be very suitable for heavy ions intermediate energy physics. Results of the first experiment realised with M.E.ω. (Ar + Ag at 35 MeV/u) are commented [fr

  5. Close collisions between light nuclei-orbiting and fusion

    International Nuclear Information System (INIS)

    Shapira, D.; Shivakumar, B.; Harmon, B.A.; Ayik, S.

    1987-01-01

    According to the authors, studies of close collisions in which nuclear matter, energy and angular momentum undergo substantial rearrangement should enhance understanding of the nuclear many-body system and of the behavior of bulk nuclear matter. The results and models based on studies of such processes between heavy nuclei bear this out. The lighter nuclei, on which this study focuses, are unique in several respects: their binding energy per nucleon increases with mass number - therefore the amalgamation of two such nuclei produces a composite at high excitation energies even for relatively low bombarding energies, and their fission into two complex fragments is also severely restricted. In these light systems the Coulomb and centrifugal barriers attain comparable magnitude and both barriers can influence the outcome of the collision. The study of collisions between light nuclei affords the possibility of full identification of all the detected reaction products, with a modest effort. The authors present their data which demonstrates that in collisions the two nuclei first form a rotating dinuclear complex (DNC) which can breakup into two complex fragments (orbiting) or evolve into a compound nucleus

  6. Intermediate algebra a textworkbook

    CERN Document Server

    McKeague, Charles P

    1985-01-01

    Intermediate Algebra: A Text/Workbook, Second Edition focuses on the principles, operations, and approaches involved in intermediate algebra. The publication first takes a look at basic properties and definitions, first-degree equations and inequalities, and exponents and polynomials. Discussions focus on properties of exponents, polynomials, sums, and differences, multiplication of polynomials, inequalities involving absolute value, word problems, first-degree inequalities, real numbers, opposites, reciprocals, and absolute value, and addition and subtraction of real numbers. The text then ex

  7. Intermediate algebra & analytic geometry

    CERN Document Server

    Gondin, William R

    1967-01-01

    Intermediate Algebra & Analytic Geometry Made Simple focuses on the principles, processes, calculations, and methodologies involved in intermediate algebra and analytic geometry. The publication first offers information on linear equations in two unknowns and variables, functions, and graphs. Discussions focus on graphic interpretations, explicit and implicit functions, first quadrant graphs, variables and functions, determinate and indeterminate systems, independent and dependent equations, and defective and redundant systems. The text then examines quadratic equations in one variable, system

  8. Beta decay rates for nuclei with 115

    Indian Academy of Sciences (India)

    ∗E-mail: chakra@csupomona.edu. MS received 13 November 2005; revised 11 January 2006; accepted 15 March 2006. Abstract. For r-process nucleosynthesis the β-decay rates for a number of neutron-rich intermediate heavy nuclei are calculated. The model for the β-strength function is able to reproduce the observed ...

  9. Electron scattering for exotic nuclei

    Indian Academy of Sciences (India)

    2014-11-04

    Nov 4, 2014 ... A brand-new electron scattering facility, the SCRIT Electron Scattering Facility, will soon start its operation at RIKEN RI Beam Factory, Japan. This is the world's first electron scattering facility dedicated to the structure studies of short-lived nuclei. The goal of this facility is to determine the charge density ...

  10. Cavitation Nuclei: Experiments and Theory

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2009-01-01

    us a chance to reflect on the character of the unknown parameters. In this way non-concordant experimental results may hold the key to the development of better theories - and to new experiments for the testing of their validity. Cavitation and cavitation nuclei are phenomena of that character....

  11. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    Abstract. The charged current pion production induced by neutrinos in 12C, 16O and 56Fe nuclei has been studied. The calculations have been done for the coherent as well as the incoherent processes assuming dominance and takes into account the effect of Pauli blocking, Fermi motion and the renormalization of in ...

  12. Percolation and multifragmentation of nuclei

    International Nuclear Information System (INIS)

    Shmakov, S.Yu.; Uzhinskij, V.V.

    1989-01-01

    A method to build the 'cold' nuclei as percolation clusters is suggested. Within the framework of definite assumptions of the character of nucleon-nucleon couplings breaking resulting from the nuclear reactions as description of the multifragmentation process in the hadron-nucleus and nucleus-nucleus reactions at high energies is obtained. 19 refs.; 6 figs

  13. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    2015-08-02

    Aug 2, 2015 ... ... nuclear configurations typical for fission processes. The deformed two-centre shell model is used to obtain single-particle energy levels for the transition region of two partially overlapped daughter and emitted fragment nuclei. The macroscopic part is obtained using the Yukawa-plus-exponential potential.

  14. Proton scattering from unstable nuclei

    Indian Academy of Sciences (India)

    Abstract. Recent improvements in the intensities and optical qualities of radioactive beams have made possible the study of elastic and inelastic proton scattering on unstable nuclei. The design and performances of an innovative silicon strip detector array devoted to such experiments are described. The quality of the data ...

  15. Nuclear astrophysics of light nuclei

    DEFF Research Database (Denmark)

    Fynbo, Hans Otto Uldall

    2013-01-01

    A review of nuclear astrophysics of light nuclei using radioactive beams or techniques developed for radioactive beams is given. We discuss Big Bang nucleosynthesis, with special focus on the lithium problem, aspects of neutrino-physics, helium-burning and finally selected examples of studies...

  16. Unintegrated parton distributions in nuclei

    Science.gov (United States)

    de Oliveira, E. G.; Martin, A. D.; Navarra, F. S.; Ryskin, M. G.

    2013-09-01

    We study how unintegrated parton distributions in nuclei can be calculated from the corresponding integrated partons using the EPS09 parametrization. The role of nuclear effects is presented in terms of the ratio R A = uPDF A / A·PDF N for both large and small x domains.

  17. Disappearance of Collective Motion in Hot Nuclei

    Science.gov (United States)

    Santonocito, D.; Blumenfeld, Y.; Agodi, C.; Alba, R.; Bellia, G.; Coniglione, R.; Delaunay, F.; Del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Hongmei, F.; Lima, V.; Maiolino, C.; Migneco, E.; Piattelli, P.; Sapienza, P.; Scarpaci, J. A.

    2005-12-01

    The evolution of the GDR γ yield as a function of excitation energy has been investigated in nuclei of mass A ≈ 126 - 136 through the reactions 116Sn + 12C at 17 and 23A MeV and the reaction 116Sn + 24Mg at 17A MeV. Hot nuclei produced in incomplete fusion reactions span an excitation energy range between 160 and 290 MeV. Gamma-rays were detected with MEDEA array in coincidence with residues detected in MACISTE. The evolution of the GDR parameters has been investigated as a function of the linear momentum transferred to the fused system. The analysis of the γ spectra and their comparison with CASCADE calculations is presented. A comparison with the gamma spectra measured in the reaction 36Ar + 98Mo at 37A MeV at higher excitation energy is presented. A progressive reduction of γ multiplicity with respect to predictions for 100% of the Energy Weighted Sum Rule is observed above 200 MeV excitation energy.

  18. A quark structure of hadrons and nuclei

    International Nuclear Information System (INIS)

    Chakrabarty, S.; Deoghuria, S.

    1992-08-01

    In this review we look into the recent understanding of mesons, baryons and nuclei as few quark bound states within the framework of quantum chromodynamics (QCD). In particular, we have reviewed our understanding of the nature of confining interaction, the spin - dependence of colour forces and the role of non-perturbative effects in the study of quark forces in the potential model approach. We also give a comparative study of results obtained by several potential models with reference to the experimental data. We find that although the Lorentz nature of confinement and the nature of spin-dependent colour forces have been better understood now, only a partial understanding of these problems are obtained so far. Our study reveals that properties of baryons could be explained by the same potential model which successfully describe the mesons. However, the nuclei require chiral symmetry and non-perturbative methods for their description. We also discuss the relation between constituent, current and dynamical quark masses. We conclude that QCD motivated approaches have shown much success in explaining many results on hadronic and nuclear data. (author). 212 refs, 14 tabs

  19. A brief review of intruder rotational bands and magnetic rotation in the A = 110 mass region

    Science.gov (United States)

    Banerjee, P.

    2018-05-01

    Nuclei in the A ∼ 110 mass region exhibit interesting structural features. One of these relates to the process by which specific configurations, built on the excitation of one or more protons across the Z = 50 shell-gap, manifest as collective rotational bands at intermediate spins and gradually lose their collectivity with increase in spin and terminate in a non-collective state at the maximum spin which the configuration can support. These bands are called terminating bands that co-exist with spherical states. Some of these bands are said to terminate smoothly underlining the continuous character of the process by which the band evolves from significant collectivity at low spin to a pure particle-hole non-collective state at the highest spin. The neutron-deficient A ∼ 110 mass region provides the best examples of smoothly terminating bands. The present experimental and theoretical status of such bands in several nuclei with 48 ≤ Z ≤ 52 spanning the 106 ≤ A ≤ 119 mass region have been reviewed in this article. The other noteworthy feature of nuclei in the A ∼ 110 mass region is the observation of regular rotation-like sequences of strongly enhanced magnetic dipole transitions in near-spherical nuclei. These bands, unlike the well-studied rotational sequences in deformed nuclei, arise from a spontaneous symmetry breaking by the anisotropic currents of a few high-j excited particles and holes. This mode of excitation is called magnetic rotation and was first reported in the Pb region. Evidence in favor of the existence of such structures, also called shears bands, are reported in the literature for a large number of Cd, In, Sn and Sb isotope with A ∼ 110. The present article provides a general overview of these reported structures across this mass region. The review also discusses antimagnetic rotation bands and a few cases of octupole correlations in the A = 110 mass region.

  20. Alpha-like resonances in nuclei

    Science.gov (United States)

    Baran, V. V.; Delion, D. S.

    2018-03-01

    We investigate normal dipole oscillations in a system of protons, neutrons and α-particles within the Brink approach. We introduce an effective mass of α-clusters in terms of the spectroscopic factor. The Pauli exclusion principle is taken into account by using the Wildermuth rule. The ratio between alpha and giant resonance energy weighted sum rule (EWSR) is investigated for N = Z and N> Z systems. In both cases we notice an unexpected decrease of this ratio versus the increase of the spectroscopic factor. Due to this fact the possibility to experimentally detect α-like oscillations is enhanced in nuclei above 100Sn. The occurrence of the pygmy mode in N> Z systems decreases the EWSR for the α-like oscillations.

  1. Nuclear structure at intermediate energies

    International Nuclear Information System (INIS)

    Bonner, B.E.; Mutchler, G.S.

    1991-01-01

    The theme that unites the sometimes seemingly disparate experiments undertaken by the Bonner Lab Medium Energy Group is a determination to understand in detail the many facets and manifestations of the strong interaction, that which is now referred to as nonperturbative QCD. Whether we are investigating the question of just what does carry the spin of baryons, or the extent of the validity of the SU(6) wavefunctions for the excited hyperons (as will be measured in their radiative decays in our CEBAF experiment), or questions associated with the formation of a new state of matter predicted by QCD (the subject of our BNL experiments E810, E854, as well as our approved experiment at RHIC), -- all these projects share this common goal. Our other experiments represent different approaches to the same broad undertaking. LAMPF E1097 will provide definitive answers to the question of the spin dependence of the inelastic channel of pion production in the n-p interaction. FNAL E683 may well open a new field of investigation in nuclear physics: that of just how quarks and gluons interact with nuclear matter as they transverse nuclei of different sizes. In most all of the experiments mentioned above, the Bonner Lab Group is playing major leadership roles as well as doing a big fraction of the hard work that such experiments require. We use many of the facilities that are unavailable to the intermediate energy physics community and we use our expertise to design and fabricate the detectors and instrumentation that are required to perform the measurements which we decide to do

  2. Nuclear structure at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Bonner, B.E.; Mutchler, G.S.

    1991-09-30

    The theme that unites the sometimes seemingly disparate experiments undertaken by the Bonner Lab Medium Energy Group is a determination to understand in detail the many facets and manifestations of the strong interaction, that which is now referred to as nonperturbative QCD. Whether we are investigating the question of just what does carry the spin of baryons, or the extent of the validity of the SU(6) wavefunctions for the excited hyperons (as will be measured in their radiative decays in our CEBAF experiment), or questions associated with the formation of a new state of matter predicted by QCD (the subject of our BNL experiments E810, E854, as well as our approved experiment at RHIC), -- all these projects share this common goal. Our other experiments represent different approaches to the same broad undertaking. LAMPF E1097 will provide definitive answers to the question of the spin dependence of the inelastic channel of pion production in the n-p interaction. FNAL E683 may well open a new field of investigation in nuclear physics: that of just how quarks and gluons interact with nuclear matter as they transverse nuclei of different sizes. In most all of the experiments mentioned above, the Bonner Lab Group is playing major leadership roles as well as doing a big fraction of the hard work that such experiments require. We use many of the facilities that are unavailable to the intermediate energy physics community and we use our expertise to design and fabricate the detectors and instrumentation that are required to perform the measurements which we decide to do.

  3. Cooper pairs in atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pittel, S. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, 19716 Delaware (United States); Dussel, G. G. [Departamento de Fisica J.J. Giambiagi, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Dukelsky, J.; Sarriguren, P. [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)

    2008-12-15

    We describe recent efforts to study Cooper pairs in atomic nuclei. We consider a self-consistent Hartree Fock mean field for the even Sm isotopes and compare results based on three treatments of pairing correlations: a BCS treatment, a number-projected BCS treatment and an exact treatment using the Richardson Ansatz. Significant differences are seen in the pairing correlation energies. Furthermore, because it does not average over the properties of the fermion pairs, the Richardson solution permits a more meaningful definition of the Cooper wave function and of the fraction of pairs that are collective. Our results confirm that only a few pairs near the Fermi surface in realistic atomic nuclei are collective. (Author)

  4. Relativistic description of deformed nuclei

    International Nuclear Information System (INIS)

    Price, C.E.

    1988-01-01

    The author has shown that relativistic Hartree calculations using parameters that have been fit to the properties of nuclear matter can provide a good description of both spherical and axially deformed nuclei. The quantitative agreement with experiment is equivalent to that which was obtained in non-relativistic calculations using Skyrme interactions. The equilibrium deformation is strongly correlated with the size of the spin-orbit splitting, and that parameter sets which give roughly the correct value for this splitting provide the best agreement with the quadrupole moments in the s-d shell. Finally, for closed shell +/- 1 nuclei, it was shown that the self-consistent calculations are able to reproduce the experimental magnetic moments. This was not possible in relativistic calculations which include only the effects of the valence orbital

  5. Multiple phonon excitation in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.; Frascaria, N.

    1994-01-01

    The studies of multiphonon excitations in nuclei are reviewed both from the theoretical and experimental points of view. The presence of giant resonances in nuclei is described in the framework of macroscopic and microscopic models and the relative merits of different probes to excite such states are illustrated. The existence of giant resonances built on excited states is stressed. An exhaustive description of the theoretical estimates of the properties of the multiphonon states is presented. The theory predicts that such multiple collective excitations should closely follow a harmonic pattern. Recent experimental results on the double giant dipole resonance using the (π + π - ) double charge exchange reaction are shown. The status of the search for isoscalar multiphonon excitations by means of the strong nuclear potential produced by heavy ions is presented. Conclusions are drawn and new prospects are discussed. (authors) 293 refs., 67 figs., 8 tabs

  6. Spectroscopy of heavy fissionable nuclei

    Indian Academy of Sciences (India)

    2015-08-05

    Aug 5, 2015 ... A comparison of aligned angular momentum in these nuclei over the range of observed frequencies (up to ¯hω ≈ 0.25 MeV) reveals a possible, small but signifi- cant contribution from j15/2 neutrons in 249Cm, as evidenced from the higher degree of alignment compared to 247Cm over the observed range ...

  7. Density functional theory of nuclei

    International Nuclear Information System (INIS)

    Terasaki, Jun

    2008-01-01

    The density functional theory of nuclei has come to draw attention of scientists in the field of nuclear structure because the theory is expected to provide reliable numerical data in wide range on the nuclear chart. This article is organized to present an overview of the theory to the people engaged in the theory of other fields as well as those people in the nuclear physics experiments. At first, the outline of the density functional theory widely used in the electronic systems (condensed matter, atoms, and molecules) was described starting from the Kohn-Sham equation derived on the variational principle. Then the theory used in the field of nuclear physics was presented. Hartree-Fock and Hartree-Fock-Bogolyubov approximation by using Skyrme interaction was explained. Comparison of the results of calculations and experiments of binding energies and ground state mean square charge radii of some magic number nuclei were shown. The similarity and dissimilarity between the two streams were summarized. Finally the activities of the international project of Universal Nuclear Energy Density Functional (UNEDF) which was started recently lead by US scientist was reported. This project is programmed for five years. One of the applications of the project is the calculation of the neutron capture cross section of nuclei on the r-process, which is absolutely necessary for the nucleosynthesis research. (S. Funahashi)

  8. Thermodynamical description of excited nuclei

    International Nuclear Information System (INIS)

    Bonche, P.

    1989-01-01

    In heavy ion collisions it has been possible to obtain composite systems at rather high excitation energies corresponding to temperatures of several MeV. The theoretical studies of these systems are based on concepts borrowed from thermodynamics or statistical physics, such as the temperature. In these lectures, we present the concepts of statistical physics which are involved in the physics of heavy ion as they are produced nowadays in the laboratory and also during the final stage of a supernova collapse. We do not attempt to describe the reaction mechanisms which yield such nuclear systems nor their decay by evaporation or fragmentation. We shall only study their static properties. The content of these lectures is organized in four main sections. The first one gives the basic features of statistical physics and thermodynamics necessary to understand quantum mechanics at finite temperature. In the second one, we present a study of the liquid-gas phase transition in nuclear physics. A phenomenological approach of the stability of hot nuclei follows. The microscopic point of view is proposed in the third part. Starting from the basic concepts derived in the first part, it provides a description of excited or hot nuclei which confirms the qualitative results of the second part. Furthermore it gives a full description of most properties of these nuclei as a function of temperature. Finally in the last part, a microscopic derivation of the equation of state of nuclear matter is proposed to study the collapse of a supernova core

  9. Atomic Mass and Nuclear Binding Energy for Y-90 (Yttrium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume A `Nuclei with Z = 1 - 54' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Y-90 (Yttrium, atomic number Z = 39, mass number A = 90).

  10. Mobile communication and intermediality

    DEFF Research Database (Denmark)

    Helles, Rasmus

    2013-01-01

    The article argues the importance of intermediality as a concept for research in mobile communication and media. The constant availability of several, partially overlapping channels for communication (texting, calls, email, Facebook, etc.) requires that we adopt an integrated view of the various...

  11. an intermediate moisture meat

    African Journals Online (AJOL)

    Bunmi

    Matured leaves of Ocimum gratissimum were harvested and the extracts used to cure. Suya (an intermediate moisture meat). O. gratissimum leaves were collected from. Oyo state south west region of Nigeria, rinsed in distilled water and squeezed to extract the fluid. The meat used was Semi membranosus muscle from beef ...

  12. Particle-hole intruder levels in {sup 67}Cu, collectivity, monopole shifts, and the hockey-stick behaviour of l - 1/2 5/2{sup -} levels in neutron-rich odd-mass Cu nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Walters, W B; Chiara, C J, E-mail: wwalters@umd.edu [University of Maryland, College Park, MD 20742 (United States)

    2011-01-01

    A new sequence of gamma rays with energies of 572, 499, 585, and 674 keV has been identified in {sup 67}Cu populating the 7/2{sup -} level at 2362 keV. Owing to the strong population of the 2362-keV level via an l = 3 proton pickup reaction, that level is assigned to be an f{sub 7/2}{sup -1} 2-particle-1-hole 'intruder' proton configuration, and the new levels are found to form a sequence consistent with intruder sequences in the adjacent odd-mass Cu isotopes and in the odd-mass Sb isotopes. The changing position of the intruder sequence in the odd-mass Cu isotopes is discussed and related to the onset of collectivity associated with the presence of g{sub 9/2} neutrons beyond N = 40. The increase in collectivity is also discussed for a number of isotonic and isotopic chains as more protons or neutrons, respectively, are added beyond an oscillator shell boundary. For most of these systems, the l -1/2 levels show a systematic 'hockey-stick-like' behaviour with a sharp decrease in energy with the addition of the first protons or neutrons, owing to both the added collectivity and the tensor interaction, and then a lower slope when collectivity changes are diminished and only the tensor interaction is influencing the changes in level positions.

  13. Particle-hole intruder levels in 67Cu, collectivity, monopole shifts, and the hockey-stick behaviour of ell - 1/2 5/2- levels in neutron-rich odd-mass Cu nuclei

    Science.gov (United States)

    Walters, W. B.; Chiara, C. J.

    2011-01-01

    A new sequence of gamma rays with energies of 572, 499, 585, and 674 keV has been identified in 67Cu populating the 7/2- level at 2362 keV. Owing to the strong population of the 2362-keV level via an ell = 3 proton pickup reaction, that level is assigned to be an f7/2-1 2-particle-1-hole "intruder" proton configuration, and the new levels are found to form a sequence consistent with intruder sequences in the adjacent odd-mass Cu isotopes and in the odd-mass Sb isotopes. The changing position of the intruder sequence in the odd-mass Cu isotopes is discussed and related to the onset of collectivity associated with the presence of g9/2 neutrons beyond N = 40. The increase in collectivity is also discussed for a number of isotonic and isotopic chains as more protons or neutrons, respectively, are added beyond an oscillator shell boundary. For most of these systems, the ell -1/2 levels show a systematic "hockey-stick-like" behaviour with a sharp decrease in energy with the addition of the first protons or neutrons, owing to both the added collectivity and the tensor interaction, and then a lower slope when collectivity changes are diminished and only the tensor interaction is influencing the changes in level positions.

  14. Disappearance of collective motion in very hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Piattelli, P.; Suomijaervi, T.; Blumenfeld, Y.; Santonocito, D.; Agodi, C.; Alamanos, N.; Alba, R.; Auger, F.; Bellia, G.; Chomaz, Ph.; Colonna, M.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Gillibert, A.; Le Faou, J.H.; Loukachine, K.; Maiolino, C.; Migneco, E.; Roynette, J. C.; Sapienza, P.; Scarpaci, J. A

    1999-03-29

    Gamma-rays emitted from hot nuclei with mass around 115 and excitation energies above 300 MeV, formed in the {sup 36}Ar + {sup 98}Mo reaction at 37 AMeV, have been measured. A comparison with previous experiments at lower bombarding energies shows a decrease of the {gamma}-yield with increasing incident energy. A tentative interpretation based on dynamical calculations is proposed.

  15. Disappearance of collective motion in very hot nuclei

    Science.gov (United States)

    Piattelli, P.; Suomijärvi, T.; Blumenfeld, Y.; Santonocito, D.; Agodi, C.; Alamanos, N.; Alba, R.; Auger, F.; Bellia, G.; Chomaz, Ph.; Colonna, M.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Gillibert, A.; Le Faou, J. H.; Loukachine, K.; Maiolino, C.; Migneco, E.; Roynette, J. C.; Sapienza, P.; Scarpaci, J. A.

    1999-03-01

    Gamma-rays emitted from hot nuclei with mass around 115 and excitation energies above 300 MeV, formed in the 36Ar + 98Mo reaction at 37 AMeV, have been measured. A comparison with previous experiments at lower bombarding energies shows a decrease of the γ-yield with increasing incident energy. A tentative interpretation based on dynamical calculations is proposed.

  16. Disappearance of collective motion in very hot nuclei

    International Nuclear Information System (INIS)

    Piattelli, P.; Suomijaervi, T.; Blumenfeld, Y.; Santonocito, D.; Agodi, C.; Alamanos, N.; Alba, R.; Auger, F.; Bellia, G.; Chomaz, Ph.; Colonna, M.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Gillibert, A.; Le Faou, J.H.; Loukachine, K.; Maiolino, C.; Migneco, E.; Roynette, J. C.; Sapienza, P.; Scarpaci, J. A.

    1999-01-01

    Gamma-rays emitted from hot nuclei with mass around 115 and excitation energies above 300 MeV, formed in the 36 Ar + 98 Mo reaction at 37 AMeV, have been measured. A comparison with previous experiments at lower bombarding energies shows a decrease of the γ-yield with increasing incident energy. A tentative interpretation based on dynamical calculations is proposed

  17. Disappearance of collective motion in very hot nuclei

    CERN Document Server

    Piattelli, P; Blumenfeld, Y; Santonocito, D; Agodi, C; Alamanos, N; Alba, R; Auger, F; Bellia, G; Chomaz, P; Colonna, M; Coniglione, R; Del Zoppo, A; Finocchiaro, P; Frascaria, N; Gillibert, A; Le Faou, J H; Loukachine, K; Maiolino, C; Migneco, E; Roynette, J C; Sapienza, P; Scarpaci, J A

    1999-01-01

    Gamma-rays emitted from hot nuclei with mass around 115 and excitation energies above 300 MeV, formed in the sup 3 sup 6 Ar + sup 9 sup 8 Mo reaction at 37 AMeV, have been measured. A comparison with previous experiments at lower bombarding energies shows a decrease of the gamma-yield with increasing incident energy. A tentative interpretation based on dynamical calculations is proposed.

  18. gamma -transition rates in transitional odd gold nuclei

    CERN Document Server

    Berg, V; Oms, J

    1981-01-01

    The results of two half-life measurements of excited states in /sup 185/Au are presented. One supports the proposed interpretation of the ground state configuration, the other one calls attention to the h 9/2 to h 11/2 M1 transitions in odd mass gold nuclei, which, in spite of considerable deformation changes of the h 9/2 state, all show the same retardation. (5 refs).

  19. Experimental First Order Pairing Phase Transition in Atomic Nuclei

    International Nuclear Information System (INIS)

    Moretto, L G; Larsen, A C; Giacoppo, F; Guttormsen, M; Siem, S

    2015-01-01

    The natural log of experimental nuclear level densities at low energy is linear with energy. This can be interpreted in terms of a nearly 1st order phase transition from a superfluid to an ideal gas of quasi particles. The transition temperature coincides with the BCS critical temperature and yields gap parameters in good agreement with the values extracted from even- odd mass differences from rotational states. This converging evidence supports the relevance of the BCS theory to atomic nuclei

  20. Fission cross section measurements at intermediate energies

    International Nuclear Information System (INIS)

    Laptev, Alexander

    2005-01-01

    The activity in intermediate energy particle induced fission cross-section measurements of Pu, U isotopes, minor actinides and sub-actinides in PNPI of Russia is reviewed. The neutron-induced fission cross-section measurements are under way in the wide energy range of incident neutrons from 0.5 MeV to 200 MeV at the GNEIS facility. In number of experiments at the GNEIS facility, the neutron-induced fission cross sections were obtained for many nuclei. In another group of experiments the proton-induced fission cross-section have been measured for proton energies ranging from 200 to 1000 MeV at 100 MeV intervals using the proton beam of PNPI synchrocyclotron. (author)

  1. No more active galactic nuclei in clumpy disks than in smooth galaxies at z ∼ 2 in CANDELS/3D-HST

    Energy Technology Data Exchange (ETDEWEB)

    Trump, Jonathan R.; Luo, Bin; Brandt, W. N. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Barro, Guillermo; Guo, Yicheng; Koo, David C.; Faber, S. M. [University of California Observatories/Lick Observatory and Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Juneau, Stéphanie [Irfu/Service d' Astrophysique, CEA-Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette Cedex (France); Weiner, Benjamin J. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Brammer, Gabriel B.; Ferguson, Henry C.; Grogin, Norman A.; Kartaltepe, Jeyhan; Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Dekel, Avishai [Center for Astrophysics and Planetary Science, Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Hopkins, Philip F. [California Institute of Technology, MC 105-24, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Kocevski, Dale D. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); McIntosh, Daniel H. [Department of Physics and Astronomy, University of Missouri-Kansas City, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Momcheva, Ivelina [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); and others

    2014-10-01

    We use CANDELS imaging, 3D-HST spectroscopy, and Chandra X-ray data to investigate if active galactic nuclei (AGNs) are preferentially fueled by violent disk instabilities funneling gas into galaxy centers at 1.3 < z < 2.4. We select galaxies undergoing gravitational instabilities using the number of clumps and degree of patchiness as proxies. The CANDELS visual classification system is used to identify 44 clumpy disk galaxies, along with mass-matched comparison samples of smooth and intermediate morphology galaxies. We note that despite being mass-matched and having similar star formation rates, the smoother galaxies tend to be smaller disks with more prominent bulges compared to the clumpy galaxies. The lack of smooth extended disks is probably a general feature of the z ∼ 2 galaxy population, and means we cannot directly compare with the clumpy and smooth extended disks observed at lower redshift. We find that z ∼ 2 clumpy galaxies have slightly enhanced AGN fractions selected by integrated line ratios (in the mass-excitation method), but the spatially resolved line ratios indicate this is likely due to extended phenomena rather than nuclear AGNs. Meanwhile, the X-ray data show that clumpy, smooth, and intermediate galaxies have nearly indistinguishable AGN fractions derived from both individual detections and stacked non-detections. The data demonstrate that AGN fueling modes at z ∼ 1.85—whether violent disk instabilities or secular processes—are as efficient in smooth galaxies as they are in clumpy galaxies.

  2. Pion inelastic scattering, pion photoproduction and inelastic electron scattering on light nuclei

    International Nuclear Information System (INIS)

    Ehramzhyan, R.A.

    1985-01-01

    Partial transitions in pion photoproduction reaction on 6 Li, 10 B, 12 C nuclei are considered. Particular stress is paied to simultaneous analysis both of (γ, π) ad (e, e'), (π, π') reactions. Such analysis is concretely ixemplified with the use of both phenomenological and microscopic approaches. Microscopic analysis is shown to give correct representation of reaction mechanism (γ, π), (e, e') and (π, π') at intermediate energies. Spin-isospin dipole resonances in 1p-shell nuclei are considered. It is shown that nuclear system excitation spectrum gross-structure is a result of resonance configuration splitting

  3. Exotic light nuclei and nuclei in the lead region

    International Nuclear Information System (INIS)

    Poppelier, N.A.F.M.

    1989-01-01

    Three methods are discussed for modifying, or renormalizing, a truncated nuclear hamiltonian such that the wave functions obtained by diagonalizing this modified or effective hamiltoniandescribe the nucleus as well as possible: deriving the hamiltonian directly from a realistic nucleon-nucleon interaction between free nucleons; parametrizing the hamiltonian in terms of a number of parameters and determining these parameters from a least-squares fit of calculated properties to experimental data; approximating the nucleon-nucleon (NN) interaction between two nucleons in a nucleus by a simple analytic expression. An effective hamiltonian derived following the second method is applied in a theoretical study of exotic nuclei in the region of Z=2-9 and A=4-30 and the problem of the neutron halo in 11 Li is discussed. Results of shell-model calculations of 20i Pb and nuclei in its neighbourhood are presented in which an effective hamiltonian was employed derived with the last method. The quenching of M1 strength in 208 Pb, and the spectroscopic factors measured in proton knock-out reactions could be described quite satisfactory. Finally, a method is presented for deriving the effective hamiltonian directly from the realistic NN interaction with algebraic techniques. (H.W.). 114 refs.; 34 figs.; 12 tabs.; schemes

  4. Octupole deformation in neutron-rich actinides and superheavy nuclei and the role of nodal structure of single-particle wavefunctions in extremely deformed structures of light nuclei

    Science.gov (United States)

    Afanasjev, A. V.; Abusara, H.; Agbemava, S. E.

    2018-03-01

    Octupole deformed shapes in neutron-rich actinides and superheavy nuclei as well as extremely deformed shapes of the N∼ Z light nuclei have been investigated within the framework of covariant density functional theory. We confirmed the presence of new region of octupole deformation in neutron-rich actinides with the center around Z∼ 96,N∼ 196 but our calculations do not predict octupole deformation in the ground states of superheavy Z≥slant 108 nuclei. As exemplified by the study of 36Ar, the nodal structure of the wavefunction of occupied single-particle orbitals in extremely deformed structures allows to understand the formation of the α-clusters in very light nuclei, the suppression of the α-clusterization with the increase of mass number, the formation of ellipsoidal mean-field type structures and nuclear molecules.

  5. Influence of the two-phonon admixture on the M1-resonance in spherical nuclei

    International Nuclear Information System (INIS)

    Ponomarev, V.Ju.; Stoyanov, Ch.; Vdovin, A.I.; Voronov, V.V.

    1979-01-01

    The influence of the two-phonon admixtures on the M1-resonance is spherical nuclei with mass numbers 60 <= A <= 140 is studied. The calculations are performed within the quasiparticle phonon nuclear model with factorized multipole and spin-multipole forces. In nuclei with the number of neutrons 50,82 the role of the two-phonon admixtures is insignificant whereas in other nuclei especially in those with strong pairing in the proton and neutron schemes it is significant. The radiative strength functions are calculated at the neutron binding energy. The results are compared with the experimental data and calculations of other authors

  6. In-target rare nuclei production rates with EURISOL single-stage configuration

    CERN Document Server

    Chabod, S P; Ene, D; Doré, D; Blideanu, V; David, J.-Ch; Ridikas, D

    2010-01-01

    We conducted calculations of exotic nuclei production rates for 320 configurations of EURISOL (European Isotope Separation On-Line Radioactive Ion Beam Facility) direct spallation targets. The nuclei yields were evaluated using neutron generation-transport codes, completed with evolution calculations to account for nuclei decays and low energy neutron interactions. The yields were optimized for 11 selected elements (Li, Be, Ne, Mg, Ar, Ni, Ga, Kr, Sn, Hg, Fr) and 23 of their isotopes, as function of the target compositions and geometries as well as the incident proton beam energies. For the considered elements, we evaluated the yield distributions as functions of the charge and mass numbers using two different spallation models.

  7. Spatial organization and correlations of cell nuclei in brain tumors.

    Directory of Open Access Journals (Sweden)

    Yang Jiao

    Full Text Available Accepting the hypothesis that cancers are self-organizing, opportunistic systems, it is crucial to understand the collective behavior of cancer cells in their tumorous heterogeneous environment. In the present paper, we ask the following basic question: Is this self-organization of tumor evolution reflected in the manner in which malignant cells are spatially distributed in their heterogeneous environment? We employ a variety of nontrivial statistical microstructural descriptors that arise in the theory of heterogeneous media to characterize the spatial distributions of the nuclei of both benign brain white matter cells and brain glioma cells as obtained from histological images. These descriptors, which include the pair correlation function, structure factor and various nearest neighbor functions, quantify how pairs of cell nuclei are correlated in space in various ways. We map the centroids of the cell nuclei into point distributions to show that while commonly used local spatial statistics (e.g., cell areas and number of neighboring cells cannot clearly distinguish spatial correlations in distributions of normal and abnormal cell nuclei, their salient structural features are captured very well by the aforementioned microstructural descriptors. We show that the tumorous cells pack more densely than normal cells and exhibit stronger effective repulsions between any pair of cells. Moreover, we demonstrate that brain gliomas are organized in a collective way rather than randomly on intermediate and large length scales. The existence of nontrivial spatial correlations between the abnormal cells strongly supports the view that cancer is not an unorganized collection of malignant cells but rather a complex emergent integrated system.

  8. Spatial organization and correlations of cell nuclei in brain tumors.

    Science.gov (United States)

    Jiao, Yang; Berman, Hal; Kiehl, Tim-Rasmus; Torquato, Salvatore

    2011-01-01

    Accepting the hypothesis that cancers are self-organizing, opportunistic systems, it is crucial to understand the collective behavior of cancer cells in their tumorous heterogeneous environment. In the present paper, we ask the following basic question: Is this self-organization of tumor evolution reflected in the manner in which malignant cells are spatially distributed in their heterogeneous environment? We employ a variety of nontrivial statistical microstructural descriptors that arise in the theory of heterogeneous media to characterize the spatial distributions of the nuclei of both benign brain white matter cells and brain glioma cells as obtained from histological images. These descriptors, which include the pair correlation function, structure factor and various nearest neighbor functions, quantify how pairs of cell nuclei are correlated in space in various ways. We map the centroids of the cell nuclei into point distributions to show that while commonly used local spatial statistics (e.g., cell areas and number of neighboring cells) cannot clearly distinguish spatial correlations in distributions of normal and abnormal cell nuclei, their salient structural features are captured very well by the aforementioned microstructural descriptors. We show that the tumorous cells pack more densely than normal cells and exhibit stronger effective repulsions between any pair of cells. Moreover, we demonstrate that brain gliomas are organized in a collective way rather than randomly on intermediate and large length scales. The existence of nontrivial spatial correlations between the abnormal cells strongly supports the view that cancer is not an unorganized collection of malignant cells but rather a complex emergent integrated system.

  9. The Intermediate Neutrino Program

    Energy Technology Data Exchange (ETDEWEB)

    Adams, C.; et al.

    2015-03-23

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.

  10. The Intermediate Neutrino Program

    CERN Document Server

    Adams, C.; Ankowski, A.M.; Asaadi, J.A.; Ashenfelter, J.; Axani, S.N.; Babu, K.; Backhouse, C.; Band, H.R.; Barbeau, P.S.; Barros, N.; Bernstein, A.; Betancourt, M.; Bishai, M.; Blucher, E.; Bouffard, J.; Bowden, N.; Brice, S.; Bryan, C.; Camilleri, L.; Cao, J.; Carlson, J.; Carr, R.E.; Chatterjee, A.; Chen, M.; Chen, S.; Chiu, M.; Church, E.D.; Collar, J.I.; Collin, G.; Conrad, J.M.; Convery, M.R.; Cooper, R.L.; Cowen, D.; Davoudiasl, H.; de Gouvea, A.; Dean, D.J.; Deichert, G.; Descamps, F.; DeYoung, T.; Diwan, M.V.; Djurcic, Z.; Dolinski, M.J.; Dolph, J.; Donnelly, B.; Dwyer, D.A.; Dytman, S.; Efremenko, Y.; Everett, L.L.; Fava, A.; Figueroa-Feliciano, E.; Fleming, B.; Friedland, A.; Fujikawa, B.K.; Gaisser, T.K.; Galeazzi, M.; Galehouse, D.C.; Galindo-Uribarri, A.; Garvey, G.T.; Gautam, S.; Gilje, K.E.; Gonzalez-Garcia, M.; Goodman, M.C.; Gordon, H.; Gramellini, E.; Green, M.P.; Guglielmi, A.; Hackenburg, R.W.; Hackenburg, A.; Halzen, F.; Han, K.; Hans, S.; Harris, D.; Heeger, K.M.; Herman, M.; Hill, R.; Holin, A.; Huber, P.; Jaffe, D.E.; Johnson, R.A.; Joshi, J.; Karagiorgi, G.; Kaufman, L.J.; Kayser, B.; Kettell, S.H.; Kirby, B.J.; Klein, J.R.; Kolomensky, Yu. G.; Kriske, R.M.; Lane, C.E.; Langford, T.J.; Lankford, A.; Lau, K.; Learned, J.G.; Ling, J.; Link, J.M.; Lissauer, D.; Littenberg, L.; Littlejohn, B.R.; Lockwitz, S.; Lokajicek, M.; Louis, W.C.; Luk, K.; Lykken, J.; Marciano, W.J.; Maricic, J.; Markoff, D.M.; Martinez Caicedo, D.A.; Mauger, C.; Mavrokoridis, K.; McCluskey, E.; McKeen, D.; McKeown, R.; Mills, G.; Mocioiu, I.; Monreal, B.; Mooney, M.R.; Morfin, J.G.; Mumm, P.; Napolitano, J.; Neilson, R.; Nelson, J.K.; Nessi, M.; Norcini, D.; Nova, F.; Nygren, D.R.; Orebi Gann, G.D.; Palamara, O.; Parsa, Z.; Patterson, R.; Paul, P.; Pocar, A.; Qian, X.; Raaf, J.L.; Rameika, R.; Ranucci, G.; Ray, H.; Reyna, D.; Rich, G.C.; Rodrigues, P.; Romero, E.Romero; Rosero, R.; Rountree, S.D.; Rybolt, B.; Sanchez, M.C.; Santucci, G.; Schmitz, D.; Scholberg, K.; Seckel, D.; Shaevitz, M.; Shrock, R.; Smy, M.B.; Soderberg, M.; Sonzogni, A.; Sousa, A.B.; Spitz, J.; St. John, J.M.; Stewart, J.; Strait, J.B.; Sullivan, G.; Svoboda, R.; Szelc, A.M.; Tayloe, R.; Thomson, M.A.; Toups, M.; Vacheret, A.; Vagins, M.; Van de Water, R.G.; Vogelaar, R.B.; Weber, M.; Weng, W.; Wetstein, M.; White, C.; White, B.R.; Whitehead, L.; Whittington, D.W.; Wilking, M.J.; Wilson, R.J.; Wilson, P.; Winklehner, D.; Winn, D.R.; Worcester, E.; Yang, L.; Yeh, M.; Yokley, Z.W.; Yoo, J.; Yu, B.; Yu, J.; Zhang, C.

    2015-01-01

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summ...

  11. The Intermediate Neutrino Program

    Energy Technology Data Exchange (ETDEWEB)

    Adams, C. [Yale Univ., New Haven, CT (United States); Alonso, J. R. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Ankowski, A. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Asaadi, J. A. [Syracuse Univ., NY (United States); Ashenfelter, J. [Yale Univ., New Haven, CT (United States); Axani, S. N. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Babu, K [Oklahoma State Univ., Stillwater, OK (United States); Backhouse, C. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Band, H. R. [Yale Univ., New Haven, CT (United States); Barbeau, P. S. [Duke Univ., Durham, NC (United States); Barros, N. [Univ. of Pennsylvania, Philadelphia, PA (United States); Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Betancourt, M. [Illinois Inst. of Technology, Chicago, IL (United States); Bishai, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blucher, E. [Univ. of Chicago, IL (United States); Bouffard, J. [State Univ. of New York (SUNY), Albany, NY (United States); Bowden, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brice, S. [Illinois Inst. of Technology, Chicago, IL (United States); Bryan, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Camilleri, L. [Columbia Univ., New York, NY (United States); Cao, J. [Inst. of High Energy Physics, Beijing (China); Carlson, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carr, R. E. [Columbia Univ., New York, NY (United States); Chatterjee, A. [Univ. of Texas, Arlington, TX (United States); Chen, M. [Univ. of California, Irvine, CA (United States); Chen, S. [Tsinghua Univ., Beijing (China); Chiu, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Church, E. D. [Illinois Inst. of Technology, Chicago, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Collar, J. I. [Univ. of Chicago, IL (United States); Collin, G. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Conrad, J. M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Convery, M. R. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Cooper, R. L. [Indiana Univ., Bloomington, IN (United States); Cowen, D. [Pennsylvania State Univ., University Park, PA (United States); Davoudiasl, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gouvea, A. D. [Northwestern Univ., Evanston, IL (United States); Dean, D. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deichert, G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Descamps, F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); DeYoung, T. [Michigan State Univ., East Lansing, MI (United States); Diwan, M. V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Djurcic, Z. [Argonne National Lab. (ANL), Argonne, IL (United States); Dolinski, M. J. [Drexel Univ., Philadelphia, PA (United States); Dolph, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Donnelly, B. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Dwyer, D. A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dytman, S. [Univ. of Pittsburgh, PA (United States); Efremenko, Y. [Univ. of Tennessee, Knoxville, TN (United States); Everett, L. L. [Univ. of Wisconsin, Madison, WI (United States); Fava, A. [University of Padua, Padova (Italy); Figueroa-Feliciano, E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Fleming, B. [Yale Univ., New Haven, CT (United States); Friedland, A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fujikawa, B. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gaisser, T. K. [Univ. of Delaware, Newark, DE (United States); Galeazzi, M. [Univ. of Miami, FL (United States); Galehouse, DC [Univ. of Akron, OH (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Garvey, G. T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gautam, S. [Tribhuvan Univ., Kirtipur (Nepal); Gilje, K. E. [Illinois Inst. of Technology, Chicago, IL (United States); Gonzalez-Garcia, M. [Stony Brook Univ., NY (United States); Goodman, M. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Gordon, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gramellini, E. [Yale Univ., New Haven, CT (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Guglielmi, A. [University of Padua, Padova (Italy); Hackenburg, R. W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hackenburg, A. [Yale Univ., New Haven, CT (United States); Halzen, F. [Univ. of Wisconsin, Madison, WI (United States); Han, K. [Yale Univ., New Haven, CT (United States); Hans, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Harris, D. [Illinois Inst. of Technology, Chicago, IL (United States); Heeger, K. M. [Yale Univ., New Haven, CT (United States); Herman, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hill, R. [Univ. of Chicago, IL (United States); Holin, A. [Univ. College London, Bloomsbury (United Kingdom); Huber, P. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Jaffe, D. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Johnson, R. A. [Univ. of Cincinnati, OH (United States); Joshi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Karagiorgi, G. [Univ. of Manchester (United Kingdom); Kaufman, L. J. [Indiana Univ., Bloomington, IN (United States); Kayser, B. [Illinois Inst. of Technology, Chicago, IL (United States); Kettell, S. H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kirby, B. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Klein, J. R. [Univ. of Texas, Arlington, TX (United States); Kolomensky, Y. G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Kriske, R. M. [Univ. of Minnesota, Minneapolis, MN (United States); Lane, C. E. [Drexel Univ., Philadelphia, PA (United States); Langford, T. J. [Yale Univ., New Haven, CT (United States); Lankford, A. [Univ. of California, Irvine, CA (United States); Lau, K. [Univ. of Houston, TX (United States); Learned, J. G. [Univ. of Hawaii, Honolulu, HI (United States); Ling, J. [Univ. of Illinois, Urbana-Champaign, IL (United States); Link, J. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Lissauer, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littenberg, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littlejohn, B. R. [Illinois Inst. of Technology, Chicago, IL (United States); Lockwitz, S. [Illinois Inst. of Technology, Chicago, IL (United States); Lokajicek, M. [Inst. of Physics of the Academy of Sciences of Czech Republic, Prague (Czech Republic); Louis, W. C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Luk, K. [Univ. of California, Berkeley, CA (United States); Lykken, J. [Illinois Inst. of Technology, Chicago, IL (United States); Marciano, W. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Maricic, J. [Univ. of Hawaii, Honolulu, HI (United States); Markoff, D. M. [North Carolina Central Univ., Durham, NC (United States); Caicedo, D. A. M. [Illinois Inst. of Technology, Chicago, IL (United States); Mauger, C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mavrokoridis, K. [Univ. of Liverpool (United Kingdom); McCluskey, E. [Illinois Inst. of Technology, Chicago, IL (United States); McKeen, D. [Univ. of Washington, Seattle, WA (United States); McKeown, R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mills, G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mocioiu, I. [Pennsylvania State Univ., University Park, PA (United States); Monreal, B. [Univ. of California, Santa Barbara, CA (United States); Mooney, M. R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Morfin, J. G. [Illinois Inst. of Technology, Chicago, IL (United States); Mumm, P. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Napolitano, J. [Temple Univ., Philadelphia, PA (United States); Neilson, R. [Drexel Univ., Philadelphia, PA (United States); Nelson, J. K. [College of William and Mary, Williamsburg, VA (United States); Nessi, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Norcini, D. [Yale Univ., New Haven, CT (United States); Nova, F. [Univ. of Texas, Austin, TX (United States); Nygren, D. R. [Univ. of Texas, Arlington, TX (United States); Gann, GDO [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Palamara, O. [Illinois Inst. of Technology, Chicago, IL (United States); Parsa, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States); Patterson, R. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Paul, P. [Stony Brook Univ., NY (United States); Pocar, A. [Univ. of Massachusetts, Amherst, MA (United States); Qian, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Raaf, J. L. [Illinois Inst. of Technology, Chicago, IL (United States); Rameika, R. [Illinois Inst. of Technology, Chicago, IL (United States); Ranucci, G. [National Inst. of Nuclear Physics, Milano (Italy); Ray, H. [Univ. of Florida, Gainesville, FL (United States); Reyna, D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rich, G. C. [Triangle Universities Nuclear Lab., Durham, NC (United States); Rodrigues, P. [Univ. of Rochester, NY (United States); Romero, E. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Rosero, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rountree, S. D. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Rybolt, B. [Univ. of Tennessee, Knoxville, TN (United States); Sanchez, M. C. [Iowa State Univ., Ames, IA (United States); Santucci, G. [Stony Brook Univ., NY (United States); Schmitz, D. [Univ. of Chicago, IL (United States); Scholberg, K. [Duke Univ., Durham, NC (United States); Seckel, D. [Univ. of Delaware, Newark, DE (United States); Shaevitz, M. [Columbia Univ., New York, NY (United States); Shrock, R. [Stony Brook Univ., NY (United States); Smy, M. B. [Univ. of California, Irvine, CA (United States); Soderberg, M. [Syracuse Univ., NY (United States); Sonzogni, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sousa, A. B. [Univ. of Cincinnati, OH (United States); Spitz, J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); John, J. M. S. [Univ. of Cincinnati, OH (United States); Stewart, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Strait, J. B. [Illinois Inst. of Technology, Chicago, IL (United States); Sullivan, G. [Univ. of Maryland, College Park, MD (United States); Svoboda, R. [Univ. of California, Davis, CA (United States); Szelc, A. M. [Yale Univ., New Haven, CT (United States); Tayloe, R. [Indiana Univ., Bloomington, IN (United States); Thomson, M. A. [Univ. of Cambridge (United Kingdom); Toups, M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Vacheret, A. [Univ. of Oxford (United Kingdom); Vagins, M. [Univ. of California, Irvine, CA (United States); Water, R. G. V. D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vogelaar, R. B. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Weber, M. [Bern (Switzerland); Weng, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wetstein, M. [Univ. of Chicago, IL (United States); White, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); White, B. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Whitehead, L. [Univ. of Houston, TX (United States); Whittington, D. W. [Indiana Univ., Bloomington, IN (United States); Wilking, M. J. [Stony Brook Univ., NY (United States); Wilson, R. J. [Colorado State Univ., Fort Collins, CO (United States); Wilson, P. [Illinois Inst. of Technology, Chicago, IL (United States); Winklehner, D. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Winn, D. R. [Fairfield Univ., CT (United States); Worcester, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, L. [Univ. of Illinois, Urbana-Champaign, IL (United States); Yeh, M [Brookhaven National Lab. (BNL), Upton, NY (United States); Yokley, Z. W. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Yoo, J. [Illinois Inst. of Technology, Chicago, IL (United States); Yu, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yu, J. [Univ. of Texas, Arlington, TX (United States); Zhang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-04-03

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.

  12. Microscopic structure for light nuclei

    International Nuclear Information System (INIS)

    Sharma, V.K.

    1995-01-01

    The microscopic structure for light nuclei e.g. 4 He, 7 Li and 8 Be is considered in the frame work of the generator coordinate method (GCM). The physical interpretation of our GCM is also discussed. The GC amplitudes are used to calculate the various properties like charge and magnetic RMS radii, form factors, electromagnetic moments, astrophysical S-factor, Bremsstrahlung weighted cross sections, relative wavefunctions and vertex functions etc. All the calculated quantities agree well with the values determined experimentally. (author). 30 refs., 10 figs., 2 tabs

  13. Nucleon transfer between heavy nuclei

    International Nuclear Information System (INIS)

    Von Oertzen, W.

    1984-02-01

    Nucleon transfer reactions between heavy nuclei are characterized by the classical behaviour of the scattering orbits. Thus semiclassical concepts are well suited for the description of these reactions. In the present contribution the characteristics of single and multinucleon transfer reactions at energies below and above the Coulomb barrier are shown for systems like Sn+Sn, Xe+U and Ni+Pb. The role of the pairing interaction in the transfer of nucleon pairs is illustrated. For strong transitions the coupling of channels and the absorption into more complicated channels is taken into account in a coupled channels calculation

  14. Quarks in hadrons and nuclei

    International Nuclear Information System (INIS)

    Close, F.E.

    1988-01-01

    The paper concerns some of the ideas underlying quarks and their interactions, the way that quarks build up hadrons, and the extent to which the QCD theory can be applied to phenomena involving nuclei. The article is part of the Proceedings of the International School of Nuclear Physics, Erice, 1987. A description is given of quarks and multiplets. Colour is discussed with respect to: evidence for colour, a non abelian Su(3) theory, the pauli principle at work in hadrons, and spin flavour correlations and magnetic moments. Colour, gluons and the inter quark potential are also examined. (UK)

  15. Design and construction of a spectrometer facility and experiment for intermediate energy proton scattering on helium

    International Nuclear Information System (INIS)

    Rolfe, R.M.

    1976-12-01

    The goal of the research was to investigate proton scattering on nuclei at intermediate energies and in particular to investigate proton scattering on helium. A theoretical investigation of the helium nucleus and the nature of the intermediate energy interaction, design and optimization of an energy-loss spectrometer facility for proton-nucleus scattering, and the unique superfluid helium target and experimental design are discussed

  16. Fueling active galactic nuclei by magnetic braking

    Science.gov (United States)

    Krolik, Julian H.; Meiksin, Avery

    1990-01-01

    Recent detections of massive concentrations of molecular gas near the centers of galaxies hosting active nuclei suggest that these concentrations may be the source of accretion fuel for the nucleus. However, for that to be true, an angular momentum barrier must be overcome before the material in such a cloud can reach the nucleus. It is suggested that magnetic braking of the cloud may remove sufficient angular momentum to permit its material to draw considerably closer to the central object. The mechanism is particularly effective in the limit that the gas becomes self-gravitating because removal of a fraction of the initial angular momentum can lead to dynamical instability and collapse. Any small misalignment between the initial rotation axis of the cloud and the rotation axis of the galaxy can be substantially amplified as a result of the braking. It is argued that mass accretion onto the central object may occur in episodes, in some cases with a constant mass accretion rate during each episode.

  17. Isospin symmetry breaking in sd shell nuclei

    International Nuclear Information System (INIS)

    Lam, Y.W.

    2011-12-01

    In the thesis, we develop a microscopic approach to describe the isospin-symmetry breaking effects in sd-shell nuclei. The work is performed within the nuclear shell model. A realistic isospin-conserving Hamiltonian is perfected by a charge-dependent part consisting of the Coulomb interaction and Yukawa-type meson exchange potentials to model charge-dependent forces of nuclear origin. The extended database of the experimental isobaric mass multiplet equation coefficients was compiled during the thesis work and has been used in a fit of the Hamiltonian parameters. The constructed Hamiltonian provides an accurate theoretical description of the isospin mixing nuclear states. A specific behaviour of the IMME (Isobaric Multiplet Mass Equation) coefficients have been revealed. We present two important applications: (i) calculations of isospin-forbidden proton emission amplitudes, which is often of interest for nuclear astrophysics, and (ii) calculation on corrections to nuclear Fermi beta decay, which is crucial for the tests of fundamental symmetries of the weak interaction. (author)

  18. Intermediate energy data

    International Nuclear Information System (INIS)

    Koning, A.J.; Fukahori, T.; Hasegawa, A.

    1998-01-01

    Subgroup 13 (SG13) on Intermediate Energy Nuclear data was formed by NEA Nuclear Science Committee to solve common problems of these types of data for nuclear applications. An overview is presented in this final report of the present activities of SG13, including data needs, high-priority nuclear data request list (nuclides), compilation of experimental data, specialists meetings and benchmarks, data formats and data libraries. Some important accomplishments are summarized, and recommendations are presented. (R.P.)

  19. Spectral statistics of rare-earth nuclei: Investigation of shell model configuration effect

    Energy Technology Data Exchange (ETDEWEB)

    Sabri, H., E-mail: h-sabri@tabrizu.ac.ir

    2015-09-15

    The spectral statistics of even–even rare-earth nuclei are investigated by using all the available empirical data for Ba, Ce, Nd, Sm, Gd, Dy, Er, Yb and Hf isotopes. The Berry–Robnik distribution and Maximum Likelihood estimation technique are used for analyses. An obvious deviation from GOE is observed for considered nuclei and there are some suggestions about the effect due to mass, deformation parameter and shell model configurations.

  20. Spectral statistics of rare-earth nuclei: Investigation of shell model configuration effect

    International Nuclear Information System (INIS)

    Sabri, H.

    2015-01-01

    The spectral statistics of even–even rare-earth nuclei are investigated by using all the available empirical data for Ba, Ce, Nd, Sm, Gd, Dy, Er, Yb and Hf isotopes. The Berry–Robnik distribution and Maximum Likelihood estimation technique are used for analyses. An obvious deviation from GOE is observed for considered nuclei and there are some suggestions about the effect due to mass, deformation parameter and shell model configurations

  1. Exotic nuclei: another aspect of nuclear structure

    International Nuclear Information System (INIS)

    Dobaczewski, J.; Blumenfeld, Y.; Flocard, H.; Garcia Borge, M.J.; Nowacki, F.; Rombouts, S.; Theisen, Ch.; Marques, F.M.; Lacroix, D.; Dessagne, P.; Gaeggeler, H.

    2002-01-01

    This document gathers the lectures made at the Joliot Curie international summer school in 2002 whose theme that year was exotic nuclei. There were 11 contributions whose titles are: 1) interactions, symmetry breaking and effective fields from quarks to nuclei; 2) status and perspectives for the study of exotic nuclei: experimental aspects; 3) the pairing interaction and the N = Z nuclei; 4) borders of stability region and exotic decays; 5) shell structure of nuclei: from stability to decay; 6) variational approach of system with a few nucleons; 7) from heavy to super-heavy nuclei; 8) halos, molecules and multi-neutrons; 9) macroscopic approaches for fusion reactions; 10) beta decay: a tool for spectroscopy; 11) the gas phase chemistry of super-heavy elements

  2. Laser method of free atom nuclei orientation

    International Nuclear Information System (INIS)

    Barabanov, A.L.

    1987-01-01

    Orientation process of free atom (atoms in beams) nuclei, scattering quanta of circularly polarized laser radiation is considered. A method for the evaluation of nuclei orientation parameters is developed. It is shown that in the process of pumping between the ground and first excited atomic states with electron shell spins J 1 and J 2 , so that J 2 = J 1 + 1, a complete orientation of nuclei can be attained

  3. Are there multiquark bags in nuclei

    International Nuclear Information System (INIS)

    Kondratyuk, L.A.; Scmatkov, M.Zh.

    1983-01-01

    Arguments are presented favouring the idea that multiquark bags do eXist in nuclei. Such hypothesis makes possible to reveal the relationship among three different scopes of phenomena: deep inelastic scattering of leptons by nUclei, large q 2 (where q 2 is a square of momentum transfer) behaviour of the form factors of light nuclei and yield of cumulative proton.s

  4. Nuclei quadrupole coupling constants in diatomic molecule

    International Nuclear Information System (INIS)

    Ivanov, A.I.; Rebane, T.K.

    1993-01-01

    An approximate relationship between the constants of quadrupole interaction of nuclei in a two-atom molecule is found. It enabled to establish proportionality of oscillatory-rotation corrections to these constants for both nuclei in the molecule. Similar results were obtained for the factors of electrical dipole-quadrupole screening of nuclei. Applicability of these relationships is proven by the example of lithium deuteride molecule. 4 refs., 1 tab

  5. g/sub R/ and g/sub K/ factors in deformed nuclei

    International Nuclear Information System (INIS)

    Krane, K.S.; Teich, W.G.

    1984-01-01

    The static and dynamic magnetic dipole moments of odd-mass and even-mass nuclei with 150 < A < 190 have been compiled and analyzed in a systematic way, in order to extract the best set of collective rotationial g-factors g/sub R/ and intrinsic g-factors g/sub K/. 2 refs., 4 tabs

  6. Emission of intermediate-mass fragments in the interaction of sup 1 sup 6 O with sup 5 sup 9 Co, sup 9 sup 3 Nb and sup 1 sup 9 sup 7 Au

    CERN Document Server

    Gadioli, E; Birattari, C; Cavinato, M; Fabrici, E; Gadioli-Erba, E; Pigni, M; Steyn, G F; Förtsch, S V; Lawrie, J J; Connell, S H; Sellschop, J P Friedel; Sideras-Haddad, E; Cowley, A A

    2003-01-01

    In this paper we study the emission of sup 8 Be sub g sub s , B and N fragments in the interaction of sup 1 sup 6 O ions with sup 5 sup 9 Co, sup 9 sup 3 Nb and sup 1 sup 9 sup 7 Au at incident energies varying from 6 to 25 MeV/nucleon. The spectra of these fragments, as well as those of C fragments studied in a previous paper, are dominated at forward angles by a component originating from break-up of sup 1 sup 6 O. At the higher incident energies break-up occurs after quite a sizeable projectile energy loss. Another mechanism which dominates at large emission angles, favours the emission of low-energy fragments and is attributed to the coalescence of nucleons during the cascade of nucleon-nucleon interactions by means of which the excited nuclei produced in the primary two-ion interaction thermalize. (orig.)

  7. Photoproduction of vector messons off nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kossov, M.

    1994-04-01

    Vector mesons play an important role in photonuclear reactions because they carry the same quantum numbers as the incident photon. It has recently been suggested by G.E. Brown and M. Rho that the mass of vector mesons could decrease with increasing baryon density. This phenomenon would provide a physical observable for chiral symmetry ({xi}{sup S}) restoration at high baryon density, an essential non-perturbative phenomenon associated with the structure of quantum chromodynamics (QCD). According to the constituent quark model the difference between the mass of the valence quark m{sub v} and the mass of the current quark m{sub c} is expected to be proportional to the mean vacuum value of the quark condensate: m{sub v}-m{sub c} {proportional_to} ({psi}{psi}){sub v}. The mass difference appears because of chiral symmetry breaking {xi}{sup SB}. QCD sum rule calculations show that the value of this difference is about 300 MeV for all quarks. If the mean vacuum value differs from that for the hadron density in nuclei, then the constituent quark mass should be renormalized as follows: m{sub v}{sup l}=m{sub c} + ({psi}{psi})n/({psi}{psi})v {center_dot}300MeV, where the indices n correspond to nuclear matter and v to vacuum. The same conclusion was reached in a nuclear matter model based on quark degrees of freedom. Using the symmetry properties of QCD in an effective Lagrangian theory, Brown and Rho have found a scaling law for the vector meson masses at finite baryon density: M{sub N}{sup n}/M{sub N}{sup v}=M{sub V}{sup n}/M{sub V}{sup v}=f{sub {pi}}{sup n}/f{sub {pi}}{sup v}, where f{sub {pi}} is the {pi} {r_arrow}{mu}{nu} decay constant playing the role of an order parameter for the chiral symmetry restoration. At nuclear density the value of f{sub {pi}} was found to be 15-20% smaller than in vacuum. In contrast to the constituent quark model, it was found that M{sup n}/M=({sub n}/{sub v}){sup 1/3}.

  8. Fusion probability and survivability in estimates of heaviest nuclei production

    International Nuclear Information System (INIS)

    Sagaidak, Roman

    2012-01-01

    . Examples of the P fus values derived with the capture-fission and ER cross-sections obtained recently for asymmetric projectile-target systems are shown. Data on the ER production in different fusion-evaporation reactions leading to the very heavy compound nuclei with ZCN ≥ 100 are considered and discussed in detail. Considering the fusion probability and survivability for the heaviest nuclei with Z > 108, one should bear in mind that the macroscopic component of fission barriers disappears as the shell-stabilized SHE region is approached. Thus the calculated survivability of nuclei produced in the 48 Ca reactions induced on actinide targets depends mainly on the microscopic (shell) corrections to nuclear masses used in calculations

  9. Proceedings of the fifth course of the international school of intermediate energy nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Bergere, R.; Costa, S.; Schaerf, C.

    1985-01-01

    This book presents the papers given at a conference on high energy physics. Topics considered at the conference included total photon absorption, scattering of photons by nuclei, pion photoproduction, nuclear structure investigations, photonuclear reactions and dispersion relations, photon spectra, quark effects, future accelerators for intermediate energy nuclear physics, bag models, polarized photons, and inelastic electron scattering.

  10. Charged current quasi elastic scattering of muon neutrino with nuclei

    Science.gov (United States)

    Saraswat, Kapil; Shukla, Prashant; Kumar, Vineet; Singh, Venktesh

    2018-02-01

    We present a study on the charge current quasi elastic scattering of ν _μ from nucleon and nuclei which gives a charged muon in the final state. To describe nuclei, the Fermi Gas model has been used with proposed Pauli suppression factor. The diffuseness parameter of the Fermi distribution has been obtained using experimental data. We also investigate different parametrizations for electric and magnetic Sach's form factors of nucleons. Calculations have been made for CCQES total and differential cross-sections for the cases of ν _{μ }-N, ν _{μ }-{^{12}}C and ν _{μ }-{^{56}}Fe scatterings and are compared with the data for different values of the axial mass. The present model gives excellent description of measured differential cross-section for all the systems.

  11. Towards limiting temperatures in nuclei: The behavior of collective motion

    International Nuclear Information System (INIS)

    Le Faou, J.H.; Suomijaervi, T.; Blumenfeld, Y.; Piattelli, P.; Agodi, C.; Alamanos, N.; Alba, R.; Auger, F.; Bellia, G.; Chomaz, P.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Gaardhoje, J.J.; Garron, J.P.; Gillibert, A.; Lamehi-Rachti, M.; Liguori-Neto, R.; Maiolino, C.; Migneco, E.; Russo, G.; Roynette, J.C.; Santonocito, D.; Sapienza, P.; Scarpaci, J.A.; Smerzi, A.

    1994-01-01

    Gamma rays emitted from hot nuclei with mass around 115 and excitation energies between 350 and 500 MeV, formed in the 36 Ar + 90 Zr reaction at 27 MeV/nucleon have been measured. The γ-ray yield from the decay of the giant dipole resonance in these nuclei remains constant over the excitation energy range studied. This quenching of the γ multiplicity cannot be explained by a continuous increase with temperature of the width of the resonance. Better agreement with the data is obtained by assuming a cutoff of γ emission from the resonance above an excitation energy of 250 MeV. The existing data do not show entrance channel effects

  12. Towards limiting temperatures in nuclei: The behavior of collective motion

    Energy Technology Data Exchange (ETDEWEB)

    Le Faou, J.H.; Suomijaervi, T.; Blumenfeld, Y.; Piattelli, P.; Agodi, C.; Alamanos, N.; Alba, R.; Auger, F.; Bellia, G.; Chomaz, P.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Frascaria, N.; Gaardhoje, J.J.; Garron, J.P.; Gillibert, A.; Lamehi-Rachti, M.; Liguori-Neto, R.; Maiolino, C.; Migneco, E.; Russo, G.; Roynette, J.C.; Santonocito, D.; Sapienza, P.; Scarpaci, J.A.; Smerzi, A. (Institut de Physique Nucleaire, Institut National de Physique Nucleaire et de Physique des Particules, Centre National de la Recherche Scientifique, 91406 Orsay (France) Istituto Nazionale di Fisica Nucleare-Laboratorio Nazionale del Sud, via A. Doria, Catania (Italy) Service de Physique Nucleaire, DAPNIA, Centre d' Etudes Nucleaires, Saclay , 91191 Gif-sur-Yvette (France) Grand Accelerateur National d' Ions Lourds BP 5027, 14021 Caen (France) The Niels Bohr Institute, University of Copenhagen, DK-2100 O (Denmark))

    1994-05-23

    Gamma rays emitted from hot nuclei with mass around 115 and excitation energies between 350 and 500 MeV, formed in the [sup 36]Ar + [sup 90]Zr reaction at 27 MeV/nucleon have been measured. The [gamma]-ray yield from the decay of the giant dipole resonance in these nuclei remains constant over the excitation energy range studied. This quenching of the [gamma] multiplicity cannot be explained by a continuous increase with temperature of the width of the resonance. Better agreement with the data is obtained by assuming a cutoff of [gamma] emission from the resonance above an excitation energy of 250 MeV. The existing data do not show entrance channel effects.

  13. The Nuclei of Nearby Radio-Loud Galaxies with HST

    Science.gov (United States)

    Verdoes Kleijn, G. A.; Baum, S. A.; de Zeeuw, P. T.

    2001-12-01

    I report on a study of the central regions in 21 nearby (v constraints on its Doppler boosting. The active nuclei of nearby elliptical galaxies which do not harbor large scale radio jets seem to follow similar correlations. HST/STIS spectroscopy was used to map the kinematics and emission-line ratios of the central emission-line gas. I report on the results from dynamical modeling to measure black hole masses. Thus, main conclusions of this study are: (i) there is no photometric indication that the activity in nearby elliptical galaxies is triggered by specific properties of the central stellar distributions, and (ii) there appears to be a continuous sequence in the properties of the radio-loud and quiet active nuclei in nearby elliptical galaxies. Financial support for this work was provided by NASA/STScI and Leiden Observatory.

  14. Limits on the scaling of nucleon magnetic moments in nuclei

    International Nuclear Information System (INIS)

    Ericson, T.E.O.; State Univ. of New York, Stony Brook; Richter, A.; State Univ. of New York, Stony Brook

    1987-01-01

    In view of the suggestion that nucleon magnetic moments inside nuclei may be modified due to a rescaling of the nucleon size, we investigate empirically how large such an effect can be. The method is based on a nearly model-independent scaling relation between the axial vector matrix element and the main part of the corresponding magnetic dipole matrix element supplemented by a small and well understood contribution from the one-pion exchange current. Taking the mass A = 3 and 12 systems as examples the upper limit, for such a change of the nucleon magnetic moment inside nuclei is found to be about 2%, considerably smaller than previous estimates in the literature. (orig.)

  15. Neutron halo in deformed nuclei

    International Nuclear Information System (INIS)

    Zhou Shangui; Meng Jie; Ring, P.; Zhao Enguang

    2010-01-01

    Halo phenomena in deformed nuclei are investigated within a deformed relativistic Hartree Bogoliubov (DRHB) theory. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Contributions of the halo, deformation effects, and large spatial extensions of these systems are described in a fully self-consistent way by the DRHB equations in a spherical Woods-Saxon basis with the proper asymptotic behavior at a large distance from the nuclear center. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nucleus 44 Mg. The core of this nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the occurrence of this decoupling effects are discussed.

  16. Atomic Mass and Nuclear Binding Energy for Cf-252 (Californium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Cf-252 (Californium, atomic number Z = 98, mass number A = 252).

  17. High-spin excitations of atomic nuclei

    International Nuclear Information System (INIS)

    Xu Furong; National Laboratory of Heavy Ion Physics, Lanzhou; Chinese Academy of Sciences, Beijing

    2004-01-01

    The authors used the cranking shell model to investigate the high-spin motions and structures of atomic nuclei. The authors focus the collective rotations of the A∼50, 80 and 110 nuclei. The A∼50 calculations show complicated g spectroscopy, which can have significant vibration effects. The A≅80 N≅Z nuclei show rich shape coexistence with prolate and oblate rotational bands. The A≅110 nuclei near the r-process path can have well-deformed oblate shapes that become yrast and more stable with increasing rotational frequency. As another important investigation, the authors used the configuration-constrained adiabatic method to calculate the multi-quasiparticle high-K states in the A∼130, 180 and superheavy regions. The calculations show significant shape polarizations due to quasi-particle excitations for soft nuclei, which should be considered in the investigations of high-K states. The authors predicted some important high-K isomers, e.g., the 8 - isomers in the unstable nuclei of 140 Dy and 188 Pb, which have been confirmed in experiments. In superheavy nuclei, our calculations show systematic existence of high-K states. The high-K excitations can increase the productions of synthesis and the survival probabilities of superheavy nuclei. (authors)

  18. Mean-field models and exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.; Buervenich, T.; Maruhn, J.A.; Greiner, W. [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany); Rutz, K. [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany)]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Reinhard, P.G. [Inst. fuer Theoretische Physik, Univ. Erlangen (Germany)

    1998-06-01

    We discuss two widely used nuclear mean-field models, the relativistic mean-field model and the (nonrelativistic) Skyrme-Hartree-Fock model, and their capability to describe exotic nuclei. Test cases are superheavy nuclei and neutron-rich Sn isotopes. New information in this regime helps to fix hitherto loosely determined aspects of the models. (orig.)

  19. Thermodynamics of pairing phase transition in nuclei

    International Nuclear Information System (INIS)

    Karim, Afaque; Ahmad, Shakeb

    2014-01-01

    The pairing gaps, pairing energy, heat capacity and entropy are calculated within BCS (Bardeen- Cooper-Schrieffer) based quasi particle approach, including thermal fluctuations on pairing field within pairing model for all nuclei (light, medium, heavy and super heavy nuclei). Quasi particles approach in BCS theory was introduced and reformulated to study various properties. For thermodynamic behavior of nuclei at finite temperatures, the anomalous averages of creation and annihilation operators are introduced. It is solved self consistently at finite temperatures to obtain BCS Hamiltonian. After doing unitary transformation, we obtained the Hamiltonian in the diagonal form. Thus, one gets temperature dependence gap parameter and pairing energy for nuclei. Moreover, the energy at finite temperatures is the sum of the condensation energy and the thermal energy of fermionic quasi particles. With the help of BCS Hamiltonian, specific heat, entropy and free energy are calculated for different nuclei. In this paper the gap parameter occupation number and pairing energy as a function of temperature which is important for all the light, medium, heavy and super heavy nuclei is calculated. Moreover, the various thermo dynamical quantities like specific heat, entropy and free energy is also obtained for different nuclei. Thus, the thermodynamics of pairing phase transition in nuclei is studied

  20. Structure of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Nazarewicz, W.; Ploszajczak, M.

    2003-01-01

    Structure of exotic radioactive nuclei having extreme neutron-to-proton ratios is different from that around the stability line. This short review discusses the progress in modeling of exotic nuclei in the nuclear ''Terra Incognita''. The consistent theoretical description of weakly bound systems requires a synergy between nuclear structure and nuclear reaction methods. (orig.)