Light unbound nuclear systems beyond the dripline
Energy Technology Data Exchange (ETDEWEB)
Aksyutina, Yuliya
2009-07-01
Starting from the first observation of the halo phenomenon 20 years ago, more and more neutron-rich light nuclei were observed. The study of unstable nuclear systems beyond the dripline is a relatively new branch of nuclear physics. In the present work, the results of an experiment at GSI (Darmstadt) with relativistic beams of the halo nuclei {sup 8}He, {sup 11}Li and {sup 14}Be with energies of 240, 280 and 305 MeV/nucleon, respectively, impinging on a liquid hydrogen target are discussed. Neutron/proton knockout reactions lead to the formation of unbound systems, followed by their immediate decay. The experimental setup, consisting of the neutron detector LAND, the dipole spectrometer ALADIN and different types of tracking detectors, allows the reconstruction of the momentum vectors of all reaction products measured in coincidence. The properties of unbound nuclei are investigated by reconstructing the relative-energy spectra as well as by studying the angular correlations between the reaction products. The observed systems are {sup 9}He, {sup 10}He, {sup 10}Li, {sup 12}Li and {sup 13}Li. The isotopes {sup 12}Li and {sup 13}Li are observed for the first time. They are produced in the {sup 1}H({sup 14}Be, 2pn){sup 12}Li and {sup 1}H({sup 14}Be, 2p){sup 13}Li knockout reactions. The obtained relative-energy spectrum of {sup 12}Li is described as a single virtual s-state with a scattering length of as = -13.7(1.6) fm. The spectrum of {sup 13}Li is interpreted as a resonance at an energy of E{sub r}=1.47(13) MeV and a width of {gamma} {approx}2 MeV superimposed on a broad correlated background distribution. The isotope {sup 10}Li is observed after one-neutron knockout from the halo nucleus {sup 11}Li. The obtained relative-energy spectrum is described by a low-lying virtual s-state with a scattering length a{sub s}=-22.4(4.8) fm and a p-wave resonance with E{sub r}=0.566(14) MeV and {gamma}=0.548(30) MeV, in agreement with previous experiments. The observation of the
Experimental studies of unbound neutron-rich nuclei
Energy Technology Data Exchange (ETDEWEB)
Lecouey, J.L
2003-10-01
The three-body description of two-neutron halo nuclei relies on the two-body interactions between the constituents. In order to provide constraints on calculations devoted to {sup 14}Be and {sup 17}B, the neutron unbound states of {sup 13}Be and {sup 16}B have been investigated by one-proton knockout. The experimental techniques and results are discussed here. (author)
Energy Technology Data Exchange (ETDEWEB)
Quaglioni, S; Navratil, P; Roth, R
2009-12-15
The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. Above all nuclear scattering and reactions, which require the solution of the many-body quantum-mechanical problem in the continuum, represent an extraordinary theoretical as well as computational challenge for ab initio approaches.We present a new ab initio many-body approach which derives from the combination of the ab initio no-core shell model with the resonating-group method [4]. By complementing a microscopic cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters, this approach is capable of describing simultaneously both bound and scattering states in light nuclei. We will discuss applications to neutron and proton scattering on sand light p-shell nuclei using realistic nucleon-nucleon potentials, and outline the progress toward the treatment of more complex reactions.
A Multi-layered target for the Study of Neutron-Unbound Nuclei
Gueye, Paul; Frank, Nathan; Thoennessen, Michael
2013-04-01
The MoNA/LISA setup at the National Superconducting Cyclotron Laboratory at Michigan State University has provided an avenue to study the nuclear structure of unbound states/nuclei at and beyond the neutron drip line for the past decade using secondary beams from the Coupled Cyclotron Facility. A new multi-layered Si/Be active target is planned to be built to specifically study neutron unbound nuclei. In these experiments the decay energy is reconstructed from fragment-neutron coincidence measurements which are typically low in count rate. The multi-layered target will allow the use of thicker targets to increase the reaction rates, thus enabling to study currently out of reach nuclei such as 21C, 23C, and 24N. A description of the new setup and physics impact will be discussed.
Studies of exotic light nuclei
Energy Technology Data Exchange (ETDEWEB)
Cerny, J.
1976-05-01
For neutron-deficient nuclei, extension of the T/sub z/ = --3/2 series of strong beta-delayed proton precursors to /sup 61/Ge is discussed. For neutron-excess nuclei, heavy-ion induced, multi-nucleon transfer reaction studies of masses and energy levels of 2sld shell nuclei with T/sub z/ greater than or equal to 5/2 are covered. In addition, preliminary attempts to employ the (/sup 7/Li,/sup 2/He) reaction for the latter studies are shown; a new detection system capable of observing unbound final states as reaction products is demonstrated via investigations of the (..cap alpha..,/sup 2/He) reaction.
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...
Continuum spectroscopy of light nuclei
Directory of Open Access Journals (Sweden)
Charity R. J.
2016-01-01
Full Text Available Resonance spectroscopy of light nuclei is discussed with emphasis on the invariant-mass measurements performed with the HiRA detector. For three-body exit channels, we consider the exact conditions necessary such that the decay can be described as either sequential or prompt. However experimentally, we find some cases where the decay is intermediate between these two limits. Finally, two-proton decay from isobaric analog states is discussed.
Geant4 Simulation of A Multi-layered target for the Study of Neutron-Unbound Nuclei
Gueye, Paul; Freeman, Jessica; Frank, Nathan; Thoennessen, Michael; MONA Collaboration
2013-10-01
The MoNA/LISA setup at the National Superconducting Cyclotron Laboratory at Michigan State University has provided an avenue to study the nuclear structure of unbound states/nuclei at and beyond the neutron dripline for the past decade using secondary beams from the Coupled Cyclotron Facility. A new multi-layered Si/Be active target is being designed to specifically study neutron-unbound nuclei. In these experiments the decay energy is reconstructed from fragment-neutron coincidence measurements that are typically low in count rate. The multi-layered target will allow the use of thicker targets to increase the reaction rates, thus enabling to study currently out of reach nuclei such as 21C, 23C and 24N. The Geant4 Monte Carlo toolkit is currently used to model these physics processes within the multi-layered target and expected invariant mass distributions. A description of the experimental setup and simulation work will be discussed. This work is supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0000979.
Quantum Monte Carlo Calculations of Light Nuclei
Pieper, Steven C
2007-01-01
During the last 15 years, there has been much progress in defining the nuclear Hamiltonian and applying quantum Monte Carlo methods to the calculation of light nuclei. I describe both aspects of this work and some recent results.
Geometric symmetries in light nuclei
Bijker, Roelof
2016-01-01
The algebraic cluster model is is applied to study cluster states in the nuclei 12C and 16O. The observed level sequences can be understood in terms of the underlying discrete symmetry that characterizes the geometrical configuration of the alpha-particles, i.e. an equilateral triangle for 12C, and a regular tetrahedron for 16O. The structure of rotational bands provides a fingerprint of the underlying geometrical configuration of alpha-particles.
Monte Carlo approaches to light nuclei
Energy Technology Data Exchange (ETDEWEB)
Carlson, J.
1990-01-01
Significant progress has been made recently in the application of Monte Carlo methods to the study of light nuclei. We review new Green's function Monte Carlo results for the alpha particle, Variational Monte Carlo studies of {sup 16}O, and methods for low-energy scattering and transitions. Through these calculations, a coherent picture of the structure and electromagnetic properties of light nuclei has arisen. In particular, we examine the effect of the three-nucleon interaction and the importance of exchange currents in a variety of experimentally measured properties, including form factors and capture cross sections. 29 refs., 7 figs.
Nucleon localization in light and heavy nuclei
Zhang, C L; Nazarewicz, W
2016-01-01
An electron localization measure was originally introduced to characterize chemical bond structures in molecules. Recently, a nucleon localization based on Hartree-Fock densities has been introduced to investigate $\\alpha$-cluster structures in light nuclei. Compared to the local nucleonic densities, the nucleon localization function has been shown to be an excellent indicator of shell effects and cluster correlations. Using the spatial nucleon localization measure, we investigate the cluster structures in deformed light nuclei and study the emergence of fragments in fissioning heavy nuclei. To illustrate basic concepts of nucleon localization, we employ the deformed harmonic oscillator model. Realistic calculations are carried out using self-consistent nuclear density functional theory with quantified energy density functionals optimized for fission studies. We study particle densities and spatial nucleon localization distributions for deformed cluster configurations of $^{8}$Be and $^{20}$Ne, and also along...
Light nuclei from chiral EFT interactions
Navrátil, P.; Gueorguiev, V. G.; Vary, J. P.; Ormand, W. E.; Nogga, A.; Quaglioni, S.
2008-12-01
Recent developments in nuclear theory allow us to make a connection between quantum chromodynamics (QCD) and low-energy nuclear physics. First, chiral effective field theory (χEFT) provides a natural hierarchy to define two-nucleon ( NN), three-nucleon ( NNN), and even four-nucleon interactions. Second, ab-initio methods have been developed capable to test these interactions for light nuclei. In this contribution, we discuss ab-initio no-core shell-model (NCSM) calculations for s-shell and p-shell nuclei with NN and NNN interactions derived within χEFT.
Precision lifetime measurements in light exotic nuclei
McCutchan, Elizabeth
2017-01-01
A new generation of ab-initio calculations, based on realistic two- and three-body forces have had a profound impact on our understanding of nuclei. They have shed light on topics such as the origin of effective forces (like spin-orbit and tensor interactions) and the mechanisms behind cluster and pairing correlations. New precise data are required to both better parameterize the three body forces and to improve numerical methods. A sensitive probe of the structure of light nuclei comes from their electromagnetic transition rates. A refined Doppler Shift Attenuation Method (DSAM) will be outlined which is used to precisely measure lifetimes in light nuclei and helps to reduce and quantity systematic uncertainties in the measurement. Using this careful DSAM, we have made a series of precise measurements of electromagnetic transition strengths in Li isotopes, A =10 nuclei, and the exotic halo nucleus, 12Be. Various phenomena, such as alpha clustering and meson-exchange currents, can be investigated in these seemingly simple systems, while the collection of data spanning stable to neutron-rich, allows us to probe the influence of additional valence neutrons. This talk will report on what has been learned, and the challenges that lie in the future, both in experiment and theory, as we push to describing and measuring even more exotic systems. Work supported by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy under contract No. DE-AC02-98CH10886.
Unified studies of structure and reactions in light unstable nuclei
Directory of Open Access Journals (Sweden)
Ito Makoto
2016-01-01
Full Text Available The generalized two-center cluster model (GTCM, which can treat covalent, ionic and atomic configurations in general systems with two inert cores plus valence nucleons, is formulated in the basis of the microscopic cluster model. In this model, the covalent configurations constructed by the molecular orbital (MO method and the atomic (or ionic configuration obtained by the valence bonding (VB method can be described in a consistent manner. GTCM is applied to the light neutron-rich system, 10,12Be = α + α + XN (X = 2,4, and the unified studies of the structural changes and the reaction problem are performed. In the structure study, the calculated energy levels are characterized in terms of the chemical bonding like structures, such as the covalent MO or ionic VB structures. The chemical bonding structures changes from level to level within a small energy interval. In the unbound region, the structure problem with the total system of α + α + XN and the reaction problem, induced by the collision of an asymptotic VB state of α+6,8He, are combined by GTCM. The properties of unbound resonant states are discussed in a close connection to the reaction mechanism, and some enhancement factors originated from the properties of the intrinsic states are predicted in the reaction observables. The unified calculation of the structures and the reactions is applied to the Coulomb shift problem in the mirror system, such the 10Be and 10C nuclei. The Coulomb displacement energy of the mirror systems are discussed.
Light nuclei production in heavy ion collisions
Khan, K H; Wazir, Z; Khan, E U; Haseeb, Mahnaz Q; Ajaz, M
2009-01-01
Light nuclei production as a result of nuclear coalescence effect can give some signals on final state of Quark Gluon Plasma formation. We are studying the behavior of nuclear modification factor as a function of different variables using the simulated data coming from the FASTMC generator. This data is necessary to extract information on coalescence mechanism from experimental data on high energy nuclear-nuclear interactions.
Probing Chiral Interactions in Light Nuclei
Energy Technology Data Exchange (ETDEWEB)
Nogga, A; Barrett, B R; Meissner, U; Witala, H; Epelbaum, E; Kamada, H; Navratil, P; Glockle, W; Vary, J P
2004-01-08
Chiral two- and three-nucleon interactions are studied in a few-nucleon systems. We investigate the cut-off dependence and convergence with respect to the chiral expansion. It is pointed out that the spectra of light nuclei are sensitive to the three-nucleon force structure. As an example, we present calculations of the 1{sup +} and 3{sup +} states of {sup 6}Li using the no-core shell model approach. The results show contributions of the next-to-next-to-leading order terms to the spectra, which are not correlated to the three-nucleon binding energy prediction.
Few-body resonances in light nuclei
Csoto, A
2000-01-01
We have localized several few-body resonances in light nuclei, using methods which can properly handle two- or three-body resonant states. Among other results, we predict the existence of a three-neutron resonance, small spin-orbit splittings between the low-lying states in He-5 and Li-5, the nonexistence of the soft dipole resonance in He-6, new 1+ states in Li-8 and B-8, and the presence of a nonlinear amplification phenomenon in the 0+_2 state of C-12.
Clusters in neutron-rich light nuclei
Directory of Open Access Journals (Sweden)
Jelavić Malenica D.
2016-01-01
Full Text Available Due to their high selectivity, transfer and sequential decay reactions are powerful tools for studies of both single particle (nucleon and cluster states in light nuclei. Their use is particularly simple for investigations of α-particle clustering (because α-particle has Jπ=0+, which simplifies spin and parity assignments to observed cluster states, but they are also easily applicable to other types of clustering. Recent results on clustering in neutron-rich isotopes of beryllium, boron and carbon obtained measuring the 10B+10B reactions (at 50 and 72 MeV are presented. The highly efficient and segmented detector systems used, built from 4 Double Sided Silicon Strip Detectors (DSSSD allowed detection of double and multiple coincidences and, in that way, studies of states populated in transfer reactions, as well as their sequential decay.
Origin of light nuclei in near earth orbit
Derome, L
2001-01-01
The possible sources of light nuclei populations observed recently below the geomagnetic cutoff by the AMS experiment are discussed in terms of nuclear processes: fragmentation of the incoming flux of cosmic helium on atmospheric nuclei, and nuclear coalescence from proton and helium induced reactions. Results of simulations for deuterium, tritium, helium 3 and 4, are presented.
New aspects of the neutron capture in light nuclei
Energy Technology Data Exchange (ETDEWEB)
Mengoni, A. [Institute of Physical and Chemical Research, Wako, Saitama (Japan)
1997-03-01
Several neutron capture cross sections of light nuclei (A {<=} 40) for neutron energies up to the MeV region have been recently calculated. Examples are (target nuclei): {sup 12}C, {sup 13}C, {sup 16}O and {sup 10}Be. The results of these calculations will be shown together with a comparison with the most recent experimental data. In the case of n + {sup 10}Be case, the cross section of the inverse process (Coulomb dissociation of {sup 11}Be) is considered and compared with the measurement. A discussion on the relevant nuclear structure information required for the evaluation of nuclear data of light nuclei is given. (author)
Green's function calculations of light nuclei
Sun, ZhongHao; Wu, Qiang; Xu, FuRong
2016-09-01
The influence of short-range correlations in nuclei was investigated with realistic nuclear force. The nucleon-nucleon interaction was renormalized with V lowk technique and applied to the Green's function calculations. The Dyson equation was reformulated with algebraic diagrammatic constructions. We also analyzed the binding energy of 4He, calculated with chiral potential and CD-Bonn potential. The properties of Green's function with realistic nuclear forces are also discussed.
AMS with light nuclei at small accelerators
Stan-Sion, C.; Enachescu, M.
2017-06-01
AMS applications with lighter nuclei are presented. It will be shown how Carbon-14, Boron-10, Beryllium-10, and Tritium-3 can be used to provide valuable information in forensic science, environmental physics, nuclear pollution, in material science and for diagnose of the plasma confinement in fusion reactors. Small accelerators are reliable, efficient and possess the highest ion beam transmissions that confer high precision in measurements.
Review of the electric dipole moment of light nuclei
Yamanaka, Nodoka
2016-01-01
In this review, we summarize the theoretical development on the electric dipole moment of light nuclei. We first describe the nucleon level CP violation and its parametrization. We then present the results of calculations of the EDM of light nuclei in the ab initio approach and in the cluster model. The analysis of the effect of several models beyond standard model is presented, together with the prospects for its discovery. The advantage of the electric dipole moment of light nuclei is focused in the point of view of the many-body physics. The evaluations of the nuclear electric dipole moment generated by the $\\theta$-term and by the CP phase of the Cabibbo-Kobayashi-Maskawa matrix are also reviewed.
MCNP6 fragmentation of light nuclei at intermediate energies
Mashnik, Stepan G
2014-01-01
Fragmentation reactions induced on light target nuclei by protons and light nuclei of energies around 1 GeV/nucleon and below are studied with the latest Los Alamos Monte Carlo transport code MCNP6 and with its cascade-exciton model (CEM) and Los Alamos version of the quark-gluon string model (LAQGSM) event generators, version 03.03, used as stand-alone codes. Such reactions are involved in different applications, like cosmic-ray-induced single event upsets (SEU's), radiation protection, and cancer therapy with proton and ion beams, among others; therefore, it is important that MCNP6 simulates them as well as possible. 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 INC. Both CEM and LAQGSM account also for coalescence of light fragments (complex particles) up to He4 from energetic nucleons ...
Haloes and clustering in light, neutron-rich nuclei
Energy Technology Data Exchange (ETDEWEB)
Orr, N.A
2001-10-01
Clustering is a relatively widespread phenomenon which takes on many guises across the nuclear landscape. Selected topics concerning the study of halo systems and clustering in light, neutron-rich nuclei are discussed here through illustrative examples taken from the Be isotopic chain. (author)
Rare βp decays in light nuclei
DEFF Research Database (Denmark)
Borge, M.J.G.; Fraile, L.M.; Fynbo, Hans Otto Uldall
2013-01-01
Beta-delayed proton emission may occur at very low rates in the decays of the light nuclei 11Be and 8B. This paper explores the potential physical significance of such decays, estimates their rates and reports on first attempts to detect them: an experiment at ISOLDE/CERN gives a branching ratio...
On the Formation Mechanism of the Atomcule of Light Nuclei
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.
Electric dipole moments of light nuclei from χEFT
Higa, Renato
2013-03-01
I present recent calculations of EDMs of light nuclei using chiral effective field theory techniques. At leading-order, we argue that they can be expressed in terms of six CP-violating low-energy constants. With our expressions, eventual non-zero measurements of EDMs of deuteron, helion, and triton can be combined to disentangle the different sources of CP-violation.
Electric dipole moments of light nuclei
Mereghetti, Emanuele
2017-01-01
Electric dipole moments (EDMs) are extremely sensitive probes of physics beyond the Standard Model (SM). A vibrant experimental program is in place, with the goal to improve the existing neutron EDM bound by one/two orders of magnitude, and to test new ideas for the measurement of EDMs of light ions, such as deuteron and helium, at a comparable level. The success of this program, and its implications for physics beyond the SM, relies on the precise calculation of the EDMs in terms of the couplings of CP-violating operators. In light of the non-perturbative nature both of QCD at low energy and of the nuclear interactions, these calculations have proven difficult, and are affected by large theoretical uncertainties. In this talk I will review the progress that in recent years has been achieved on different aspects of the calculation of hadronic and nuclear EDMs. In particular, I will discuss how the interplay between lattice QCD and Chiral Effective Field Theory (EFT) has allowed to reduce a set of hadronic uncertainties. Finally, I will discuss how the measurements of th EDMs of one, two and three nucleon systems can be used to discriminate between various possible mechanisms of time-reversal violation at high energy.
Precision measurement of the mass difference between light nuclei and anti-nuclei
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...
Energy Technology Data Exchange (ETDEWEB)
Xu, Xiaodong
2016-06-30
Two-proton (2p) radioactivity is an exotic nuclear decay mode resulting in the simultaneous emission of two protons. The ground-state 2p radioactivity was discovered in the decay of {sup 45}Fe in 2002. Later, this novel decay mode was also found in the decays of {sup 48}Ni, {sup 54}Zn, and {sup 19}Mg. In order to study a promising 2p radioactivity candidate {sup 30}Ar, an experiment was performed at the Fragment Separator of GSI in Darmstadt (Germany). The in-flight decay technique, which is based on the tracking of the in-flight decay products by using the silicon strip detectors, was employed. Several calibration and alignment procedures were performed to achieve the best-possible accuracy of position and angle measurements. In order to determine the angular and half-life resolutions as well as the detection efficiency, the decays of the previously-known 2p emitter {sup 19}Mg were remeasured. The 2p radioactivity of {sup 19}Mg ground state and sequential emission of protons from several known excited states in {sup 19}Mg were confirmed. The deduced 2p decay energies are consistent with previous data. The evidence on a new excited state in {sup 19}Mg at 8.9{sup +0.8}{sub -0.7} MeV above the 2p threshold was found. It was tentatively suggested that this new {sup 19}Mg state decays by sequential emission of protons via two unknown 18Na resonances at 2.5{sup +0.7}{sub -0.3} MeV and 4.0{sup +1.5}{sub -0.6} MeV above the 1p threshold, respectively. Two previously-unknown proton-unbound nuclei {sup 30}Ar and {sup 29}Cl were identified by measuring the trajectories of their in-flight decay products {sup 28}S+p+p and {sup 28}S+p, respectively. The analysis of {sup 28}S-proton angular correlations provided information on the decay energies and structure of the observed states in {sup 30}Ar and {sup 29}Cl. The assigned ground state and first excited state of {sup 29}Cl were found at 1.8{sup +0.1}{sub -0.1} MeV and 2.3{sup +0.1}{sub 0.1} MeV above the one-proton threshold
From the stable to the exotic: clustering in light nuclei
Beck, C
2016-01-01
A great deal of research work has been undertaken in alpha-clustering study since the pioneering discovery of 12C+12C molecular resonances half a century ago. Our knowledge on physics of nuclear molecules has increased considerably and nuclear clustering remains one of the most fruitful domains of nuclear physics, facing some of the greatest challenges and opportunities in the years ahead. The occurrence of "exotic" shapes in light N=Z alpha-like nuclei is investigated. Various approaches of the superdeformed and hyperdeformed bands associated with quasimolecular resonant structures are presented. Evolution of clustering from stability to the drip-lines is examined: clustering aspects are, in particular, discussed for light exotic nuclei with large neutron excess such as neutron-rich Oxygen isotopes with their complete spectroscopy.
Electric Dipole Moments of Light Nuclei from Chiral EFT
Higa, Renato
2012-01-01
Recent calculations of EDMs of light nuclei in the framework of chiral effective field theory are presented. We argue that they can be written in terms of the leading six low-energy constants encoding CP-violating physics. EDMs of the deuteron, triton, and helion are explicitly given in order to corroborate our claim. An eventual non-zero measurement of these EDMs can be used to disentangle the different sources and strengths of CP-violation.
Fusion Enhancement for Neutron-Rich Light Nuclei
Singh, Varinderjit; Steinbach, T K; Hudan, S; deSouza, R T; Baby, L T; Kuvin, S A; Tripathi, V; Wiedenhover, I
2016-01-01
Measurement of the fusion cross-section for neutron-rich light nuclei is crucial in ascertaining if fusion of these nuclei occurs in the outer crust of a neutron star. The fusion excitation function at near-barrier energies for the $^{19}$O + $^{12}$C system was measured and the experimental results are compared to the fusion excitation function of $^{18}$O + $^{12}$C and $^{16}$O + $^{12}$C. The experiment was performed by utilizing a beam of $^{19}$O, produced via the $^{18}$O(d,p) reaction, to bombard a $^{12}$C target at energies near the Coulomb barrier. Evaporation residues produced in fusion of $^{18,19}$O ions with $^{12}$C target nuclei were detected with good geometric efficiency and identified by measuring their energy and time-of-flight. A significant enhancement is observed in the fusion probability of $^{19}$O ions with a $^{12}$C target as compared to $^{18}$O ions. The larger cross-sections observed at near barrier energies is related to significant narrowing of the fusion barrier indicating a...
Strictly finite-range potential for light and heavy nuclei
Salamon, P.; Lovas, R. G.; Betan, R. M. Id; Vertse, T.; Balkay, L.
2014-05-01
Strictly finite-range (SFR) potentials are exactly zero beyond their finite range. Single-particle energies and densities, as well as S-matrix pole trajectories, are studied in a few SFR potentials suited for the description of neutrons interacting with light and heavy nuclei. The SFR potentials considered are the standard cutoff Woods-Saxon (CWS) potentials and two potentials approaching zero smoothly: the SV potential introduced by Salamon and Vertse [Phys. Rev. C 77, 037302 (2008), 10.1103/PhysRevC.77.037302] and the SS potential of Sahu and Sahu [Int. J. Mod. Phys. E 21, 1250067 (2012), 10.1142/S021830131250067X]. The parameters of these latter potentials were set so that the potentials may be similar to the CWS shape. The range of the SV and SS potentials scales with the cube root of the mass number of the core like the nuclear radius itself. For light nuclei a single term of the SV potential (with a single parameter) is enough for a good description of the neutron-nucleus interaction. The trajectories are compared with a benchmark for which the starting points (belonging to potential depth zero) can be determined independently. Even the CWS potential is found to conform to this benchmark if the range is identified with the cutoff radius. For the CWS potentials some trajectories show irregular shapes, while for the SV and SS potentials all trajectories behave regularly.
One- and two neutron decay of light neutron-rich nuclei
Thoennessen, Michael
2014-09-01
Direct reactions with radioactive beams have been used very successfully to populate and measure nuclei beyond the neutron dripline and neutron unbound excited states of nuclei close to the neutron dripline. The use of different reactions (for example neutron removal and proton removal) to populate the same final nucleus can be used to selectively populate different states. Recent results from the MoNA-LISA setup at the NSCL, including 10He, 10,11Li, and 12,13Be will be presented. Direct reactions with radioactive beams have been used very successfully to populate and measure nuclei beyond the neutron dripline and neutron unbound excited states of nuclei close to the neutron dripline. The use of different reactions (for example neutron removal and proton removal) to populate the same final nucleus can be used to selectively populate different states. Recent results from the MoNA-LISA setup at the NSCL, including 10He, 10,11Li, and 12,13Be will be presented. This work was supported in part by the NSF, Grant PHY-11-02511.
Ab initio calculations of reactions of light nuclei
Hupin, Guillaume; Quaglioni, Sofia; Navrátil, Petr
2017-09-01
An ab initio (i.e., from first principles) theoretical framework capable of providing a unified description of the structure and low-energy reaction properties of light nuclei is desirable as a support tool for accurate evaluations of crucial reaction data for nuclear astrophysics, fusion-energy research, and other applications. We present an efficient many-body approach to nuclear bound and scattering states alike, known as the ab initio no-core shell model with continuum. In this approach, square-integrable energy eigenstates of the A-nucleon system are coupled to (A-A)+A target-plus-projectile wave functions in the spirit of the resonating group method to obtain an efficient description of the many-body nuclear dynamics both at short and medium distances and at long ranges. We show that predictive results for nucleon and deuterium scattering on 4He nuclei can be obtained from the direct solution of the Schröedinger equation with modern nuclear potentials.
Elastic scattering, fusion, and breakup of light exotic nuclei
Energy Technology Data Exchange (ETDEWEB)
Kolata, J.J. [University of Notre Dame, Physics Department, Notre Dame, IN (United States); Guimaraes, V. [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo, SP (Brazil); Aguilera, E.F. [Instituto Nacional de Investigaciones Nucleares, Departamento de Aceleradores, Mexico, Distrito Federal (Mexico)
2016-05-15
The present status of fusion reactions involving light (A< 20) radioactive projectiles at energies around the Coulomb barrier (E<10 MeV per nucleon) is reviewed, emphasizing measurements made within the last decade. Data on elastic scattering (providing total reaction cross section information) and breakup channels for the involved systems, demonstrating the relationship between these and the fusion channel, are also reviewed. Similarities and differences in the behavior of fusion and total reaction cross section data concerning halo nuclei, weakly-bound but less exotic projectiles, and strongly-bound systems are discussed. One difference in the behavior of fusion excitation functions near the Coulomb barrier seems to emerge between neutron-halo and proton-halo systems. The role of charge has been investigated by comparing the fusion excitation functions, properly scaled, for different neutron- and proton-rich systems. Possible physical explanations for the observed differences are also reviewed. (orig.)
Ab initio theories for light nuclei and neutron stars
Gezerlis, Alexandros
2016-09-01
In this talk I will touch upon several features of modern ab initio low-energy nuclear theory. I will start by discussing what ``ab initio'' means in this context. Specifically, I will spend some time going over nucleon-nucleon and three-nucleon interactions and their connections with the underlying theory of Quantum Chromodynamics. I will then show how these interactions are used to describe light nuclei using essentially exact few-body methods. I will then discuss heavier systems, especially those of astrophysical relevance, as well as the methods used to tackle them. This work was supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada and the Canada Foundation for Innovation (CFI).
The Magnetic Structure of Light Nuclei from Lattice QCD
Chang, Emmanuel; Orginos, Kostas; Parreno, Assumpta; Savage, Martin J; Tiburzi, Brian C; Beane, Silas R
2015-01-01
Lattice QCD with background magnetic fields is used to calculate the magnetic moments and magnetic polarizabilities of the nucleons and of light nuclei with $A\\le4$, along with the cross-section for the $M1$ transition $np\\rightarrow d\\gamma$, at the flavor SU(3)-symmetric point where the pion mass is $m_\\pi\\sim 806$ MeV. These magnetic properties are extracted from nucleon and nuclear energies in six uniform magnetic fields of varying strengths. The magnetic moments are presented in a recent Letter. For the charged states, the extraction of the polarizability requires careful treatment of Landau levels, which enter non-trivially in the method that is employed. The nucleon polarizabilities are found to be of similar magnitude to their physical values, with $\\beta_p=5.22(+0.66/-0.45)(0.23) \\times 10^{-4}$ fm$^3$ and $\\beta_n=1.253(+0.056/-0.067)(0.055) \\times 10^{-4}$ fm$^3$, exhibiting a significant isovector component. The dineutron is bound at these heavy quark masses and its magnetic polarizability, $\\beta...
Improved variational many-body wave function in light nuclei
Usmani, Q. N.; Singh, A.; Anwar, K.; Rawitscher, G.
2009-09-01
We propose and implement a simple method for improving the variational wave function of a many-body system. We have obtained a significant improvement in the binding energies, wave functions, and variance for the light nuclei H3, He4, and Li6, using the fully realistic Argonne (AV18) two-body and Urbana-IX (UIX) three-body interactions. The energy of He4 was improved by about 0.2 MeV and the Li6 binding energy was increased by ≈1.7 MeV compared to earlier variational Monte Carlo results. The latter result demonstrates the significant progress achieved by our method, and detailed analyses of the improved results are given. With central interactions the results are found to be in agreement with the “exact” calculations. Our study shows that the relative error in the many-body wave functions, compared to two-body pair correlations, increases rapidly at least proportionally to the number of pairs in the system. However, this error does not increase indefinitely since the pair interactions saturate owing to convergence of cluster expansion.
Energy Technology Data Exchange (ETDEWEB)
Al Falou, H
2007-07-15
The unbound nuclei {sup 7,9}He and {sup 10}Li have been investigated via the high-energy breakup of beams of neutron-rich nuclei ({sup 8}He, {sup 11}Be and {sup 14}B). The decay-energy spectra were reconstructed from coincident measurements of the charged fragments ({sup 6,8}He and {sup 9}Li) with a {delta}E-E telescope (CHARISSA) and the neutrons with the DEMON array. A theoretical approach based on the sudden approximation was used to model the reactions populating the unbound final states. The calculated decay-energy spectra were convoluted with the response function of the experimental setup using a simulation developed specifically for the present study and compared with the experimental results. The {sup 10}Li system was produced using an {sup 11}Be beam and the results confirm the continuation of the inversion of the {nu}1s1/2 and {nu}0p1/2 levels in the N = 7 isotopic chain. The {sup 9}He system was produced in two different ways with the breakup of {sup 11}Be and {sup 14}B, and was the most exotic system studied here. In this case, a structure was observed at very low decay energy which very probably corresponds to a virtual s state (a{sub s} {approx_equal} -2 - 0 fm). This result suggests that the level inversion also occurs in {sup 9}He, but with a much weaker core-neutron interaction than for {sup 10}Li (a{sub s} equals -14 {+-} 2 fm). For the data acquired from the breakup of the {sup 14}B beam, the decay energy spectrum exhibits a resonance around E{sub r} equals 1.2 MeV, which most probably corresponds to an excited 1/2{sup -} state in {sup 9}He. The {sup 7}He system was investigated with three different beams ({sup 8}He, {sup 11}Be and {sup 14}B). No evidence for the existence of the proposed low-lying (E{sub r} {approx} 1 MeV) spin-orbit partner (1/2{sup -}) of the ground state (3/2{sup -}) could be found. (author)
Evaluation of Coulomb Energy Difference for Light Mirror Nuclei Using Slater—Type Orbitals
Institute of Scientific and Technical Information of China (English)
F.Oner; R.A.Mamedoy
2002-01-01
Behavior of the Coulomb energy difference for light nuclei is explained in terms of the different values of the average Coulomb interaction between two particles.Coulomb energy difference according to shell model of light mirror nuclei in the Coulomb and exchange integrals in the formula can be explained with exponential-type wavefunctions.In this study,using the one-center expansion of exponential-type wavefunctions in terms of Slater-type orbitals with the same center,we derived formula for Coulomb energy difference of light mirror nuclei.
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.
MCNP6 simulation of light and medium nuclei fragmentation at intermediate energies
Directory of Open Access Journals (Sweden)
Mashnik Stepan G.
2016-01-01
Full Text Available 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 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.
MCNP6 simulation of light and medium nuclei fragmentation at intermediate energies
Mashnik, Stepan G
2015-01-01
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 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
MCNP6 simulation of light and medium nuclei fragmentation at intermediate energies
Mashnik, Stepan G.; Kerby, Leslie M.
2016-05-01
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 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.
Structure and reactions of light neutron rich nuclei
Energy Technology Data Exchange (ETDEWEB)
Esbensen, H.
1993-01-01
Radioactive beam experiments have made it possible to study the structure of nuclei at the neutron drip line. Pair correlations play a crucial role in such nuclei and characteristic features include an extended neutron halo density and a large dipole strength near threshold. The most detailed studies have been performed for [sup 11]Li. I will present a 3-body model that explains the main features of the data obtained for this nucleus.
Structure and reactions of light neutron rich nuclei
Energy Technology Data Exchange (ETDEWEB)
Esbensen, H.
1993-04-01
Radioactive beam experiments have made it possible to study the structure of nuclei at the neutron drip line. Pair correlations play a crucial role in such nuclei and characteristic features include an extended neutron halo density and a large dipole strength near threshold. The most detailed studies have been performed for {sup 11}Li. I will present a 3-body model that explains the main features of the data obtained for this nucleus.
Search for Beta Decay of the Neutron Halo in Light Nuclei
2002-01-01
The low binding energies of the last neutrons in neutron-rich nuclei lead to the formation of a neutron halo around the nuclear core. We are looking in light nuclei for beta-decay of the neutrons in the halo, a process which in $^1
N3LO NN interaction adjusted to light nuclei in ab exitu approach
Shirokov, A. M.; Shin, I. J.; Kim, Y.; Sosonkina, M.; Maris, P.; Vary, J. P.
2016-10-01
We use phase-equivalent transformations to adjust off-shell properties of similarity renormalization group evolved chiral effective field theory NN interaction (Idaho N3LO) to fit selected binding energies and spectra of light nuclei in an ab exitu approach. We then test the transformed interaction on a set of additional observables in light nuclei to verify that it provides reasonable descriptions of these observables with an apparent reduced need for three- and many-nucleon interactions.
Unstable nuclei in dissociation of light stable and radioactive nuclei in nuclear track emulsion
Artemenkov, D A; Zarubin, P I
2016-01-01
A role of the unstable nuclei ${}^{6}$Be, ${}^{8}$Be and ${}^{9}$B in the dissociation of relativistic nuclei ${}^{7,9}$Be, ${}^{10}$B and ${}^{10,11}$C is under study on the basis of nuclear track emulsion exposed to secondary beams of the JINR Nuclotron. Contribution of the configuration ${}^{6}$Be + $\\mit{n}$ to the ${}^{7}$Be nucleus structure is 8 $\\pm$ 1% which is near the value for the configuration ${}^{6}$Li + $\\mit{p}$. Distributions over the opening angle of $\\alpha$-particle pairs indicate to a simultaneous presence of virtual ${}^{8}$Be$_{g.s.}$ and ${}^{8}$Be$_{2^+}$ states in the ground states of the ${}^{9}$Be and ${}^{10}$C nuclei. The core ${}^{9}$B is manifested in the {${}^{10}$C} nucleus with a probability of 30 $\\pm$ 4%. Selection of the ${}^{10}$C "white" stars accompanied by ${}^{8}$Be$_{g.s.}$ (${}^{9}$B) leads to appearance in the excitation energy distribution of 2$\\alpha$2$\\mit{p}$ "quartets" of the distinct peak with a maximum at 4.1 $\\pm$ 0.3 MeV. ${}^{8}$Be$_{g.s.}$ decays are p...
Three-particle decays of light-nuclei resonances
DEFF Research Database (Denmark)
Álvarez-Rodríguez, R.; Jensen, A.S.; Garrido, E.
2012-01-01
We have studied the three-particle decay of 12C, 9Be and 6Be resonances. These nuclei have been described as three-body systems by means of the complex scaled hyperspherical adiabatic expansion method. The short-distance part of the wave function is responsible for the energies, whereas the infor...
Structure of light neutron-rich nuclei through Coulomb dissociation
Indian Academy of Sciences (India)
U Datta Pramanik; T Aumann; D Cortina; H Emling; H Geissel; M Hellström; R Holzmann; N Iwasa; Y Leifels; G Münzenberg; M Rejmund; C Scheidenberger; K Sümmerer; A Leistenschneider; Th W Elze; A Grünschloss; S Ilievski; K Boretzky; J V Kratz; R Kulessa; E Lubkiewicz; E Wajda; W Walus; P Reiter; H Simon
2001-08-01
Coulomb breakup of neutron-rich nuclei around mass ∼ 20 has been studied experimentally using secondary beams (∼ 500–600 MeV/u) of unstable nuclei produced at GSI. The spectroscopic factor deduced for the neutron occupying 1/2 level in 15C ground state is consistent with the earlier reported value. The data analysis for Coulomb breakup of 17C shows that most of the cross section yields the 16C core in its excited state. For 17-22O, the low-lying E1 strength amounts up to about 12% of the energy weighted dipole sum rule strength depending on neutron excess. The cluster sum rule limit with 16O as a core is almost exhausted for 17,18O, while for more neutron rich isotopes the strength with respect to that limit decreases.
Light nuclei in the vicinity of the dripline and beyond
Energy Technology Data Exchange (ETDEWEB)
Chulkov, L.V. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Kurchatov Institute, Moscow (Russian Federation); Jonson, B.; Zhukov, M.V. [Chalmers Tekniska Hoegskola, Fundamental Fysik, Goeteborg (Sweden)
2015-08-15
After a brief historical overview of the field of physics with radioactive beams, we give an update of the most recent experimental achievements for nuclei at or beyond the nuclear driplines. Long-lived exotic nuclear states are discussed including multi-nucleon radioactivity and exotic isomers. Studies of correlations between decay products in three-body decays and analysis in a Jacobi-coordinate framework are discussed with special emphasis on the difficulty in the interpretations of data obtained in different reactions. We give examples of systematic studies that the vast amount of now existing data allows, such as shell closures, competition between single-particle states in isotopes, isotones and mirror nuclei. The Thomas-Ehrman shift, Garvey-Kelson-type mass relations and IMME analysis of isobaric multiplets with isospin T = 3/2 and 2 are also discussed as well as alternative interpretations in certain cases. (orig.)
The study of initial conditions in collisions of light, intermediate and heavy nuclei
Directory of Open Access Journals (Sweden)
Loctionov A.A.
2017-01-01
Full Text Available The system size dependence for multiparticle processes has been recognized in both cosmic ray (“Stratosphere” collaboration and at accelerator (“EMU” collaboration experiments. The strong enhancement in multiplicity fluctuations for the most central light-light – (C, O, Ne + (C/N/O – collisions has been revealed at JINR-AGS-SPS energies. The sharp difference of light nuclear interactions are interpreted as the sign of intrinsic alpha-clustering in light nuclei.
Light nuclei production in relativistic Au+nucleus collisions
Energy Technology Data Exchange (ETDEWEB)
Bennett, M. J. [Yale Univ., A.W. Wright Nuclear Structure Laboratory, New Haven, CT (United States); Pope, J. K. [Yale Univ., A.W. Wright Nuclear Structure Laboratory, New Haven, CT (United States); Beavis, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Carroll, J. B. [Univ. of California, Los Angeles, CA (United States); Chiba, J. [KEK, Tsukuba (Japan); Chikanian, A. [Yale Univ., A.W. Wright Nuclear Structure Laboratory, New Haven, CT (United States); Crawford, H. J. [Univ. of California, Space Sciences Laboratory, Berkeley, CA (United States); Cronqvist, M. [Univ. of California, Space Sciences Laboratory, Berkeley, CA (United States); Dardenne, Y. [Univ. of California, Space Sciences Laboratory, Berkeley, CA (United States); Kumar, B. S. [Yale Univ., A.W. Wright Nuclear Structure Laboratory, New Haven, CT (United States); Nagle, J. L. [Yale University, A.W. Wright Nuclear Structure Laboratory, New Haven, CT (United States); Debbe, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Doke, T. [Waseda Univ., Science and Engineering Research Institute, Waseda (Japan); Engelage, J. [Univ. of California, Space Sciences Laboratory, Berkeley, CA (United States); Greiner, L. [Univ. of California, Space Sciences Laboratory, Berkeley, CA (United States); Hayano, R S [University of Tokyo, Tokyo (Japan); Hallman, Timothy J. [Univ. of California, Los Angeles, CA (United States); Heckman, H. H. [E.O. Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Kashiwagi, T. [Waseda Univ., Science and Engineering Research Institute, Waseda (Japan); Kikuchi, J. [Waseda Univ., Science and Engineering Research Institute, Waseda (Japan); Tanaka, K. H. [KEK, Tsukuba (Japan); Kumar, B. S. [Yale Univ., A.W. Wright Nuclear Structure Laboratory, New Haven, CT (United States); Kuo, C. [Univ. of California, Space Sciences Laboratory, Berkeley, CA (United States); Lindstrom, P. J. [E.O. Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Mitchell, J. W. [USRA/Goddard Space Flight Center, Greenbelt, Maryland (United States); Nagamiya, S. [Columbia Univ., Nevis Laboratory, Irvington, NY (United States); Nagle, J. L. [Yale Univ., A.W. Wright Nuclear Structure Laboratory, New Haven, CT (United States); Stankus, P. [Columbia Univ., Nevis Laboratory, Irvington, NY (United States); Tanaka, K. H. [KEK, Tsukuba (Japan); Welsh, R. C. [Johns Hopkins University, Baltimore, MD (United States); Zhan, W. [Columbia Univ., Nevis Laboratory, Irvington, NY (United States)
1998-08-01
We have measured the yields of protons and A=2-4 nuclei in collisions between 10.8 A GeV/ c Au beams and targets of Al, Cu, and Au. The data, which cover a broad rapidity range at low transverse momenta, were measured as a function of collision centrality using a focusing beam line spectrometer and a high-rate centrality detector. We investigate the dependence of coalescence parameters on event geometry. The data are compared with the predictions of an RQMD+coalescence model. {copyright} {ital 1998} {ital The American Physical Society}
Scattering of light halo nuclei on heavy target at energies around the Coulomb barrier
Directory of Open Access Journals (Sweden)
Tengblad O.
2014-03-01
Full Text Available We report here on experiments performed at TRIUMF to study the scattering of the light halo nuclei 11Li on lead at energies below and around the Coulomb barrier. The the elastic and break-up differential cross section are interpreted in the framework of Continuum-Discretized Coupled-Channel calculations. The departure from Rutherford scattering at energies below the barrier is well beyond the behavior of normal nuclei.
Scattering of light halo nuclei on heavy target at energies around the Coulomb barrier
Tengblad O.; Borge M.J.G.; Cubero M.; Nacher E.; Pesudo V.; Perea A.; Gomez-Camacho J.; Moro A. M.; Fernandez-Garcia J.P.; Alvarez M.A.G.; Rodriguez-Gallardo M.; Lay J. A.; Martel I.; Acosta L.; Sanchez-Benitez A.M.
2014-01-01
INPC 2013 – International Nuclear Physics Conference We report here on experiments performed at TRIUMF to study the scattering of the light halo nuclei 11Li on lead at energies below and around the Coulomb barrier. The the elastic and break-up differential cross section are interpreted in the framework of Continuum-Discretized Coupled-Channel calculations. The departure from Rutherford scattering at energies below the barrier is well beyond the behavior of normal nuclei Consejo Interins...
Statistical theory of light nucleus reactions with 1p-shell light nuclei
Xiaojun, Sun; Jingshang, Zhang
2017-09-01
The 1p-shell light elements (Li, Be, B, C, N, and O) had long been selected as the most important materials for improving neutron economy in thermal and fast fission reactors and in the design of accelerator-driven spallation neutron sources. A statistical theory of light nucleus reactions (STLN) is proposed to describe the double-differential cross sections for both neutron and light charged particle induced nuclear reactions with 1p-shell light nuclei. The dynamics of STLN is described by the unified Hauser-Feshbach and exciton model, in which the angular momentum and parity conservations are strictly considered in equilibrium and pre-equilibrium processes. The Coulomb barriers of the incoming and outgoing charged particles, which significantly influence the open channels of the reaction, can be reasonably considered in incident channel and different outgoing channels. In kinematics, the recoiling effects in various emission processes are strictly taken into account. The analytical energy and angular spectra of the reaction products in sequential and simultaneous emission processes are obtained in terms of the new integral formula proposed in our recent paper. Taking 12C(n, xn), 9Be(n, xn), 16O(n, xn), and 9Be(p,xn) reactions as examples, we had calculated the double-differential cross sections of outgoing neutrons and compared with the experimental data. In addition, we had also calculated the partition and total kerma coefficients for 12C(n, xn) and 16O(n, xn) reactions, respectively. The existing experimental data can be remarkably well reproduced by STLN, which had been used to set up file-6 in CENDL database.
Inner Radiation Belt Generation of Light Nuclei Isotope
Galper, A. M.; Koldashov, S. V.; Leonv, A. A.; Mikhailov, V. V.
2003-07-01
Nuclear interactions between inner zone protons and atoms in the upper atmosphere provide the essential source of H and He isotop es nuclei in radiation belt. This paper reports the calculations of these isotop es intensities from the inner zone proton intensity model AP-8, the atmosphere drift-averaged composition and densities model MSIS-90, and cross sections for the various interaction processes. To calculate drift-averaged densities and energy losses of secondaries the particles are traced in geomagnetic field according IGRF-95 model by numerical solution of motion equation. The calculations account for nuclear interactions kinematic along the whole trapped protons trajectories. The results of calculations are compared with experimental data from SAMPEX, CRRES, RESURS-04 and MITA satellites taken during different solar activity phases. The comparison with observational data shows that the atmosphere is sufficient source for inner zone 4 He, 3 He,2 H and 3 H for L-shell less than 1.3.
Energy Technology Data Exchange (ETDEWEB)
Furusawa, Shun; Yamada, Shoichi [Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Sumiyoshi, Kohsuke [Numazu College of Technology, Ooka 3600, Numazu, Shizuoka 410-8501 (Japan); Suzuki, Hideyuki, E-mail: furusawa@heap.phys.waseda.ac.jp [Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 (Japan)
2013-08-01
We construct new equations of state for baryons at subnuclear densities for the use in core-collapse simulations of massive stars. The abundance of various nuclei is obtained together with thermodynamic quantities. A model free energy is constructed, based on the relativistic mean field theory for nucleons and the mass formula for nuclei with the proton number up to {approx}1000. The formulation is an extension of the previous model, in which we adopted the liquid drop model to all nuclei under the nuclear statistical equilibrium. We reformulate the new liquid drop model so that the temperature dependences of bulk energies could be taken into account. Furthermore, we extend the region in the nuclear chart, in which shell effects are included, by using theoretical mass data in addition to experimental ones. We also adopt a quantum-theoretical mass evaluation of light nuclei, which incorporates the Pauli- and self-energy shifts that are not included in the ordinary liquid drop model. The pasta phases for heavy nuclei are taken into account in the same way as in the previous model. We find that the abundances of heavy nuclei are modified by the shell effects of nuclei and temperature dependence of bulk energies. These changes may have an important effect on the rates of electron captures and coherent neutrino scatterings on nuclei in supernova cores. The abundances of light nuclei are also modified by the new mass evaluation, which may affect the heating and cooling rates of supernova cores and shocked envelopes.
Axial-Current Matrix Elements in Light Nuclei from Lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Savage, Martin [Univ. of Washington, Seattle, WA (United States); Shanahan, Phiala E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Tiburzi, Brian C. [Univ. of Maryland, College Park, MD (United States); Wagman, Michael L. [Univ. of Washington, Seattle, WA (United States); Winter, Frank T. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Beane, Silas [Univ. of New Hampshire, Durham, NH (United States); Chang, Emmanuel [Univ. of Washington, Seattle, WA (United States); Davoudi, Zohreh; Detmold, William [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Orginos, Konstantinos [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States)
2016-12-01
I present results from the first lattice QCD calculations of axial-current matrix elements in light nuclei, performed by the NPLQCD collaboration. Precision calculations of these matrix elements, and the subsequent extraction of multi-nucleon axial-current operators, are essential in refining theoretical predictions of the proton-proton fusion cross section, neutrino-nucleus cross sections and $\\beta\\beta$-decay rates of nuclei. In addition, they are expected to shed light on the phenomenological quenching of $g_A$ that is required in nuclear many-body calculations.
Axial-Current Matrix Elements in Light Nuclei from Lattice QCD
Savage, Martin J; Tiburzi, Brian C; Wagman, Michael L; Winter, Frank; Beane, Silas R; Chang, Emmanuel; Davoudi, Zohreh; Detmold, William; Orginos, Kostas
2016-01-01
I present results from the first lattice QCD calculations of axial-current matrix elements in light nuclei, performed by the NPLQCD collaboration. Precision calculations of these matrix elements, and the subsequent extraction of multi-nucleon axial-current operators, are essential in refining theoretical predictions of the proton-proton fusion cross section, neutrino-nucleus cross sections and $\\beta\\beta$-decay rates of nuclei. In addition, they are expected to shed light on the phenomenological quenching of $g_A$ that is required in nuclear many-body calculations.
Deformation change in light iridium nuclei from laser spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Verney, D.; Le Blanc, F.; Obert, J.; Oms, J.; Puteaux, J.C.; Roussiere, B.; Sauvage, J. [IN2P3-CNRS/Universite Paris Sud-XI, Institut de Physique Nucleaire, Orsay Cedex (France); Cabaret, L.; Duong, H.T.; Pinard, J. [CNRS, Laboratoire Aime Cotton, Orsay Cedex (France); Crawford, J.E.; Lee, J.K.P. [McGill University, Physics Department, Montreal (Canada); Fricke, B.; Rashid, K. [Institut fuer Theoretische Physik der Universitaet Kassel, Kassel (Germany); Genevey, J.; Ibrahim, F. [IN2P3-CNRS/Universite Joseph Fourier-Grenoble I, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble Cedex (France); Huber, G.; Krieg, M.; Sebastian, V. [Institut fuer Physik der Universitaet Mainz, Mainz (Germany); Le Scornet, G.; Lunney, D. [IN2P3-CNRS/Universite Paris Sud-XI, Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, Orsay Cedex (France)
2006-12-15
Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-color, two-step resonant scheme was used to selectively ionize the desorbed Ir atoms. The hyperfine structure (HFS) and isotope shift (IS) of the first transition of the ionization path 5d{sup 7}6s{sup 24}F{sub 9/2}{yields}5d{sup 7}6s6p{sup 6}F{sub 11/2} at 351.5nm were measured for {sup 182-189}Ir, {sup 186}Ir{sup m} and the stable {sup 191,193}Ir. The nuclear magnetic moments {mu}{sub I} and the spectroscopic quadrupole moments Q{sub s} were obtained from the HFS spectra and the change of the mean square charge radii from the IS measurements. The sign of {mu}{sub I} was experimentally determined for the first time for the masses 182{<=}A{<=}189 and the isomeric state {sup 186}Ir{sup m}. The spectroscopic quadrupole moments of {sup 182}Ir and {sup 183}Ir were measured also for the first time. A large mean square charge radius change between {sup 187}Ir and {sup 186}Ir{sup g} and between {sup 186}Ir{sup m} and {sup 186}Ir{sup g} was observed corresponding to a sudden increase in deformation: from {beta}{sub 2}{approx_equal}+0.16 for the heavier group A = 193, 191, 189, 187 and 186m to {beta}{sub 2}{>=}+0.2 for the lighter group A=186g, 185, 184, 183 and 182. These results were analyzed in the framework of a microscopic treatment of an axial rotor plus one or two quasiparticle(s). This sudden deformation change is associated with a change in the proton state that describes the odd-nuclei ground state or that participates in the coupling with the neutron in the odd-odd nuclei. This state is identified with the {pi}3/2 {sup +}[402 ] orbital for the heavier group and with the {pi}1/2{sup -}[541 ] orbital stemming from the 1h
Iwabuchi, Kosei; Takagi, Shingo
2010-08-01
The plant organelles, chloroplast and nucleus, change their position in response to light. In Arabidopsis thaliana leaf cells, chloroplasts and nuclei are distributed along the inner periclinal wall in darkness. In strong blue light, they become positioned along the anticlinal wall, while in weak blue light, only chloroplasts are accumulated along the inner and outer periclinal walls. Blue-light dependent positioning of both organelles is mediated by the blue-light receptor phototropin and controlled by the actin cytoskeleton. Interestingly, however, it seems that chloroplast movement requires short, fine actin filaments organized at the chloroplast edge, whereas nuclear movement does cytoplasmic, thick actin bundles intimately associated with the nucleus. Although there are many similarities between photo-relocation movements of chloroplasts and nuclei, plant cells appear to have evolved distinct mechanisms to regulate actin organization required for driving the movements of these organelles.
Quantum Monte Carlo studies of relativistic effects in light nuclei
Forest, J. L.; Pandharipande, V. R.; Arriaga, A.
1999-07-01
Relativistic Hamiltonians are defined as the sum of relativistic one-body kinetic energy, two- and three-body potentials, and their boost corrections. In this work we use the variational Monte Carlo method to study two kinds of relativistic effects in 3H and 4He, using relativistic Hamiltonians. The first is due to the nonlocalities in the relativistic kinetic energy and relativistic one-pion exchange potential (OPEP), and the second is from boost interaction. The OPEP contribution is reduced by ~15% by the relativistic nonlocality, which may also have significant effects on pion exchange currents. However, almost all of this reduction is canceled by changes in the kinetic energy and other interaction terms, and the total effect of the nonlocalities on the binding energy is very small. The boost interactions, on the other hand, give repulsive contributions of ~0.4 (1.9) MeV in 3H (4He) and account for ~37% of the phenomenological part of the three-nucleon interaction needed in the nonrelativistic Hamiltonians. The wave functions of nuclei are not significantly changed by these effects.
Local chiral potentials and the structure of light nuclei
Piarulli, Maria; Schiavilla, Rocco; Kievsky, Alejandro; Lovato, Alessandro; Marcucci, Laura E; Pieper, Steven C; Viviani, Michele; Wiringa, Robert B
2016-01-01
We present fully local versions of the minimally non-local nucleon-nucleon potentials constructed in a previous paper [M.\\ Piarulli {\\it et al.}, Phys.\\ Rev.\\ C {\\bf 91}, 024003 (2015)], and use them in hypersperical-harmonics and quantum Monte Carlo calculations of ground and excited states of $^3$H, $^3$He, $^4$He, $^6$He, and $^6$Li nuclei. The long-range part of these local potentials includes one- and two-pion exchange contributions without and with $\\Delta$-isobars in the intermediate states up to order $Q^3$ ($Q$ denotes generically the low momentum scale) in the chiral expansion, while the short-range part consists of contact interactions up to order $Q^4$. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in two different ranges of laboratory energies, either 0--125 MeV or 0--200 MeV, and to the deuteron binding energy and $nn$ singlet scattering length. Fits to these data are performed for three models characterized by long- and short-range cutof...
Identification of Light Cosmic-Ray Nuclei with AMS-02
Tomassetti, Nicola
2015-01-01
AMS-02 is a wide acceptance (0.5 m2 sr) and long duration (up to 20 years) magnetic spectrometer operating onboard the International Space Station since May 2011. Its main scientific objectives are the indirect research of Dark Matter, searches of primitive Anti-Matter and the precise measurement of the Cosmic-Ray (CR) spectra. Among charged CR species, AMS-02 will be able to measure relative abundances and absolute fluxes of CRs nuclei from Hydrogen up to at least Iron (Z = 26) in a kinetic energy range from hundreds MeV to TeV per nucleon. The high statistics measurement of the chemical composition of CRs in this extended energy range will reveal new insights about the CRs life in the Galaxy, from their origin to the propagation in the interstellar medium, giving new constraints to astrophysical models of Galactic CRs. The nucleus absolute charge, Z, is measured several times along the trajectory of the particle inside AMS-02 using different detection techniques: in the 9 planes of the Silicon Tracker, in t...
AMS results on the fluxes of light nuclei in cosmic rays
Bertucci, Bruna; AMS Collaboration
2017-01-01
AMS-02 is a wide acceptance high-energy physics experiment installed on the International Space Station in May 2011 and it has been operating continuously since then. AMS-02 is able to separate cosmic rays light nuclei species (1 AMS will be presented, including proton, helium, boron to carbon flux ratio, and highlights of ongoing analyses discussed. On behalf of the AMS Collaboration.
Benchmark calculation of no-core Monte Carlo shell model in light nuclei
Abe, T; Otsuka, T; Shimizu, N; Utsuno, Y; Vary, J P; 10.1063/1.3584062
2011-01-01
The Monte Carlo shell model is firstly applied to the calculation of the no-core shell model in light nuclei. The results are compared with those of the full configuration interaction. The agreements between them are within a few % at most.
Unraveling models of CP violation through electric dipole moments of light nuclei
Dekens, W.; Vries, J. de; Bsaisou, J.; Bernreuther, W.; Hanhart, C.; Meißner, Ulf-G; Nogga, A.; Wirzba, A.
2014-01-01
We show that the proposed measurements of the electric dipole moments of light nuclei in storage rings would put strong constraints on models of flavor-diagonal CP violation. Our analysis is exemplified by a comparison of the Standard Model including the QCD theta term, the minimal left-right symmet
Electric dipole moments of light nuclei from chiral effective field theory
de Vries, J.; Higa, R.; Liu, C. -P.; Mereghetti, E.; Stetcu, I.; Timmermans, R. G. E.; van Kolck, U.
2011-01-01
We set up the framework for the calculation of electric dipole moments (EDMs) of light nuclei using the systematic expansion provided by chiral effective field theory (EFT). We take into account parity (P) and timer-reversal (T) violation which, at the quark-gluon level, originates from the QCD vacu
Data Covariances from R-Matrix Analyses of Light Nuclei
Energy Technology Data Exchange (ETDEWEB)
Hale, G.M., E-mail: ghale@lanl.gov; Paris, M.W.
2015-01-15
After first reviewing the parametric description of light-element reactions in multichannel systems using R-matrix theory and features of the general LANL R-matrix analysis code EDA, we describe how its chi-square minimization procedure gives parameter covariances. This information is used, together with analytically calculated sensitivity derivatives, to obtain cross section covariances for all reactions included in the analysis by first-order error propagation. Examples are given of the covariances obtained for systems with few resonances ({sup 5}He) and with many resonances ({sup 13}C ). We discuss the prevalent problem of this method leading to cross section uncertainty estimates that are unreasonably small for large data sets. The answer to this problem appears to be using parameter confidence intervals in place of standard errors.
Timing Analysis of Light Curves in the Tartarus Active Galactic Nuclei Database
O'Neill, P M; Papadakis, I E; Turner, T J; Neill, Paul M. O'; Nandra, Kirpal; Papadakis, Iossif E.
2004-01-01
The Tartarus database contains products for 529 ASCA observations of active galactic nuclei. We have been updating Tartarus to include observing sequences conducted after 1999 January. The revised database will contain products for 375 objects, with a total of 614 observing sequences. We have begun a systematic timing analysis of the Tartarus light curves. We present here some preliminary results of an investigation into the relation between excess variance and black-hole mass. Having optimised our analysis to minimize the scatter in the variance measurements, we find that the narrow-line active galactic nuclei follow roughly the same relation as the broad-line objects.
Evaluation of Coulomb Energy Difference for Light Mirror Nuclei Using Slater-Type Orbitals
Institute of Scientific and Technical Information of China (English)
F. Oner; B.A. Mainedov
2002-01-01
Behavior of the Coulomb energy difference for light nuclei is explained in terms of the different values of theaverage Coulomb interaction between two particles. Coulomb energy difference according to shell model of light mirrornuclei in the Coulomb and exchange integrals in the formula can be explained with exponential-type wavefunctions. Inthis study, using the one-center expansion of exponential-type wavcfunctions in terms of Slater-type orbitals with thesame center, we derived formula for Coulomb energy difference of light mirror mulei.
"Tomography" of the cluster structure of light nuclei via relativistic dissociation
Zarubin, P I
2013-01-01
These lecture notes present the capabilities of relativistic nuclear physics for the development of the physics of nuclear clusters. Nuclear track emulsion continues to be an effective technique for pilot studies that allows one, in particular, to study the cluster dissociation of a wide variety of light relativistic nuclei within a common approach. Despite the fact that the capabilities of the relativistic fragmentation for the study of nuclear clustering were recognized quite a long time ago, electronic experiments have not been able to come closer to an integrated analysis of ensembles of relativistic fragments. The continued pause in the investigation of the "fine" structure of relativistic fragmentation has led to resumption of regular exposures of nuclear emulsions in beams of light nuclei produced for the first time at the Nuclotron of the Joint Institute for Nuclear Research (JINR, Dubna). To date, an analysis of the peripheral interactions of relativistic isotopes of beryllium, boron, carbon and nitr...
Lattice Simulations for Light Nuclei: Chiral Effective Field Theory at Leading Order
Borasoy, B; Krebs, H; Lee, D; Meißner, Ulf G; Borasoy, Bugra; Epelbaum, Evgeny; Krebs, Hermann; Lee, Dean; Mei{\\ss}ner, Ulf-G.
2006-01-01
We discuss lattice simulations of light nuclei at leading order in chiral effective field theory. Using lattice pion fields and auxiliary fields, we include the physics of instantaneous one-pion exchange and the leading-order S-wave contact interactions. We also consider higher-derivative contact interactions which adjust the S-wave scattering amplitude at higher momenta. By construction our lattice path integral is positive definite in the limit of exact Wigner SU(4) symmetry for any even number of nucleons. This SU(4) positivity and the approximate SU(4) symmetry of the low-energy interactions play an important role in suppressing sign and phase oscillations in Monte Carlo simulations. We assess the computational scaling of the lattice algorithm for light nuclei with up to eight nucleons and analyze in detail calculations of the deuteron, triton, and helium-4.
Molecular structures and clustering effects in reactions induced by light nuclei
Beck, C
2014-01-01
$\\alpha$-clustering study since the pioneering discovery of $^{12}$C+$^{12}$C molecular resonances half a century ago. Our knowledge on physics of nuclear molecules has increased considerably and nuclear clustering remains one of the most fruitful domains of nuclear physics, facing some of the greatest challenges and opportunities in the years ahead. The occurrence of "exotic" shapes in light $N$=$Z$ $\\alpha$-like nuclei is investigated. Various approaches of the superdeformed and hyperdeformed bands associated with quasimolecular resonant structures are presented. Evolution of clustering from stability to the drip-lines is examined: clustering aspects are, in particular, discussed for light exotic nuclei with large neutron excess such as neutron-rich Oxygen isotopes with their complete spectrocopy.
Electric Dipole Moments of Light Nuclei From Chiral Effective Field Theory
Higa, R.
2013-08-01
Recent calculations of EDMs of light nuclei in the framework of chiral effective field theory are presented. We argue that they can be written in terms of the leading six low-energy constants encoding CP-violating physics. EDMs of the deuteron, triton, and helion are explicitly given in order to corroborate our claim. An eventual non-zero measurement of these EDMs can be used to disentangle the different sources and strengths of CP-violation.
Energy Technology Data Exchange (ETDEWEB)
Normand, G
2004-10-01
Correlations play a crucial role in understanding the structure of light nuclei at and beyond the neutron drip-line. In this context, the two-neutron halo nucleus He{sup 6} and the unbound systems H{sup 5}, He{sup 7,9} and Li{sup 10} have been studied via measurements of the breakup of beams of He{sup 6} and Be{sup 11,12}. The CHARISSA and DEMON detector arrays were employed. The interpretation was facilitated by a simulation code (SILLAGE) which provided for the setup. In the case of He{sup 7}, the existence of an excited state with E{sub r} {approx} 1 MeV and gamma {approx} 0.75 MeV was confirmed. The virtual character of the s-wave ground state of Li{sup 10} was also confirmed and a scattering length of as {approx} -16 fm deduced. The results obtained for He{sup 9} suggest that a virtual s-wave state may exist just above threshold. The study of the three-body breakup of He{sup 6} found that the decay of the first 2+ state is essentially direct, while the decay of the remaining continuum strength is sequential - passage via He{sup 5}. Using the technique of intensity interferometry an rms separation between the halo neutrons of 7.7 +- 0.8 fm was derived. This result was confirmed by a complementary method utilizing Dalitz plots. In the case of H{sup 5}, the invariant mass spectrum was found to exhibit a broad (gamma {approx} 2 MeV) structure some 1.8 MeV above threshold. Comparison with recent three-body model calculations suggest that this corresponds to the predicted 1/2+ ground state. An rms valence neutron separation of some 5.5 fm was estimated. A search was also carried out for the 4n system using the Be{sup 12*} (2 alpha + Xn decay channel). No signal was observed beyond that expected on the basis of the known background processes. (author)
Transition between nuclear and quark-gluon descriptions of hadrons and light nuclei.
Holt, R J; Gilman, R
2012-08-01
We provide a perspective on studies aimed at observing the transition between hadronic and quark-gluonic descriptions of reactions involving light nuclei. We begin by summarizing the results for relatively simple reactions such as the pion form factor and the neutral pion transition form factor as well as that for the nucleon and end with exclusive photoreactions in our simplest nuclei. A particular focus will be on reactions involving the deuteron. It is noted that a firm understanding of these issues is essential for unravelling important structure information from processes such as deeply virtual Compton scattering as well as deeply virtual meson production. The connection to exotic phenomena such as color transparency will be discussed. A number of outstanding challenges will require new experiments at modern facilities on the horizon as well as further theoretical developments.
Thermonuclear breakup reactions of light nuclei. I - Processes and effects. [in astrophysic plasmas
Guessoum, Nidhal; Gould, Robert J.
1989-01-01
Temperature and density conditions are considered for the occurrence of breakup reactions of light nuclei in astrophysical plasmas. The proton-induced endothermic process is shown to be the principal mechanism for nuclear breakdown in a plasma. The phenomenon occurs at a temperature of about 1 MeV, which is a fraction of the typical binding energy per nucleon in nuclei. The temperature for breakup of He-4 is about twice as large, because of the higher binding energy. Depending on the temperature attained in the plasma, the initial concentration of elements heavier than hydrogen can be depleted. However, if it attains a temperature of about 1 MeV, breaking up the metals (C, N, O, Ne, Mg) but not He-4, an increase in the He-4 abundance by as much as 10 percent can result, since these elements essentially break down to alpha particles.
2017-01-01
This note complements the paper titled: ``Production of deuterons, tritons, $^{3}$He nuclei and their anti-nuclei in pp collisions at $\\sqrt{s}$~=~0.9, 2.76 and 7~TeV'' with additional material related to Monte Carlo simulations necessary to compare the results with lower energy experiments. It describes a coalescence-based afterburner for QCD-inspired event generators, which allows the generation of light nuclei, hyper-nuclei and their charge conjugates in proton--proton (pp) collisions at LHC energies. The event generators with the afterburner are able to reproduce the differential cross sections of light (anti-)nuclei ($A<4)$ with the same degree of agreement as those of protons and anti-protons at the same momentum per nucleon. They also explain the transverse momentum dependence of the coalescence parameters as the result of hard scattering effects.
Enhancement of fusion at near and sub-barrier energies for neutron-rich light nuclei
Singh, Varinderjit; Steinbach, T K; Wiggins, B B; Hudan, S; Lin, R T deSouza Zidu; Horowitz, C J; Baby, L T; Kuvin, S A; Tripathi, Vandana; Wiedenhover, I
2016-01-01
Measurement of the fusion cross-section for neutron-rich light nuclei is crucial in ascertaining if fusion of these nuclei occurs in the outer crust of a neutron star. We have therefore measured the fusion excitation function at near-barrier energies for the 19O + 12C system and compared the experimental results with the fusion excitation function of 18O + 12C and 16O + 12C. In the experiment a beam of 19O, produced via the 18O(d,p) reaction, was incident on a 12C target at energies near the Coulomb barrier. Evaporation residues produced in fusion of 18,19O ions with 12C target nuclei were detected with good geometric efficiency and identified by measuring their energy and time-of-flight. A significant enhancement in the fusion probability of 19O ions with a 12C target as compared to 18O ions is observed. The significantly larger cross-sections observed at near barrier energies are not predicted by a static model of fusion for 19O + 12C indicating that dynamics play an important role in the fusion of neutron-...
Coupled channel alpha decay theory for even- and odd-mass light and heavy nuclei
Energy Technology Data Exchange (ETDEWEB)
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. (JFP)
Nucleon and cluster knockout reactions induced in light nuclei by intermediate-energy protons
Energy Technology Data Exchange (ETDEWEB)
Vdovin, A.I.; Golovin, A.V.; Loshchakov, I.I.
1987-11-01
Experimental and theoretical studies of nucleon and cluster knockout reactions induced in light nuclei by intermediate-energy (30--150 MeV) protons are reviewed. The methods of theoretical analysis of knockout reactions are considered. The main attention is devoted to the t-matrix approximation with distorted waves. It is shown for the example of cluster knockout reactions how quasielastic and two-step processes can be coherently included in the matrix element when the t-matrix approximation is used.
The meaning of the UHECR Hot Spots: A Light Nuclei Nearby Astronomy
Fargion, Daniele
2014-01-01
We update all the recent UHECR events reported by AUGER, Telescope Array as well as by AGASA in common coordinate maps. We confirm our earliest (2008-2013) model where UHECR are mostly light nuclei (He,Be,B), explaining the Virgo absence and confirming M82 as the main source of North TA Hot Spot. Many more sources , as NGC 253 and galactic ones, are possibly source of most of the 376 UHECR events. Several correlated map, already considered in recent years, are shown with all the events
Plano, Santiago A; Golombek, Diego A; Chiesa, Juan J
2010-03-01
The ability to synchronize to light-dark (LD) cycles is an essential property of the circadian clock, located in mammals within the hypothalamic suprachiasmatic nuclei (SCN). Single light pulses activate nitric oxide (NO) intracellular signaling, leading to circadian phase-shifts required for synchronization. In addition, extracellular NO has a role in the SCN paracrine communication of photic phase advances. In this work, the extracellular nitrergic transmission was assessed in steady-state synchronization to LD cycles of locomotor rhythms in the golden hamster (Mesocricetus auratus). Extracellular NO levels were pharmacologically decreased in vivo with the specific scavenger, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO). Hamsters were subjected to LD cycles different from normal 24 h (LD 14 : 10) cycles (i.e. T-cycles), with a single 30-min light pulse presented either every 23 h (T23 cycles), or every 25 h (T25 cycles), thus allowing synchronization by advances or delays, respectively. Acute PTIO intracerebroventricular microinjections, delivered 30 min previous to the light pulse, inhibited synchronization by phase advances to T23 cycles, but did not alter phase delays under T25 cycles. In addition, NO scavenging inhibited light-induced expression of PERIOD1 protein at circadian time 18 (i.e. the time for light-induced phase advances). These findings demonstrate the role of extracellular NO communication within the SCN in the steady-state synchronization to LD cycles.
Relative Composition and Energy Spectra of Light Nuclei in Cosmic Rays: Results from AMS-01
Aguilar, M.; Alcaraz, J.; Allaby, J.; Alpat, B.; Ambrosi, G.; Anderhub, H.; Ao, L.; Arefiev, A.; Arruda, L.; Azzarello, P.; Basile, M.; Barao, F.; Barreira, G.; Bartoloni, A.; Battiston, R.; Becker, R.; Becker, U.; Bellagamba, L.; Béné, P.; Berdugo, J.; Berges, P.; Bertucci, B.; Biland, A.; Bindi, V.; Boella, G.; Boschini, M.; Bourquin, M.; Bruni, G.; Buénerd, M.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Cannarsa, P.; Capell, M.; Casadei, D.; Casaus, J.; Castellini, G.; Cernuda, I.; Chang, Y. H.; Chen, H. F.; Chen, H. S.; Chen, Z. G.; Chernoplekov, N. A.; Chiueh, T. H.; Choi, Y. Y.; Cindolo, F.; Commichau, V.; Contin, A.; Cortina-Gil, E.; Crespo, D.; Cristinziani, M.; Dai, T. S.; dela Guia, C.; Delgado, C.; Di Falco, S.; Djambazov, L.; D'Antone, I.; Dong, Z. R.; Duranti, M.; Engelberg, J.; Eppling, F. J.; Eronen, T.; Extermann, P.; Favier, J.; Fiandrini, E.; Fisher, P. H.; Flügge, G.; Fouque, N.; Galaktionov, Y.; Gervasi, M.; Giovacchini, F.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W. Q.; Haino, S.; Hangarter, K.; Hasan, A.; Hermel, V.; Hofer, H.; Hungerford, W.; Ionica, M.; Jongmanns, M.; Karlamaa, K.; Karpinski, W.; Kenney, G.; Kim, D. H.; Kim, G. N.; Kim, K. S.; Kirn, T.; Klimentov, A.; Kossakowski, R.; Kounine, A.; Koutsenko, V.; Kraeber, M.; Laborie, G.; Laitinen, T.; Lamanna, G.; Laurenti, G.; Lebedev, A.; Lechanoine-Leluc, C.; Lee, M. W.; Lee, S. C.; Levi, G.; Lin, C. H.; Liu, H. T.; Lu, G.; Lu, Y. S.; Lübelsmeyer, K.; Luckey, D.; Lustermann, W.; Maña, C.; Margotti, A.; Mayet, F.; McNeil, R. R.; Menichelli, M.; Mihul, A.; Mujunen, A.; Oliva, A.; Palmonari, F.; Park, H. B.; Park, W. H.; Pauluzzi, M.; Pauss, F.; Pereira, R.; Perrin, E.; Pevsner, A.; Pilo, F.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Pohl, M.; Produit, N.; Quadrani, L.; Rancoita, P. G.; Rapin, D.; Ren, D.; Ren, Z.; Ribordy, M.; Richeux, J. P.; Riihonen, E.; Ritakari, J.; Ro, S.; Roeser, U.; Sagdeev, R.; Santos, D.; Sartorelli, G.; Sbarra, C.; Schael, S.; Schultz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shin, J. W.; Shoumilov, E.; Shoutko, V.; Siedenburg, T.; Siedling, R.; Son, D.; Song, T.; Spada, F. R.; Spinella, F.; Steuer, M.; Sun, G. S.; Suter, H.; Tang, X. W.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Tornikoski, M.; Torsti, J.; Trümper, J.; Ulbricht, J.; Urpo, S.; Valtonen, E.; Vandenhirtz, J.; Velikhov, E.; Verlaat, B.; Vetlitsky, I.; Vezzu, F.; Vialle, J. P.; Viertel, G.; Vité, D.; Von Gunten, H.; Waldmeier Wicki, S.; Wallraff, W.; Wang, J. Z.; Wiik, K.; Williams, C.; Wu, S. X.; Xia, P. C.; Xu, S.; Xu, Z. Z.; Yan, J. L.; Yan, L. G.; Yang, C. G.; Yang, J.; Yang, M.; Ye, S. W.; Zhang, H. Y.; Zhang, Z. P.; Zhao, D. X.; Zhou, F.; Zhou, Y.; Zhu, G. Y.; Zhu, W. Z.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zuccon, P.
2010-11-01
Measurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the study of extended sets of ratios can provide stronger constraints on the propagation models. In this paper, the relative abundances of light-nuclei lithium, beryllium, boron, and carbon are presented. The secondary-to-primary ratios Li/C, Be/C, and B/C have been measured in the kinetic energy range 0.35-45 GeV nucleon-1. The isotopic ratio 7Li/6Li is also determined in the magnetic rigidity interval 2.5-6.3 GV. The secondary-to-secondary ratios Li/Be, Li/B, and Be/B are also reported. These measurements are based on the data collected by the Alpha Magnetic Spectrometer AMS-01 during the STS-91 space shuttle flight in 1998 June. Our experimental results are in substantial agreement with other measurements, where they exist. We describe our light-nuclei data with a diffusive-reacceleration model. A 10%-15% overproduction of Be is found in the model predictions and can be attributed to uncertainties in the production cross-section data.
Relative Composition and Energy Spectra of Light Nuclei in Cosmic Rays. Results from AMS-01
Aguilar, M; Allaby, J; Alpat, B; Ambrosi, G; Anderhub, H; Ao, L; Arefiev, A; Arruda, L; Azzarello, P; Basile, M; Barao, F; Barreira, G; Vartoloni, A; Battiston, R; Becker, R; Becker, U; Bellagamba, L; Bene, P; Berdugo, J; Berges, P; Bertucci, B; Biland, A; Bindi, V; Boella, G; Boschini, M; Bourquin, M; Bruni, G; Buenerd, M; Burger, J D; Burger, W J; Cai, X D; Cannarsa, P; Capell, M; Casadei, D; Casaus, J; Castellini, G; Cernuda, I; Chang, Y H; Chen, H F; Chen, H S; Chen, Z G; Chernoplekov, N A; Chiueh, T H; Choi, Y Y; Cindolo, F; Commichau, V; Contin, A; Cortina-Gil, E; Crespo, D; Cristinziani, M; Dai, T S; Dela Guia, C; Delgado, C; Di Falco, S; Djambazov, L; D'Antoine, I; Dong, Z R; Duranti, M; Engelberg, J; Eppling, F J; Eronen, T; Extermann, P; Favier, J; Fiandrini, E; Fisher, P H; Flugge, G; Fouque, N; Galaktionov, Y; Gervasi, M; Giovacchini, F; Giusti, P; Grandi, D; Grimm, O; Gu, W Q; Haino, S; Hangarter, K; Hasan, A; Hermel, V; Hofer, H; Hungerford, W; Ionica, M; Jongmanns, M; Karlamaa, K; Karpinski, W; Kenney, G; Kim, D H; Kim, G N; Kim, K S; Kirn, T; Klimentov, A; Kossakowski, R; Kounine, A; Koutsenko, V; Kraeber, M; Laborie, G; Laitinen, T; Lamanna, G; Laurenti, G; Lebedev, A; Lechanoine-Leluc, C; Lee, M W; Lee, S C; Levi, G; Lin, C H; Liu, H T; Lu, G; Lubelsmeyer, K; Luckey, D; Lustermann, W; Mana, C; Margotti, A; Mayet, F; McNeil, R R; Menichelli, M; Mihul, A; Mujunen, A; Oliva, A; Palmonari, F; Park, H B; Park, W H; Pauluzzi, M; Pauss, F; Pereira, R; Perrin, E; Pevsner, A; Pilo, F; Pimenta, M; Plyaskin, V; Pojidaev, V; Pohl, M; Produit, N; Quadrani, L; Rancoita, P G; Rapin, D; Ren, D; Ren, Z; Ribordy, M; Richeux, J P; Riihonen, E; Ritakari, J; Ro, S; Roeser, U; Sagdeev, R; Santos, D; Sartorelli, G; Sbarra, C; Schael, S; Schultz von Dratzig, A; Schwering, G; Seo, E S; Shin, J W; Shoumilov, E; Shoutko, V; Siedenburg, T; Siedling, R; Son, D; Song, T; Spada, F R; Spinella, F; Steuer, M; Sun, G S; Suter, H; Tang, X W; Ting, Samuel C C; Ting, S M; Tomassetti, N; Tornikoski, M; Torsti, J; Trumper, J; Ulbricht, J; Urpo, S; Valtonen, E; Vandenhirtz, J; Velikhov, E; Verlaat, B; Vetlitsky, I; Vezzu, F; Vialle, J P; Viertel, G; Vite, D; Von Gunten, H; Waldmeier Wicki, S; Wallraff, W; Wang, J Z; Wiik, K; Williams, C; Wu, S X; Xia, P C; Xu, S; Xu, Z Z; Yan, J L; Yan, L G; Yang, C G; Yang, J; Yang, M; Ye, S W; Zhang, H Y; Zhang, Z P; Zhao, D X; Zhou, F; Zhou, Y; Zhu, G Y; Zhu, W Z; Zhuang, H L; Zichichi, A; Zimmermann, B; Zuccon, P
2010-01-01
Measurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the study of extended sets of ratios can provide stronger constraints on the propagation models. In this paper the relative abundances of the light nuclei lithium, beryllium, boron and carbon are presented. The secondary to primary ratios Li/C, Be/C and B/C have been measured in the kinetic energy range 0.35-45 GeV/nucleon. The isotopic ratio 7Li/6Li is also determined in the magnetic rigidity interval 2.5-6.3 GV. The secondary to secondary ratios Li/Be, Li/B and Be/B are also reported. These measurements are based on the data collected by the Alpha Magnetic Spectrometer AMS-01 during the STS-91 space shuttle flight in 1998 June. Our experimental results are in substantial agreement with other measurements, where they exist. We describe our light-nuclei data with a diffusive-reacceleration model....
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)
2015-05-22
MCNP6, the latest and most advanced LANL Monte Carlo transport code, representing a merger of MCNP5 and MCNPX, is actually much more than the sum of those two computer codes; MCNP6 is available to the public via RSICC at Oak Ridge, TN, USA. In the present work, MCNP6 was validated and verified (V&V) against different experimental data on intermediate-energy fragmentation reactions, and results by several other codes, using mainly the latest modifications of the Cascade-Exciton Model (CEM) and of the Los Alamos version of the Quark-Gluon String Model (LAQGSM) event generators CEM03.03 and LAQGSM03.03. It was found that MCNP6 using CEM03.03 and LAQGSM03.03 describes well fragmentation reactions induced on light and medium target nuclei by protons and light nuclei of energies around 1 GeV/nucleon and below, and can serve as a reliable simulation tool for different applications, like cosmic-ray-induced single event upsets (SEU’s), radiation protection, and cancer therapy with proton and ion beams, to name just a few. Future improvements of the predicting capabilities of MCNP6 for such reactions are possible, and are discussed in this work.
Freeze-out conditions for production of resonances, hadronic molecules, and light nuclei
Cho, Sungtae; Lee, Su Houng
2015-01-01
We investigate the freeze-out conditions of a particle in an expanding system of interacting particles in order to understand the productions of resonances, hadronic molecules and light nuclei in heavy ion collisions. Applying the kinetic freeze-out condition with explicit hydrodynamic calculations for the expanding hadronic phase to the daughter particles of $K^*$ mesons, we find that the larger suppression of the yield ratio of $K^*/K$ at LHC than at RHIC compared to the expectations from the statistical hadronization model based on chemical freeze-out parameters reflects the lower kinetic freeze-out temperature at LHC than at RHIC. Furthermore, we point out that for the light nuclei or hadronic molecules that are bound, the yields are affected by the freeze-out condition of the respective particle in the hadronic matter, which leads to the observation that the deuteron production yields are independent of the size of deuteron, and depend only on the number of ground state constituents.
Directory of Open Access Journals (Sweden)
Kirsch Lee E
2008-07-01
Full Text Available Abstract Background Glucagon is a peptide hormone with many uses as a therapeutic agent, including the emergency treatment of hypoglycemia. Physical instability of glucagon in solution leads to problems with the manufacture, formulation, and delivery of this pharmaceutical product. Glucagon has been shown to aggregate and form fibrils and gels in vitro. Small oligomeric precursors serve to initiate and nucleate the aggregation process. In this study, these initial aggregates, or seed nuclei, are characterized in bulk solution using light scattering methods and field-flow fractionation. Results High molecular weight aggregates of glucagon were detected in otherwise monomeric solutions using light scattering techniques. These aggregates were detected upon initial mixing of glucagon powder in dilute HCl and NaOH. In the pharmaceutically relevant case of acidic glucagon, the removal of aggregates by filtration significantly slowed the aggregation process. Field-flow fractionation was used to separate aggregates from monomeric glucagon and determine relative mass. The molar mass of the large aggregates was shown to grow appreciably over time as the glucagon solutions gelled. Conclusion The results of this study indicate that initial glucagon solutions are predominantly monomeric, but contain small quantities of large aggregates. These results suggest that the initial aggregates are seed nuclei, or intermediates which catalyze the aggregation process, even at low concentrations.
Do light nuclei display a universal γ-ray strength function?
Directory of Open Access Journals (Sweden)
Voinov A.
2012-02-01
Full Text Available In this work we focus on properties in the quasi-continuum of light nuclei. Generally, both level density and γ-ray strength function (γ-SF differ from nucleus to nucleus. In order to investigate this closer, we have performed particle-γ coincidences using the reactions (p, p', (p, d and (p, t on a 46Ti target. In particular, the very rich data set of the 46Ti(p, p'46Ti inelastic scattering reaction allows analysis of the coincidence data for many independent data sets. Using the Oslo method, we find one common level density for all data sets. If transitions to well-separated low-energy levels are included, the deduced γ-SF may change by a factor of 2 – 3, due strong to Porter-Thomas fluctuations. However, a universal γ-SF with small fluctuations is found provided that only excitation energies above 3 MeV are taken into account. The nuclear structure of the titaniums is discussed within a combinatorial quasi-particle model, showing that only few Nilsson orbitals participate in building up the level density for these light nuclei.
Furusawa, Shun; Yamada, Shoichi; Suzuki, Hideyuki
2013-01-01
We construct new equations of state for baryons at sub-nuclear densities for the use in core-collapse simulations of massive stars. The abundance of various nuclei is obtained together with thermodynamic quantities. A model free energy is constructed, based on the relativistic mean field theory for nucleons and the mass formula for nuclei with the proton number up to ~ 1000. The formulation is an extension of the previous model, in which we adopted the liquid drop model to all nuclei under the nuclear statistical equilibrium. We reformulate the new liquid drop model so that the temperature dependences of bulk energies could be taken into account. Furthermore, we extend the region in the nuclear chart, in which shell affects are included, by using theoretical mass data in addition to experimental ones. We also adopt a quantum theoretical mass evaluation of light nuclei, which incorporates the Pauli- and self-energy shifts that are not included in the ordinary liquid drop model. The pasta phases for heavy nucle...
Light Nuclei in the Framework of the Symplectic No-Core Shell Model
Energy Technology Data Exchange (ETDEWEB)
Draayer, Jerry P.; Dytrych, Tomas; Sviratcheva, Kristina D.; Bahri, Chairul; /Louisiana State U.; Vary, James P.; /Iowa State U. /LLNL, Livermore /SLAC
2007-04-02
A symplectic no-core shell model (Sp-NCSM) is constructed with the goal of extending the ab-initio NCSM to include strongly deformed higher-oscillator-shell configurations and to reach heavier nuclei that cannot be studied currently because the spaces encountered are too large to handle, even with the best of modern-day computers. This goal is achieved by integrating two powerful concepts: the ab-initio NCSM with that of the Sp(3,R) {contains} SU(3) group-theoretical approach. The NCSM uses modern realistic nuclear interactions in model spaces that consists of many-body configurations up to a given number of {h_bar}{Upsilon} excitations together with modern high-performance parallel computing techniques. The symplectic theory extends this picture by recognizing that when deformed configurations dominate, which they often do, the model space can be better selected so less relevant low-lying {h_bar}{Upsilon} configurations yield to more relevant high-lying {h_bar}{Upsilon} configurations, ones that respect a near symplectic symmetry found in the Hamiltonian. Results from an application of the Sp-NCSM to light nuclei are compared with those for the NCSM and with experiment.
Ab-initio Hamiltonian approach to light nuclei and to quantum field theory
Indian Academy of Sciences (India)
J P Vary; H Honkanen; Jun Li; P Maris; A M Shirokov; S J Brodsky; A Harindranath; G F De Teramond; E G Ng; C Yang; M Sosonkina
2010-07-01
Nuclear structure physics is on the threshold of confronting several long-standing problems such as the origin of shell structure from basic nucleon–nucleon and three-nucleon interactions. At the same time those interactions are being developed with increasing contact to QCD, the underlying theory of the strong interactions, using effective field theory. The motivation is clear – QCD offers the promise of great predictive power spanning phenomena on multiple scales from quarks and gluons to nuclear structure. However, new tools that involve non-perturbative methods are required to build bridges from one scale to the next. We present an overview of recent theoretical and computational progress with a Hamiltonian approach to build these bridges and provide illustrative results for the nuclear structure of light nuclei and quantum field theory.
Light Nuclei and Hypernuclei from Quantum Chromodynamics in the Limit of SU(3) Flavor Symmetry
Beane, S R; Cohen, S D; Detmold, W; Lin, H W; Luu, T C; Orginos, K; Parreno, A; Savage, M J; Walker-Loud, A
2012-01-01
The binding energies of a range of nuclei and hypernuclei with atomic number A <= 4 and strangeness |s| <= 2, including the deuteron, di-neutron, H-dibaryon, 3He, Lambda 3He, Lambda 4He, and Lambda Lambda 4He, are calculated in the limit of flavor-SU(3) symmetry at the physical strange quark mass with quantum chromodynamics (without electromagnetic interactions). The nuclear states are extracted from Lattice QCD calculations performed with n_f=3 dynamical light quarks using an isotropic clover discretization of the quark-action in three lattice volumes of spatial extent L ~ 3.4 fm, 4.5 fm and 6.7 fm, and with a single lattice spacing b ~ 0.145 fm.
Exotic Properties of Light Nuclei and their Neutron Capture Cross Sections
Mengoni, A; Nakamura, T; Ishihara, M
1996-01-01
We have investigated the implications of the neutron halo configuration, observed in the ground-state of some neutron-rich light nuclei, on neutron radiative transition processes. In particular, we have studied the influence of the neutron halo on the direct radiative capture (DRC) process. The energy dependence as well as the strength of E1 emission due to incident p-wave neutrons is strongly influenced by the halo configuration of the residual nucleus capturing state. We have compared the calculated 10Be(n,gamma)11Be DRC cross section with that derived from the experiment in the inverse kinematics (Coulomb dissociation of 11Be). We show from the comparison that some important information on the structure of the halo nucleus 11Be can be derived.
Finite nuclei in relativistic models with a light chiral scalar meson
Furnstahl, R. J.; Serot, Brian D.
1993-05-01
Relativistic chiral models with a light scalar meson appear to provide an economical marriage of successful relativistic mean-field theories and chiral symmetry. The scalar meson serves as both the chiral partner of the pion and the mediator of the intermediate-range nucleon-nucleon (NN) attraction. However, while some of these models can reproduce the empirical nuclear matter saturation point, they fail to reproduce observed properties of finite nuclei, such as spin-orbit splittings, shell structure, charge densities, and surface energetics. These deficiencies imply that this realization of chiral symmetry is incorrect. An alternative scenario, which features a heavy chiral scalar and dynamical generation of the NN attraction, is discussed.
Chiral Three-Nucleon Interactions in Light Nuclei, Neutron-$\\alpha$ Scattering, and Neutron Matter
Lynn, J E; Carlson, J; Gandolfi, S; Gezerlis, A; Schmidt, K E; Schwenk, A
2015-01-01
We present quantum Monte Carlo calculations of light nuclei, neutron-$\\alpha$ scattering, and neutron matter using local two- and three-nucleon (3N) interactions derived from chiral effective field theory up to next-to-next-to-leading order (N$^2$LO). The two undetermined 3N low-energy couplings are fit to the $^4$He binding energy and, for the first time, to the spin-orbit splitting in the neutron-$\\alpha$ $P$-wave phase shifts. Furthermore, we investigate different choices of local 3N operator structures and find that chiral interactions at N$^2$LO are able to simultaneously reproduce the properties of $A=4,5$ systems and of neutron matter, in contrast to commonly used phenomenological 3N interactions.
Gamma ray astronomy and the origin of the light nuclei. [cosmic ray and interstellar gas reactions
Reeves, H.
1978-01-01
Nuclear reactions induced by the collisions of the protons and alphas of the galactic cosmic ray with heavy nuclei of the interstellar gas are responsible for the continuous production of the light elements lithium, beryllium, and boron in the galaxy. To better than one order of magnitude, the observed ratios of these abundances to hydrogen abundance and the nuclidic abundance ratios between themselves are accounted for by simply considering the effect of fast protons and alphas with a flux and an energy spectrum as observed in galactic cosmic rays, for a period comparable with the life of our galaxy. The role of gamma ray astronomy in solving problems that occur when accurate agreement is sought with increasingly accurate data is discussed.
Toroidal high-spin isomers in light nuclei with N not equal to Z
Staszczak, Andrzej
2014-01-01
The combined considerations of both the bulk liquid-drop-type behavior and the quantized aligned rotation with cranked Skyrme-Hartree-Fock approach revealed previously that even-even, N=Z, toroidal high-spin isomeric states have general occurrences for light nuclei with A between 28 and 52. We find that in this mass region there are in addition N not equal to Z toroidal high-spin isomers when the single-particle shells for neutrons and protons occur at the same cranked frequency $\\hbar \\omega$. Examples of N not equal to Z toroidal high-spin isomers, $^{36}_{16}$S$_{20}$($I$=74$\\hbar$) and $^{40}_{18}$Ar$_{22}$($I$=80,102$\\hbar$), are located and examined. The systematic properties of these N not equal to Z toroidal high-spin isomers fall into the same regular (muti-particle)-(muti-hole) patterns as other N=Z toroidal high-spin isomers.
The muon-positron conversion in nuclei mediated by light Majorana neutrinos
Simkovic, F; Kovalenko, S V; Faessler, A; Faessler, Amand
2001-01-01
We study the lepton number violating muon-positron conversion in nuclei mediated by the exchange of virtual light Majorana neutrinos. We found that a previously overlooked imaginary part of this amplitude plays an important role. The numerical calculation has been made for the experimentally interesting muon-positron conversion in Ti48 using realistic renormalized proton-neutron QRPA wave functions. We also discuss the very similar case of the neutrinoless double beta decay of Ca48 The ratio of muon-positron conversion over the total muon absorption has been computed taking into account the current constraints from neutrino oscillation phenomenology. We compare our results with the experimental limits as well as with previous theoretical predictions. We have found that the Majorana neutrino mode of muon-positron conversion in Ti48 is too small to be measurable in the foreseeable future.
Alpha cluster states in light nuclei populated through the (6Li,d) reaction
Energy Technology Data Exchange (ETDEWEB)
Borello-Lewin, Thereza; Rodrigues, M.R.D.; Horodynski-Matsushigue, L.B.; Duarte, J.L.M.; Rodrigues, C.L.; Souza, M.A. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Cunsolo, A.; Cappuzzello, F. [Universita di Catania (Italy). Istituto Nazionale di Fisica Nucleare. Lab. Nazionali del Sud; Ukita, Gilberto Mitsuo [Universidade de Santo Amaro (UNISA), Sao Paulo, SP (Brazil). Fac. de Psicologia
2011-07-01
Full text: The alpha cluster correlation is an important concept in the nuclear physics of light nuclei. The main purpose of the research program in progress is the investigation of the alpha clustering phenomenon in (x{alpha}) and(x{alpha}+{nu}) nuclei through the ({sup 6}Li,d) alpha transfer reaction. In fact, there is scarce experimental information on the subject, in particular associated with resonant states predicted near (x{alpha}) and (x{alpha}+{nu}) thresholds. Measurements of the {sup 12},{sup 13}C({sup 6}Li,d) {sup 16},{sup 17}O reactions, at an incident energy of 25.5 MeV, have been performed employing the Sao Paulo Pelletron-Enge Split-Pole facility and the nuclear emulsion detection technique. The work is under way and an experimental energy resolution of 30 keV was obtained. Near the (4{alpha}) breakup threshold in {sup 16}O, three narrow alpha resonances, not previously measured, were detected, revealing important {alpha} + {sup 12}C(G.S.) components. One of these resonances corresponds to the known 0{sup +} state at 15.1 MeV[5] of excitation that has probably, according to Funaki et al., the gas like configuration of the 4{alpha} condensate state, with a very dilute density and a large component of {alpha} + {sup 12}C(Hoyle) configuration. As was already mentioned, our experimental information points to the necessity of including the {alpha} + {sup 12}C(G.S.) component in the wave function. (author)
Electric dipole moments of light nuclei in chiral effective field theory
Energy Technology Data Exchange (ETDEWEB)
Bsaisou, Jan
2014-04-25
Dimensional Analysis (NDA) estimates of the coupling constants. These estimates prove to be sufficient to reveal certain hierarchies of coupling constants. The different hierarchies of coupling constants translate into different hierarchies of the nuclear contributions to the EDMs of light nuclei. We calculate within the framework of ChPT the two-nucleon contributions to the EDM of the deuteron up to and including next-to-next-to leading order and the two-nucleon contributions to the EDMs of the helion ({sup 3}He nucleus) and the triton ({sup 3}H nucleus) up to and including next-to-leading order. These computations comprise thorough investigations of the uncertainties of the results from the P- and T-violating component as well as the P- and T-conserving component of the nuclear potential. We present quantitative predictions of the nuclear contributions to the EDMs of the deuteron, the helion and the triton induced by the QCD θ-term as functions of anti θ with well-defined uncertainties. The EDM predictions for the effective dimension-six sources are given as function of the yet unknown LECs with NDA estimates. We present several strategies to falsify the QCD θ-term as a relevant source of P and T violation by a suitable combination of measurements of several light nuclei and, if needed, supplementary lattice QCD input. If the QCD θ-term fails these tests, one or several of the effective dimension-six sources encoding physics beyond the Standard Model are most likely the source(s) of P and T violation. We demonstrate how particular effective dimension-six sources can be tested by EDM measurements of light nuclei with eventually supplementary Lattice QCD input.
Measuring the fusion cross-section of light nuclei with low-intensity beams
Energy Technology Data Exchange (ETDEWEB)
Steinbach, T.K.; Rudolph, M.J.; Gosser, Z.Q.; Brown, K.; Floyd, B.; Hudan, S. [Department of Chemistry and Center for Exploration of Energy and Matter, Indiana University, 2401 Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Souza, R.T. de, E-mail: desouza@indiana.edu [Department of Chemistry and Center for Exploration of Energy and Matter, Indiana University, 2401 Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Liang, J.F.; Shapira, D. [Oak Ridge National Laboratory, Physics Division, Oak Ridge, TN 37831 (United States); Famiano, M. [Department of Physics, Western Michigan University, Kalamazoo, MI 49008 (United States)
2014-04-11
We demonstrate an approach to measure the total fusion cross-section for beams of low-intensity light nuclei. Fusion residues resulting from the fusion of {sup 20,16}O+{sup 12}C are directly measured and distinguished from unreacted beam particles on the basis of their energy and time-of-flight. The time-of-flight is measured between a microchannel plate (MCP) detector, which serves as a start, and a segmented silicon detector, which provides a stop. The two main difficulties associated with the initial implementation of this approach are charge trapping in the silicon detector and slit scattering in the MCP detector. Both these obstacles have been characterized and overcome. To reduce atomic slit scattering in the measurement we have eliminated wires from the beam path by developing a gridless MCP detector. The total fusion cross-section for {sup 16}O+{sup 12}C in the energy range E{sub CM}=8.0–12.0 MeV has been measured in agreement with established literature values (down to the 100 mb level)
Nuclear matter saturation with chiral three-nucleon interactions fitted to light nuclei properties
Energy Technology Data Exchange (ETDEWEB)
Logoteta, Domenico [INFN, Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); Bombaci, Ignazio, E-mail: ignazio.bombaci@unipi.it [Dipartimento di Fisica, Universitá di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); INFN, Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); European Gravitational Observatory, Via E. Amaldi, I-56021 S. Stefano a Macerata, Cascina (Italy); Kievsky, Alejandro [INFN, Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy)
2016-07-10
The energy per particle of symmetric nuclear matter and pure neutron matter is calculated using the many-body Brueckner–Hartree–Fock approach and employing the Chiral Next-to-next-to-next-to leading order (N3LO) nucleon–nucleon (NN) potential, supplemented with various parametrizations of the Chiral Next-to-next-to leading order (N2LO) three-nucleon interaction. Such combination is able to reproduce several observables of the physics of light nuclei for suitable choices of the parameters entering in the three-nucleon interaction. We find that some of these parametrizations provide a satisfactory saturation point of symmetric nuclear matter and values of the symmetry energy and its slope parameter L in very good agreement with those extracted from various nuclear experimental data. Thus, our results represent a significant step toward a unified description of few- and many-body nuclear systems starting from two- and three-nucleon interactions based on the symmetries of QCD.
Thermal properties of light nuclei from 12C + 12C fusion-evaporation reactions
Morelli, L.; Baiocco, G.; D'Agostino, M.; Gulminelli, F.; Bruno, M.; Abbondanno, U.; Appannababu, S.; Barlini, S.; Bini, M.; Casini, G.; Cinausero, M.; Degerlier, M.; Fabris, D.; Gelli, N.; Gramegna, F.; Kravchuk, V. L.; Marchi, T.; Olmi, A.; Pasquali, G.; Piantelli, S.; Valdré, S.; Raduta, Ad R.
2014-07-01
The 12C + 12C reaction at 95 MeV has been studied through the complete charge identification of its products by means of the GARFIELD+RCo experimental set-up at INFN Laboratori Nazionali di Legnaro (LNL). In this paper, the first of a series of two, a comparison to a dedicated Hauser-Feshbach calculation allows selecting a set of dissipative events which corresponds, to a large extent, to the statistical evaporation of highly excited 24Mg. Information on the isotopic distribution of the evaporation residues in coincidence with their complete evaporation chain is also extracted. The set of data puts strong constraints on the behaviour of the level density (LD) of light nuclei above the threshold for particle emission. In particular, a fast increase of the LD parameter with excitation energy is supported by the data. Residual deviations from a statistical behaviour are seen in two specific channels, and tentatively associated with a contamination from direct reactions and/or α-clustering effects. These channels are studied in further details in the second paper of the series.
Quantal self-consistent cranking model for monopole excitations in even-even light nuclei
Gulshani, P
2014-01-01
In this article, we derive a quantal self-consistent time-reversal invariant cranking model for isoscalar monopole excitation coupled to intrinsic motion in even-even light nuclei. The model uses a wavefunction that is a product of monopole and intrinsic wavefunctions and a constrained variational method to derive, from a many-particle Schrodinger equation, a pair of coupled self-consistent cranking-type Schrodinger equations for the monopole and intrinsic systems. The monopole and intrinsic wavefunctions are coupled to each other by the two cranking equations and their associated parameters and by two constraints imposed on the intrinsic system. For an isotropic Nilsson shell model and an effective residual two-body interaction, the two coupled cranking equations are solved in the Tamm Dancoff approximation. The strength of the interaction is determined from a Hartree-Fock self-consistency argument. The excitation energy of the first excited state is determined and found to agree closely with those observed ...
Nuclear matter saturation with chiral three-nucleon interactions fitted to light nuclei properties
Logoteta, Domenico; Bombaci, Ignazio; Kievsky, Alejandro
2016-07-01
The energy per particle of symmetric nuclear matter and pure neutron matter is calculated using the many-body Brueckner-Hartree-Fock approach and employing the Chiral Next-to-next-to-next-to leading order (N3LO) nucleon-nucleon (NN) potential, supplemented with various parametrizations of the Chiral Next-to-next-to leading order (N2LO) three-nucleon interaction. Such combination is able to reproduce several observables of the physics of light nuclei for suitable choices of the parameters entering in the three-nucleon interaction. We find that some of these parametrizations provide a satisfactory saturation point of symmetric nuclear matter and values of the symmetry energy and its slope parameter L in very good agreement with those extracted from various nuclear experimental data. Thus, our results represent a significant step toward a unified description of few- and many-body nuclear systems starting from two- and three-nucleon interactions based on the symmetries of QCD.
Thermal properties of light nuclei from $^{12}$C+$^{12}$C fusion-evaporation reactions
Morelli, L; D'Agostino, M; Gulminelli, F; Bruno, M; Abbondanno, U; Appannababu, S; Barlini, S; Bini, M; Casini, G; Cinausero, M; Degerlier, M; Fabris, D; Gelli, N; Gramegna, F; Kravchuk, V L; Marchi, T; Pasquali, G; Piantelli, S; Valdré, S; Raduta, Ad R
2014-01-01
The $^{12}$C+$^{12}$C reaction at 95 MeV has been studied through the complete charge identification of its products by means of the GARFIELD+RCo experimental set-up at INFN Laboratori Nazionali di Legnaro (LNL). In this paper, the first of a series of two, a comparison to a dedicated Hauser-Feshbach calculation allows to select a set of dissipative events which corresponds, to a large extent, to the statistical evaporation of highly excited $^{24}$Mg. Information on the isotopic distribution of the evaporation residues in coincidence with their complete evaporation chain is also extracted. The set of data puts strong constraints on the behaviour of the level density of light nuclei above the threshold for particle emission. In particular, a fast increase of the level density parameter with excitation energy is supported by the data. Residual deviations from a statistical behaviour are seen in two specific channels, and tentatively associated with a contamination from direct reactions and/or $\\alpha$-clusteri...
Fermi-LAT high-z active galactic nuclei and the extragalactic background light
Armstrong, Thomas; Brown, Anthony M.; Chadwick, Paula M.
2017-10-01
Observations of distant gamma-ray sources are hindered by the presence of the extragalactic background light (EBL). In order to understand the physical processes that result in the observed spectrum of sources, it is imperative that a good understanding of the EBL is included. In this work, an investigation into the imprint of the EBL on the observed spectra of high-redshift Fermi-LAT active galactic nuclei is presented. By fitting the spectrum below ˜10 GeV, an estimation of the unabsorbed intrinsic source spectrum is obtained; by applying this spectrum to data up to 300 GeV, it is then possible to derive a scaling factor for different EBL models. A second approach uses five sources (PKS 0426-380, 4C +55.17, Ton 116, PG 1246+586 and RBS 1432) that were found to exhibit very high energy (VHE) emission (Eγ > 100 GeV). Through Monte Carlo simulations, it is shown that the observation of VHE photons, despite the large distances of these objects, is consistent with current EBL models. Many of these sources would be observable with the upcoming ground-based observatory, the Cherenkov Telescope Array, leading to a better understanding of the EBL.
Are there good probes for the di-neutron correlation in light neutron-rich nuclei?
Hagino, K
2015-01-01
The di-neutron correlation is a spatial correlation with which two valence neutrons are located at a similar position inside a nucleus. We discuss possible experimental probes for the di-neutron correlation. This includes the Coulomb breakup and the pair transfer reactions of neutron-rich nuclei, and the direct two-neutron decays of nuclei beyond the neutron drip-line.
Sugiyama, Yuka; Kadota, Akeo
2011-03-01
Chloroplasts change their positions in the cell depending on the light conditions. In the dark, chloroplasts in fern prothallia locate along the anticlinal wall (dark position). However, chloroplasts become relocated to the periclinal wall (light position) when the light shines perpendicularly to the prothallia. Red light is effective in inducing this relocation in Adiantum capillus-veneris, and neochrome1 (neo1) has been identified as the red light receptor regulating this movement. Nevertheless, we found here that chloroplasts in neo1 mutants still become relocated from the dark position to the light position under red light. We tested four neo1 mutant alleles (neo1-1, neo1-2, neo1-3, and neo1-4), and all of them showed the red-light-induced chloroplast relocation. Furthermore, chloroplast light positioning under red light occurred also in Pteris vittata, another fern species naturally lacking the neo1-dependent phenomenon. The light positioning of chloroplasts occurred independently of the direction of red light, a response different to that of the neo1-dependent movement. Photosynthesis inhibitors 3-(3,4 dichlorophenyl)-1,1-dimethylurea or 2,5-dibromo-3-isopropyl-6-methyl-p-benzoquinone blocked this movement. Addition of sucrose (Suc) or glucose to the culture medium induced migration of the chloroplasts to the periclinal wall in darkness. Furthermore, Suc could override the effects of 3-(3,4 dichlorophenyl)-1,1-dimethylurea. Interestingly, the same light positioning was evident for nuclei under red light in the neo1 mutant. The nuclear light positioning was also induced in darkness with the addition of Suc or glucose. These results indicate that photosynthesis-dependent nondirectional movement contributes to the light positioning of these organelles in addition to the neo1-dependent directional movement toward light.
Interactions of 200 GeV gold nuclei in light elements
Brewster, N. R.; Fickle, R. K.; Waddington, C. J.; Binns, W. R.; Israel, M. H.; Jones, M. D.; Klarmann, J.; Garrard, T. L.; Newport, B. J.; Stone, E. C.
1983-01-01
Total charge-changing cross sections and partial cross-sections for interactions of 200 GeV Au-197 nuclei incident on carbon and polyethylene (CH2) targets have been measured during a calibration of the HEAO-3 Heavy Nuclei Experiment. From these, the total and partial cross-sections for Au-197 incident on hydrogen are inferred. The effects of using these cross-sections in one model of cosmic ray propagation are illustrated. Comparisons to predictions using semi-empirical formulas are shown.
Production of light (anti-)nuclei and (anti-)hypernuclei with ALICE at the LHC
CERN. Geneva
2017-01-01
The measurements in smaller collision systems may also provide an input to cosmological searches for segregated primordial anti-matter and dark matter, since anti-nuclei produced in pp and p--A collisions in interstellar space represent a background source in these measurements. Thanks to its excellent particle identification and tracking capabilities, the ALICE detector allows for the measurement of deuterons, tritons, 3He, 4He and their corresponding anti-nuclei. Moreover, the secondary vertices from the mesonic decays of (anti-)hypernuclei can ...
The unbound isotopes He-9,He-10
Jonson, B; Cortina-Gil, D; Simon, H; Emling, H; Nyman, G; Nilsson, T; Johansson, H T; Borge, M J G; Paschalis, S; Muenzenberg, G; Zhukov, M V; Weick, H; Pramanik, U Datta; LeBleis, T; Meister, M; Reifarth, R; Chulkov, L V; Lantz, M; Riisager, K; Mahata, K; Suemmerer, K; Langer, C; Chatillon, A; Richter, A; Kulessa, R; Palit, R; Aksyutina, Yu; Geissel, H; Aumann, T; Prokopowicz, W; Forssen, C; Ickert, G; Fynbo, H O U; Tengblad, O; Boretzky, K
2010-01-01
The unbound nuclei He-9 and He-10 have been produced in proton-knockout reactions from a 280 MeV/u Li-11 beam impinging on a liquid hydrogen target at the ALADIN-LAND setup at GSI. Information on their nuclear structure has been obtained from the relative-energy spectra, He-8 + n and He-8 + 2n, employing reaction models incorporating the structure of Li-11. The (8H)e + n relative-energy spectrum is dominated by a strong peak-like structure at low energy, which may be interpreted within the effective-range approximation as the result of an s-wave interaction with a neutron scattering length of -3.17(66) fm. This spectrum also shows evidence for resonance states at 1.33(8) MeV and at 2.4 MeV above the He-8 + n threshold. It is argued that the s-state might not be the He-9 ground state. For He-8 + n + n, the analysis of the relative-energy spectrum gives two alternative possibilities for an interpretation: either a narrow resonance at 1.42(10) MeV (Gamma = 1.11(76) MeV) superimposed on a correlated background, o...
ERM Learning with Unbounded Sampling
Institute of Scientific and Technical Information of China (English)
Cheng WANG; Zheng Chu GUO
2012-01-01
The learning approach of empirical risk minimization (ERM) is taken for the regression problem in the least square framework.A standard assumption for the error analysis in the literature is the uniform boundedness of the output sampling process.In this paper we abandon this boundedness assumption and conduct error analysis for the ERM learning algorithm with unbounded sampling processes satisfying an increment condition for the moments of the output.The key novelty of our analysis is a covering number argument for estimating the sample error.
Self-adjointness of deformed unbounded operators
Energy Technology Data Exchange (ETDEWEB)
Much, Albert [Instituto de Ciencias Nucleares, UNAM, México D.F. 04510 (Mexico)
2015-09-15
We consider deformations of unbounded operators by using the novel construction tool of warped convolutions. By using the Kato-Rellich theorem, we show that unbounded self-adjoint deformed operators are self-adjoint if they satisfy a certain condition. This condition proves itself to be necessary for the oscillatory integral to be well-defined. Moreover, different proofs are given for self-adjointness of deformed unbounded operators in the context of quantum mechanics and quantum field theory.
Quantum dissipation in unbounded systems.
Maddox, Jeremy B; Bittner, Eric R
2002-02-01
In recent years trajectory based methodologies have become increasingly popular for evaluating the time evolution of quantum systems. A revival of the de Broglie--Bohm interpretation of quantum mechanics has spawned several such techniques for examining quantum dynamics from a hydrodynamic perspective. Using techniques similar to those found in computational fluid dynamics one can construct the wave function of a quantum system at any time from the trajectories of a discrete ensemble of hydrodynamic fluid elements (Bohm particles) which evolve according to nonclassical equations of motion. Until very recently these schemes have been limited to conservative systems. In this paper, we present our methodology for including the effects of a thermal environment into the hydrodynamic formulation of quantum dynamics. We derive hydrodynamic equations of motion from the Caldeira-Leggett master equation for the reduced density matrix and give a brief overview of our computational scheme that incorporates an adaptive Lagrangian mesh. Our applications focus upon the dissipative dynamics of open unbounded quantum systems. Using both the Wigner phase space representation and the linear entropy, we probe the breakdown of the Markov approximation of the bath dynamics at low temperatures. We suggest a criteria for rationalizing the validity of the Markov approximation in open unbound systems and discuss decoherence, energy relaxation, and quantum/classical correspondence in the context of the Bohmian paths.
Losa, C; Dossing, T; Vigezzi, E; Broglia, R A
2010-01-01
We present a calculation of the properties of vibrational states in deformed, axially--symmetric even--even nuclei, within the framework of a fully self--consistent Quasparticle Random Phase Approximation (QRPA). The same Skyrme energy density and density-dependent pairing functionals are used to calculate the mean field and the residual interaction in the particle-hole and particle-particle channels. We have tested our software in the case of spherical nuclei against fully self consistent calculations published in the literature, finding excellent agreement. We investigate the consequences of neglecting the spin-orbit and Coulomb residual interactions in QRPA. Furthermore we discuss the improvement obtained in the QRPA result associated with the removal of spurious modes. Isoscalar and isovector responses in the deformed ${}^{24}{}^{-}{}^{26}$Mg, ${}^{34}$Mg isotopes are presented and compared to experimental findings.
Stark, Julian; Rothe, Thomas; Kieß, Steffen; Simon, Sven; Kienle, Alwin
2016-04-01
Single cell nuclei were investigated using two-dimensional angularly and spectrally resolved scattering microscopy. We show that even for a qualitative comparison of experimental and theoretical data, the standard Mie model of a homogeneous sphere proves to be insufficient. Hence, an accelerated finite-difference time-domain method using a graphics processor unit and domain decomposition was implemented to analyze the experimental scattering patterns. The measured cell nuclei were modeled as single spheres with randomly distributed spherical inclusions of different size and refractive index representing the nucleoli and clumps of chromatin. Taking into account the nuclear heterogeneity of a large number of inclusions yields a qualitative agreement between experimental and theoretical spectra and illustrates the impact of the nuclear micro- and nanostructure on the scattering patterns.
Neutron-pair emission following pi /sup -/ absorption on some light nuclei
Furic, M; Engelhardt, H D; Klotz, W D; Takeutchi, F; Ullrich, H
1977-01-01
Large-area position-sensitive neutron counters with subnanosecond time resolution have been used to study the ( pi /sup -/,2n) reaction with a resolution comparable to or better than the existing ( pi /sup + /,2p) data. The measurement of the momenta of both neutrons enabled a determination of the excitation energy spectra of the residual nuclei to be made. The momentum distributions for the absorbing nucleon pair were also extracted assuming the quasifree mechanism for the ( pi /sup -/,2n) process. The pi /sup -/ beam obtained from the CERN SC II was brought to rest in the targets of /sup 9/Be, /sup 10/B, /sup 12/C and /sup 14/N. The excitation spectra of the residual nuclei were compared with the predictions based on the coefficients of fractional parentage for the removal of the two nucleons. The data and the predictions are in good agreement within the experimental resolution. (4 refs).
Energy Technology Data Exchange (ETDEWEB)
Lister, C.J. [Department of Physics, University of Massachusetts, Lowell, Lowell MA 01854 (United States); McCutchan, E.A. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)
2014-06-15
A new generation of ab-initio calculations, based on realistic two- and three-body forces, is having a profound impact on our view of how nuclei work. To improve the numerical methods, and the parameterization of 3-body forces, new precise data are needed. Electromagnetic transitions are very sensitive to the dynamics which drive mixing between configurations. We have made a series of precise (< 3%) measurements of electromagnetic transitions in the A=10 nuclei {sup 10}C and {sup 10}Be by using the Doppler Shift Attenuation method carefully. Many interesting features can be reproduced including the strong α clustering. New measurements on {sup 8}Be and {sup 12}Be highlight the interplay between the alpha clusters and their valence neutrons.
Geometrical symmetries of nuclear systems: D(3h) and T(d) symmetries in light nuclei
Bijker, Roelof
2016-01-01
The role of discrete (or point-group) symmetries in alpha-cluster nuclei is discussed in the framework of the algebraic cluster model which describes the relative motion of the alpha-particles. Particular attention is paid to the discrete symmetry of the geometric arrangement of the alpha-particles, and the consequences for the structure of the corresponding rotational bands. The method is applied to study cluster states in the nuclei 12C and 16O. The observed level sequences can be understood in a simple way as a consequence of the underlying discrete symmetry that characterizes the geometrical configuration of the alpha-particles, i.e. an equilateral triangle with D(3h) symmetry for 12C, and a tetrahedron with T(d) symmetry for 16O. The structure of rotational bands provides a fingerprint of the underlying geometrical configuration of alpha-particles.
Bulk properties of light deformed nuclei derived from a medium-modified meson-exchange interaction
Grümmer, F; Ma, Z Y; Krewald, S
1996-01-01
Deformed Hartree-Fock-Bogoliubov calculations for finite nuclei are carried out. As residual interaction, a Brueckner G-matrix derived from a meson-exchange potential is taken. Phenomenological medium modifications of the meson masses are introduced. The binding energies, radii, and deformation parameters of the Carbon, Oxygen, Neon, and Magnesium isotope chains are found to be in good agreement with the experimental data.
Study of quark mass dependence of binding energy for light nuclei in 2+1 flavor lattice QCD
Yamazaki, Takeshi; Kuramashi, Yoshinobu; Ukawa, Akira
2015-01-01
We investigate the formation of light nuclei with the nuclear mass number less than or equal to four in 2+1 flavor QCD using a non-perturbative improved Wilson quark and Iwasaki gauge actions. The quark mass is decreased from our previous work to the one corresponding to the pion mass of 0.30 GeV. In each multi-nucleon channel, the energy shift of the ground state relative to the assembly of free nucleons is calculated on two volumes, whose spatial extents are 4.3 fm and 5.8 fm. From the volume dependence of the energy shift, we distinguish a bound state of multi nucleons from an attractive scattering state. We find that all the ground states measured in this calculation are bound states. As in the previous studies at larger $m_\\pi$, our result indicates that at $m_\\pi = 0.30$ GeV the effective interaction between nucleons in the light nuclei is relatively stronger than the one in nature, since the results for the binding energies are larger than the experimental values and a bound state appears in the dineut...
Corrections for nuclear interaction in the case of light nuclei detection in NaI(Tl) crystal
Energy Technology Data Exchange (ETDEWEB)
Avdejchikov, V.V.; Bogdanov, A.I.; Zlomanchuk, Yu.; Majsyukov, V.D.; Abashidze, L.I.; Budilov, V. A.; Zhidkov, N.K.; Nikitin, V.A.; Nomokonov, P.V.; Povtorejko, A.A.
1985-01-01
Losses for nuclear interaction in a NaI(Tl) monocrystal forming together with a silicon semiconductor detector a ..delta..E-E telescope used for the light nucleus identification were measured experimentally. The measurements were performed with 3He nucleus beam extracted from the JINR synchrophasotron at five energy values: 428; 387; 295; 172 and 70 MeV. Nuclear losses for hydrogen and helium isotopes in NaI(Tl) crystals were calculated theoretically using the Glauber model. Comparing the estimated and experimental data obtained the conclusion is drawn on the serviceability of the model considered for determining corrections for the nuclear interaction during light nuclei recording by scintillation NaI(Tl) crystal detectors.
Method for precise charge measurements of relativistic light nuclei, Z<=3, in nuclear track emulsion
Energy Technology Data Exchange (ETDEWEB)
Bloomer, M.A.; Heckman, H.H.; Karant, Y.J. (California Univ., Berkeley (USA). Div. of Nuclear Science)
1983-09-15
A technique for precise charge measurement of particle tracks in nuclear emulsion is described. The method is based on measurements of the lacunarity, i.e., fractional transparency, and/or the fractional opacity in the linear track structure of ionization tracks observed in the developed emulsion. The method yields estimates of charge for relativistic Z=1 and 2 nuclei to a precision of proportional +- 0.05 charge units, in agreement with Barkas' theoretical model of track structure. The technique is applicable up to Zapprox.=6, but with diminished charge resolution with increasing charge above Z=3. Systematics that affect the accuracy of the method are noted and discussed.
Monte-Carlo calculations of light nuclei with the Reid potential
Energy Technology Data Exchange (ETDEWEB)
Lomnitz-Adler, J. (Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Fisica)
1981-01-01
A Monte-Carlo method is developed to calculate the binding energy and density distribution of the /sup 3/H and /sup 4/He nuclei for a variational wave function written as a symmetrized product of correlation operators. The upper bounds obtained with the Reid potential are -6.86 +- .08 and -22.9 +- .5 MeV respectively. The Coulomb interaction in /sup 4/He is ignored. The calculated density distributions have reasonable radii, but they do not show any dip at the center.
Three-Body Potentials in {\\varvec{α }}-Particle Model of Light Nuclei
Ishikawa, Souichi
2017-03-01
In three-body model calculations of atomic nuclei, e.g., the {}^{12}C nucleus as α -α -α system and the {}9Be nucleus as α -α - n system, the Hamiltonians of the systems consisting of two- and three-body potentials are important inputs. However, our knowledge of three-body potentials is quite restricted. In this paper, I will examine a relation between α -α -α and α -α - n three-body potentials that is obtained in a simple cluster model picture, which gives a phenomenological constraint condition on the three-body potential models to be used.
No-Core Shell Model Calculations in Light Nuclei with Three-Nucleon Forces
Energy Technology Data Exchange (ETDEWEB)
Barrett, B R; Vary, J P; Nogga, A; Navratil, P; Ormand, W E
2004-01-08
The ab initio No-Core Shell Model (NCSM) has recently been expanded to include nucleon-nucleon (NN) and three-nucleon (3N) interactions at the three-body cluster level. Here it is used to predict binding energies and spectra of p-shell nuclei based on realistic NN and 3N interactions. It is shown that 3N force (3NF) properties can be studied in these nuclear systems. First results show that interactions based on chiral perturbation theory lead to a realistic description of {sup 6}Li.
Ebersbach, Mirjam; Luwel, Koen; Verschaffel, Lieven
2015-01-01
Children's estimation skills on a bounded and unbounded number line task were assessed in the light of their familiarity with numbers. Kindergartners, first graders, and second graders (N = 120) estimated the position of numbers on a 1--100 number line, marked with either two reference points (i.e., 1 and 10: unbounded condition) or three…
Study of light nuclei (antinuclei) production and Photon Multiplicity Detector in ALICE at the LHC
Sharma, Natasha
The primary goal of the heavy-ion program at the Large Hadron Collider (LHC) at CERN, Geneva, Switzerland is to search for the possible formation of Quark-Gluon Plasma. It also aims to understand the production mechanism of matter and antimatter in a collision. The details of the ALICE detector and its subsystems are presented in this thesis. The details of the fabrication, electronics, readout and installation of the PMD (Photon Multiplicity Detector) in the ALICE experiment are also presented. The PMD detector measures the photons in the 2.3 $<$ $\\eta$ $<$ 3.7 region. The software details including the reconstruction chain are also discussed. The detailed study of efficiency and purity calculation for the PMD detector using the embedding technique are also presented for pp and Pb-Pb collisions. The detailed study of nuclei and anti-nuclei production using the statistical-thermal model (THERMUS) is discussed. Their ratios are compared with the existing experimental data and predictions are made for pp ...
Evidence for Symplectic Symmetry in Ab Initio No-Core Shell Model Results for Light Nuclei
Energy Technology Data Exchange (ETDEWEB)
Dytrych, Tomas; Sviratcheva, Kristina D.; Bahri, Chairul; Draayer, Jerry P.; /Louisiana State U.; Vary, James P.; /Iowa State U. /LLNL, Livermore /SLAC
2007-04-24
Clear evidence for symplectic symmetry in low-lying states of {sup 12}C and {sup 16}O is reported. Eigenstates of {sup 12}C and {sup 16}O, determined within the framework of the no-core shell model using the JISP16 NN realistic interaction, typically project at the 85-90% level onto a few of the most deformed symplectic basis states that span only a small fraction of the full model space. The results are nearly independent of whether the bare or renormalized effective interactions are used in the analysis. The outcome confirms Elliott's SU(3) model which underpins the symplectic scheme, and above all, points to the relevance of a symplectic no-core shell model that can reproduce experimental B(E2) values without effective charges as well as deformed spatial modes associated with clustering phenomena in nuclei.
Secondary cosmic ray nuclei in the light of the Single Source Model
Erlykin, Anatoly
2016-01-01
Evidence for a local 'Single Source' of cosmic rays is amassing by way of the recent precise measurements of various cosmic ray energy spectra from the AMS-02 instrument. To observations of individual cosmic ray nuclei, electrons, positrons and antiprotons must now be added the determination of the boron-to-carbon ratio and the energy spectrum of lithium to 2000 GV with high precision. Our analysis leads us to claim that, with certain assumptions about the propagation in the Galaxy, the results confirm our arguments regarding the presence of a local single source, perhaps, a supernova remnant (SNR). An attempt is made to determine some of the properties of this SNR and its progenitor star.
A statistical model for simulating the emission of light particles from excited nuclei
Sannikov, A. V.; Savitskaya, E. N.
2016-05-01
The algorithms and basic equations of a novel evaporation model that have been implemented in the program package EVAP15 are detailed. The level density of an excited nucleus is described by the composite Gilbert-Cameron formula with parameter values as suggested by the IAEA working group RIPL-3. Special attention is paid to the cross sections of inverse reactions and, in particular, to those for the interactions of low-energy neutrons with nuclei and for crossing of the Coulomb barrier by low-energy charged particles. The model predictions are compared with a large volume of experimental data on the spectra of particles emitted in the reactions ( n, xn), ( n, xp), and ( n, xα) induced by neutrons with energy near 14 MeV and on the four spectra for the reaction ( p, xp) induced by 62-MeV protons.
Secondary Cosmic Ray Nuclei in the Light of the Single Source Model
Erlykin, Anatoly
2016-01-01
Evidence for a local 'Single Source' of cosmic rays is amassing by way of the recent precise measurements of various cosmic ray energy spectra from the AMS-02 instrument. To observations of individual cosmic ray nuclei, electrons, positrons and antiprotons must now be added the determination of the boron-to-carbon ratio and the energy spectrum of lithium to 2000 GV with high precision. Our analysis leads us to claim that, with certain assumptions about propagation in the Galaxy, the results confirm our arguments regarding the presence of a local single source, perhaps, a supernova remnant (SNR). An attempt is made to determine some of the properties of this SNR and its progenitor star.
Lensky, Vadim; Birse, Michael C.; Walet, Niels R.
2016-09-01
We construct a coordinate-space potential based on pionless effective field theory (EFT) with a Gaussian regulator. Charge-symmetry breaking is included through the Coulomb potential and through two- and three-body contact interactions. Starting with the effective field theory potential, we apply the stochastic variational method to determine the ground states of nuclei with mass number A ≤4 . At next-to-next-to-leading order, two out of three independent three-body parameters can be fitted to the three-body binding energies. To fix the remaining one, we look for a simultaneous description of the binding energy of 4He and the charge radii of 3He and 4He. We show that at the order considered we can find an acceptable solution, within the uncertainty of the expansion. We find that the EFT expansion shows good agreement with empirical data within the estimated uncertainty, even for a system as dense as 4He.
Lensky, Vadim; Walet, Niels R
2016-01-01
We construct a coordinate-space potential based on pionless effective field theory with a Gaussian regulator. Charge-symmetry breaking is included through the Coulomb potential and through two- and three-body contact interactions. Starting with the effective field theory potential, we apply the stochastic variational method to determine the ground states of nuclei with mass number $A\\leq 4$. At next-to-next-to-leading order, two out of three independent three-body parameters can be fitted to the three-body binding energies. To fix the remaining one, we look for a simultaneous description of the binding energy of $^4$He and the charge radii of $^3$He and $^4$He. We show that at the order considered we can find an acceptable solution, within the uncertainty of the expansion. We find that the EFT expansion shows good convergence, even for a system as dense as $^4$He.
Proton Halo or Skin in the Excited States of Light Nuclei
Institute of Scientific and Technical Information of China (English)
陈金根; 蔡翔舟; 张虎勇; 沈文庆; 任中洲; 蒋维洲; 马余刚; 钟晨; 魏义彬; 郭威; 周星飞; 马国亮; 王鲲
2003-01-01
Properties of nuclei 13,15N and 9B are investigated in the relativistic mean-field theory with NLZ and NL3 force parameters. The calculated binding energies are very close to the experimental ones. The calculations show that the first excited state (1p1/2) in 9B, the first excited state (2s1/2) in 13N and the second excited state (2s1/2) in 15N are weakly bound. In particular, for 13N and 15N, the proton density distributions in the two above excited states have a long tail and the rms radii of the last proton are greatly larger compared with their respective matter radii. It is predicted that a proton halo exists in the first excited state of 13N and in the second excited state of 15N, respectively. It also indicates that the first excited state in 9B is a proton skin state.
Structure of light neutron-rich nuclei and mechanism of elastic proton scattering
Energy Technology Data Exchange (ETDEWEB)
Ibraeva, E. T., E-mail: ibr@inp.kz [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Zhusupov, M. A. [Al-Farabi Kazakh National University (Kazakhstan); Imambekov, O. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan)
2011-11-15
Differential cross sections for elastic p{sup 6}He, p{sup 8}Li, and p{sup 9}Li scattering at two energies of 70 and 700 MeV per nucleon were calculated within the Glauber theory of multiple diffractive scattering. Threeparticle wave functions ({alpha}-n-n for {sup 6}He, {alpha}-t-n for {sup 8}Li, and {sup 7}Li-n-n for {sup 9}Li) were used for realistic potentials of intercluster interactions. The sensitivity of elastic scattering to proton-nucleus interaction and to the structure of nuclei was explored. In particular, the dependence of the differential cross section on the contribution of higher order collisions, on scattering on the core and peripheral nucleons, and on the contribution of small wave-function components and their asymptotic behavior was determined. A comparison with available experimental data and with the results of calculations within different formalisms was performed.
Energy Technology Data Exchange (ETDEWEB)
Kabir, Al Amin [Kent State Univ., Kent, OH (United States)
2015-12-01
Analysis of high-energy electron scattering has been used to determine the charge radii of nuclei for several decades. Recent analysis of the Lamb shift in muonic hydrogen found an r.m.s. radius significantly different than the electron scattering result. To understand this puzzle we have analyzed the "LEDEX" data for the (e, e'p) reaction. This experiment includes measurements on several light nuclei, hydrogen, deuterium, lithium, boron, and carbon. To test our ability to measure absolute cross sections, as well as our ability to extract the charge radius, we tested our technique against the extremely well-measured carbon case and found excellent agreement using the Fourier-Bessel parametrization. We then extended the procedure to boron and lithium, which show nice agreement with the latest theoretical calculations. For hydrogen, we see clearly the limits of this technique and therefore, the charge radius is determined from the traditional extrapolation to q^{2} = 0. We will show that there is a model dependence in extracting the charge radius of hydrogen and its unambiguous determination is very difficult with available electron-scattering measurements.
Unbound particles in dark matter halos
Energy Technology Data Exchange (ETDEWEB)
Behroozi, Peter S.; Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, Physics Department, Stanford University and SLAC National Accelerator Laboratory 2575 Sand Hill Road, Menlo Park, CA (United States); Loeb, Abraham, E-mail: behroozi@stanford.edu, E-mail: aloeb@cfa.harvard.edu, E-mail: rwechsler@stanford.edu [Department of Astronomy, Harvard University 60 Garden St, Cambridge, MA (United States)
2013-06-01
We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which dark matter particles will eventually become unbound from halos. We also study the mass fraction of unbound particles, which increases strongly towards the edges of halos, and decreases significantly at higher redshifts. We discuss implications for dark matter detection experiments, precision calibrations of the halo mass function, the use of baryon fractions to constrain dark energy, and searches for intergalactic supernovae.
Unbound particles in dark matter halos
Energy Technology Data Exchange (ETDEWEB)
Behroozi, Peter S.; Loeb, Abraham; Wechsler, Risa H.
2013-06-13
We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which dark matter particles will eventually become unbound from halos. We also study the mass fraction of unbound particles, which increases strongly towards the edges of halos, and decreases significantly at higher redshifts. We discuss implications for dark matter detection experiments, precision calibrations of the halo mass function, the use of baryon fractions to constrain dark energy, and searches for intergalactic supernovae.
I. Unbound serum gold: procedure for quantitation.
Lorber, A; Vibert, G J; Harralson, A F; Simon, T M
1983-08-01
The unbound fraction of many drugs appears to be the therapeutically active component. However, the major problem encountered in following unbound serum gold (UBSG) concentration during chrysotherapy has been the ability to quantitate such a small quantity of gold reliably without matrix interference. The methodology detailed here overcomes these difficulties and provides an effective means of monitoring the UBSG fraction during chrysotherapy. We have observed that the unbound fraction of gold dissipates quickly after gold sodium thiomalate administration and constitutes less than 2% of the total serum gold concentration.
Unbounded subnormal weighted shifts on directed trees
Budzynski, Piotr; Jung, Il Bong; Stochel, Jan
2011-01-01
A new method of verifying the subnormality of unbounded Hilbert space operators based on an approximation technique is proposed. Diverse sufficient conditions for subnormality of unbounded weighted shifts on directed trees are established. An approach to this issue via consistent systems of probability measures is invented. The role played by determinate Stieltjes moment sequences is elucidated. Lambert's characterization of subnormality of bounded operators is shown to be valid for unbounded weighted shifts on directed trees that have sufficiently many quasi-analytic vectors, which is a new phenomenon in this area. The cases of classical weighted shifts and weighted shifts on leafless directed trees with one branching vertex are studied.
Stable approximate evaluation of unbounded operators
Groetsch, Charles W
2007-01-01
Spectral theory of bounded linear operators teams up with von Neumann’s theory of unbounded operators in this monograph to provide a general framework for the study of stable methods for the evaluation of unbounded operators. An introductory chapter provides numerous illustrations of unbounded linear operators that arise in various inverse problems of mathematical physics. Before the general theory of stabilization methods is developed, an extensive exposition of the necessary background material from the theory of operators on Hilbert space is provided. Several specific stabilization methods are studied in detail, with particular attention to the Tikhonov-Morozov method and its iterated version.
Energy Technology Data Exchange (ETDEWEB)
Sawahata, K. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Ozawa, A., E-mail: ozawa@tac.tsukuba.ac.jp [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Saito, Y.; Abe, Y.; Ichikawa, Y.; Inaba, N.; Ishibashi, Y. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Kitagawa, A. [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Matsunaga, S. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Moriguchi, T.; Nagae, D.; Okada, S. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Sato, S. [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); Suzuki, S. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Suzuki, T.; Takeuchi, Y.; Yamaguchi, T. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Zenihiro, J. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan)
2017-05-15
We investigated charge-changing processes (total charge-changing cross sections and partial charge-changing cross sections) for light proton-rich nuclei ({sup 34–36}Ar, {sup 33}Cl, {sup 25–28}Si) at around 300A MeV on carbon and solid-hydrogen targets. We estimated the nuclear proton point radii of {sup 33}Cl and {sup 25,26,27}Si from the observed total charge-changing cross sections by using Glauber-model calculations with a phenomenological correction factor. Furthermore, we estimated the proton skin thickness for {sup 33}Cl coupled with its previously observed matter radius. From investigations of the partial charge-changing cross sections, clear zigzag pattern was observed for all isotopes. The present studies suggest that the pattern may be common in the proton-rich side, and depends on the odd–even nature of the fragment charge.
Collectivity in the light radon nuclei measured directly via Coulomb excitation
Gaffney, L P; Jenkins, D G; Andreyev, A N; Bender, M; Blazhev, A; Bree, N; Bruyneel, B; Butler, P A; Cocolios, T E; Davinson, T; Deacon, A N; De Witte, H; DiJulio, D; Diriken, J; Ekström, A; Fransen, Ch; Freeman, S J; Geibel, K; Grahn, T; Hadinia, B; Hass, M; Heenen, P -H; Hess, H; Huyse, M; Jakobsson, U; Kesteloot, N; Konki, J; Kröll, Th; Kumar, V; Ivanov, O; Martin-Haugh, S; Mücher, D; Orlandi, R; Pakarinen, J; Petts, A; Peura, P; Rahkila, P; Reiter, P; Scheck, M; Seidlitz, M; Singh, K; Smith, J F; Van de Walle, J; Van Duppen, P; Voulot, D; Wadsworth, R; Warr, N; Wenander, F; Wimmer, K; Wrzosek-Lipska, K; Zielińska, M
2015-01-01
Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around $Z=82$ and the neutron mid-shell at $N=104$. Purpose: Evidence for shape coexistence has been inferred from $\\alpha$-decay measurements, laser spectroscopy and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of $^{202}$Rn and $^{204}$Rn were studied by means of low-energy Coulomb excitation at the REX-ISOLDE facility in CERN. Results: The electric-quadrupole ($E2$) matrix element connecting the ground state and first-excited $2^{+}_{1}$ state was extracted for both $^{202}$Rn and $^{204}$Rn, corresponding to ${B(E2;2^{+}_{1} \\to 2^...
Local chiral potentials with Δ-intermediate states and the structure of light nuclei
Piarulli, Maria
2017-01-01
We present a fully local nucleon-nucleon potential in chiral effective field theory (χEFT) retaining pions, nucleons and Δ-isobars as explicit degrees of freedom, and use it in hypersperical-harmonics and quantum Monte Carlo calculations of ground and excited states of 3H, 3He, 4He, 6He, and 6Li nuclei. The calculation of the potential is carried out by including one- and two-pion-exchange contributions up to next-to-next-to-leading order (N2LO) and contact interactions up to next-to-next-to-next-to-leading order (N3LO). The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in two different ranges of laboratory energies, either 0-125 MeV or 0-200 MeV, and to the deuteron binding energy and nn singlet scattering length. Fits to these data are performed for three models characterized by long- and short-range cutoffs, RL and RS respectively, ranging from (RL ,RS) =(1 . 2 , 0 . 8) fm down to (0 . 8 , 0 . 6) fm. The long-range (short-range) cutoff regularizes the one- and two-pion exchange (contact) part of the potential.
Interpretations of Recursion under Unbounded Nondeterminacy
Hesselink, Wim H.
1988-01-01
A language is constructed that supports arbitrary atomic statements, composition, alternatives, and mutual recursion in the presence of unbounded nondeterminacy. The concept of interpretation is defined axiomatically. By operational means a standard interpretation is constructed, which is proved to
Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmed, I.; Ahn, S. U.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Ball, M.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biswas, S.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Buxton, J. T.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; De Caro, A.; De Cataldo, G.; De Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; Deisting, A.; Deloff, A.; Dénes, E.; D'erasmo, G.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erhardt, F.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-solis, E.; Gargiulo, C.; Gasik, P.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; González-zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-oetringhaus, J. F.; Grossiord, J.-y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.
2016-01-01
The production of (anti-)deuteron and (anti-)He 3 nuclei in Pb-Pb collisions at s NN − − − √ =2.76 TeV has been studied using the ALICE detector at the LHC. The spectra exhibit a significant hardening with increasing centrality. Combined blast-wave fits of several particles support the
Expected impact from weak reactions with light nuclei in corecollapse supernova simulations
Directory of Open Access Journals (Sweden)
Fischer T.
2016-01-01
Full Text Available We study the role of light nuclear clusters in simulations of core-collapse supernovae. Expressions for the reaction rates are developed for a large selection of charged current absorption and scattering processes with light clusters. Medium modifications are taken into account at the mean-field level. We explore the possible impact on the supernova dynamics and the neutrino signal during the mass accretion phase prior to the possible explosion onset as well as during the subsequent protoneutron star deleptnoization after the explosion onset has been launched.
CHROMATIN TEXTURE OF MELANOCYTIC NUCLEI - CORRELATION BETWEEN LIGHT AND ELECTRON-MICROSCOPY
ABMAYR, W; STOLZ, W; KORHERR, S; WILD, W; SCHMOECKEL, C
1987-01-01
Cells of a benign pigmented mole and a malignant melanoma were used to compare electron microscopy (EM) and light microscopy (LM) with high-resolution TV-scanning and multivariate analysis methods. Special emphasis was placed on different kinds of chromatin texture features and their discriminating
Shah, N.; Ma, Y. G.; Chen, J. H.; Zhang, S.
2016-03-01
The production of dibaryons, light nuclei and hypertriton in the most central Au+Au collisions at √{sNN} = 11.5 and 200 GeV is investigated by using a naive coalescence model. The production of light nuclei is studied and found that the production rate reduces by a factor of 330 (1200) for each extra nucleon added to nuclei at √{sNN} = 11.5 (200) GeV. The pT integrated yield of multistrange hadrons falls exponentially as strangeness quantum number increases. We further investigate strangeness population factors S3 ,S2 as a function of transverse momentum as well as √{sNN}. The calculations for √{sNN} = 11.5 GeV presented here will stimulate interest to carry out these measurements during the phase-II of beam energy scan program at STAR experiment.
Extension of the Li\\`ege Intranuclear-Cascade model to reactions induced by light nuclei
Mancusi, Davide; Cugnon, Joseph; David, Jean-Christophe; Kaitaniemi, Pekka; Leray, Sylvie
2014-01-01
The purpose of this paper is twofold. First, we present the extension of the Li\\`ege Intranuclear Cascade model to reactions induced by light ions. Second, we describe the C++ version of the code, which it is physics-wise equivalent to the legacy version, is available in Geant4 and will serve as the basis for all future development of the model. We describe the ideas upon which we built our treatment of nucleus-nucleus reactions and we compare the model predictions against a vast set of heterogeneous experimental data. In spite of the discussed limitations of the intranuclear-cascade scheme, we find that our model yields valid predictions for a number of observables and positions itself as one of the most attractive alternatives available to Geant4 users for the simulation of light-ion-induced reactions.
Measurement of light charged particles in the decay channels of medium-mass excited compound nuclei
Valdre', S; Casini, G; Pasquali, G; Piantelli, S; Carboni, S; Cinausero, M; Gramegna, F; Marchi, T; Baiocco, G; Bardelli, L; Benzoni, G; Bini, M; Blasi, N; Bracco, A; Brambilla, S; Bruno, M; Camera, F; Corsi, A; Crespi, F; Agostino, M D; Degerlier, M; Kravchuk, V L; Leoni, S; Million, B; Montanari, D; Morelli, L; Nannini, A; Nicolini, R; Poggi, G; Vannini, G; Wieland, O; Bednarczyk, P; Ciemała, M; Dudek, J; Fornal, B; Kmiecik, M; Maj, A; Matejska-Minda, M; Mazurek, K; Meczynski, W; Myalski, S; Styczen, J; Zieblinski, M
2013-01-01
The 48Ti on 40Ca 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. Indeed, in this mass region (A about 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 region 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.
Transfer reactions on light exotic nuclei studied with CHIMERA detector at LNS
Directory of Open Access Journals (Sweden)
Cardella Giuseppe
2014-03-01
Full Text Available The kinematical coincidence method is used to extract angular distribution of elastic scattering and transfer reactions. The detected light particle energy spectra are used to extract the angular distribution with around 1° resolution in the Center of Mass (CM system. Examples with 10Be beam are presented. In the case of proton scattering, γ-ray coincidences are used to discriminate excited levels population from elastic scattering.
Lee, Hyekyung; Baek, Tae Hwa; Park, Meeja; Lee, Seung Yun; Son, Hyun Jin; Kang, Dong Wook; Kim, Joo Heon; Kim, Soo Young
2016-01-01
Background There is subjective disagreement regarding nuclear clearing in papillary thyroid carcinoma. In this study, using digital instruments, we were able to quantify many ambiguous pathologic features and use numeric data to express our findings. Methods We examined 30 papillary thyroid carcinomas. For each case, we selected representative cancer cells showing clear nuclei and surrounding non-neoplastic follicular epithelial cells and evaluated objective values of green light intensity (GLI) for quantitative analysis of nuclear clearing in papillary thyroid carcinoma. Results From 16,274 GLI values from 600 cancer cell nuclei and 13,752 GLI values from 596 non-neoplastic follicular epithelial nuclei, we found a high correlation of 94.9% between GLI and clear nuclei. GLI between the cancer group showing clear nuclei and non-neoplastic follicular epithelia was statistically significant. The overall average level of GLI in the cancer group was over two times higher than the non-neoplastic group despite a wide range of GLI. On a polygonal line graph, there was a fluctuating unique difference between both the cancer and non-neoplastic groups in each patient, which was comparable to the microscopic findings. Conclusions Nuclear GLI could be a useful factor for discriminating between carcinoma cells showing clear nuclei and non-neoplastic follicular epithelia in papillary thyroid carcinoma. PMID:27550048
Measurement of light charged particles in the decay channels of medium-mass excited compound nuclei
Directory of Open Access Journals (Sweden)
Valdré S.
2014-03-01
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 region 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 pre-equilibrium emissions from 300 to 600 MeV bombarding energy.
Bystritsky, V. M.; Bystritsky, Vit. M.; Dudkin, G. N.; Nechaev, B. A.; Padalko, V. N.
2017-07-01
The factors defining the constraints on the current characteristics of the magnetically insulated ion diode (IDM) are considered. The specific current parameters close to the maximum possible ones are obtained for the particular IDM-40 design assigned for acceleration of light ions and investigation of nuclear reactions with small cross sections in the astrophysical energy range (2-40 keV) in the entrance channel. It is experimentally demonstrated that the chosen optimal operation conditions for IDM-40 units provide high stability of the parameters (energy distribution and composition of accelerated particle beams, degree of neutralization) of the accelerated particle flux, which increases during the working pulse.
Measurement of light charged particles in the decay channels of medium-mass excited compound nuclei
Valdré, S.; Barlini, S.; Casini, G.; Pasquali, G.; Piantelli, S.; Carboni, S.; Cinausero, M.; Gramegna, F.; Marchi, T.; Baiocco, G.; Bardelli, L.; Benzoni, G.; Bini, M.; Blasi, N.; Bracco, A.; Brambilla, S.; Bruno, M.; Camera, F.; Corsi, A.; Crespi, F.; D'Agostino, M.; Degerlier, M.; Kravchuk, V. L.; Leoni, S.; Million, B.; Montanari, D.; Morelli, L.; Nannini, A.; Nicolini, R.; Poggi, G.; Vannini, G.; Wieland, O.; Bednarczyk, P.; Ciemała, M.; Dudek, J.; Fornal, B.; Kmiecik, M.; Maj, A.; Matejska-Minda, M.; Mazurek, K.; Męczyński, W. M.; Myalski, S.; Styczeń, J.; Ziębliński, M.
2014-03-01
The 48Ti on 40Ca 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. 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 region 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 pre-equilibrium emissions from 300 to 600 MeV bombarding energy.
Energy Technology Data Exchange (ETDEWEB)
Zerguerras, T
2001-09-01
Proton and two proton emission from light neutron deficient nuclei around A=20 have been studied. A radioactive beam of {sup 18}Ne, {sup 17}F and {sup 20}Mg, produced at the Grand Accelerateur National d'Ions Lourds by fragmentation of a {sup 24}Mg primary beam at 95 MeV/A, bombarded a {sup 9}Be target to form unbound states. Proton(s) and nuclei from the decay were detected respectively in the MUST array and the SPEG spectrometer. From energy and angle measurements, the invariant mass of the decaying nucleus could be reconstructed. Double coincidence events between a proton and {sup 17}F, {sup 16}O, {sup 15}O, {sup 14}O and {sup 18}Ne were registered to obtain excitation energy spectra of {sup 18}Ne, {sup 17}F, {sup 16}F, {sup 15}F et {sup 19}Na. Generally, the masses measures are in agreement with previous experiments. In the case of {sup 18}Ne, excitation energy and angular distributions agree well with the predictions of a break up model calculation. From {sup 17}Ne proton coincidences, a first experimental measurement of the ground state mass excess of {sup 18}Na has been obtained and yields 24,19(0,15)MeV. Two proton emission from {sup 17}Ne and {sup 18}Ne excited states and the {sup 19}Mg ground state was studied through triple coincidences between two proton and {sup 15}O, {sup 16}O and {sup 17}Ne respectively. In the first case, the proton-proton relative angle distribution in the center of mass has been compared with model calculation. Sequential emission from excited states of {sup 17}Ne, above the proton emission threshold, through {sup 16}F is dominant but a {sup 2}He decay channel could not be excluded. No {sup 2}He emission from the 1.288 MeV {sup 17}Ne state, or from the 6.15 MeV {sup 18}Ne state has been observed. Only one coincidence event between {sup 17}Ne and two proton was registered, the value of the one neutron stripping reaction cross section of {sup 20}Mg being much lower than predicted. (author)
Fusion of light exotic nuclei at near-barrier energies: Effect of inelastic excitation
Indian Academy of Sciences (India)
P Banerjee; K Krishan; S Bhattacharya; C Bhattacharya
2003-09-01
The effect of inelastic excitation of exotic light projectiles (proton- as well as neutron-rich) 17F and 11Be on fusion with heavy target has been studied at near-barrier energies. The calculations have been performed in the coupled channels approach where, in addition to the normal coupling of the ground state of the projectile to the continuum, inelastic excitation of the projectile to the bound excited state and its coupling to the continuum have also been taken into consideration. The inclusion of these additional couplings has been found to have signiﬁcant effect on the fusion excitation function of neutron-rich 11Be on 208Pb whereas the effect has been observed to be nominal for the case of proton-rich 17F on the same target. The pronounced effect of the channel coupling on the fusion process in the case of 11Be is attributed to its well-developed halo structure.
Production of light flavor hadrons and anti-nuclei at the LHC
Kalweit, Alexander
With the recording of the first collisions of the Large Hadron Collider (LHC) in November 2009, a new era in the domain of high energy and relativistic heavy-ion physics has started. As one of the early observables which can be addressed, the measurement of light quark flavor production is presented in this thesis. Hadrons that consist only of u, d, and s quarks constitute the majority of the produced particles in pp and Pb–Pb collisions. Their measurement forms the basis for a detailed understanding of the collision and for the answer of the question if hadronic matter undergoes a phase transition to the deconfined quark-gluon plasma at high temperatures. The basics of ultra-relativistic heavy- ion physics are briefly introduced in the first chapter followed by a short description of the ALICE experiment. A particular focus is put on the unique particle identification (PID) capabilities as they provide the basis of the measurements which are presented in the following chapters. The particle identification ...
Characterization of Unbound Granular Materials for Pavements
Araya, A.A.
2011-01-01
This research is focused on the characterization of the mechanical behavior of unbound granular road base materials (UGMs). An extensive laboratory investigation is described, in which various methods for determination of the mechanical properties of granular materials are examined for their applica
Coupled-cluster computations of atomic nuclei
Hagen, G; Hjorth-Jensen, M; Dean, D J
2013-01-01
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.
Pereira, J.; Montes, F.
2016-03-01
Background: Neutrino-driven winds following core-collapse supernova explosions have been proposed as a possible site where light r -process nuclei (between Fe and Ag) might be synthesized. In these events, (α ,n ) reactions are key to moving matter towards the region of higher proton number. Abundance network calculations are very sensitive to the rates for this type of reactions. Purpose: The present work aims at evaluating the theoretical uncertainty of these (α ,n ) reactions calculated with reaction codes based on the Hauser-Feshbach model. Method: We compared several (α ,n ) rates taken from talys and the non-smoker database to determine the uncertainties owing to the existing technical differences between both codes. In addition, we evaluated the sensitivity of talys rates to variations in the α optical potentials, masses, level densities, optical potentials, preequilibrium intranuclear transition rates, level structure, radiative transmission coefficients, and width-fluctuation correction factors. Results: The main source of uncertainty at low temperature is mostly attributable to the use of different α optical potentials. Differences between talys and non-smoker at high temperatures arise from the energy-binning algorithm used by each code. We have also noticed that the (α ,n ) rates from the non-smoker database correspond to the inclusive reaction, instead of the exclusive (α ,1 n ) channel calculated in the present work and used in network calculations. Conclusions: Theoretical uncertainties in calculated reaction rates can be as high as one to two orders of magnitude and strongly dependent on the temperature of the environment. Besides direct measurements of the inclusive and exclusive (α ,1 n ) reaction rates, experimental studies of α optical potentials are crucial to improve the performance of reaction codes.
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; Eum, Jongsik; 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 Coral, Diego Mauricio; 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; Kour, Mandeep; Kouzinopoulos, Charalampos; Kovalenko, Oleksandr; 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, Ajay; 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; 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; Masui, Hiroshi; 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; Perez Moreno, Luis Alberto; 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; 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, Monika; 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; Villatoro Tello, Abraham; 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
2016-02-29
The production of (anti-)deuteron and (anti-)$^{3}$He nuclei in Pb-Pb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV has been studied using the ALICE detector at the LHC. The spectra exhibit a significant hardening with increasing centrality. Combined blast-wave fits of several particles support the interpretation that this behavior is caused by an increase of radial flow. The integrated particle yields are discussed in the context of coalescence and thermal-statistical model expectations. The particle ratios, $^3$He/d and $^3$He/p, in Pb-Pb collisions are found to be in agreement with a common chemical freeze-out temperature of $T_{\\rm chem} \\approx 156$ MeV. These ratios do not vary with centrality which is in agreement with the thermal-statistical model. In a coalescence approach, it excludes models in which nucleus production is proportional to the particle multiplicity and favors those in which it is proportional to the particle density instead. In addition, the observation of 31 anti-tritons in Pb-Pb coll...
Adamczyk, L; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Aparin, A; Arkhipkin, D; Aschenauer, E C; Ashraf, M U; Attri, A; Averichev, G S; Bai, X; Bairathi, V; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Bouchet, J; Brandenburg, J D; Brandin, A V; Bunzarov, I; Butterworth, J; Caines, H; Sánchez, M Calderón de la Barca; Campbell, J M; Cebra, D; Chakaberia, I; Chaloupka, P; Chang, Z; Chatterjee, A; Chattopadhyay, S; Chen, X; Chen, J H; Cheng, J; Cherney, M; Christie, W; Contin, G; Crawford, H J; Das, S; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; di Ruzza, B; Didenko, L; Dilks, C; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Eppley, G; Esha, R; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Federic, P; Fedorisin, J; Feng, Z; Filip, P; Fisyak, Y; Flores, C E; Fulek, L; Gagliardi, C A; Garand, D; Geurts, F; Gibson, A; Girard, M; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, S; Gupta, A; Guryn, W; Hamad, A I; Hamed, A; Haque, R; Harris, J W; He, L; Heppelmann, S; Hirsch, A; Hoffmann, G W; Horvat, S; Huang, T; Huang, H Z; Huang, X; Huang, B; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Jentsch, A; Jia, J; Jiang, K; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Khan, Z H; Kikoła, D P; Kisel, I; Kisiel, A; Kochenda, L; Koetke, D D; Kosarzewski, L K; Kraishan, A F; Kravtsov, P; Krueger, K; Kumar, L; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Li, W; Li, X; Li, C; Li, Y; Lin, T; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, R; Ma, Y G; Ma, L; Magdy, N; Majka, R; Manion, A; Margetis, S; Markert, C; Matis, H S; McDonald, D; McKinzie, S; Meehan, K; Mei, J C; Minaev, N G; Mioduszewski, S; Mishra, D; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nigmatkulov, G; Niida, T; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Okorokov, V A; Olvitt, D; Page, B S; Pak, R; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlik, B; Pei, H; Perkins, C; Pile, P; Pluta, J; Poniatowska, K; Porter, J; Posik, M; Poskanzer, A M; Pruthi, N K; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, S; Raniwala, R; Ray, R L; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Sharma, A; Sharma, M K; Shen, W Q; Shi, Z; Shi, S S; Shou, Q Y; Sichtermann, E P; Sikora, R; Simko, M; Singha, S; Skoby, M J; Smirnov, D; Smirnov, N; Solyst, W; Song, L; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stepanov, M; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Summa, B; Sun, Y; Sun, X M; Sun, Z; Surrow, B; Svirida, D N; Tang, Z; Tang, A H; Tarnowsky, T; Tawfik, A; Thäder, J; Thomas, J H; Timmins, A R; Tlusty, D; Todoroki, T; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Tripathy, S K; Tsai, O D; Ullrich, T; Underwood, D G; Upsal, I; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Varma, R; Vasiliev, A N; Vertesi, R; Videbæk, F; Vokal, S; Voloshin, S A; Vossen, A; Wang, H; Wang, J S; Wang, Y; Wang, F; Wang, G; Webb, G; Webb, J C; Wen, L; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y; Xiao, Z G; Xie, G; Xie, W; Xin, K; Xu, N; Xu, H; Xu, Z; Xu, Y F; Xu, J; Xu, Q H; Yang, C; Yang, Y; Yang, S; Yang, Q; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I -K; Yu, N; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J; Zhang, Z; Zhang, S; Zhang, Y; Zhang, X P; Zhao, J; Zhong, C; Zhou, L; Zhu, X; Zoulkarneeva, Y; Zyzak, M
2016-01-01
We present measurements of 2$^{nd}$ order azimuthal anisotropy ($v_{2}$) at mid-rapidity $(|y|<1.0)$ for light nuclei d, t, $^{3}$He (for $\\sqrt{s_{NN}}$ = 200, 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV) and anti-nuclei $\\bar{\\rm d}$ ($\\sqrt{s_{NN}}$ = 200, 62.4, 39, 27, and 19.6 GeV) and $^{3}\\bar{\\rm He}$ ($\\sqrt{s_{NN}}$ = 200 GeV) in the STAR (Solenoidal Tracker at RHIC) experiment. The $v_{2}$ for these light nuclei produced in heavy-ion collisions is compared with those for p and $\\bar{\\rm p}$. We observe mass ordering in nuclei $v_{2}(p_{T})$ at low transverse momenta ($p_{T}<2.0$ GeV/$c$). We also find a centrality dependence of $v_{2}$ for d and $\\bar{\\rm d}$. The magnitude of $v_{2}$ for t and $^{3}$He agree within statistical errors. Light-nuclei $v_{2}$ are compared with predictions from a blast wave model. Atomic mass number ($A$) scaling of light-nuclei $v_{2}(p_{T})$ seems to hold for $p_{T}/A < 1.5$ GeV/$c$. Results on light-nuclei $v_{2}$ from a transport-plus-coalescence model are consi...
Shah, N; Chen, J H; Zhang, and S
2015-01-01
The production of dibaryons, light nuclei and hypertriton in the most central Au+Au collisions at $\\sqrt{s_{NN}}=$ 11.5 and 200 GeV are investigated by using a naive coalescence model. The production of light nuclei is studied and found that the production rate reduces by a factor of 330 (1200) for each extra nucleon added to nuclei at $\\sqrt{s_{NN}}=$ 11.5 (200) GeV. The $p_{T}$ integrated yield of multistrange hadrons falls exponentially as strangeness quantum number increases. We further investigate strangeness population factor $S_{3}, S_{2}$ as a function of transverse momentum as well as $\\sqrt{s_{NN}}$. The baryon-strangeness correlation coefficient $C_{BS}$ is also investigated for $\\sqrt{s_{NN}}=$ 11.5 and 200 GeV. The calculations for $\\sqrt{s_{NN}}=$ 11.5 GeV presented here will stimulate interest to carry out these measurements during the phase-II of beam energy scan program at STAR experiment.
Unbounded random operators and Feynman formulae
Orlov, Yu. N.; Sakbaev, V. Zh.; Smolyanov, O. G.
2016-12-01
We introduce and study probabilistic interpolations of various quantization methods. To do this, we develop a method for finding the expectations of unbounded random operators on a Hilbert space by averaging (with the help of Feynman formulae) the random one-parameter semigroups generated by these operators (the usual method for finding the expectations of bounded random operators is generally inapplicable to unbounded ones). Although the averaging of families of semigroups generates a function that need not possess the semigroup property, the Chernoff iterates of this function approximate a certain semigroup, whose generator is taken for the expectation of the original random operator. In the case of bounded random operators, this expectation coincides with the ordinary one.
Lupu, Sergiu; Gazit, Doron
2015-01-01
The large nucleon-nucleon scattering length, and the isospin approximate symmetry, are low energy properties of quantum chromodynamics (QCD). These entail correlations in the binding energies of light nuclei, e.g., the A=3 iso-multiplet, and Tjon's correlation between the binding energy of three and four body nuclei. Using a new representation of these, we establish that they translate into a correlation between different short-range contributions to three body forces in chiral effective field theory of low-energy nuclear physics. We demonstrate that these correlations should be taken into account in order to avoid fine-tuning in the calibration of three body forces. We relate this to the role of correlations in uncertainty quantification of non-renormalizable effective field theories of the nuclear regime. In addition, we show that correlations can be useful in assessing the importance of forces induced by renormalization group (RG) transformations. We give numerical evidence that such RG transformations can...
Energy Technology Data Exchange (ETDEWEB)
Zhilei, She; Hongge, Xu; Tingting, Zeng; Dikai, Li [China University of Geosciences, Physical Department, School of Mathematics and Physics, Wuhan (China); Gang, Chen [China University of Geosciences, Physical Department, School of Mathematics and Physics, Wuhan (China); Central China Normal University, Key Laboratory of Quark and Lepton Physics (MOE), Wuhan (China)
2016-04-15
The centrality dependence of light (anti)nuclei and (anti)hypertriton production in Pb-Pb collisions at √(s{sub NN}) = 2.76 TeV are investigated using the dynamically constrained phase-space coalescence (DCPC) model and the parton and hadron cascade (PACIAE) model. We found that the yields of light (anti)nuclei and (anti)hypertriton strongly depend on the centrality, i.e., their yields decrease rapidly with the increase of centrality; but their yield ratios are independent of centrality. The results from our theoretical model are well consistent with ALICE data. Furthermore, we found that the integrated yields of (anti)nuclei per participant nucleon increase from peripheral to central collisions, and a higher mass number corresponds to a more rapid increase of such yields. The coalescence parameters B{sub A} of light (anti)nuclei and (anti)hypernuclei are also analyzed. (orig.)
Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A. I.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, X.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jentsch, A.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, X.; Li, Y.; Li, W.; Lin, T.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, R.; Ma, G. L.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Matis, H. S.; McDonald, D.; McKinzie, S.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X. M.; Sun, Z.; Sun, Y.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, Y.; Wang, G.; Wang, J. S.; Wang, H.; Wang, Y.; Wang, F.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xin, K.; Xu, H.; Xu, Z.; Xu, J.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, S.; Yang, C.; Yang, Y.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J.; Zhang, Y.; Zhang, X. P.; Zhang, Z.; Zhang, J. B.; Zhang, S.; Zhang, S.; Zhang, J.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration
2016-09-01
We present measurements of second-order azimuthal anisotropy (v2) at midrapidity (|y |<1.0 ) for light nuclei d ,t ,3He (for √{sN N}=200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV) and antinuclei d ¯ (√{sN N}=200 , 62.4, 39, 27, and 19.6 GeV) and ¯3He (√{sN N}=200 GeV) in the STAR (Solenoidal Tracker at RHIC) experiment. The v2 for these light nuclei produced in heavy-ion collisions is compared with those for p and p ¯. We observe mass ordering in nuclei v2(pT) at low transverse momenta (pT<2.0 GeV/c ). We also find a centrality dependence of v2 for d and d ¯. The magnitude of v2 for t and 3He agree within statistical errors. Light-nuclei v2 are compared with predictions from a blast-wave model. Atomic mass number (A ) scaling of light-nuclei v2(pT) seems to hold for pT/A <1.5 GeV /c . Results on light-nuclei v2 from a transport-plus-coalescence model are consistent with the experimental measurements.
Ordering of the $0d_{5/2}$ and $1s_{1/2}$ proton levels in light nuclei
Hoffman, C R; Schiffer, J P
2016-01-01
A survey of the available single-proton data in $A\\leq17$ nuclei, along with calculations using a Woods-Saxon potential, show that the ordering of the $0d_{5/2}$ and $1s_{1/2}$ proton orbitals are determined primarily by the proximity of the $s$-state proton energy to the Coulomb barrier. This is analogous to the dependence of the corresponding neutron orbitals in proximity to the neutron threshold, that was previously discussed.
Lower bounds for unbounded operators and semigroups
2016-01-01
Let $A$ be an unbounded operator on a Banach space $X$. It is sometimes useful to improve the operator $A$ by extending it to an operator $B$ on a larger Banach space $Y$ with smaller spectrum. It would be preferable to do this with some estimates for the resolvent of $B$, and also to extend bounded operators related to $A$, for example a semigroup generated by $A$. When $X$ is a Hilbert space, one may also want $Y$ to be Hilbert space. Results of this type for bounded operators have been giv...
Weighted monotonicity inequalities for unbounded operators
Hoa, Dinh Trung
2011-01-01
Let $\\tau$ be a faithful normal semifinite trace on a von Neumann algebra $\\mathcal{M}$. For a continuous nonnegative convex monotone nondecreasing function $f$ on convex subset $\\Omega$ of $\\mathbb{R}$ and weight nonnegative Borel function $w$ we consider weighted monotonicity inequalities of the form {equation*} \\tau(w(A)^{1/2}f(A)w(A)^{1/2}) \\le \\tau (w(A)^{1/2}f(B)w(A)^{1/2}), {equation*} where $A$ and $B$ are unbounded operators affiliated with respect to algebra $\\mathcal{M}$.
Fractal Dimension of Certain Continuous Functions of Unbounded Variation
Liang, Y. S.; Su, W. Y.
Continuous functions on closed intervals are composed of bounded variation functions and unbounded variation functions. Fractal dimension of continuous functions with bounded variation must be one-dimensional (1D). While fractal dimension of continuous functions with unbounded variation may be 1 or not. Certain continuous functions of unbounded variation whose fractal dimensions are 1 have been mainly investigated in the paper. A continuous function on a closed interval with finite unbounded variation points has been proved to be 1D. Furthermore, we deal with continuous functions which have infinite unbounded variation points and part of them have been proved to be 1D. Certain examples of 1D continuous functions which have uncountable unbounded variation points have been given in the present paper.
A relativistic mean-ﬁeld study of magic numbers in light nuclei from neutron to proton drip-lines
Indian Academy of Sciences (India)
T K Jha; M S Mehta; S K Patra; B K Raj; Raj K Gupta
2003-09-01
In an axially deformed relativistic mean-ﬁeld calculation of single-particle energy spectra of = 8 (Li–Mg) and = 14, 16 (C–Mg) isotonic chain and the one- and two-neutron separation energies of various isotopes of Li–Mg, new magic numbers are found to exist at = 6 and = 16 and/or = 14, which are in addition to the = 8 and = 20 magic numbers. In neutron-rich nuclei, the shell gap at = 6 is larger than at = 8 and a large gap is observed for = 16 or 14 for the neutron-rich and = 14 for proton-rich nuclei. Large shell gaps are also found to exist at = 14 and 16 or = 16 alone for nuclei near the -stability line. The above results are independent of the parameter sets TM2, NL3 and NL–SH used here. Similarly, new large shell gaps are predicted at = 6, 16 and/or 14 for protons.
PROBABILITY INEQUALITIES FOR SUMS OF INDEPENDENT UNBOUNDED RANDOM VARIABLES
Institute of Scientific and Technical Information of China (English)
张涤新; 王志诚
2001-01-01
The tail probability inequalities for the sum of independent unbounded random variables on a probability space ( Ω , T, P) were studied and a new method was proposed to treat the sum of independent unbounded random variables by truncating the original probability space (Ω, T, P ). The probability exponential inequalities for sums of independent unbounded random variables were given. As applications of the results, some interesting examples were given. The examples show that the method proposed in the paper and the results of the paper are quite useful in the study of the large sample properties of the sums of independent unbounded random variables.
Energy Technology Data Exchange (ETDEWEB)
Morelli, L., E-mail: luca.morelli@bo.infn.it; D’Agostino, M.; Bruno, M. [Dipartimento di Fisica e Astronomia dell’Università and INFN, Bologna (Italy); Baiocco, G. [Dipartimento di Fisica dell’Università and INFN, Pavia (Italy); Gulminelli, F. [CNRS, LPC, Caen, France and ENSICAEN, Caen (France); Cinausero, M.; Gramegna, F.; Marchi, T. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy); Degerlier, M. [University of Nevsehir, Physics Department, Nevsehir (Turkey); Fabris, D. [INFN, Sezione di Padova, Padova (Italy); Barlini, S.; Bini, M.; Casini, G.; Gelli, N.; Olmi, A.; Pasquali, G.; Piantelli, S. [Dipartimento di Fisica e Astronomia dell’Università and INFN, Firenze (Italy)
2015-10-15
In the recent years, cluster structures have been evidenced in many ground and excited states of light nuclei [1, 2]. Within the currently ongoing experimental campaign by the NUCL-EX collaboration we have measured the {sup 12}C+{sup 12}C and {sup 14}N+{sup 10}B reactions at 95 MeV and 80 MeV respectively, and compared experimental data corresponding to complete fusion of target and projectile into an excited {sup 24}Mg nucleus to the results of a pure statistical model[3, 4]. We found clear deviations from the statstical model in the decay pattern: emission channels involving multiple α particles are more probable than expected from a purely statistical behavior. To continue the investigation on light systems, we have recentely measured the {sup 16}O+{sup 12}C reaction at three different beam energies, namely E{sub beam} = 90, 110 and 130 MeV.
Nakamura, T
2015-01-01
Large acceptance spectrometers at in-flight RI separators have played significant roles in investigating the structure of exotic nuclei. Such spectrometers are in particular useful for probing unbound states of exotic nuclei, using invariant mass spectroscopy with reactions at intermediate and high energies. We discuss here the key characteristic features of such spectrometers, by introducing the recently commissioned SAMURAI facility at the RIBF, RIKEN. We also explore the issue of cross talk in the detection of multiple neutrons, which has become crucial for exploring further unbound states and nuclei beyond the neutron drip line. Finally we discuss future perspectives for large acceptance spectrometers at the new-generation RI-beam facilities.
Energy Technology Data Exchange (ETDEWEB)
Nakamura, T.; Kondo, Y.
2016-06-01
Large acceptance spectrometers at in-flight RI separators have played significant roles in investigating the structure of exotic nuclei. Such spectrometers are in particular useful for probing unbound states of exotic nuclei, using invariant mass spectroscopy with reactions at intermediate and high energies. We discuss here the key characteristic features of such spectrometers, by introducing the recently commissioned SAMURAI facility at the RIBF, RIKEN. We also investigate the issue of cross talk in the detection of multiple neutrons, which has become crucial for exploring further unbound states and nuclei beyond the neutron drip line. Finally we discuss future perspectives for large acceptance spectrometers at the new-generation RI-beam facilities.
Sáro, S
2003-01-01
Experiments leading to transuranium and far transuranium nuclei as far as element 106 (seaborgium) are described. Physical knowledge derived from experimental data at this stage of complete synthesis nuclear reactions since the 1980s is analyzed. The effect of the shell structure on the stability of the nuclei, the extra-push effect, and the effect of isospin are discussed. Experiments leading to the synthesis of nuclei with Z = 107 - 112 by cold fusion are also described, as are hot fusion reactions resulting in superheavy nuclei Z = 114, 116 where, however, confirmation is only pending. Current state of the art in this area is also highlighted
The 1.6 micron near infrared nuclei of 3C radio galaxies: Jets, thermal emission or scattered light?
Baldi, R D; Capetti, A; Sparks, W; Macchetto, F D; O'Dea, C P; Axon, D J; Baum, S A; Quillen, A C
2010-01-01
Using HST NICMOS 2 observations we have measured 1.6-micron near infrared nuclear luminosities of 100 3CR radio galaxies with z<0.3, by modeling and subtracting the extended emission from the host galaxy. We performed a multi-wavelength statistical analysis (including optical and radio data) of the properties of the nuclei following classification of the objects into FRI and FRII, and LIG (low-ionization galaxies), HIG (high-ionization galaxies) and BLO (broad-lined objects) using the radio morphology and optical spectra, respectively. The correlations among near infrared, optical, and radio nuclear luminosity support the idea that the near infrared nuclear emission of FRIs has a non-thermal origin. Despite the difference in radio morphology, the multi-wavelength properties of FRII LIG nuclei are statistically indistinguishable from those of FRIs, an indication of a common structure of the central engine. All BLOs show an unresolved near infrared nucleus and a large near infrared excess with respect to FRI...
Effects of the spin-orbit and tensor interactions on the M1 and E2 excitations in light nuclei
Fayache, M S; Zamick, L; Von Neumann-Cosel, P; Richter, A
1996-01-01
The effects of varying the spin-orbit and tensor components of a realistic interaction on M1 excitation rates and B(E2)'s are studied on nuclei in the 0p and 1s-0d shells. Not only the total M1 but also the spin and orbital parts separately are studied. The single-particle energies are first calculated with the same interaction that is used between the valence nucleons. Later this stringent condition is relaxed somewhat and the 1s level is raised relative to 0d. For nuclei up to ^{28}Si, much better results i.e stronger B(M1) rates are obtained by increasing the strength of the spin-orbit interaction relative to the free value. This is probably also true for ^{32}S, but ^{36}Ar presents some difficulties. The effects of weakening the tensor interaction are also studied. On a more subtle level, the optimum spin-orbit interaction in the lower half of the s-d shell, as far as M1 excitations are concerned, is substantially larger than the difference E(J=3/2^+)_1-E(J=5/2^+)_1=5.2~MeV in ^{17}O. A larger spin-orbit...
Rough differential equations with unbounded drift term
Riedel, S.; Scheutzow, M.
2017-01-01
We study controlled differential equations driven by a rough path (in the sense of T. Lyons) with an additional, possibly unbounded drift term. We show that the equation induces a solution flow if the drift grows at most linearly. Furthermore, we show that the semiflow exists assuming only appropriate one-sided growth conditions. We provide bounds for both the flow and the semiflow. Applied to stochastic analysis, our results imply strong completeness and the existence of a stochastic (semi)flow for a large class of stochastic differential equations. If the driving process is Gaussian, we can further deduce (essentially) sharp tail estimates for the (semi)flow and a Freidlin-Wentzell-type large deviation result.
Memory effect from spinning unbound binaries
De Vittori, Lorenzo; Gupta, Anuradha; Jetzer, Philippe
2014-01-01
We present a recently developed prescription to obtain ready-to-use gravitational wave (GW) polarization states for spinning compact binaries on hyperbolic orbits. We include leading order spin-orbit interactions, invoking 1.5PN-accurate quasi-Keplerian parametrization for the radial part of the orbital dynamics. We also include radiation reaction effects on $h_+$ and $h_{\\times}$ during the interaction. In the GW signals from spinning binaries there is evidence of the memory effect in both polarizations, in contrast to the non-spinning case, where only the cross polarizations exhibits non-vanishing amplitudes at infinite time. We also compute 1PN-accurate GW polarization states for non-spinning compact binaries in unbound orbits in a fully parametric way, and compare them with existing waveforms.
High order Poisson Solver for unbounded flows
DEFF Research Database (Denmark)
Hejlesen, Mads Mølholm; Rasmussen, Johannes Tophøj; Chatelain, Philippe
2015-01-01
as regularisation we document an increased convergence rate up to tenth order. The method however, can easily be extended well beyond the tenth order. To show the full extend of the method we present the special case of a spectrally ideal regularisation of the velocity formulated integration kernel, which achieves......This paper presents a high order method for solving the unbounded Poisson equation on a regular mesh using a Green’s function solution. The high order convergence was achieved by formulating mollified integration kernels, that were derived from a filter regularisation of the solution field...... or by performing the differentiation as a multiplication of the Fourier coefficients. In this way, differential operators such as the divergence or curl of the solution field could be solved to the same high order convergence without additional computational effort. The method was applied and validated using...
Erlykin, A. D.; Wolfendale, A. W.
2016-10-01
Evidence for a local ‘single source’ of cosmic rays is amassing by way of the recent precise measurements of various cosmic ray energy spectra from the AMS-02 instrument. To observations of individual cosmic ray nuclei, electrons, positrons and antiprotons must now be added the determination of the boron-to-carbon ratio and the energy spectrum of lithium to 2000 GV with high precision. Our analysis leads us to claim that, with certain assumptions about propagation in the Galaxy, the results confirm our arguments regarding the presence of a local single source, perhaps, a supernova remnant (SNR). An attempt is made to determine some of the properties of this SNR and its progenitor star.
Pantic, Igor; Pantic, Senka; Basta-Jovanovic, Gordana
2012-06-01
In our study we investigated the relationship between conventional morphometric indicators of nuclear size and shape (area and circularity) and the parameters of gray level co-occurrence matrix texture analysis (entropy, homogeneity, and angular second moment) in cells committed to apoptosis. A total of 432 lymphocyte nuclei images from the spleen germinal center light zones (cells in early stages of apoptosis) were obtained from eight healthy male guinea pigs previously immunized with sheep red blood cells (antigen). For each nucleus, area, circularity, entropy, homogeneity, and angular second moment were determined. All measured parameters of gray level co-occurrence matrix (GLCM) were significantly correlated with morphometric indicators of nuclear size and shape. The strongest correlation was observed between GLCM homogeneity and nuclear area (p GLCM method may be a powerful tool in evaluation of ultrastructural nuclear changes during early stages of the apoptotic process.
G4MoNA - A Geant4 Simulation for unbound nuclides detected with MoNA/LISA
Gueye, Paul; Freeman, Jessica; Frank, Nathan; MoNA Collaboration
2017-01-01
The MoNA Collaboration has conducted a plethora of experiments to study unbound nuclei near the neutron dripline using the invariant mass technique since 2005. These experiments used a variety of secondary beams from the Coupled Cyclotron Facility of the National Superconducting Cyclotron Laboratory. The experimental setup consists of a large gap superconducting Sweeper magnet for charged fragments separation and the MoNA/LISA neutron detector arrays for neutron detection. Recently, a multi-layered Si/Be segmented target consisting of three 700 mg/cm2 thick 9Be slabs and four 140 μ m Si detectors were added to the setup. This target improves the resolution of the reconstructed decay energy spectra of the unbound nuclides. The Geant4 Monte Carlo simulation toolkit was used to develop a complete realistic model of the setup including a new class to treat the decay of unbound nuclei, the Si/Be segmented target, the MoNA/LISA and the charged fragments detector systems. Comparison between simulated and experimental data will be presented. DoENNSA - DE-NA0000979.
Energy Technology Data Exchange (ETDEWEB)
Sundaralingam, N.
1993-06-08
We study multiple muon events (muon bundles) recorded underground at a depth of 2090 mwe. To penetrate to this depth, the muons must have energies above 0.8 TeV at the Earth`s surface; the primary cosmic ray nuclei which give rise to the observed muon bundles have energies at incidence upon the upper atmosphere of 10 to 10{sup 5}TeV. The events are detected using the Soudan 2 experiment`s fine grained tracking calorimeter which is surrounded by a 14 m {times}10 m {times} 31 m proportional tube array (the ``active shield``). Muon bundles which have at least one muon traversing the calorimeter, are reconstructed using tracks in the calorimeter together with hit patterns in the proportional tube shield. All ionization pulses are required to be coincident within 3 microseconds. A goal of this study is to investigate the relative nuclear abundances in the primary cosmic radiation around the ``knee`` region (10{sup 3} {minus} 10{sup 4} TeV) of the incident energy spectrum. Four models for the nuclear composition of cosmic rays are considered: The Linsley model, the Constant Mass Composition model (CMC), the Maryland model and the Proton-poor model. A Monte Carlo which incorporates one model at a time is used to simulate events which are then reconstructed using the same computer algorithms that are used for the data. Identical cuts and selections are applied to the data and to the simulated events.
Ciemała, M.; Kmiecik, M.; Maj, A.; Mazurek, K.; Bracco, A.; Kravchuk, V. L.; Casini, G.; Barlini, S.; Baiocco, G.; Bardelli, L.; Bednarczyk, P.; Benzoni, G.; Bini, M.; Blasi, N.; Brambilla, S.; Bruno, M.; Camera, F.; Carboni, S.; Cinausero, M.; Chbihi, A.; Chiari, M.; Corsi, A.; Crespi, F. C. L.; D'Agostino, M.; Degerlier, M.; Fornal, B.; Giaz, A.; Gramegna, F.; Krzysiek, M.; Leoni, S.; Marchi, T.; Matejska-Minda, M.; Mazumdar, I.; Meczyński, W.; Million, B.; Montanari, D.; Morelli, L.; Myalski, S.; Nannini, A.; Nicolini, R.; Pasquali, G.; Piantelli, S.; Prete, G.; Roberts, O. J.; Schmitt, Ch.; Styczeń, J.; Szpak, B.; Valdré, S.; Wasilewska, B.; Wieland, O.; Wieleczko, J. P.; Ziebliński, M.; Dudek, J.; Dinh Dang, N.
2015-05-01
High-energy giant dipole resonance (GDR) γ rays were measured following the decay of the hot, rotating compound nucleus of 88Mo, produced at excitation energies of 124 and 261 MeV. The reaction 48Ti + 40Ca at 300 and 600 MeV bombarding energies has been used. The data were analyzed using the statistical model Monte Carlo code gemini++. It allowed extracting the giant dipole resonance parameters by fitting the high-energy γ -ray spectra. The extracted GDR widths were compared with the available data at lower excitation energy and with theoretical predictions based on (i) The Lublin-Strasbourg drop macroscopic model, supplemented with thermal shape fluctuations analysis, and (ii) The phonon damping model. The theoretical predictions were convoluted with the population matrices of evaporated nuclei from the statistical model gemini++. Also a comparison with the results of a phenomenological expression based on the existing systematics, mainly for lower temperature data, is presented and discussed. A possible onset of a saturation of the GDR width was observed around T =3 MeV.
Bertsch, G F
2016-01-01
Gerry Brown initiated some early studies on the coexistence of different nuclear shapes. The subject has continued to be of interest and is crucial for understanding nuclear fission. We now have a very good picture of the potential energy surface with respect to shape degrees of freedom in heavy nuclei, but the dynamics remain problematic. In contrast, the early studies on light nuclei were quite successful in describing the mixing between shapes. Perhaps a new approach in the spirit of the old calculations could better elucidate the character of the fission dynamics and explain phenomena that current theory does not model well.
Unbounded subnormal weighted shifts on directed trees I
Budzyński, Piotr; Jung, Il Bong
2012-01-01
A new method of verifying the subnormality of unbounded Hilbert space operators based on an approximation technique is proposed. Diverse sufficient conditions for subnormality of unbounded weighted shifts on directed trees are established. An approach to this issue via consistent systems of probability measures is invented. The role played by determinate Stieltjes moment sequences is elucidated. Lambert's characterization of subnormality of bounded operators is shown to be valid for unbounded weighted shifts on directed trees that have sufficiently many quasi-analytic vectors, which is a new phenomenon in this area.
Holt, Roy J.
2016-03-01
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.
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.
Marinova, K P
2002-01-01
Nuclear Moments and radii of light unstable isotopes are investigated by applying different high-sensitivity and high-resolution techniques based on collinear fast-beam laser spectroscopy. A study of nuclear structure in the sd shell is performed on neon isotopes in the extended chain of $^{17-28}$Ne, in particular on the proton-halo candidate $^{17}$Ne. Measurements of hyperfine structure and isotope shift have become possible by introducing an ultra-sensitive non-optical detection method which is based on optical pumping, state-selective collisional ionization and $\\beta$-activity counting. The small effect of nuclear radii on the optical isotope shifts of light elements requires very accurate measurements. The errors are dominated by uncertainties of the Doppler shifts which are conventionally determined from precisely measured acceleration voltages. These uncertainties are removed by measuring the beam energy with simultaneous excitation of two optical lines in parallel / antiparallel beam configuration. ...
Mente, Scot; Doran, Angela; Wager, Travis T
2012-06-14
The objective of this work was to establish that unbound maximum concentrations may be reasonably predicted from a combination of computed molecular properties assuming subcutaneous (SQ) dosing. Additionally, we show that the maximum unbound plasma and brain concentrations may be projected from a mixture of in vitro absorption, distribution, metabolism, excretion experimental parameters in combination with computed properties (volume of distribution, fraction unbound in microsomes). Finally, we demonstrate the utility of the underlying equations by showing that the maximum total plasma concentrations can be projected from the experimental parameters for a set of compounds with data collected from clinical research.
Orlin, V N
2002-01-01
A coupled-channels approach in intermediate coupling shell model for describing the non-compound component of nucleon-nucleus reactions is proposed. The goal of the model is to take into account the influence of collective doorway states (giant resonances) on the characteristics of nucleon-induced reactions on light and medium nuclei for incident energies epsilon <= 12 MeV
Directory of Open Access Journals (Sweden)
Y. Shinozuka
2015-01-01
Full Text Available We examine the relationship between the number concentration of boundary-layer cloud condensation nuclei (CCN and light extinction to investigate underlying aerosol processes and satellite-based CCN estimates. Regression applied to a variety of airborne and ground-based measurements identifies the CCN (cm−3 at 0.4 ± 0.1% supersaturation with 100.3α +1.3 σ0.75 where σ (M m−1 is the 500 nm extinction coefficient by dried particles and α is the Angstrom exponent. The deviation of one kilometer horizontal average data from this approximation is typically within a factor of 2.0. ∂ log CCN/∂ log σ is less than unity because, among other explanations, aerosol growth processes generally make particles scatter more light without increasing their number. This, barring extensive data aggregation and special meteorology-aerosol connections, associates doubling of aerosol optical depth with less than doubling of CCN, contrary to common assumptions in satellite-based analysis of aerosol-cloud interactions.
Morelli, L.; Bruno, M.; D'Agostino, M.; Baiocco, G.; Gulminelli, F.; Cinausero, M.; Degerlier, M.; Fabris, D.; Gramegna, F.; Marchi, T.; Barlini, S.; Bini, M.; Casini, G.; Gelli, N.; Pasquali, G.; Piantelli, S.; Valdrè, S.
2016-06-01
In the recent years, cluster structures have been evidenced in many ground and excited states of light nuclei [1, 2]. The decay of highly excited states of 24Mg is studied in fusion evaporation events completely detected in charge in the reactions 12C+12C and 14N+10B at 95 and 80 MeV incident energy, respectively, and compared to the results of a pure statistical model [3, 4]. Inclusive variables are in general well reproduced by the model. We found clear deviations from the statistical model if we select emission channels involving multiple α particles which are more probable than expected from a purely statistical behavior. Data from 12C+12C reaction have been analyzed in order to study the decay of the Hoyle state of 12C* with two different selections: peripheral binary collisions and 6α decay channel in central events. To continue the investigation on light systems, we have recently measured the 16O+12C reaction at three different beam energies, namely Ebeam = 90, 110 and 130 MeV. Preliminary results are presented.
Semilinear elliptic problems on unbounded subsets of the Heisenberg group
Directory of Open Access Journals (Sweden)
K. Tintarev
2001-03-01
Full Text Available In this paper we discuss the applications of an abstract version of concentration compactness to minimax problems. In particular, we prove the existence of solutions to semilinear elliptic problems on unbounded subsets of the Heisenberg group.
Approximate controllability of neutral functional differential system with unbounded delay
Directory of Open Access Journals (Sweden)
Jong Yeoul Park
2001-01-01
Full Text Available We consider a class of control systems governed by the neutral functional differential equation with unbounded delay and study the approximate controllability of the system. An example is given to illustrate the result.
Energy Technology Data Exchange (ETDEWEB)
Akram, W.; Schönbächler, M. [School of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Sprung, P. [Institut für Planetologie, Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster (Germany); Vogel, N. [Institute for Geochemistry and Petrology, ETH, Clausiusstrasse 25, 8092 Zürich (Switzerland)
2013-11-10
Recent work based on analyses of meteorite and terrestrial whole-rock samples showed that the r- and s- process isotopes of Hf were homogeneously distributed throughout the inner solar system. We report new Hf isotope data for Calcium-Aluminum-rich inclusions (CAIs) of the CV3 carbonaceous chondrite Allende, and novel high-precision Zr isotope data for these CAIs and three carbonaceous chondrites (CM, CO, CK). Our Zr data reveal enrichments in the neutron-rich isotope {sup 96}Zr (≤1ε in {sup 96}Zr/{sup 90}Zr) for bulk chondrites and CAIs (∼2ε). Potential isotope effects due to incomplete sample dissolution, galactic and cosmic ray spallation, and the nuclear field shift are assessed and excluded, leading to the conclusion that the {sup 96}Zr isotope variations are of nucleosynthetic origin. The {sup 96}Zr enrichments are coupled with {sup 50}Ti excesses suggesting that both nuclides were produced in the same astrophysical environment. The same CAIs also exhibit deficits in r-process Hf isotopes, which provides strong evidence for a decoupling between the nucleosynthetic processes that produce the light (A ≤ 130) and heavy (A > 130) neutron-rich isotopes. We propose that the light neutron-capture isotopes largely formed in Type II supernovae (SNeII) with higher mass progenitors than the supernovae that produced the heavy r-process isotopes. In the context of our model, the light isotopes (e.g. {sup 96}Zr) are predominantly synthesized via charged-particle reactions in a high entropy wind environment, in which Hf isotopes are not produced. Collectively, our data indicates that CAIs sampled an excess of materials produced in a normal mass (12-25 M{sub ☉}) SNII.
Use of unbound volumes of drug distribution in pharmacokinetic calculations.
Stepensky, David
2011-01-18
Volume of drug distribution is a primary pharmacokinetic parameter. This study assessed effects of drugs' plasma protein binding and tissue distribution on volume of drug distribution and identified the most appropriate ways for its calculation. Effects of the distribution factors on the unbound and total drug plasma concentrations and on the corresponding volumes of distribution were studied using pharmacokinetic modeling and simulation approach based on in vitro and in vivo concentration vs. time data of diazepam, a model drug with extensive plasma protein binding and tissue distribution. Pharmacokinetics of diazepam were appropriately described by three-compartment pharmacokinetic model that incorporated the processes of plasma protein binding and tissue permeation. According to this model, displacement of the drug from plasma proteins increases the unbound (but not the total) plasma concentrations and induces faster drug elimination from the body. The distribution pattern of the drug in the body and the time course of unbound (pharmacologically active) drug concentrations correlated with the unbound volumes of distribution, but not with the total volumes of distribution. In conclusion, unbound volumes of distribution appropriately describe the drug distribution pattern and the time course of unbound drug concentrations and are recommended for use as primary pharmacokinetic parameters in pharmaceutical research. Copyright © 2010 Elsevier B.V. All rights reserved.
Unbound (bioavailable IGF1 enhances somatic growth
Directory of Open Access Journals (Sweden)
Sebastien Elis
2011-09-01
Understanding insulin-like growth factor-1 (IGF1 biology is of particular importance because, apart from its role in mediating growth, it plays key roles in cellular transformation, organ regeneration, immune function, development of the musculoskeletal system and aging. IGF1 bioactivity is modulated by its binding to IGF-binding proteins (IGFBPs and the acid labile subunit (ALS, which are present in serum and tissues. To determine whether IGF1 binding to IGFBPs is necessary to facilitate normal growth and development, we used a gene-targeting approach and generated two novel knock-in mouse models of mutated IGF1, in which the native Igf1 gene was replaced by Des-Igf1 (KID mice or R3-Igf1 (KIR mice. The KID and KIR mutant proteins have reduced affinity for the IGFBPs, and therefore present as unbound IGF1, or ‘free IGF1’. We found that both KID and KIR mice have reduced serum IGF1 levels and a concomitant increase in serum growth hormone levels. Ternary complex formation of IGF1 with the IGFBPs and the ALS was markedly reduced in sera from KID and KIR mice compared with wild type. Both mutant mice showed increased body weight, body and bone lengths, and relative lean mass. We found selective organomegaly of the spleen, kidneys and uterus, enhanced mammary gland complexity, and increased skeletal acquisition. The KID and KIR models show unequivocally that IGF1-complex formation with the IGFBPs is fundamental for establishing normal body and organ size, and that uncontrolled IGF bioactivity could lead to pathological conditions.
Institute of Scientific and Technical Information of China (English)
Wu Fuke; Hu Shigeng; Mao Xuerong
2011-01-01
This paper establishes the Razumikhin-type theorem on stability for neutral stochastic functional differential equations with unbounded delay.To overcome difficulties from unbounded delay,we develop several different techniques to investigate stability.To show our idea clearly,we examine neutral stochastic delay differential equations with unbounded delay and linear neutral stochastic Volterra unbounded-delay-integro-differential equations.
Indian Academy of Sciences (India)
Arti Goyal; Mukul Mhaskey; Gopal-Krishna; Paul J. Wiita; C. S. Stalin; Ram Sagar
2013-09-01
It is important to quantify the underestimation of rms photometric errors returned by the commonly used APPHOT algorithm in the IRAF software, in the context of differential photometry of point-like AGN, because of the crucial role it plays in evaluating their variability properties. Published values of the underestimation factor, , using several different telescopes, lie in the range 1.3–1.75. The present study aims to revisit this question by employing an exceptionally large data set of 262 differential light curves (DLCs) derived from 262 pairs of non-varying stars monitored under our ARIES AGN monitoring program for characterizing the intra-night optical variability (INOV) of prominent AGN classes. The bulk of these data were taken with the 1-m Sampurnanad Telescope (ST). We find = 1.54 ± 0.05 which is close to our recently reported value of = 1.5. Moreover, this consistency holds at least up to a brightness mismatch of 1.5 mag between the paired stars. From this we infer that a magnitude difference of at least up to 1.5 mag between a point-like AGN and comparison star(s) monitored simultaneously is within the same CCD chip acceptable, as it should not lead to spurious claims of INOV.
Energy Technology Data Exchange (ETDEWEB)
Kokalova, T.; Oertzen, W. von; Torilov, S. [Fachbereich Physik, Freie Universitaet Berlin, Berlin (Germany); Hahn-Meitner-Institut Berlin, Berlin (Germany); Thummerer, S. [Hahn-Meitner-Institut Berlin, Berlin (Germany); Milin, M. [Fachbereich Physik, Freie Universitaet Berlin, Berlin (Germany); Hahn-Meitner-Institut Berlin, Berlin (Germany); Ruder Boskovic Institute, Zagreb (Croatia); Tumino, A. [Hahn-Meitner-Institut Berlin, Berlin (Germany); INFN-Laboratori Nazionali del Sud, Universita di Catania, Catania (Italy); Angelis, G. de [Hahn-Meitner-Institut Berlin, Berlin (Germany); INFN-Laboratori Nazionali di Legnaro, Legnaro (Italy); Farnea, E.; Lenzi, S.M.; Ur, C. [Dipartimento di Fisica and INFN, Padova (Italy); Gadea, A.; Napoli, D.R.; Kroell, T.; Marginean, M.; Martinez, T.; Axiotis, M. [INFN-Laboratori Nazionali di Legnaro, Legnaro (Italy); Papka, P.; Rousseau, M. [IReS, Institut de Recherches Subatomiques, Strasbourg (France)
2005-01-01
We have studied the emission of light unbound clusters, {sup 8}Be and {sup 12}C{sup *}(0{sup +}{sub 2}), in the reactions {sup 18}O+{sup 13}C{yields}{sup 31}Si{yields}{sup 23}Ne+{sup 8}Be and {sup 28}Si+{sup 24}Mg{yields}{sup 52}Fe{yields}{sup 40}Ca+{sup 12}C{sup *}(0{sup +}{sub 2}). The {gamma}-ray spectra obtained in coincidence with {sup 8}Be and {sup 12}C{sup *}(0{sup +}{sub 2}) emission have been studied relative to the statistical emission of two or three {alpha}-particles. The angular-momentum-to-energy balance of the cluster emission is compared with that of multiple-{alpha} emission. The properties of the energy spectra of the binary process and the population of the residual nuclei by cluster emission are discussed. It is observed that cluster emission carries away less excitation energy on average than the sequential emission of the individual components. (orig.)
Kunieda, Satoshi
2017-09-01
We report the status of the R-matrix code AMUR toward consistent cross-section evaluation and covariance analysis for the light-mass nuclei. The applicable limit of the code is extended by including computational capability for the charged-particle elastic scattering cross-sections and the neutron capture cross-sections as example results are shown in the main texts. A simultaneous analysis is performed on the 17O compound system including the 16O(n,tot) and 13C(α,n)16O reactions together with the 16O(n,n) and 13C(α,α) scattering cross-sections. It is found that a large theoretical background is required for each reaction process to obtain a simultaneous fit with all the experimental cross-sections we analyzed. Also, the hard-sphere radii should be assumed to be different from the channel radii. Although these are technical approaches, we could learn roles and sources of the theoretical background in the standard R-matrix.
Drobyshevski, E M
2004-01-01
In 1997, we proposed a model of the ball lightning (BL) whose activity is accounted for by energy release in the fusion of light nuclei, most probably, carbon in organic fibers (Proc. ISBL 97, p.157). The fusion is provided by catalytic action of superheavy negative particles making up the Galactic Dark Matter. We called them DArk Electric Matter Objects, or daemons. The daemons are assumed to be elementary black holes (M ~ 10^-5 g) carrying a charge of up to Ze = 10e. Experiments have culminated in 2000 by the discovery of daemons. We used the two-screen scintillation technique with a scintillator ZnS(Ag). Measurements showed the daemon flux striking the Earth to be ~10^-9 cm^-2s^-1 for an object velocity of as low as ~<10-30 km/s. The half-year periodicity of the flux was revealed, which can be assigned to daemons being captured into helio- and geocentric orbits as the Solar system moves through the DM background (see astro-ph/0402367). The next step in creating a daemon-mediated BL to achieve controlled...
A Novel Method for Solving Unbounded Knapsack Problem
Institute of Scientific and Technical Information of China (English)
CHEN Rung-Ching; LIN Ming-Hsian
2009-01-01
Knapsack problem is one kind of NP-Complete problem. Unbounded knapsack problems are more complex and harder than general knapsack problem. In this paper, we apply QGAs (Quantum Genetic Algorithms) to solve unbounded knapsack problem and then follow other procedures. First, present the problem into the mode of QGAs and figure out the corresponding genes types and their fitness functions. Then, find the perfect combination of limitation and largest benefit. Finally, the best solution will be found. Primary experiment indicates that our method has well results.
Spectroscopy of neutron-unbound $^{27,28}$F
Christian, G; Ash, S; Baumann, T; DeYoung, P A; Finck, J E; Gade, A; Grinyer, G F; Luther, B; Mosby, M; Mosby, S; Smith, J K; Snyder, J; Spyrou, A; Strongman, M J; Thoennessen, M; Warren, M; Weisshaar, D; Wersal, A
2012-01-01
The ground state of $^{28}$F has been observed as an unbound resonance $2\\underline{2}0$ keV above the ground state of $^{27}$F. Comparison of this result with USDA/USDB shell model predictions leads to the conclusion that the $^{28}$F ground state is primarily dominated by $sd$-shell configurations. Here we present a detailed report on the experiment in which the ground state resonance of $^{28}$F was first observed. Additionally, we report the first observation of a neutron-unbound excited state in $^{27}$F at an excitation energy of $25\\underline{0}0 (2\\underline{2}0)$ keV.
Verifying Multi-Agent Systems via Unbounded Model Checking
Kacprzak, M.; Lomuscio, A.; Lasica, T.; Penczek, W.; Szreter, M.
2004-01-01
We present an approach to the problem of verification of epistemic properties in multi-agent systems by means of symbolic model checking. In particular, it is shown how to extend the technique of unbounded model checking from a purely temporal setting to a temporal-epistemic one. In order to achieve this, we base our discussion on interpreted systems semantics, a popular semantics used in multi-agent systems literature. We give details of the technique and show how it can be applied to the well known train, gate and controller problem. Keywords: model checking, unbounded model checking, multi-agent systems
Distributions on unbounded moment spaces and random moment sequences
Nagel, Jan
2010-01-01
In this paper we define distributions on moment spaces corresponding to measures on the real line with an unbounded support. We identify these distributions as limiting distributions of random moment vectors defined on compact moment spaces and as distributions corresponding to random spectral measures associated with the Jacobi, Laguerre and Hermite ensemble from random matrix theory. For random vectors on the unbounded moment spaces we prove a central limit theorem where the centering vectors correspond to the moments of the Marchenko-Pastur distribution and Wigner's semi-circle law.
A high order solver for the unbounded Poisson equation
DEFF Research Database (Denmark)
Hejlesen, Mads Mølholm; Rasmussen, Johannes Tophøj; Chatelain, Philippe
and the integration kernel. In this work we show an implementation of high order regularised integration kernels in the HE algorithm for the unbounded Poisson equation to formally achieve an arbitrary high order convergence. We further present a quantitative study of the convergence rate to give further insight......In mesh-free particle methods a high order solution to the unbounded Poisson equation is usually achieved by constructing regularised integration kernels for the Biot-Savart law. Here the singular, point particles are regularised using smoothed particles to obtain an accurate solution with an order...
Reactions with light exotic nuclei
Energy Technology Data Exchange (ETDEWEB)
Lichtenthäler, R.; Faria, P.N. de; Pires, K.C.C.; Lepine-Szily, A.; Guimaraes, V.; Mendes Junior, D.R.; Assuncao, M.; Barioni, A.; Morcelle, V.; Morais, M.C.; Camargo Junior, O.; Alcantara Nuñez, J. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Fisica; Moro, A.M. [Departamento de FAMN, Universidad de Sevilla, Sevilla (Spain); Arazi, A. [Laboratorio Tandar, Departamento de Fisica, Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Rodriguez-Gallardo, M. [Instituto de Estructura de la Materia, CSIC, Madrid (Spain)
2014-07-01
Experimental cross sections for the {sup 6}He+{sup 120}Sn are analysed. Elastic scattering angular distributions and alpha particle production cross sections have been measured and are compared with the total reaction cross sections. (author)
Reactions with light exotic nuclei
Directory of Open Access Journals (Sweden)
Lichtenthäler R.
2014-04-01
Full Text Available Experimental cross sections for the 6He+120Sn are analysed. Elastic scattering angular distributions and alpha particle production cross sections have been measured and are compared with the total reaction cross sections.
Strengths of gamma-ray transitions in A = 6–44 nuclei (III)
Endt, P.M.
1979-01-01
The present tables list the strengths (in Weisskopf units) of over 2400 γ-ray transitions in A = 6–44 nuclei, classified according to character (electric or magnetic, multipolarity, isospin forbiddenness). Selected transitions from unbound states are included. The strengths for isovector E1 and M1 t
NUMERICAL SOLUTIONS OF AN EIGENVALUE PROBLEM IN UNBOUNDED DOMAINS
Institute of Scientific and Technical Information of China (English)
Han Houde; Zhou Zhenya; Zheng Chunxiong
2005-01-01
A coupling method of finite element and infinite large element is proposed for the numerical solution of an eigenvalue problem in unbounded domains in this paper. With some conditions satisfied, the considered problem is proved to have discrete spectra. Several numerical experiments are presented. The results demonstrate the feasibility of the proposed method.
Edge-clique graphs of cocktail parties have unbounded rankwidth
Chang, Maw-Shang; Liu, Ching-Hao
2012-01-01
In an attempt to find a polynomial-time algorithm for the edge-clique cover problem on cographs we tried to prove that the edge-clique graphs of cographs have bounded rankwidth. However, this is not the case. In this note we show that the edge-clique graphs of cocktail party graphs have unbounded rankwidth.
ASYMPTOTIC STABILITY OF SINGULAR NONLINEAR DIFFERENTIAL SYSTEMS WITH UNBOUNDED DELAYS
Institute of Scientific and Technical Information of China (English)
无
2012-01-01
In this paper,the asymptotic stability of singular nonlinear differential systems with unbounded delays is considered.The stability criteria are derived based on a kind of Lyapunov-functional and some technique of matrix inequalities.The criteria are described as matrix equation and matrix inequalities,which are computationally flexible and efficient.Two examples are given to illustrate the results.
Asymptotic Properties of Unbounded Quadrature Domains in the Plane
Karp, Lavi
2013-01-01
We prove that if $\\Omega$ is a simply connected quadrature domain for a distribution with compact support and the infinity point belongs the boundary, then the boundary has an asymptotic curve that is either a straight line or a parabola or an infinite ray. In other words, unbounded quadrature domains in the plane are perturbations of null quadrature domains.
NON-ISOTROPIC JACOBI SPECTRAL METHODS FOR UNBOUNDED DOMAINS
Institute of Scientific and Technical Information of China (English)
王立联; 郭本瑜
2004-01-01
Some specific non-isotropic Jacobi approximations in multiple-dimensions are investigated, which are used for numerical solutions of differential equations on various unbounded domains. The convergence of proposed schemes are proved. Some efficient algorithms are provided. Numerical results are presented to illustrate the efficiency of this new approach.
Superatomic Boolean algebras constructed from strongly unbounded functions
Martinez, Juan Carlos
2010-01-01
Using Koszmider's strongly unbounded functions, we show the following consistency result: Suppose that $\\kappa,\\lambda$ are infinite cardinals such that $\\kappa^{+++} \\leq \\lambda$, $\\kappa^{_{{\\omega}_1}\\concatenation \\$ and $\\_{{\\omega}_2}\\concatenation \\$ can be cardinal sequences of superatomic Boolean algebras.
Static analysis of unbounded structures in object-oriented programs
Grabe, Immo
2012-01-01
In this thesis we investigate different techniques and formalisms to address complexity introduced by unbounded structures in object-oriented programs. We give a representation of a weakest precondition calculus for abstract object creation in dynamic logic. Based on this calculus we define symbolic
Static analysis of unbounded structures in object-oriented programs
Grabe, Immo
2012-01-01
In this thesis we investigate different techniques and formalisms to address complexity introduced by unbounded structures in object-oriented programs. We give a representation of a weakest precondition calculus for abstract object creation in dynamic logic. Based on this calculus we define symbolic
Variational construction of unbounded orbits in Lagrangian systems
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
We show the existence of unbounded orbits in perturbations of generic geodesic flow in T2 by a generic periodic potential. Different from previous work such as in Mather (1997), the initial values of the orbits obtained here are not required sufficiently large.
STABILITY OF STOCHASTIC DIFFERENTIAL EQUATIONS WITH UNBOUNDED DELAY
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
In this paper,we obtain suffcient conditions for the stability in p-th moment of the analytical solutions and the mean square stability of a stochastic differential equation with unbounded delay proposed in [6,10] using the explicit Euler method.
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...
Photoproduction of mesons off nuclei
Krusche, B
2011-01-01
Recent results for the photoproduction of mesons off nuclei are reviewed. These experiments have been performed for two major lines of research related to the properties of the strong interaction. The investigation of nucleon resonances requires light nuclei as targets for the extraction of the isospin composition of the electromagnetic excitations. This is done with quasi-free meson photoproduction off the bound neutron and supplemented with the measurement of coherent photoproduction reactions, serving as spin and/or isospin filters. Furthermore, photoproduction from light and heavy nuclei is a very efficient tool for the study of the interactions of mesons with nuclear matter and the in-medium properties of hadrons. Experiments are currently rapidly developing due to the combination of high quality tagged (and polarized) photon beams with state-of-the-art 4pi detectors and polarized targets.
Towards the exact calculation of medium nuclei
Energy Technology Data Exchange (ETDEWEB)
Gandolfi, Stefano [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carlson, Joseph Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lonardoni, Diego [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wang, Xiaobao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-12-19
The prediction of the structure of light and medium nuclei is crucial to test our knowledge of nuclear interactions. The calculation of the nuclei from two- and three-nucleon interactions obtained from rst principle is, however, one of the most challenging problems for many-body nuclear physics.
Absolute Stability for Lurie Control System with Unbound Time Delays
Institute of Scientific and Technical Information of China (English)
王天成; 王耀才; 洪留荣
2004-01-01
Time delay existes widely in various real engineering systems and can result in unsatisfactory performance or even an instability of control systems. Therefore, to investigate the stability for time delay systems is of vitul importance in control theory and its applications. Many researchers have studied the stability criteria of systems with constant delay or bound varying time delay, but few of them studied large time delay or unbound time delay. Large time delay existes commonly in various engineering applications. In this paper, the absolute stability of Lurie type direct control systems and indirect control systems with several time delays are discussed. Based on Lyapunov theory, the new delay dependent absolute stability criteria are derived. In our theorem, time delays can be unbound functions, which shows that the results are less conservative than that of existed criteria.
Asymptotic Stability of Neutral Differential Equations with Unbounded Delay
Institute of Scientific and Technical Information of China (English)
YE Hai-ping; GAO Guo-zhu
2002-01-01
Consider the neutral differential equation with positive and negative coefficients and unbounded delay ddt [x(t)- P(t)x(h(t))] + Q(t)x(q(t)) -R(t)x(r(t))= 0, t ≥ t0,where P(t)∈ C([t0, ∞), R), Q(t), R(t) ∈ C([t0,∞ ), R+ ), and h, q, r: [ t0, ∞ ) → R are continuously differentiable and strictly increasing, h( t) ＜ t, q( t) ＜t, r(t) ＜ t for all t ≥ t0. In this paper, the authors obtain sufficient conditions for the zero solution of this equation with unbounded delay to be uniformly stable as well as asymptotically stable.
Computation of Steady Incompressible Flows in Unbounded Domains
Gustafsson, Jonathan
2014-01-01
In this study we revisit the problem of computing steady Navier-Stokes flows in two-dimensional unbounded domains. Precise quantitative characterization of such flows in the high-Reynolds number limit remains an open problem of theoretical fluid dynamics. Following a review of key mathematical properties of such solutions related to the slow decay of the velocity field at large distances from the obstacle, we develop and carefully validate a spectrally-accurate computational approach which ensures the correct behavior of the solution at infinity. In the proposed method the numerical solution is defined on the entire unbounded domain without the need to truncate this domain to a finite box with some artificial boundary conditions prescribed at its boundaries. Since our approach relies on the streamfunction-vorticity formulation, the main complication is the presence of a discontinuity in the streamfunction field at infinity which is related to the slow decay of this field. We demonstrate how this difficulty ca...
On the Decidability of Non Interference over Unbounded Petri Nets
Best, Eike; Gorrieri, Roberto; 10.4204/EPTCS.51.2
2011-01-01
Non-interference, in transitive or intransitive form, is defined here over unbounded (Place/Transition) Petri nets. The definitions are adaptations of similar, well-accepted definitions introduced earlier in the framework of labelled transition systems. The interpretation of intransitive non-interference which we propose for Petri nets is as follows. A Petri net represents the composition of a controlled and a controller systems, possibly sharing places and transitions. Low transitions represent local actions of the controlled system, high transitions represent local decisions of the controller, and downgrading transitions represent synchronized actions of both components. Intransitive non-interference means the impossibility for the controlled system to follow any local strategy that would force or dodge synchronized actions depending upon the decisions taken by the controller after the last synchronized action. The fact that both language equivalence and bisimulation equivalence are undecidable for unbounde...
Pseudo-Hermitian quantum mechanics with unbounded metric operators.
Mostafazadeh, Ali
2013-04-28
I extend the formulation of pseudo-Hermitian quantum mechanics to η(+)-pseudo-Hermitian Hamiltonian operators H with an unbounded metric operator η(+). In particular, I give the details of the construction of the physical Hilbert space, observables and equivalent Hermitian Hamiltonian for the case that H has a real and discrete spectrum and its eigenvectors belong to the domain of η(+) and consequently √η(+).
Zonal structure of unbounded external-flow and aerodynamics
Liu, Luoqin; Wu, Jiezhi
2016-01-01
This paper starts from the far-field behaviours of velocity field in externally-unbounded flow. We find that the well-known algebraic decay of disturbance velocity as derived kinematically is too conservative. Once the kinetics is taken into account by working on the fundamental solutions of far-field linearized Navier-Stokes equations, it is proven that the furthest far-field zone adjacent to the uniform fluid at infinity must be unsteady, viscous and compressible, where all disturbances degenerate to sound waves that decay exponentially. But this optimal rate does not exist in some commonly used simplified flow models, such as steady flow, incompressible flow and inviscid flow, because they actually work in true subspaces of the unbounded free space, which are surrounded by further far fields of different nature. This finding naturally leads to a zonal structure of externally-unbounded flow field. The significance of the zonal structure is demonstrated by its close relevance to existing theories of aerodyna...
Unbounded dynamics in dissipative flows: Rössler model
Energy Technology Data Exchange (ETDEWEB)
Barrio, Roberto, E-mail: rbarrio@unizar.es; Serrano, Sergio, E-mail: sserrano@unizar.es [Computational Dynamics Group, Dpto. Matemática Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Blesa, Fernando, E-mail: fblesa@unizar.es [Computational Dynamics Group, Dpto. Física Aplicada and IUMA, Universidad de Zaragoza, E-50009 Zaragoza (Spain)
2014-06-15
Transient chaos and unbounded dynamics are two outstanding phenomena that dominate in chaotic systems with large regions of positive and negative divergences. Here, we investigate the mechanism that leads the unbounded dynamics to be the dominant behavior in a dissipative flow. We describe in detail the particular case of boundary crisis related to the generation of unbounded dynamics. The mechanism of the creation of this crisis in flows is related to the existence of an unstable focus-node (or a saddle-focus) equilibrium point and the crossing of a chaotic invariant set of the system with the weak-(un)stable manifold of the equilibrium point. This behavior is illustrated in the well-known Rössler model. The numerical analysis of the system combines different techniques as chaos indicators, the numerical computation of the bounded regions, and bifurcation analysis. For large values of the parameters, the system is studied by means of Fenichel's theory, providing formulas for computing the slow manifold which influences the evolution of the first stages of the orbit.
Energy Technology Data Exchange (ETDEWEB)
Bednarczyk, P. [Institut de Recherches Subatomiques, Strasbourg (France); H. Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Styczen, J.; Grebosz, J.; Lach, M.; Maj, A.; Meczynski, W.; Zieblinski, M. [H. Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Bracco, A. [Universita degli Studi di Milano and INFN, Milano (Italy); Curien, D.; Merdinger, J.C.; Nowacki, F.; Vivien, J.P. [Institut de Recherches Subatomiques, Strasbourg (France); Smith, M.B.; Spohr, K. [University of Paisley, Paisley, Scotland (United Kingdom)
2004-04-01
Intruder rotational bands in {sup 45}Sc and {sup 45}Ti have been investigated up to the maximum aligned angular momentum by means of EUROBALL IV and the Recoil Filter Detector (RFD). The use of the RFD allowed for a reduction of the {gamma}-line Doppler broadening and, moreover, for a determination of very short level lifetimes. In the studied nuclei, the estimated deformation shows a gradual disappearance of the collectivity at the highest available spins. (orig.)
Zhang, Ying; Meng, Jie
2010-01-01
The neutron pair correlation in nuclei near the neutron drip-line is investigated using the selfconsistent continuum Skyrme-Hartree-Fock-Bogoliubov theory formulated with the coordinate-space Green's function technique. Numerical analysis is performed for even-even N = 86 isotones in the Mo-Sn region, where the 3p3/2 and 3p1/2 orbits lying near the Fermi energy are either weakly bound or unbound. The quasiparticle states originating from the l = 1 orbits form resonances with large widths, which are due to the low barrier height and the strong continuum coupling caused by the pair potential. Analyzing in detail the pairing properties and roles of the quasiparticle resonances, we found that the l = 1 broad quasiparticle resonances persist to feel the pair potential and contribute to the pair correlation even when their widths are comparable with the resonance energy.
Wave motions in unbounded poroelastic solids infused with compressible fluids
Quiligotti, S; dell'Isola, F
2010-01-01
Looking at rational solid-fluid mixture theories in the context of their biomechanical perspectives, this work aims at proposing a two-scale constitutive theory of a poroelastic solid infused with an inviscid compressible fluid. The propagation of steady-state harmonic plane waves in unbounded media is investigated in both cases of unconstrained solid-fluid mixtures and fluid-saturated poroelastic solids. Relevant effects on the resulting characteristic speed of longitudinal and transverse elastic waves, due to the constitutive parameters introduced, are finally highlighted and discussed.
RELATIVE ESSENTIAL SPECTRA INVOLVING RELATIVE DEMICOMPACT UNBOUNDED LINEAR OPERATORS
Institute of Scientific and Technical Information of China (English)
Bilel KRICHEN
2014-01-01
In this article, we introduce the concept of demicompactness with respect to a closed densely defined linear operator, as a generalization of the class of demicompact operator introduced by Petryshyn in [24] and we establish some new results in Fredholm theory. Moreover, we apply the obtained results to discuss the incidence of some perturbation results on the behavior of relative essential spectra of unbounded linear operators acting on Banach spaces. We conclude by characterizations of the relative Schechter’s and approximate essential spectrum.
Unbounded Periodic Solutions to Serrin's Overdetermined Boundary Value Problem
Fall, Mouhamed Moustapha; Minlend, Ignace Aristide; Weth, Tobias
2017-02-01
We study the existence of nontrivial unbounded domains {Ω} in RN such that the overdetermined problem {-Δ u = 1 quad in Ω}, quad u = 0, quad partial_{ν} u = const quad on partial Ω admits a solution u. By this, we complement Serrin's classification result from 1971, which yields that every bounded domain admitting a solution of the above problem is a ball in RN. The domains we construct are periodic in some variables and radial in the other variables, and they bifurcate from a straight (generalized) cylinder or slab. We also show that these domains are uniquely self Cheeger relative to a period cell for the problem.
Selective population of unbound states in 10Li
Smith, J. K.; Baumann, T.; Brown, J.; DeYoung, P. A.; Frank, N.; Hinnefeld, J.; Kohley, Z.; Luther, B.; Marks, B.; Spyrou, A.; Stephenson, S. L.; Thoennessen, M.; Williams, S. J.
2015-08-01
Unbound positive-parity states in 10Li have been populated with a two-proton removal reaction from a 71 MeV/u 12B beam. The 9Li fragments and emitted neutrons were measured with the MoNA-LISA-Sweeper setup. The measured decay energy spectrum was best fit with three states at 110 ± 40, 500 ± 100, and 1100 ± 100 keV decay energy. This is the second observation of a resonance below 200 keV. The lower two states likely belong to the expected 1+, 2+ doublet.
Nikishin systems are perfect. Case of unbounded and touching supports
Prieto, Fidalgo; Lagomasino, G López
2010-01-01
K. Mahler introduced the concept of perfect systems in the theory of simultaneous Hermite-Pad\\'{e} approximation of analytic functions. Recently, we proved that Nikishin systems, generated by measures with bounded support and non-intersecting consecutive supports contained on the real line, are perfect. Here, we prove that they are also perfect when the supports of the generating measures are unbounded or touch at one point. As an application, we give a version of Stieltjes' theorem in the context of simultaneous Hermite-Pad\\'e approximation.
Dynamics of an unbounded interface between ordered phases.
Krapivsky, P L; Redner, S; Tailleur, J
2004-02-01
We investigate the evolution of a single unbounded interface between ordered phases in two-dimensional Ising ferromagnets that are endowed with single-spin-flip zero-temperature Glauber dynamics. We examine specifically the cases where the interface initially has either one or two corners. In both examples, the interface evolves to a limiting self-similar form. We apply the continuum time-dependent Ginzburg-Landau equation and a microscopic approach to calculate the interface shape. For the single corner system, we also discuss a correspondence between the interface and the Young diagram that represents the partition of the integers.
Functional differential equations with unbounded delay in extrapolation spaces
Directory of Open Access Journals (Sweden)
Mostafa Adimy
2014-08-01
Full Text Available We study the existence, regularity and stability of solutions for nonlinear partial neutral functional differential equations with unbounded delay and a Hille-Yosida operator on a Banach space X. We consider two nonlinear perturbations: the first one is a function taking its values in X and the second one is a function belonging to a space larger than X, an extrapolated space. We use the extrapolation techniques to prove the existence and regularity of solutions and we establish a linearization principle for the stability of the equilibria of our equation.
Erosive Hit-and-Run Impact Events: Debris Unbound
Sarid, Gal; Leinhardt, Zoe M
2015-01-01
Erosive collisions among planetary embryos in the inner solar system can lead to multiple remnant bodies, varied in mass, composition and residual velocity. Some of the smaller, unbound debris may become available to seed the main asteroid belt. The makeup of these collisionally produced bodies is different from the canonical chondritic composition, in terms of rock/iron ratio and may contain further shock-processed material. Having some of the material in the asteroid belt owe its origin from collisions of larger planetary bodies may help in explaining some of the diversity and oddities in composition of different asteroid groups.
Ensemble-based characterization of unbound and bound states on protein energy landscape
Ruvinsky, Anatoly M; Tuzikov, Alexander V; Vakser, Ilya A
2012-01-01
Characterization of protein energy landscape and conformational ensembles is important for understanding mechanisms of protein folding and function. We studied ensembles of bound and unbound conformations of six proteins to explore their binding mechanisms and characterize the energy landscapes in implicit solvent. First, results show that bound and unbound spectra often significantly overlap. Moreover, the larger the overlap the smaller the RMSD between bound and unbound conformational ensembles. Second, the analysis of the unbound-to-bound changes points to conformational selection as the binding mechanism for four of the proteins. Third, the center of the unbound spectrum has a higher energy than the center of the corresponding bound spectrum of the dimeric and multimeric states for most of the proteins. This suggests that the unbound states often have larger entropy than the bound states considered outside of the complex. Fourth, the exhaustively long minimization, making small intra-rotamer adjustments, ...
21 CFR 862.1113 - Bilirubin (total and unbound) in the neonate test system.
2010-04-01
... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1113 Bilirubin (total and unbound) in the neonate test system....
Transient solutions to groundwater mounding in bounded and unbounded aquifers.
Korkmaz, Serdar
2013-01-01
In this study, the well-known Hantush solution procedure for groundwater mounding under infinitely long infiltration strips is extended to finite and semi-infinite aquifer cases. Initially, the solution for infinite aquifers is presented and compared to those available in literature and to the numerical results of MODFLOW. For the finite aquifer case, the method of images, which is commonly used in well hydraulics, is used to be able to represent the constant-head boundaries at both sides. It is shown that a finite number of images is enough to obtain the results and sustain the steady state. The effect of parameters on the growth of the mound and on the time required to reach the steady state is investigated. The semi-infinite aquifer case is emphasized because the growth of the mound is not symmetric. As the constant-head boundary limits the growth, the unbounded side grows continuously. For this reason, the groundwater divide shifts toward the unbounded side. An iterative solution procedure is proposed. To perform the necessary computations a code was written in Visual Basic of which the algorithm is presented. The proposed methodology has a wide range of applicability and this is demonstrated using two practical examples. The first one is mounding under a stormwater dispersion trench in an infinite aquifer and the other is infiltration from a flood control channel into a semi-infinite aquifer. Results fit very well with those of MODFLOW.
Federal Laboratory Consortium — Lighting Systems Test Facilities aid research that improves the energy efficiency of lighting systems. • Gonio-Photometer: Measures illuminance from each portion of...
DEFF Research Database (Denmark)
Prescott, N.B.; Kristensen, Helle Halkjær; Wathes, C.M.
2004-01-01
This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality......This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality...
A Continuation Method for Solving Fixed Point Problems in Unbounded Convex Sets
Institute of Scientific and Technical Information of China (English)
SU MENG-LONG; LU XIAN-RUI; MA YONG
2009-01-01
In this paper, an unbounded condition is presented, under which we are able to utilize the interior point homotopy method to solve the Brouwer fixed point problem on unbounded sets. Two numerical examples in R3 are presented to illustrate the results in this paper.
On the quantification of unbound hydrogen in diamond-like carbon-based thin films
Pei, Y.T.; Chechenin, N.G.; Chernykh, P.N.; Turkin, A; Vainchtein, David; Hosson, J.Th.M. De
2009-01-01
This paper presents a new and straightforward approach to quantify the content of unbound hydrogen in diamond-like carbon-based films. In the case of TiC/a-C:H nanocomposite films it is shown that the content of unbound and bound hydrogen can be deconvoluted via thermal release and elastic recoil de
On the quantification of unbound hydrogen in diamond-like carbon-based thin films
Pei, Y.T.; Chechenin, N.G.; Chernykh, P.N.; Turkin, A; Vainchtein, David; Hosson, J.Th.M. De
2009-01-01
This paper presents a new and straightforward approach to quantify the content of unbound hydrogen in diamond-like carbon-based films. In the case of TiC/a-C:H nanocomposite films it is shown that the content of unbound and bound hydrogen can be deconvoluted via thermal release and elastic recoil de
Local chiral potentials with ${\Delta}$ -intermediate states and the structure of light nuclei
Energy Technology Data Exchange (ETDEWEB)
Piarulli, M.; Girlanda, L.; Schiavilla, R.; Kievsky, A.; Lovato, A.; Marcucci, L. E.; Pieper, Steven C.; Viviani, M.; Wiringa, R. B.
2016-11-01
We present fully local versions of the minimally non-local nucleon-nucleon potentials constructed in a previous paper [M.\\ Piarulli {\\it et al.}, Phys.\\ Rev.\\ C {\\bf 91}, 024003 (2015)], and use them in hypersperical-harmonics and quantum Monte Carlo calculations of ground and excited states of $^3$H/$^3$He, $^4$He, and $^6$He/$^6$Li nuclei. The long-range part of these local potentials includes one- and two-pion exchange contributions without and with $\\Delta$-isobars in the intermediate states up to order $Q^3$ ($Q$ denotes generically the low momentum scale) in the chiral expansion, while the short-range part consists of contact interactions up to order $Q^4$. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in two different ranges of laboratory energies, either 0--125 MeV or 0--200 MeV, and to the deuteron binding energy and $nn$ singlet scattering length. Fits to these data are performed for three models characterized by long- and short-range cutoffs, $R_{\\rm L}$ and $R_{\\rm S}$ respectively, ranging from $(R_{\\rm L},R_{\\rm S})=(1.2,0.8)$ fm down to $(0.8,0.6)$ fm. The long-range (short-range) cutoff regularizes the one- and two-pion exchange (contact) part of the potential.
Evolution of active galactic nuclei
Merloni, Andrea
2012-01-01
[Abriged] Supermassive black holes (SMBH) lurk in the nuclei of most massive galaxies, perhaps in all of them. The tight observed scaling relations between SMBH masses and structural properties of their host spheroids likely indicate that the processes fostering the growth of both components are physically linked, despite the many orders of magnitude difference in their physical size. This chapter discusses how we constrain the evolution of SMBH, probed by their actively growing phases, when they shine as active galactic nuclei (AGN) with luminosities often in excess of that of the entire stellar population of their host galaxies. Following loosely the chronological developments of the field, we begin by discussing early evolutionary studies, when AGN represented beacons of light probing the most distant reaches of the universe and were used as tracers of the large scale structure. This early study turned into AGN "Demography", once it was realized that the strong evolution (in luminosity, number density) of ...
Energy Technology Data Exchange (ETDEWEB)
Atchison, F.
1998-09-01
The PSIMECX library contains calculated nuclide production cross-sections from neutron-induced reactions in the energy range about 2 to 800 MeV in the following 72 stable isotopes of 24 elements: {sup 12}C, {sup 13}C, {sup 16}O, {sup 17}O, {sup 18}O, {sup 23}Na, {sup 24}Mg, {sup 25}Mg, {sup 26}Mg, {sup 27}Al, {sup 28}Si, {sup 29}Si, {sup 30}Si, {sup 31}P, {sup 32}S, {sup 33}S, {sup 34}S, {sup 36}S, {sup 35}Cl, {sup 37}Cl, {sup 39}K, {sup 40}K, {sup 41}K, {sup 40}Ca, {sup 42}Ca, {sup 43}Ca, {sup 44}Ca, {sup 46}Ca, {sup 48}Ca, {sup 46}Ti, {sup 47}Ti, {sup 48}Ti, {sup 49}Ti, {sup 50}Ti, {sup 50}V, {sup 51}V, {sup 50}Cr, {sup 52}Cr, {sup 53}Cr, {sup 54}Cr, {sup 55}Mn, {sup 54}Fe, {sup 56}Fe, {sup 57}Fe, {sup 58}Fe, {sup 58}Ni, {sup 60}Ni, {sup 61}Ni, {sup 62}Ni, {sup 64}Ni, {sup 63}Cu, {sup 65}Cu, {sup 64}Zn, {sup 66}Zn, {sup 67}Zn, {sup 68}Zn, {sup 70}Zn, {sup 92}Mo, {sup 94}Mo, {sup 95}Mo, {sup 96}Mo, {sup 97}Mo, {sup 98}Mo, {sup 100}Mo, {sup 121}Sb, {sup 123}Sb, {sup 204}Pb, {sup 206}Pb, {sup 207}Pb, {sup 208}Pb, {sup 232}Th and {sup 238}U. The energy range covers essentially all transmutation channels other than capture. The majority of the selected elements are principal constituents of normal materials of construction used in and around accelerator facilities and the library is, first and foremost, designed to be a tool for the estimation of their activation in wide-band neutron fields. This second report, of a series of three, describes and discusses the calculational methods used for the stable isotopes up to and including {sup 123}Sb. The library itself has been described in the first report of the series and the treatment for the heavy nuclei is given in the third. (author)
Beyond the Halo: Redefining environment with unbound matter in N-body simulations
Shattow, Genevieve M
2015-01-01
Approximately half of the matter in the Universe is "unbound" at z = 0, according to N-body simulations such as the Millennium Run. Here, we use the milli-Millennium simulation to examine the distribution of unbound matter in relation to the dark matter halos which host galaxies. We measure the unbound matter within two types of windows, using a halo dependent radius and a fixed radius at several different scales. We also consider the timescales over which a halo can accrete the local unbound matter at z = 2 and z = 0. Finally, we compare the unbound matter to observable properties of galaxies, such as local galaxy count environment and stellar mass. We find that halos at z = 2 can accrete far more of the nearby unbound matter over a Hubble time than halos at z = 0 and that 78% of particles within 5 $R_{vir}$ of a halo at z = 2 will be accreted by z = 0, compared to 36% of particles within 5 $h^{-1}$ Mpc of the halo. We also find that galaxy count environment is closely related to the amount of nearby unbound...
Electric monopole transitions from low energy excitations in nuclei
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.
Thielmann, H W; Popanda, O
1998-02-01
DNA topoisomerase II was monitored with the monoclonal antibody Ki-S1 in human fibroblasts after irradiation of cells with 254-nm UV light and -rays from a 137Cs source. DNA topoisomerase II was localized immunohistochemically as bright fluorescent dots in the karyoplasm. Investigated fibroblasts originated from normal human donors and a xeroderma pigmentosum patient (XP12BE). All cell lines showed a time and dose-dependent increase in DNA topoisomerase II abundance after irradiation. The increase may reflect enhanced accessibility of the enzyme, enhanced gene expression or enhanced stabilization of mRNA or protein molecules. The effect was detectable as early as 1 h after irradiation at doses 3 J/m2 or 3 Gy. It passed through a maximum and decreased within 18 h (UV light) or 6 h ( -rays). Except for the duration of the response, no principal differences were seen between the effects caused by UV light and those elicited by -rays. The increase in enzyme levels might be part of the well-known DNA damage responses which operate in cell-protective or DNA-reparative pathways or may reflect initiation of apoptosis. DNA topoisomerase I was detected with a commercially available polyclonal antibody raised against human DNA topoisomerase I. In unirradiated cells, DNA topoisomerase I was found to be mainly concentrated in nucleoli. Irradiation with -rays changed the staining pattern in that it caused a multitude of DNA topoisomerase I-rich centers to occur which may reflect sites of transcription of radiation-inducible genes.
Directory of Open Access Journals (Sweden)
Noriyuki Suetsugu
Full Text Available Light-induced chloroplast movement and attachment to the plasma membrane are dependent on actin filaments. In Arabidopsis thaliana, the short actin filaments on the chloroplast envelope, cp-actin filaments, are essential for chloroplast movement and positioning. Furthermore, cp-actin-filament-mediated chloroplast movement is necessary for the strong-light-induced nuclear avoidance response. The proteins CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1, KINESIN-LIKE PROTEIN FOR ACTIN-BASED CHLOROPLAST MOVEMENT 1 (KAC1 and KAC2 are required for the generation and/or maintenance of cp-actin filaments in Arabidopsis. In land plants, CHUP1 and KAC family proteins play pivotal roles in the proper movement of chloroplasts and their attachment to the plasma membrane. Here, we report similar but distinct phenotypes in chloroplast and nuclear photorelocation movements between chup1 and kac1kac2 mutants. Measurement of chloroplast photorelocation movement indicated that kac1kac2, but not chup1, exhibited a clear strong-light-induced increase in leaf transmittance changes. The chloroplast movement in kac1kac2 depended on phototropin 2, CHUP1 and two other regulators for cp-actin filaments, PLASTID MOVEMENT IMPAIRED 1 and THRUMIN 1. Furthermore, kac1kac2 retained a weak but significant nuclear avoidance response although chup1 displayed a severe defect in the nuclear avoidance response. The kac1kac2chup1 triple mutant was completely defective in both chloroplast and nuclear avoidance responses. These results indicate that CHUP1 and the KACs function somewhat independently, but interdependently mediate both chloroplast and nuclear photorelocation movements.
Suetsugu, Noriyuki; Higa, Takeshi; Gotoh, Eiji; Wada, Masamitsu
2016-01-01
Light-induced chloroplast movement and attachment to the plasma membrane are dependent on actin filaments. In Arabidopsis thaliana, the short actin filaments on the chloroplast envelope, cp-actin filaments, are essential for chloroplast movement and positioning. Furthermore, cp-actin-filament-mediated chloroplast movement is necessary for the strong-light-induced nuclear avoidance response. The proteins CHLOROPLAST UNUSUAL POSITIONING 1 (CHUP1), KINESIN-LIKE PROTEIN FOR ACTIN-BASED CHLOROPLAST MOVEMENT 1 (KAC1) and KAC2 are required for the generation and/or maintenance of cp-actin filaments in Arabidopsis. In land plants, CHUP1 and KAC family proteins play pivotal roles in the proper movement of chloroplasts and their attachment to the plasma membrane. Here, we report similar but distinct phenotypes in chloroplast and nuclear photorelocation movements between chup1 and kac1kac2 mutants. Measurement of chloroplast photorelocation movement indicated that kac1kac2, but not chup1, exhibited a clear strong-light-induced increase in leaf transmittance changes. The chloroplast movement in kac1kac2 depended on phototropin 2, CHUP1 and two other regulators for cp-actin filaments, PLASTID MOVEMENT IMPAIRED 1 and THRUMIN 1. Furthermore, kac1kac2 retained a weak but significant nuclear avoidance response although chup1 displayed a severe defect in the nuclear avoidance response. The kac1kac2chup1 triple mutant was completely defective in both chloroplast and nuclear avoidance responses. These results indicate that CHUP1 and the KACs function somewhat independently, but interdependently mediate both chloroplast and nuclear photorelocation movements.
Directory of Open Access Journals (Sweden)
Morelli L.
2016-01-01
Inclusive variables are in general well reproduced by the model. We found clear deviations from the statistical model if we select emission channels involving multiple α particles which are more probable than expected from a purely statistical behavior. Data from 12C+12C reaction have been analyzed in order to study the decay of the Hoyle state of 12C* with two different selections: peripheral binary collisions and 6α decay channel in central events. To continue the investigation on light systems, we have recently measured the 16O+12C reaction at three different beam energies, namely Ebeam = 90, 110 and 130 MeV. Preliminary results are presented.
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Lecouey, J.L
2002-12-01
A description of a study of the neutron-rich unbound systems {sup 16}B and {sup 13}Be is presented. The structure of these nuclei provides strong constraints on current models and vital information for a three-body description of the Borromean two-neutron halo nuclei {sup 17}B and {sup 14}Be. The experimental work was undertaken at GANIL. Single-proton removal reactions were employed to populate the nuclei of interest, starting with a secondary beam of {sup 17}C at 35 MeV/nucleon (for {sup 16}B) and {sup 14}B at 41 MeV/nucleon (for {sup 13}Be). The charged fragments were detected using a position-sensitive Si-Si-CsI telescope of the CHARISSA collaboration, and the neutron using the DEMON modular array. The decay energy spectra for {sup 16}B and {sup 13}Be were thus reconstructed from the measured {sup 15}B-n and {sup 12}Be-n coincidences. A theoretical description, based on the sudden approximation, of the population of unbound final states was developed. The predicted decay energy spectra were compared with the measurements after folding in the response of the experimental setup. This involved the use of simulations based on GEANT and a code, BELZEBUTH, developed specifically for the present work. In the case of {sup 15}B+n the data were best reproduced assuming the population of a narrow ({gamma} {<=} 100 keV), low-lying (E{sub r} = 85 keV) d-wave resonance(s). The {sup 12}Be+n data were consistent with the population of a very broad ({gamma} {approx_equal} 1-2 MeV) s-wave state at around 600-800 keV and a d-wave resonance at 2.5 MeV ({gamma} {approx} 400 keV). (author)
Tail Bounds for the Supremums of Empirical Processes over Unbounded Classes of Functions
Institute of Scientific and Technical Information of China (English)
Di Xin ZHANG
2006-01-01
So far the study of exponential bounds of an empirical process has been restricted to a bounded index class of functions. The case of an unbounded index class of functions is now studied on the basis of a new symmetrization idea and a new method of truncating the original probability space; the exponential bounds of the tail probabilities for the supremum of the empirical process over an unbounded class of functions are obtained. The exponential bounds can be used to establish laws of the logarithm for the empirical processes over unbounded classes of functions.
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Klimentowski, Jaroslaw; Lokas, Ewa L.; /Warsaw, Copernicus Astron. Ctr.; Kazantzidis, Stelios; /KIPAC, Menlo Park; Prada, Francisco; /IAA, Granada; Mayer, Lucio; /Zurich,; Mamon, Gary A.; /Paris, Inst. Astrophys. /Meudon Observ.
2006-11-14
We study the origin and properties of the population of unbound stars in the kinematic samples of dwarf spheroidal galaxies. For this purpose we have run a high resolution N- body simulation of a two-component dwarf galaxy orbiting in a Milky Way potential. In agreement with the tidal stirring scenario of Mayer et al., the dwarf is placed on a highly eccentric orbit, its initial stellar component is in the form of an exponential disk and it has a NFW-like dark matter halo. After 10 Gyrs of evolution the dwarf produces a spheroidal stellar component and is strongly tidally stripped so that mass follows light and the stars are on almost isotropic orbits. From this final state, we create mock kinematic data sets for 200 stars by observing the dwarf in different directions.We find that when the dwarf is observed along the tidal tails the kinematic samples are strongly contaminated by unbound stars from the tails.We also study another source of possible contamination by adding stars from the Milky Way. We demonstrate that most of the unbound stars can be removed by the method of interloper rejection proposed by den Hartog & Katgert and recently tested on simulated dark matter haloes. We model the cleaned up kinematic samples using solutions of the Jeans equation with constant mass-to-light ratio and velocity anisotropy parameter. We show that even for such strongly stripped dwarf the Jeans analysis, when applied to cleaned samples, allows us to reproduce the mass and mass-to-light ratio of the dwarf with accuracy typically better than 25 percent and almost exactly in the case when the line of sight is perpendicular to the tidal tails. The analysis was applied to the new data for the Fornax dSph galaxy for which we find a mass-to-light ratio of 11 solar units and isotropic orbits. We demonstrate that most of the contamination in the kinematic sample of Fornax probably originates from the Milky Way.
Neutron radioactivity-Lifetime measurements of neutron-unbound states
Kahlbow, J.; Caesar, C.; Aumann, T.; Panin, V.; Paschalis, S.; Scheit, H.; Simon, H.
2017-09-01
A new technique to measure the lifetime τ of a neutron-radioactive nucleus that decays in-flight via neutron emission is presented and demonstrated utilizing MonteCarlo simulations. The method is based on the production of the neutron-unbound nucleus in a target, which at the same time slows down the produced nucleus and the residual nucleus after (multi-) neutron emission. The spectrum of the velocity difference of neutron(s) and the residual nucleus has a characteristic shape, that allows to extract the lifetime. If the decay happens outside the target there will be a peak in the spectrum, while events where the decay is in the target show a broad flat distribution due to the continuous slowing down of the residual nucleus. The method itself and the analysis procedure are discussed in detail for the specific candidate 26O. A stack of targets with decreasing target thicknesses can expand the measurable lifetime range and improve the sensitivity by increasing the ratio between decays outside and inside the target. The simulations indicate a lower limit of measurable lifetime τ ∼ 0 . 2 ps for the given conditions.
Estimation of Bounded and Unbounded Trajectories in Diffusion MRI.
Ning, Lipeng; Westin, Carl-Fredrik; Rathi, Yogesh
2016-01-01
Disentangling the tissue microstructural information from the diffusion magnetic resonance imaging (dMRI) measurements is quite important for extracting brain tissue specific measures. The autocorrelation function of diffusing spins is key for understanding the relation between dMRI signals and the acquisition gradient sequences. In this paper, we demonstrate that the autocorrelation of diffusion in restricted or bounded spaces can be well approximated by exponential functions. To this end, we propose to use the multivariate Ornstein-Uhlenbeck (OU) process to model the matrix-valued exponential autocorrelation function of three-dimensional diffusion processes with bounded trajectories. We present detailed analysis on the relation between the model parameters and the time-dependent apparent axon radius and provide a general model for dMRI signals from the frequency domain perspective. For our experimental setup, we model the diffusion signal as a mixture of two compartments that correspond to diffusing spins with bounded and unbounded trajectories, and analyze the corpus-callosum in an ex-vivo data set of a monkey brain.
Estimation of bounded and unbounded trajectories in diffusion MRI
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Lipeng eNing
2016-03-01
Full Text Available Disentangling the tissue microstructural information from the diffusion magnetic resonance imaging (dMRI measurements is quite important for extracting brain tissue specific measures. The autocorrelation function of diffusing spins is key for understanding the relation between dMRI signals and the acquisition gradient sequences. In this paper, we demonstrate that the autocorrelation of diffusion in restricted or bounded spaces can be well approximated by exponential functions. To this end, we propose to use the multivariate Ornstein-Uhlenbeck (OU process to model the matrix-valued exponential autocorrelation function of three-dimensional diffusion processes with bounded trajectories. We present detailed analysis on the relation between the model parameters and the time-dependent apparent axon radius and provide a general model for dMRI signals from the frequency domain perspective. For our experimental setup, we model the diffusion signal as a mixture of two compartments that correspond to diffusing spins with bounded and unbounded trajectories, and analyze the corpus-callosum in an ex-vivo data set of a monkey brain.
Clines with partial panmixia in an unbounded unidimensional habitat.
Nagylaki, Thomas
2012-08-01
In geographically structured populations, global panmixia can be regarded as the limiting case of long-distance migration. The effect of incorporating partial panmixia into diallelic single-locus clines maintained by migration and selection in an unbounded unidimensional habitat is investigated. Migration and selection are both weak. The former is homogenous and isotropic; the latter has no dominance. The population density is uniform. A simple, explicit formula is derived for the maximum value β(0) of the scaled panmictic rate β for which a cline exists. The former depends only on the asymptotic values of the scaled selection coefficient. If the two alleles have the same average selection coefficient, there exists a unique, globally asymptotically stable cline for every β ≥ 0. Otherwise, if β ≥ β(0), the allele with the greater average selection coefficient is ultimately fixed. If β < β(0), there exists a unique, globally asymptotically stable cline, and some polymorphism is retained even infinitely far from its center. The gene frequencies at infinity are determined by a continuous-time, two-deme migration-selection model. An explicit expression is deduced for the monotone cline in a step-environment. These results differ fundamentally from those for the classical cline without panmixia.
Trivelpiece-Gould modes in a uniform unbounded plasma
Stenzel, R. L.; Urrutia, J. M.
2016-09-01
Trivelpiece-Gould (TG) modes originally described electrostatic surface waves on an axially magnetized cylindrical plasma column. Subsequent studies of electromagnetic waves in such plasma columns revealed two modes, a predominantly magnetic helicon mode (H) and the mixed magnetic and electrostatic Trivelpiece-Gould modes (TG). The latter are similar to whistler modes near the oblique cyclotron resonance in unbounded plasmas. The wave propagation in cylindrical geometry is assumed to be paraxial while the modes exhibit radial standing waves. The present work shows that TG modes also arise in a uniform plasma without radial standing waves. It is shown experimentally that oblique cyclotron resonance arises in large mode number helicons. Their azimuthal wave number far exceeds the axial wave number which creates whistlers near the oblique cyclotron resonance. Cyclotron damping absorbs the TG mode and can energize electrons in the center of a plasma column rather than the edge of conventional TG modes. The angular orbital field momentum can produce new perpendicular wave-particle interactions.
Klimentowski, J; Kazantzidis, S; Prada, F; Mayer, L; Mamon, G A; Klimentowski, Jaroslaw; Lokas, Ewa L.; Kazantzidis, Stelios; Prada, Francisco; Mayer, Lucio; Mamon, Gary A.
2006-01-01
We study the origin and properties of the population of unbound stars in the kinematic samples of dwarf spheroidal galaxies. For this purpose we have run a high resolution N-body simulation of a two-component dwarf galaxy orbiting in a Milky Way potential. In agreement with the tidal stirring scenario of Mayer et al., the dwarf is placed on a highly eccentric orbit, its initial stellar component is in the form of an exponential disk and it has a NFW-like dark matter halo. After 10 Gyrs of evolution the dwarf produces a spheroidal stellar component and is strongly tidally stripped so that mass follows light and the stars are on almost isotropic orbits. From this final state, we create mock kinematic data sets for 200 stars by observing the dwarf in different directions. We find that when the dwarf is observed along the tidal tails the kinematic samples are strongly contaminated by unbound stars from the tails. We also study another source of possible contamination by adding stars from the Milky Way. We demonst...
Robertson, William C
2003-01-01
Why is left right and right left in the mirror? Baffled by the basics of reflection and refraction? Wondering just how the eye works? If you have trouble teaching concepts about light that you don t fully grasp yourself, get help from a book that s both scientifically accurate and entertaining with Light. By combining clear explanations, clever drawings, and activities that use easy-to-find materials, this book covers what science teachers and parents need to know to teach about light with confidence. It uses ray, wave, and particle models of light to explain the basics of reflection and refraction, optical instruments, polarization of light, and interference and diffraction. There s also an entire chapter on how the eye works. Each chapter ends with a Summary and Applications section that reinforces concepts with everyday examples. Whether you need a deeper understanding of how light bends or a good explanation of why the sky is blue, you ll find Light more illuminating and accessible than a college textbook...
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
In this paper, we consider a one-dimensional nonautonomous neutral differential equation. We obtain sufficient conditions under which the zero solution to this equation with unbounded delay and perturbation is uniformly asymptotically stable.
The spectral theorem for quaternionic unbounded normal operators based on the S-spectrum
Energy Technology Data Exchange (ETDEWEB)
Alpay, Daniel, E-mail: dany@math.bgu.ac.il; Kimsey, David P., E-mail: dpkimsey@gmail.com [Department of Mathematics, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Colombo, Fabrizio, E-mail: fabrizio.colombo@polimi.it [Politecnico di Milano, Dipartimento di Matematica, Via E. Bonardi, 9, 20133 Milano (Italy)
2016-02-15
In this paper we prove the spectral theorem for quaternionic unbounded normal operators using the notion of S-spectrum. The proof technique consists of first establishing a spectral theorem for quaternionic bounded normal operators and then using a transformation which maps a quaternionic unbounded normal operator to a quaternionic bounded normal operator. With this paper we complete the foundation of spectral analysis of quaternionic operators. The S-spectrum has been introduced to define the quaternionic functional calculus but it turns out to be the correct object also for the spectral theorem for quaternionic normal operators. The lack of a suitable notion of spectrum was a major obstruction to fully understand the spectral theorem for quaternionic normal operators. A prime motivation for studying the spectral theorem for quaternionic unbounded normal operators is given by the subclass of unbounded anti-self adjoint quaternionic operators which play a crucial role in the quaternionic quantum mechanics.
Deformation from symmetry for Schrodinger equations of higher order on unbounded domains
Directory of Open Access Journals (Sweden)
Addolorata Salvatore
2003-06-01
Full Text Available By means of a perturbation method recently introduced by Bolle, we discuss the existence of infinitely many solutions for a class of perturbed symmetric higher order Schrodinger equations with non-homogeneous boundary data on unbounded domains.
ON THE UNIQUENESS THEOREMS FOR THE UNBOUNDED CLASSICAL SOLUTION OF THE MAGNETIC B NARD SYSTEM
Institute of Scientific and Technical Information of China (English)
MIAO Changxing
2000-01-01
In this note we prove two theorems on the uniqueness of unbounded classical solutions of the magnetic Bénard system which includes the classical Navier-Stokes equation, the Boussinesq equation and the magnetohydrodynamic equation as special cases.
On bounded and unbounded dynamics of the Hamiltonian system for unified scalar field cosmology
Energy Technology Data Exchange (ETDEWEB)
Starkov, Konstantin E., E-mail: kstarkov@ipn.mx
2016-05-27
This paper is devoted to the research of global dynamics for the Hamiltonian system formed by the unified scalar field cosmology. We prove that this system possesses only unbounded dynamics in the space of negative curvature. It is found the invariant domain filled only by unbounded dynamics for the space with positive curvature. Further, we construct a set of polytopes depending on the Hamiltonian level surface that contain all compact invariant sets. Besides, one invariant two dimensional plane is described. Finally, we establish nonchaoticity of dynamics in one special case. - Highlights: • Unbounded dynamics is stated in case of negative curvature. • Domain with unbounded dynamics is got in case of positive curvature. • Localization polytope for compact invariant sets is computed. • One two dimensional invariant plane is described. • Nonchaotic dynamics is stated in one special case.
The limiting absorption principle for the acoustic wave operators in two unbounded media
Kadowaki, Mitsuteru
1993-01-01
In the present paper we study the limiting absorption principle for the acoustic wave operators in two unbounded media. We assume that the propagation speed is discontinuous at the interface and the equilibrium density is 1. ...
Attractors for the Ginzburg—Landau—BBM Equations in an Unbounded Domain
Institute of Scientific and Technical Information of China (English)
BolingGUO; MurongJIANG
1998-01-01
In this paper,the long time behavior of the global solutions of the Ginzburg-Landau equation coupled with BBM equation in an unbounded domain is considered,The existence of the maximal attractor is obtained.
Klimentowski, Jarosław; Łokas, Ewa L.; Kazantzidis, Stelios; Prada, Francisco; Mayer, Lucio; Mamon, Gary A.
2007-06-01
We study the origin and properties of the population of unbound stars in the kinematic samples of dwarf spheroidal (dSph) galaxies. For this purpose we have run a high-resolution N-body simulation of a two-component dwarf galaxy orbiting in a Milky Way potential. In agreement with the tidal stirring scenario of Mayer et al., the dwarf is placed on a highly eccentric orbit, its initial stellar component is in the form of an exponential disc and it has a NFW-like dark matter (DM) halo. After 10 Gyr of evolution the dwarf produces a spheroidal stellar component and is strongly tidally stripped so that mass follows light and the stars are on almost isotropic orbits. From this final state, we create mock kinematic data sets for 200 stars by observing the dwarf in different directions. We find that when the dwarf is observed along the tidal tails the kinematic samples are strongly contaminated by unbound stars from the tails. We also study another source of possible contamination by adding stars from the Milky Way. We demonstrate that most of the unbound stars can be removed by the method of interloper rejection proposed by den Hartog & Katgert and recently tested on simulated DM haloes. We model the cleaned-up kinematic samples using solutions of the Jeans equation with constant mass-to-light ratio (M/L) and velocity anisotropy parameter. We show that even for such a strongly stripped dwarf the Jeans analysis, when applied to cleaned samples, allows us to reproduce the mass and M/L of the dwarf with accuracy typically better than 25 per cent and almost exactly in the case when the line of sight is perpendicular to the tidal tails. The analysis was applied to the new data for the Fornax dSph galaxy. We show that after careful removal of interlopers the velocity dispersion profile of Fornax can be reproduced by a model in which mass traces light with a M/L of 11 solar units and isotropic orbits. We demonstrate that most of the contamination in the kinematic sample of
Convergence of implicit iterates with errors for mappings with unbounded domain in Banach spaces
Directory of Open Access Journals (Sweden)
Hafiz Fukhar-Ud-Din
2005-01-01
Full Text Available We prove that an implicit iterative process with errors converges weakly and strongly to a common fixed point of a finite family of asymptotically quasi-nonexpansive mappings on unbounded sets in a uniformly convex Banach space. Our results generalize and improve upon, among others, the corresponding recent results of Sun (2003 in the following two different directions: (i domain of the mappings is unbounded, (ii the iterative sequence contains an error term.
On asymptotic time decay of solutions to a parabolic equation in unbounded domains
Directory of Open Access Journals (Sweden)
P. Maremonti
1991-05-01
Full Text Available Estimates on the asymptotic behaviour of solutions to a parabolic equation are given, when the I.B.V.P. is posed in particular domains. More precisely, the domain Ω is unbounded, unbounded in any direction, and Ω is enclosed in a wedge or in a cone of two or three-dimensional Euclidean space. It is proved that the order of decay is increasing for decreasing opening of the wedge or of the cone.
Dynamics of proteins aggregation. I. Universal scaling in unbounded media
Zheng, Size; Javidpour, Leili; Shing, Katherine S.; Sahimi, Muhammad
2016-10-01
It is well understood that in some cases proteins do not fold correctly and, depending on their environment, even properly-folded proteins change their conformation spontaneously, taking on a misfolded state that leads to protein aggregation and formation of large aggregates. An important factor that contributes to the aggregation is the interactions between the misfolded proteins. Depending on the aggregation environment, the aggregates may take on various shapes forming larger structures, such as protein plaques that are often toxic. Their deposition in tissues is a major contributing factor to many neuro-degenerative diseases, such as Alzheimer's, Parkinson's, amyotrophic lateral sclerosis, and prion. This paper represents the first part in a series devoted to molecular simulation of protein aggregation. We use the PRIME, a meso-scale model of proteins, together with extensive discontinuous molecular dynamics simulation to study the aggregation process in an unbounded fluid system, as the first step toward MD simulation of the same phenomenon in crowded cellular environments. Various properties of the aggregates have been computed, including dynamic evolution of aggregate-size distribution, mean aggregate size, number of peptides that contribute to the formation of β sheets, number of various types of hydrogen bonds formed in the system, radius of gyration of the aggregates, and the aggregates' diffusivity. We show that many of such quantities follow dynamic scaling, similar to those for aggregation of colloidal clusters. In particular, at long times the mean aggregate size S(t) grows with time as, S(t) ˜ tz, where z is the dynamic exponent. To our knowledge, this is the first time that the qualitative similarity between aggregation of proteins and colloidal aggregates has been pointed out.
Unbounded Trace Orbits of Thue-Morse Hamiltonian
Liu, Qinghui; Qu, Yanhui; Yao, Xiao
2017-03-01
It is well known that, an energy is in the spectrum of Fibonacci Hamiltonian if and only if the corresponding trace orbit is bounded. However, it is not known whether the same result holds for the Thue-Morse Hamiltonian. In this paper, we give a negative answer to this question. More precisely, we construct two subsets Σ _{II} and Σ _{III} of the spectrum of the Thue-Morse Hamiltonian, both of which are dense and uncountable, such that each energy in Σ _{II}&ucedil;p Σ _{III} corresponds to an unbounded trace orbit. Exact estimates on the norm of the transfer matrices are also obtained for these energies: for Ein Σ _{II}&ucedil;p Σ _{III}, the norms of the transfer matrices behave like e^{c_1γ √{n}}≤Vert T_{ n}(E)Vert ≤e^{c_2γ √{n}}. However, two types of energies are quite different in the sense that each energy in Σ _{II} is associated with a two-sided pseudo-localized state, while each energy in Σ _{III} is associated with a one-sided pseudo-localized state. The difference is also reflected by the local dimensions of the spectral measure: the local dimension is 0 for energies in Σ _{II} and is larger than 1 for energies in Σ _{III}. As a comparison, we mention another known countable dense subset Σ _I. Each energy in Σ _I corresponds to an eventually constant trace map and the associated eigenvector is an extended state. In summary, the Thue-Morse Hamiltonian exhibits "mixed spectral nature".
Guichon, P A M; Thomas, A W
1996-01-01
We describe the development of a theoretical description of the structure of finite nuclei based on a relativistic quark model of the structure of the bound nucleons which interact through the (self-consistent) exchange of scalar and vector mesons.
Directory of Open Access Journals (Sweden)
Gleyce Alves Machado
2013-05-01
Full Text Available The aim of the present study was to analyse Taenia solium metacestode antigens that were derived from the unbound fraction of jacalin affinity chromatography and subsequent tert-octylphenoxy poly (oxyethylene ethanol Triton X-114 (TX-114 partitioning in the diagnosis of human neurocysticercosis (NCC. Immunoassays were designed to detect T. solium-specific IgG antibodies by ELISA and immunoblot. Serum samples were collected from 132 individuals who were categorised as follows: 40 had NCC, 62 presented Taenia spp or other parasitic diseases and 30 were healthy individuals. The jacalin-unbound (J unbound fraction presented higher sensitivity and specificity rates than the jacalin-bound fraction and only this fraction was subjected to subsequent TX-114 partitioning, resulting in detergent (DJ unbound and aqueous (AJ unbound fractions. The ELISA sensitivity and specificity were 85% and 84.8% for J unbound , 92.5% and 93.5% for DJ unbound and 82.5% and 82.6% for AJ unbound . By immunoblot, the DJ unbound fraction showed 100% sensitivity and specificity and only serum samples from patients with NCC recognised the 50-70 kDa T. solium-specific components. We conclude that the DJ unbound fraction can serve as a useful tool for the differential immunodiagnosis of NCC by immunoblot.
Total and unbound darunavir (DRV pharmacokinetics (PK in HIV-1-infected pregnant women
Directory of Open Access Journals (Sweden)
C Zorrilla
2012-11-01
Full Text Available Antiretroviral (ARV therapy during pregnancy is recommended to reduce the risk of mother-to-child transmission (MTCT. Physiologic changes during pregnancy can affect PK. We present the PK of total and unbound (pharmacologically active DRV in HIV-1-infected pregnant women receiving twice-daily (bid DRV/ritonavir (rtv. This Phase IIIb study enrolled HIV-1-infected pregnant women≥18 years old in the 2nd trimester of pregnancy receiving DRV/rtv 600/100 mg bid and other ARVs. DRV (total and unbound and rtv (total plasma concentrations were obtained predose and 1, 2, 3, 4, 6, 9 and 12 hours postdose during the 2nd and 3rd trimesters and postpartum. Total DRV and rtv plasma concentrations were determined using a previously validated HPLC-MS/MS assay (lower limit of quantification 5.00 ng/mL. Unbound DRV was determined by fortifying plasma samples with 14-C DRV and separating total and unbound DRV using ultrafiltration. Total and unbound 14-C DRV were measured using liquid scintillation counting. Total and unbound PK parameters were derived using a noncompartmental analysis. Safety and efficacy were investigated at each visit and summarized using descriptive statistics. Sixteen women (10 black, 4 Hispanic, 2 white were enrolled; 11 had evaluable PK data. Total DRV AUC12h was 24% and 17% lower during 2nd and 3rd trimesters, respectively, vs postpartum (Table. Unbound DRV AUC12h was unchanged during 2nd and 3rd trimesters vs postpartum. Total and unbound DRV Cmin increased by 43% and 10%, respectively, during 2nd trimester and by 86% and 14%, respectively, during 3rd trimester vs postpartum. Unbound DRV was above the EC50 (27.5 ng/mL for PI-resistant HIV in all patients. Albumin and α1-acid glycoprotein (AAG concentrations were 22%–29% lower during pregnancy vs postpartum. Viral load decreased and CD4+ count increased over time. One serious adverse event was reported (increased transaminase. Three of 12 infants were born prior to 37 weeks (30, 36 and
Ditchburn, R W
2011-01-01
This classic study, available for the first time in paperback, clearly demonstrates how quantum theory is a natural development of wave theory, and how these two theories, once thought to be irreconcilable, together comprise a single valid theory of light. Aimed at students with an intermediate-level knowledge of physics, the book first offers a historical introduction to the subject, then covers topics such as wave theory, interference, diffraction, Huygens' Principle, Fermat's Principle, and the accuracy of optical measurements. Additional topics include the velocity of light, relativistic o
Energy Technology Data Exchange (ETDEWEB)
Scholl, Clemens
2010-07-07
Excited states in the light nuclei {sup 9}B and {sup 13}C were studied using the ({sup 3}He,t) charge-exchange reaction on {sup 9}Be and {sup 13}C targets. The measurements were performed at the research center for nuclear physics (RCNP) in Osaka, Japan, using the magnetic spectrometer Grand Raiden and the dispersive WS course. The {sup 3}He beam with an energy of 420 MeV was accelerated by the RCNP Ring Cyclotron. The Grand Raiden spectrometer and the WS course allow to study the ({sup 3}He,t) charge-exchange reaction with an energy resolution of around 30 keV, which is one order of magnitude better than measurements with the (p,n) charge-exchange reaction. The high resolution allows to better separate individual states and to determine weak excitation strengths because of low background in the spectra. A total of 19 states in {sup 13}N were studied, and a total of 20 states were observed in {sup 9}B. Of these, 9 states in {sup 13}C and 10 states in {sup 9}B were identified as being excited by a Gamow-Teller transition. Charge-exchange reactions are related to beta-decay, and at zero momentum transfer a simple proportionality exists between the cross-section of the charge-exchange experiment and the Fermi (F) or Gamow-Teller (GT) beta-decay strength. While the Fermi strength B(F) is concentrated in the transition to the isobaric analog state, the Gamow-Teller strength B(GT) is scattered among the excited states. The main aim of the present study is to determine the B(GT) strengths in the nuclei {sup 9}B and {sup 13}N. The only charge-exchange study of {sup 9}B was made 30 years ago with the (p,n) reaction and a resolution of around 300-400 keV. Many states, especially at high excitation energy, could not be resolved by that study. The present work was able to separate many weakly excited states with small decay width at high excitation energies (12-19 MeV) in {sup 9}B and determine the B(GT) strength distribution by using recent high-precision beta-decay data. The
Studies of exotic nuclei; Etudes des noyaux exotiques
Energy Technology Data Exchange (ETDEWEB)
Angelique, J.C.; Orr, N.A. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France); Collaboratio: CATANE (Italy), DAPNIA-Saclay, CSNSM-Orsay, GANIL-Caen, IPN-Orsay, NSCL-MSU (USA), Los Alamos (USA), University of Manchester (United Kingdom), University of Surrey (United Kingdom), FLNR JINR Dubna (Russia), IAP-Bucharest (Romania), NPI-Rez (Czech Republic), CCLRLC-Daresbury (United Kingdom)
1997-12-31
The study of the nuclei far off stability valley is of much interest for testing the nuclear models established for the stable nuclei but also for astrophysics to understand the nucleosynthesis. Experiments aim to measure the mass and lifetime, to build the decay schemes and also to study the structure and the properties of these nuclei. The radioactive beam group focused its research on light neutron-rich nuclei having a halo neutron structure. Mass measurements in N {approx} Z nuclei namely in A {approx} 60-80 proton-rich nuclei, important for understanding the rp process, are mentioned, as well as in nuclei in the {sup 100}Sn region. In the newly obtained {sup 26}O and {sup 28}O nuclei the lifetimes, the probabilities of emission of one for more neutrons were determined. The data analysis has permitted to determine also for the first time the lifetimes of {sup 27,29}F and {sup 30}Ne. Studies of nuclei in the {sup 100}Sn region, near the proton drip line in the ground and isomeric states are now under way. The spectroscopy (energy levels, gamma emissions, etc.) of the neutron-rich nuclei produced by the {sup 36}S fragmentation has been carried out in {sup 31}Ne, {sup 17}B and {sup 29}F. Studies by Coulomb excitation of the 2{sup +} excited states and associated probability B (E2) in O, Ne, Ni and Zn are now analysed 6 refs.
The Scattering of Fast Nucleons from Nuclei
Kerman, A. K.; McManus, H.; Thaler, R. M.
2000-04-01
The formal theory of the scattering of high-energy nucleons by nuclei is developed in terms of the nucleon-nucleon scattering amplitude. The most important approximations necessary to make numerical calculation feasible are then examined. The optical model potential is derived on this basis and compared with the optical model parameters found from experiment. The elastic scattering and polarization of nucleons from light nuclei is predicted and compared with experiment. The effect of nuclear correlations is discussed. The polarization of inelastically scattered nucleons is discussed and predictions compared with experiments. To within the validity of the approximations the experimental data on the scattering of nucleons from nuclei at energies above ˜100 Mev appears to be consistent with the theory.
The scattering of fast nucleons from nuclei
Energy Technology Data Exchange (ETDEWEB)
Kerman, A. K. [Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); McManus, H. [Chalk River Laboratory, Chalk River, Ontario, (Canada); Thaler, R. M. [Los Alamos Scientific Laboratory, Los Alamos, New Mexico (United States)
2000-04-10
The formal theory of the scattering of high-energy nucleons by nuclei is developed in terms of the nucleon nucleon scattering amplitude. The most important approximations necessary to make numerical calculation feasible are then examined. The optical model potential is derived on this basis and compared with the optical model parameters found from experiment. The elastic scattering and polarization of nucleons from light nuclei is predicted and compared with experiment. The effect of nuclear correlations is discussed. The polarization of inelastically scattered nucleons is discussed and predictions compared with experiments. To within the validity of the approximations the experimental data on the scattering of nucleons from nuclei at energies above {approx}100 Mev appears to be consistent with the theory. (c) 2000 Academic Press, Inc.
Electromagnetic and Weak transitions in light nuclei
Energy Technology Data Exchange (ETDEWEB)
M. Viviani; L.E. Marcucci; A. Kievsky; S. Rosati; R. Schiavilla
2002-09-01
Recent advances in the study of the p -- d radiative and mu -- {sup 3}He weak capture processes by our group are presented and discussed. The trinucleon bound and scattering states have been obtained from variational calculations by expanding the corresponding wave functions in terms of correlated hyper-spherical harmonic functions. The electromagnetic and weak transition currents include one- and two-body operators. The accuracy achieved in these calculations allows for interesting comparisons with experimental data.
Coulomb dissociation of light unstable nuclei
Energy Technology Data Exchange (ETDEWEB)
Kido, Toshihiko [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yabana, Kazuhiro; Suzuki, Yoshiyuki
1997-05-01
The aim of this study is that a simulation method applicable to the atomic nucleus with neutron halo structure developed till now is applied to a wider range unstable nucleus containing proton excess nucleus to also attribute understanding of nuclear reaction with interest in astronomical nuclear reaction. The proton dissociation energy in {sup 8}B nucleus is small value of 138 eV, which is thought to have a structure of proton at the most outer shell bound much weakly by core nucleus and spread in thinner thickness. For the coulomb excitation of such weak bound system, quantum theoretical and non-perturbational treatment is important. Therefore, 3-dimensional time-dependent Schroedinger equation on relative wave function of the core nucleus {sup 7}Be and halo proton p will be dissolved in time space and will execute a time developmental simulation. (G.K.)
Electric dipole moment of light nuclei
Afnan, Iraj R.; Gibson, Benjamin F.
2010-07-01
We examine the sensitivity of the deuteron Electric Dipole Moment (EDM) to variation in the nucleon-nucleon interaction. In particular, we write the EDM as a sum of two terms, one depends on the target wave function, the second on intermediate multiple scattering states in the 3P1 channel. This second contribution is sensitive to off-shell behavior of the 3P1 amplitude.
Electric dipole moment of light nuclei
Energy Technology Data Exchange (ETDEWEB)
Gibson, Benjamin [Los Alamos National Laboratory; Afnan, I R [Los Alamos National Laboratory
2010-01-01
We examine the sensitivity of the deuteron Electric Dipole Moment (EDM) to variation in the nucleon-nucleon interaction. In particular, we write the EDM as a sum of two terms, one depends on the target wave function, the second on intermediate multiple scattering states in the {sup 3}P{sub 1} channel. This second contribution is sensitive to off-shell behavior of the {sup 3}P{sub 1} amplitude.
Electric dipole moment of light nuclei
Energy Technology Data Exchange (ETDEWEB)
Gibson, Benjamin [Los Alamos National Laboratory; Afnan, I R [Los Alamos National Laboratory
2010-01-01
We examine the sensitivity of the deuteron Electric Dipole Moment (EDM) to variation in the nucleon-nucleon interaction. In particular, we write the EDM as a sum of two terms, one depends on the target wave function, the second on intermediate multiple scattering states in the {sup 3}P{sub 1} channel. This second contribution is sensitive to off-shell behavior of the {sup 3}P{sub 1} amplitude.
Radiative muon capture in light nuclei
Energy Technology Data Exchange (ETDEWEB)
Hasinoff, M.D.; Ahmad, S; Armstrong, D.S.; Azuelos, G.; Bertl, W.; Blecher, M.; Burnham, R.A.; Clifford, E.T.H.; Chen, C.Q.; Ding, Z.H.; Depommier, P.; Gorringe, T.P.; Henderson, R.; Larabee, A.J.; Macdonald, J.A.; Mes, H.; Numao, T.; Poutissou, J.M.; Poutissou, R.; Robertson, B.C.; Serna-Angel, A.; Summhammer, J.; Taylor, G.N.; Waltham, C.E.; Wright, D.H.; Zhang, N.S.; MacDonald, S.C. (British Columbia Univ., Vancouver,
1989-06-01
Radiative muon capture rates have been measured for carbon, oxygen and calcium targets. The carbon and oxygen rates yield large values for g{sub p} when compared to detailed microscopic calculations but the conventional Goldberger-Treiman value when compared to phenomenological model calculations. A progress report on the TRIUMF RMC measurement on hydrogen is also given. 16 refs., 2 figs., 1 tab.
Annihilation of Antiprotons in Light Nuclei
Institute of Scientific and Technical Information of China (English)
M. A. Rana; E. U. Khan; M. I. Shahzad; I. E. Qureshi; F. Malik; G. Sher; S. Manzoor; H. A. Khan
2006-01-01
@@ CR-39 detectors have been exposed to a 5.9-MeV antiproton beam using the low energy antiproton ring (LEAR) facility at CERN. At this energy, tracks of antiprotons appear in a CR-39 detector after 135 min of etching in 6 M NaOH at 70℃ . Fluence of the antiproton beam has been determined using track density. We have also found tracks in the etched CR-39 detector at different depths (250-500μm). These tracks have resulted from the annihilation of antiprotons with the constituents (H, C and O) of the CR-39 detector. The goal of the experiment is to develop a simple and low-cost method to study properties of antiparticles and those formed after annihilation of these particles with the target matter.
Separation and analysis techniques for bound and unbound alkyl ketene dimer (AKD in paper: A review
Directory of Open Access Journals (Sweden)
Sunil Kumar
2016-11-01
Full Text Available Alkyl ketene dimer (AKD is the reactive synthetic sizing agent that is used in alkaline or neutral papermaking conditions to provide certain level of hydrophobicity to the paper and board. The sizing mechanism of AKD involves its reaction with the hydroxyl groups on cellulose. However, all of AKD does not chemically react with fibers; some of it may undergo hydrolysis in water to form unstable β-keto acids, which decarboxylate to the corresponding ketone. This portion of AKD remains non-reacted (unbound and adsorbs onto fibers. The sizing effect depends mainly on the quantity of chemically reacted (bound AKD in paper, while the role of unbound forms, that is ketone and oligomer, is still not clear. Both bound and unbound portions of AKD have their own effect on paper. It is important to know the proportion of bound and unbound form of AKD in paper. The different techniques have been adopted for the separation and analysis of bound and unbound AKD present in paper. The aim of this paper is to review and summarize the various techniques provided by the researchers to separate the different forms of AKD and highlight the most important aspects for their separation.
Ionizing feedback from massive stars in massive clusters III: Disruption of partially unbound clouds
Dale, J E; Bonnell, I A
2012-01-01
We extend our previous SPH parameter study of the effects of photoionization from O-stars on star-forming clouds to include initially unbound clouds. We generate a set of model clouds in the mass range $10^{4}-10^{6}$M$_{\\odot}$ with initial virial ratios $E_{\\rm kin}/E_{\\rm pot}$=2.3, allow them to form stars, and study the impact of the photoionizing radiation produced by the massive stars. We find that, on the 3Myr timescale before supernovae are expected to begin detonating, the fractions of mass expelled by ionizing feedback is a very strong function of the cloud escape velocities. High-mass clouds are largely unaffected dynamically, while lower-mass clouds have large fractions of their gas reserves expelled on this timescale. However, the fractions of stellar mass unbound are modest and significant portions of the unbound stars are so only because the clouds themselves are initially partially unbound. We find that ionization is much more able to create well-cleared bubbles in the unbound clouds, owing t...
Anharmonic vibrations in nuclei
Fallot, M; Andrés, M V; Catara, F; Lanza, E G; Scarpaci, J A; Chomaz, Ph.
2003-01-01
In this letter, we show that the non-linearitites of large amplitude motions in atomic nuclei induce giant quadrupole and monopole vibrations. As a consequence, the main source of anharmonicity is the coupling with configurations including one of these two giant resonances on top of any state. Two-phonon energies are often lowered by one or two MeV because of the large matrix elements with such three phonon configurations. These effects are studied in two nuclei, 40Ca and 208Pb.
Toward concordance of Ex and J^{π} values for proton unbound 31S states
Parikh, A.; Wrede, C.; Fry, C.
2016-09-01
Nucleosynthesis in classical novae on oxygen-neon white dwarfs is sensitive to the poorly constrained thermonuclear rate of the 30 P( p,γ)31 S reaction. In order to improve this situation, a variety of experiments have been performed over the past decade to determine the properties of proton unbound 31S levels up to an excitation energy of ≈ 6.7 MeV. Inconsistencies in the energies and J^{π} values for these levels have made it difficult to produce a useful 30 P( p, γ)31 S reaction rate based on experimental information. In the present work, we revisit a subset of published data on the structure of 31S in order to shed light on these problems. First, we present an alternative calibration of 31 P(3 He, t)31 S spectra using newly available high-precision data in order to address discrepant 31S excitation energies. Second, we apply a similar method to a recently acquired 32 S( d, t)31 S spectrum. Third, for a different 31 P(3 He, t)31 S experiment in which angular distributions were acquired, we present alternative fits to the experimental data in order to address discrepant 31S J^{π} values. Finally, we compare the J^{π} values from 31 P(3 He, t)31 S to those reported from in beam γ-ray spectroscopy experiments in order to search for potential resolutions to the inconsistencies. Overall, viable new solutions to some of the problems emerge, but other problems persist.
Use of Finite Point Method for Wave Propagation in Nonhomogeneous Unbounded Domains
Directory of Open Access Journals (Sweden)
S. Moazam
2015-01-01
Full Text Available Wave propagation in an unbounded domain surrounding the stimulation resource is one of the important issues for engineers. Past literature is mainly concentrated on the modelling and estimation of the wave propagation in partially layered, homogeneous, and unbounded domains with harmonic properties. In this study, a new approach based on the Finite Point Method (FPM has been introduced to analyze and solve the problems of wave propagation in any nonhomogeneous unbounded domain. The proposed method has the ability to use the domain properties by coordinate as an input. Therefore, there is no restriction in the form of the domain properties, such as being periodical as in the case of existing similar numerical methods. The proposed method can model the boundary points between phases with trace of errors and the results of this method satisfy both conditions of decay and radiation.
Directory of Open Access Journals (Sweden)
M. Bounkhel
2012-01-01
Full Text Available We prove the existence of solutions for third-order nonconvex state-dependent sweeping process with unbounded perturbations of the form: -A(x(3(t∈N(K(t,ẋ(t; A(ẍ(t+F(t,x(t,ẋ(t,ẍ(t+G(x(t,ẋ(t,ẍ(t a.e. [0,T], A(ẍ(t∈K(t,ẋ(t, a.e. t∈[0,T], x(0=x0,ẋ(0=u0, ẍ(0=υ0, where T>0, K is a nonconvex Lipschitz set-valued mapping, F is an unbounded scalarly upper semicontinuous convex set-valued mapping, and G is an unbounded uniformly continuous nonconvex set-valued mapping in a separable Hilbert space H.
Energy Technology Data Exchange (ETDEWEB)
Starkov, Konstantin E., E-mail: kstarkov@ipn.mx
2015-06-12
In this paper we study some features of global dynamics for one Hamiltonian system arisen in cosmology which is formed by the minimally coupled field; this system was introduced by Maciejewski et al. in 2007. We establish that under some simple conditions imposed on parameters of this system all trajectories are unbounded in both of time directions. Further, we present other conditions for system parameters under which we localize the domain with unbounded dynamics; this domain is defined with help of bounds for values of the Hamiltonian level surface parameter. We describe the case when our system possesses periodic orbits which are found explicitly. In the rest of the cases we get some localization bounds for compact invariant sets. - Highlights: • Domain with unbounded dynamics is localized. • Equations for periodic orbits are given in one level set. • Localizations for compact invariant sets are got.
Elusive active galactic nuclei
Maiolino, R; Comastri, A; Gilli, R; Nagar, NM; Bianchi, S; Boker, T; Colbert, E; Krabbe, A; Marconi, A; Matt, G; Salvati, M
2003-01-01
A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically 'elusive'. X-ray observations are an optimal tool to identify this class of objects. We combine new Chandra observations with archival X-ray data in order to obtai
Unbounding the mental number line – New evidence on children’s spatial representation of numbers
Directory of Open Access Journals (Sweden)
Tanja eLink
2014-01-01
Full Text Available Number line estimation (i.e., indicating the position of a given number on a physical line is a standard assessment of children’s spatial representation of number magnitude. Importantly, there is an ongoing debate on the question in how far the bounded task version with start and endpoint given (e.g., 0 and 100 might induce specific estimation strategies and thus may not allow for unbiased inferences on the underlying representation. Recently, a new unbounded version of the task was suggested with only the start point and a unit fixed (e.g., the distance from 0 to 1. In adults this task provided a less biased index of the spatial representation of number magnitude. Yet, so far there are no children data available for the unbounded number line estimation task. Therefore, we conducted a cross-sectional study on primary school children performing both, the bounded and the unbounded version of the task. We observed clear evidence for systematic strategic influences (i.e., the consideration of reference points in the bounded number line estimation task for children older than grade two whereas there were no such indications for the unbounded version for any one of the age groups. In summary, the current data corroborate the unbounded number line estimation task to be a valuable tool for assessing children's spatial representation of number magnitude in a systematic and unbiased manner. Yet, similar results for the bounded and the unbounded version of the task for first- and second-graders may indicate that both versions of the task might assess the same underlying representation for relatively younger children - at least in number ranges familiar to the children assessed. This is of particular importance for inferences about the nature and development of children's magnitude representation.
Chen, Haoran; Sun, Yuanfei; Shen, Yang
2017-03-01
Predicting protein conformational changes from unbound structures or even homology models to bound structures remains a critical challenge for protein docking. Here we present a study directly addressing the challenge by reducing the dimensionality and narrowing the range of the corresponding conformational space. The study builds on cNMA-our new framework of partner- and contact-specific normal mode analysis that exploits encounter complexes and considers both intrinsic and induced flexibility. First, we established over a CAPRI (Critical Assessment of PRedicted Interactions) target set that the direction of conformational changes from unbound structures and homology models can be reproduced to a great extent by a small set of cNMA modes. In particular, homology-to-bound interface root-mean-square deviation (iRMSD) can be reduced by 40% on average with the slowest 30 modes. Second, we developed novel and interpretable features from cNMA and used various machine learning approaches to predict the extent of conformational changes. The models learned from a set of unbound-to-bound conformational changes could predict the actual extent of iRMSD with errors around 0.6 Å for unbound proteins in a held-out benchmark subset, around 0.8 Å for unbound proteins in the CAPRI set, and around 1 Å even for homology models in the CAPRI set. Our results shed new insights into origins of conformational differences between homology models and bound structures and provide new support for the low-dimensionality of conformational adjustment during protein associations. The results also provide new tools for ensemble generation and conformational sampling in unbound and homology docking. Proteins 2017; 85:544-556. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Local absorbing boundary conditions for nonlinear wave equation on unbounded domain.
Li, Hongwei; Wu, Xiaonan; Zhang, Jiwei
2011-09-01
The numerical solution of the nonlinear wave equation on unbounded spatial domain is considered. The artificial boundary method is introduced to reduce the nonlinear problem on unbounded spatial domain to an initial boundary value problem on a bounded domain. Using the unified approach, which is based on the operator splitting method, we construct the efficient nonlinear local absorbing boundary conditions for the nonlinear wave equation, and give the stability analysis of the resulting boundary conditions. Finally, several numerical examples are given to demonstrate the effectiveness of our method.
Directory of Open Access Journals (Sweden)
Anhui Gu
2013-01-01
Full Text Available The long time behavior of solutions of the nonautonomous three-components reversible Gray-Scott system defined on the entire space ℝn is studied when the external forcing terms are unbounded in a phase space. The existence of a pullback global attractor for the equation is established in L2ℝn3 and H1ℝn3, respectively. The pullback asymptotic compactness of solutions is proved by using uniform estimates on the tails of solutions on unbounded domains.
Observation of a low-lying neutron-unbound state in 19C
Thoennessen, M; Badger, N S; Baumann, T; Bazin, D; Bennett, M; Brown, J; Christian, G; DeYoung, P A; Finck, J E; Gardner, M; Hook, E A; Luther, B; Meyer, D A; Mosby, M; Rogers, W F; Smith, J K; Spyrou, A; Strongman, M J
2013-01-01
Proton removal reactions from a secondary 22N beam were utilized to populate unbound states in neutron-rich carbon isotopes. Neutrons were measured with the Modular Neutron Array (MoNA) in coincidence with carbon fragments. A resonance with a decay energy of 76(14) keV was observed in the system 18C+n corresponding to a state in 19C at an excitation energy of 653(95)keV. This resonance could correspond to the first 5/2+ state which was recently speculated to be unbound in order to describe 1n and 2n removal cross section measurements from 20C.
Neutron knockout of 12Be populating neutron-unbound states in 11Be
Peters, William A; Brown, B A; Brown, J; DeYoung, P A; Finck, J E; Frank, N; Jones, K L; Lecouey, J -L; Luther, B; Peaslee, G F; Rogers, W F; Schiller, A; Thoennessen, M; Tostevin, J A; Yoneda, K
2011-01-01
Neutron-unbound resonant states of 11Be were populated in neutron knock-out reactions from 12Be and identified by 10Be-n coincidence measurements. A resonance in the decay-energy spectrum at 80(2) keV was attributed to a highly excited unbound state in 11Be at 3.949(2) MeV decaying to the 2+ excited state in 10Be. A knockout cross section of 15(3) mb was inferred for this 3.949(2) MeV state suggesting a spectroscopic factor near unity for this 0p3/2- level, consistent with the detailed shell model calculations.
GLOBAL STABILITY ANALYSIS IN CELLULAR NEURAL NETWORKS WITH UNBOUNDED TIME DELAYS
Institute of Scientific and Technical Information of China (English)
张继业
2004-01-01
Without assuming the boundedness and differentiability of the activation functions,the conditions ensuring existence,uniqueness,and global asymptotical stability of the equilibrium point of cellular neural networks with unbounded time delays and variable delays were studied.Using the idea of vector Liapunov method,the intero-differential inequalities with unbounded delay and variable delays were constructed.By the stability analysis of the intero-differential inequalities,the sufficient conditions for global asymptotic stability of cellular neural networks were obtained.
Some equivalent conditions for exponential stabilization of linear systems with unbounded contro1
Institute of Scientific and Technical Information of China (English)
吴汉忠
1999-01-01
It is proved that the equivalences among the exponential stabilizability of the control system, the existences of admissible controls for every initial state condition and the solvability of some Riccati equation or some LQ problem also hold for the case in Hilbert space with unbounded control. The results do not need the compactness assumption for the resolvents of the infinitesimal generator, and improve the results available. They can be applied to the parabolic systems with boundary control through Dirichlet, Neumann condition or pointwise control on not only bounded domain but also unbounded domain.
Coexistence of bounded and unbounded motions in a bouncing ball model
Marò, Stefano
2013-05-01
We consider the model describing the vertical motion of a ball falling with constant acceleration on a wall and elastically reflected. The wall is supposed to move in the vertical direction according to a given periodic function f. We apply the Aubry-Mather theory to the generating function in order to prove the existence of bounded motions with prescribed mean time between the bounces. As the existence of unbounded motions is known, it is possible to find a class of functions f that allow both bounded and unbounded motions.
Improvement of Bearing Capacity in Recycled Aggregates Suitable for Use as Unbound Road Sub-Base
Directory of Open Access Journals (Sweden)
Laura Garach
2015-12-01
Full Text Available Recycled concrete aggregates and mixed recycled aggregates are specified as types of aggregates with lower densities, higher water absorption capacities, and lower mechanical strength than natural aggregates. In this paper, the mechanical behaviour and microstructural properties of natural aggregates, recycled concrete aggregates and mixed recycled aggregates were compared. Different specimens of unbound recycled mixtures demonstrated increased resistance properties. The formation of new cement hydrated particles was observed, and pozzolanic reactions were discovered by electronon microscopy in these novel materials. The properties of recycled concrete aggregates and mixed recycled aggregates suggest that these recycled materials can be used in unbound road layers to improve their mechanical behaviour in the long term.
Resonance scattering of 12C nuclei on protons in the Maya active target
Khodery, Mohammad
This work is related to the realm of exotic nuclei. These are nuclei that exist far from the valley of stability. Study of these nuclei introduced many interesting phenomena and changed our understanding about the nuclear structure. As exotic nuclei are very short lived, their study has to be at the time of their production using radioactive beams of the exotic nuclei. The goal of the experiment was to study the $^{13}$Be low-lying energy levels. The experiment was performed at ISOLDE at CERN as $^{12}$Be beams are produced at this facility with suitable intensity and energy. The method used to study $^{13}$Be was elastic resonance reactions. This is a powerful tool to study unbound states. This thesis concentrates on the $^{12}$C nuclei that are present in the beam as isobaric contamination. $^{12}$C in the beam is scattered on the protons which is the target. The protons are introduced in the form of isobutene gas. The aim of this work is to prove the principle of the technique of elastic resonance scatteri...
Shape Deformations in Atomic Nuclei
Hamamoto, Ikuko
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.
Clustering in stable and exotic nuclei
Beck, C
2016-01-01
Since the pioneering discovery of molecular resonances in the 12C+12C reaction more than half a century ago a great deal of research work has been undertaken in alpha clustering. Our knowledge on physics of nuclear molecules has increased considerably and nuclear clustering remains one of the most fruitful domains of nuclear physics, facing some of the greatest challenges and opportunities in the years ahead. The occurrence of "exotic" shapes and Bose-Einstein alpha condensates in light N=Z alpha-conjugate nuclei is investigated. Various approaches of the superdeformed and hyperdeformed bands associated with quasimolecular resonant structures are presented. Evolution of clustering from stability to the drip-lines is examined: clustering aspects are, in particular, discussed for light exotic nuclei with large neutron excess such as neutron-rich Oxygen isotopes with their complete spectroscopy.
Ultra High Energy Nuclei Propagation
Aloisio, Roberto
2008-01-01
We discuss the problem of ultra high energy nuclei propagation in astrophysical backgrounds. We present a new analytical computation scheme based on the hypothesis of continuos energy losses in a kinetic formulation of the particles propagation. This scheme enables the computation of the fluxes of ultra high energy nuclei as well as the fluxes of secondaries (nuclei and nucleons) produced by the process of photo-disintegration suffered by nuclei.
Invariant-Mass Spectroscopy of Extremely Neutron-Rich Nuclei with SAMURAI at RIBF
Kondo, Yosuke; Nakamura, Takashi; Achouri, N. Lynda; Aumann, Thomas; Baba, Hidetada; Delaunay, Franck; Doornenbal, Pieter; Fukuda, Naoki; Gibelin, Julien; Hwang, Jongwon; Inabe, Naohito; Isobe, Tadaaki; Kameda, Daisuke; Kanno, Daiki; Kim, Sunji; Kobayashi, Nobuyuki; Kobayashi, Toshio; Kubo, Toshiyuki; Leblond, Sylvain; Lee, Jenny; Marqués, F. Miguel; Minakata, Ryogo; Motobayashi, Tohru; Murai, Daichi; Murakami, Tetsuya; Muto, Kotomi; Nakashima, Tomohiro; Nakatsuka, Noritsugu; Navin, Alahari; Nishi, Seijiro; Ogoshi, Shun; Orr, Nigel A.; Otsu, Hideaki; Sato, Hiromi; Satou, Yoshiteru; Shimizu, Yohei; Suzuki, Hiroshi; Takahashi, Kento; Takeda, Hiroyuki; Takeuchi, Satoshi; Tanaka, Ryuki; Togano, Yasuhiro; Tuff, Adam G.; Vandebrouck, Marine; Yoneda, Ken-ichiro
A first experimental campaign for three physics programs using a spectrometer SAMURAI, which is newly constructed at RIBF at RIKEN, was performed in May 2012. In this campaign, the unbound nuclei 25O and 26O produced by one-proton removal reactions at ˜200 MeV/nucleon were investigated by means of invariant mass method. High statistics data compared with previous experiments could be obtained together with good particle identification resolution for outgoing heavy ion. Preliminary results show high performance of the SAMURAI spectrometer combined with high intense RI beams provided by RIBF.
Creswell, Sam
2013-01-01
In a prior paper [1] we showed that there is a nonlinear, continuous, dense bijection from $\\ell^{2}$ onto a subset of $\\ell^{2}$ whose inverse is everywhere unboundedly discontinuous. We now show that there is a linear, continuous, dense bijection whose inverse is everywhere unboundedly discontinuous.
Energy Technology Data Exchange (ETDEWEB)
Legoll, F. [Service de Physique Theorique, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)
1998-07-22
For nuclei with very high electrical charge, the Coulomb field is expected to drive the protons away from the centre to the surface of the nucleus. Such a nucleus would be no more compact but look like a bubble. The goal of this work is to confirm this idea. We are interested in only the ground state of spherical nuclei. We use the Skyrme potential with the Sly4 parametrization to calculate the mean-field Hamiltonian. Paring correlations are described by a surface-active delta paring interaction. In its ground state the nucleus {sup A=900} X{sub Z=274} is shown to be a bubble. Another stable state is found with a little higher energy: it is also a bubble. (author) 11 refs., 18 figs., 33 tabs.
Energy Technology Data Exchange (ETDEWEB)
Legoll, F. [Service de Physique Theorique, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)
1998-07-22
For nuclei with very high electrical charge, the Coulomb field is expected to drive the protons away from the centre to the surface of the nucleus. Such a nucleus would be no more compact but look like a bubble. The goal of this work is to confirm this idea. We are interested in only the ground state of spherical nuclei. We use the Skyrme potential with the Sly4 parametrization to calculate the mean-field Hamiltonian. Paring correlations are described by a surface-active delta paring interaction. In its ground state the nucleus {sup A=900} X{sub Z=274} is shown to be a bubble. Another stable state is found with a little higher energy: it is also a bubble. (author) 11 refs., 18 figs., 33 tabs.
Van Isacker, P
2010-01-01
The use of dynamical symmetries or spectrum generating algebras for the solution of the nuclear many-body problem is reviewed. General notions of symmetry and dynamical symmetry in quantum mechanics are introduced and illustrated with simple examples such as the SO(4) symmetry of the hydrogen atom and the isospin symmetry in nuclei. Two nuclear models, the shell model and the interacting boson model, are reviewed with particular emphasis on their use of group-theoretical techniques.
On the Method of Multiplier-enlargement and Approximation of Unbounded Continuous Functions
Institute of Scientific and Technical Information of China (English)
ZHENG Cheng-De; WANG Ren-Hong
2001-01-01
By combining the classical appropriate functions “1, x, x2” with the method of multiplier enlargement, this paper establishes a theorem to approximate any unbounded continuous functions with modified positive linear operators. As an example, Hermite-Fejéinterpolation polynomial operators are analysed and studied, and a general conclusion is obtained.
Population of neutron unbound states via two-proton knockout reactions
Frank, N; Bazin, D; Gade, A; Lecouey, J -L; Peters, W A; Scheit, H; Schiller, A; Thoennessen, M; Brown, J; DeYoung, P A; Finck, J E; Hinnefeld, J; Howes, R; Luther, B
2007-01-01
The two-proton knockout reaction 9Be(26Ne,O2p) was used to explore excited unbound states of 23O and 24O. In 23O a state at an excitation energy of 2.79(13) MeV was observed. There was no conclusive evidence for the population of excited states in 24O.
EXISTENCE OF SOLUTIONS FOR QUASILINEAR ELLIPTIC EQUATIONS WITH UNBOUNDED COEFFICIENTS ON RN
Institute of Scientific and Technical Information of China (English)
Wei Gongming
2008-01-01
In this paper a class of p-Laplace type elliptic equations with unbounded coefficients on RN is considered.It is proved that there exist radial solutions on RN.On sufiiciently large ball,radial and nonradial solutions axe obtained.Finally,some necessary conditions for the existence of solutions axe given.
Directory of Open Access Journals (Sweden)
Maria Transirico
2008-10-01
Full Text Available This paper is concerned with the study of the Dirichlet problem for a class of second-order linear elliptic equations in weighted Sobolev spaces on unbounded domains of Ã¢Â„Ân, nÃ¢Â‰Â¥3. We state a regularity result and we can deduce an existence and uniqueness theorem.
Directory of Open Access Journals (Sweden)
Boccia Serena
2008-01-01
Full Text Available This paper is concerned with the study of the Dirichlet problem for a class of second-order linear elliptic equations in weighted Sobolev spaces on unbounded domains of , . We state a regularity result and we can deduce an existence and uniqueness theorem.
Kelkar, N G; Moskal, P
2015-01-01
The possibility for the existence of unstable bound states of the S11 nucleon resonance N$^*$(1535) and nuclei is investigated. These quasibound states are speculated to be closely related to the existence of the quasibound states of the eta mesons and nuclei. Within a simple model for the N N$^*$ interaction involving a pion and eta meson exchange, N$^*$-nucleus potentials for N*-$^3$He and N*-$^{24}$Mg are evaluated and found to be of a Woods-Saxon like form which supports two to three bound states. In case of N*-$^3$He, one state bound by only a few keV and another by 4 MeV is found. The results are however quite sensitive to the N N$^*$ $\\pi$ and N N$^*$ $\\eta$ vertex parameters. A rough estimate of the width of these states, based on the mean free path of the exchanged mesons in the nuclei leads to very broad states with $\\Gamma \\sim$ 80 and 110 MeV for N*-$^3$He and N*-$^{24}$Mg respectively.
Relativistic Mean Field Study on Halo Structures of Mirror Nuclei
Institute of Scientific and Technical Information of China (English)
LIANG Yu-Jie; LI Yan-Song; LIU Zu-Hua; ZHOU Hong-Yu
2009-01-01
Halo structures of some light mirror nuclei are investigated with the relativistic mean field (RMF) theory.The calculations show that the dispersion of the valence proton is larger than that of the valence neutron in its mirror nucleus,the difference between the root-mean-square (rms) radius of the valence nucleon in each pair of mirror nuclei becomes smailer with the increase of the mass number A,and all the ratios of the rms radius of the valence nucleon to that of the matter in each pair o~ mirror nuclei decrease almost linearly with the increase of the mass number A.
Detecting and Identifying Heavy Nuclei and Antinuclei with Standard Detectors
Swain, J; Widom, A; Srivastava, Y N
2011-01-01
Most data gathered from high energy experiments at colliders are analyzed assuming that particles stable enough to not decay in the detector volume, and able to interact strongly or electromagnetically, must be electrons, muons, protons, neutrons, photons, kaons, and charged pions, or their antiparticles. While light nuclei and antinuclei such as (anti)deuterons have been detected, we argue that it is experimentally interesting to look for even heavier nuclei in high energy collisions. To this end, we point out that using only tracking and calorimetry information it is, in principle, possible to also search for high energy nuclei and antinuclei and determine, with errors, their charge Z and atomic weight A.
The intergalactic propagation of ultrahigh energy cosmic ray nuclei
Energy Technology Data Exchange (ETDEWEB)
Hooper, Dan; /Fermilab; Sarkar, Subir; /Oxford U., Theor. Phys.; Taylor, Andrew M.; /Oxford U.
2006-08-01
We investigate the propagation of ultra-high energy cosmic ray nuclei (A = 1-56) from cosmologically distant sources through the cosmic radiation backgrounds. Various models for the injected composition and spectrum and of the cosmic infrared background are studied using updated photodisintegration cross-sections. The observational data on the spectrum and the composition of ultra-high energy cosmic rays are jointly consistent with a model where all of the injected primary cosmic rays are iron nuclei (or a mixture of heavy and light nuclei).
Quantum-Information Content of Fractional Occupation Probabilities in Nuclei
Chatzisavvas, K C
2004-01-01
Three measures of the information content of a probability distribution are briefly reviewed. They are applied to fractional occupation probabilities in light nuclei, taking into account short-range correlations. The effect of short-range correlations is to increase the information entropy (or disorder) of nuclei, comparing with the independent particle model. It is also indicated that the information entropy can serve as a sensitive index of order and short-range correlations in nuclei. It is concluded that increasing $Z$, the information entropy increases i.e. the disorder of the nucleus increases for all measures of information considered in the present work.
Assessing the risk of drug-induced cholestasis using unbound intrahepatic concentrations.
Riede, Julia; Poller, Birk; Huwyler, Jorg; Camenisch, Gian
2017-03-02
Inhibition of the bile salt export pump (BSEP) has been recognized as a key factor in the development of drug-induced cholestasis (DIC). The risk of DIC in human has previously been assessed using in vitro BSEP inhibition data (IC50) and unbound systemic drug exposure under assumption of the "free drug hypothesis". This concept, however, is unlikely valid as unbound intrahepatic drug concentrations are affected by active transport and metabolism. To investigate this hypothesis we experimentally determined the in vitro liver-to-blood partition coefficients (Kp,uu) for 18 drug compounds using the hepatic Extended Clearance Model (ECM). In vitro-in vivo translatability of Kp,uu values was verified for a subset of compounds in rat. Consequently, unbound intrahepatic concentrations were calculated from clinical exposure (systemic and hepatic inlet) and measured Kp,uu data. Using these values, corresponding safety margins against BSEP IC50 values were determined and compared to the clinical incidence of DIC. Depending on the ECM class of a drug, in vitro Kp,uu values deviated up to 14-fold from unity and unbound intrahepatic concentrations were affected accordingly. The use of in vitro Kp,uu-based safety margins allowed to separate clinical cholestasis frequency into three classes (no cholestasis, cholestasis in ≤ 2%, and in > 2% of subjects) for 17 out of 18 compounds. This assessment was significantly superior compared to using unbound extracellular concentrations as a surrogate for intrahepatic concentrations. Furthermore, the assessment of Kpuu according to ECM provides useful guidance for the quantitative evaluation of genetic and physiological risk factors for the development of cholestasis.
Social Cognition Unbound: Insights Into Anthropomorphism and Dehumanization.
Waytz, Adam; Epley, Nicholas; Cacioppo, John T
2010-02-01
People conceive of wrathful gods, fickle computers, and selfish genes, attributing human characteristics to a variety of supernatural, technological, and biological agents. This tendency to anthropomorphize nonhuman agents figures prominently in domains ranging from religion to marketing to computer science. Perceiving an agent to be humanlike has important implications for whether the agent is capable of social influence, accountable for its actions, and worthy of moral care and consideration. Three primary factors-elicited agent knowledge, sociality motivation, and effectance motivation-appear to account for a significant amount of variability in anthropomorphism. Identifying these factors that lead people to see nonhuman agents as humanlike also sheds light on the inverse process of dehumanization, whereby people treat human agents as animals or objects. Understanding anthropomorphism can contribute to a more expansive view of social cognition that applies social psychological theory to a wide variety of both human and nonhuman agents.
Battye, R. A.; Manton, N. S.; Sutcliffe, P. M.
We review recent work on the modelling of atomic nuclei as quantised Skyrmions, using Skyrme's original model with pion fields only. Skyrmions are topological soliton solutions, whose conserved topological charge B is identified with the baryon number of a nucleus. Apart from an energy and length scale, the Skyrme model has just one dimensionless parameter m, proportional to the pion mass. It has been found that a good fit to experimental nuclear data requires m to be of order 1. The Skyrmions for B up to 7 have been known for some time, and are qualitatively insensitive to whether m is zero or of order 1. However, for baryon numbers B = 8 and above, the Skyrmions have quite a compact structure for m of order 1, rather than the hollow polyhedral structure found when m = 0. One finds for baryon numbers which are multiples of four, that the Skyrmions are composed of B = 4 sub-units, as in the α-particle model of nuclei. The rational map ansatz gives a useful approximation to the Skyrmion solutions for all baryon numbers when m = 0. For m of order 1, it gives a good approximation for baryon numbers up to 7, and generalisations of this ansatz are helpful for higher baryon numbers. We briefly review the work from the 1980s and 90s on the semiclassical rigidbody quantisation of Skyrmions for B = 1, 2, 3 and 4. We then discuss more recent work extending this method to B = 6, 7, 8, 10 and 12. We determine the quantum states of the Skyrmions, finding their spins, isospins and parities, and compare with the experimental data on the ground and excited states of nuclei up to mass number 12.
Decay spectroscopy of N < Z nuclei around 100Sn
Park, Joochun (Jason); Eurica Collaboration
2016-09-01
Many interesting topics in both nuclear structure and nuclear astrophysics converge on the doubly-magic nucleus 100Sn and nuclei in its vicinity. Among them are the boundaries of proton dripline, the effect of pn interaction in self-conjugate nuclei, and the decay properties required for rp -process calculations in nucleosynthesis models. Despite many studies, experimental knowledge of these nuclides has remained scarce due to low production cross sections and a lack of intense beams. However, record quantities of exotic N = Z isotopes around 100Sn were produced at RIKEN Radioactive Isotope Beam Factory, via fragmentation of a 124Xe beam on a thin 9Be target. Based on the obtained data, 89Rh and 93Ag have been confirmed to be proton unbound. Half-lives of isotopes near the proton dripline will be presented with improved precision compared to literature values. In addition, strategies to determine Qβ for ft values, and consequently the Fermi/Gamow-Teller transition strengths of these isotope decays will be discussed. Work supported by the Natural Sciences and Engineering Research Council of Canada and the National Research Council of Canada.
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
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
Energy Technology Data Exchange (ETDEWEB)
Ney, E.P.
1982-01-22
Photography of the nucleus of comet Halley is the goal of several planned space missions. The nucleus of a comet is surrounded by a cloud of dust particles. If this cloud is optically thick, it will prevent observation of the nuclear surface. Broadband photometry of nine comets has been analyzed to determine the visibility of their nuclei. Only in the case of comet West near perihelion was the dust dense enough to interfere with imaging. Comparison of the visual brightness of the well-observed comets with that of Halley in 1910 leads to the conclusion that the nucleus of Halley can be imaged without significant obscuration by the dust.
Elusive Active Galactic Nuclei
Maiolino, R; Gilli, R; Nagar, N M; Bianchi, S; Böker, T; Colbert, E; Krabbe, A; Marconi, A; Matt, G; Salvati, M
2003-01-01
A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically "elusive". X-ray observations are an optimal tool to identify this class of objects. We combine new Chandra observations with archival X-ray data in order to obtain a first estimate of the fraction of elusive AGN in local galaxies and to constrain their nature. Our results suggest that elusive AGN have a local density comparable to or even higher than optically classified Seyfert nuclei. Most elusive AGN are heavily absorbed in the X-rays, with gas column densities exceeding 10^24 cm^-2, suggesting that their peculiar nature is associated with obscuration. It is likely that in elusive AGN, the nuclear UV source is completely embedded and the ionizing photons cannot escape, which prevents the formation of a classical Narrow Line Region. Elusive AGN may contribute significantly to the 30 keV bump of the X-ray background.
Electron scattering for exotic nuclei
Indian Academy of Sciences (India)
Toshimi Suda
2014-11-01
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 distributions of short-lived exotic nuclei by elastic electron scattering. The first collision between electrons and exotic nuclei will be observed in the year 2014.
DEFF Research Database (Denmark)
Hejlesen, Mads Mølholm; Spietz, Henrik J.; Walther, Jens Honore
2014-01-01
In resent work we have developed a new FFT based Poisson solver, which uses regularized Greens functions to obtain arbitrary high order convergence to the unbounded Poisson equation. The high order Poisson solver has been implemented in an unbounded particle-mesh based vortex method which uses a re......-meshing of the vortex particles to ensure the convergence of the method. Furthermore, we use a re-projection of the vorticity field to include the constraint of a divergence-free stream function which is essential for the underlying Helmholtz decomposition and ensures a divergence free vorticity field. The high order...... with the principal axis of the strain rate tensor. We find that the dynamics of the enstrophy density is dominated by the local flow deformation and axis of rotation, which is used to infer some concrete tendencies related to the topology of the vorticity field....
Observation of a low-lying neutron-unbound state in {sup 19}C
Energy Technology Data Exchange (ETDEWEB)
Thoennessen, M., E-mail: thoennessen@nscl.msu.edu [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Mosby, S. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Badger, N.S. [Department of Physics, Rhodes College, Memphis, TN 38112 (United States); Baumann, T.; Bazin, D. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Bennett, M. [Department of Physics, Westmont College, Santa Barbara, CA 93108 (United States); Brown, J. [Department of Physics, Wabash College, Crawfordsville, IN 47933 (United States); Christian, G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); DeYoung, P.A. [Department of Physics, Hope College, Holland, MI 49423 (United States); Finck, J.E. [Department of Physics, Central Michigan University, Mt. Pleasant, MI 48859 (United States); Gardner, M. [Department of Physics, Westmont College, Santa Barbara, CA 93108 (United States); Hook, E.A. [Department of Physics, Rhodes College, Memphis, TN 38112 (United States); Luther, B. [Department of Physics, Concordia College, Moorhead, MN 56562 (United States); Meyer, D.A. [Department of Physics, Rhodes College, Memphis, TN 38112 (United States); Mosby, M. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Rogers, W.F. [Department of Physics, Westmont College, Santa Barbara, CA 93108 (United States); and others
2013-08-21
Proton removal reactions from a secondary {sup 22}N beam were utilized to populate unbound states in neutron-rich carbon isotopes. Neutrons were measured with the Modular Neutron Array (MoNA) in coincidence with carbon fragments. A resonance with a decay energy of 76(14) keV was observed in the system {sup 18}C+n corresponding to a state in {sup 19}C at an excitation energy of 653(95) keV. This resonance could correspond to the first 5/2{sup +} state which was recently speculated to be unbound in order to describe 1n and 2n removal cross section measurements from {sup 20}C.
Abboud, Toufic; Joly, Patrick; Rodríguez, Jerónimo; Terrasse, Isabelle
2011-07-01
This work deals with the numerical simulation of wave propagation on unbounded domains with localized heterogeneities. To do so, we propose to combine a discretization based on a discontinuous Galerkin method in space and explicit finite differences in time on the regions containing heterogeneities with the retarded potential method to account the unbounded nature of the computational domain. The coupling formula enforces a discrete energy identity ensuring the stability under the usual CFL condition in the interior. Moreover, the scheme allows to use a smaller time step in the interior domain yielding to quasi-optimal discretization parameters for both methods. The aliasing phenomena introduced by the local time stepping are reduced by a post-processing by averaging in time obtaining a stable and second order consistent (in time) coupling algorithm. We compute the numerical rate of convergence of the method for an academic problem. The numerical results show the feasibility of the whole discretization procedure.
The Properties of Bound and Unbound Molecular Cloud Populations Formed in Galactic Disc Simulations
Ward, Rachel L; Wadsley, James; Sills, Alison; Couchman, H M P
2015-01-01
We explore the effect of galactic environment on properties of molecular clouds. Using clouds formed in a large-scale galactic disc simulation, we measure the observable properties from synthetic column density maps. We confirm that a significant fraction of unbound clouds forms naturally in a galactic disc environment and that a mixed population of bound and unbound clouds can match observed scaling relations and distributions for extragalactic molecular clouds. By dividing the clouds into inner and outer disc populations, we compare their distributions of properties and test whether there are statistically significant differences between them. We find that clouds in the outer disc have lower masses, sizes, and velocity dispersions as compared to those in the inner disc for reasonable choices of the inner/outer boundary. We attribute the differences to the strong impact of galactic shear on the disc stability at large galactocentric radii. In particular, our Toomre analysis of the disc shows a narrowing enve...
Koike, Shigeaki
2010-01-01
We are concerned with fully nonlinear possibly degenerate elliptic partial differential equations (PDEs) with superlinear terms with respect to $Du$. We prove several comparison principles among viscosity solutions which may be unbounded under some polynomial-type growth conditions. Our main result applies to PDEs with convex superlinear terms but we also obtain some results in nonconvex cases. Applications to monotone systems of PDEs are given.
Studies of unbound states in isotopes at the N = 8 shell closure
We propose to study low-lying resonances in the two unbound isotopes $^{13}$Be and $^{10}$Li as well as low-lying resonances in $^{12}$Be. This will be done using an $^{11}$Be beam impinging on a tritium target leading to one- or two-particle transfer reactions. The decay scheme of the resonances will be studied using the MINIBALL and differential cross sections will be determined using T-REX.
Population processes with unbounded extinction rate conditioned to non-extinction
Champagnat, Nicolas; Villemonais, Denis
2016-01-01
This article studies the quasi-stationary behaviour of population processes with unbounded absorption rate, including one-dimensional birth and death processes with catastrophes and multi-dimensional birth and death processes, modeling biological populations in interaction. To handle this situation, we develop original non-linear Lyapunov criteria. We obtain the exponential convergence in total variation of the conditional distributions to a unique quasi-stationary distribution, uniformly wit...
NORM SUMMABILITY OF N(O)RLUND LOGARITHMIC MEANS ON UNBOUNDED VILENKIN GROUPS
Institute of Scientific and Technical Information of China (English)
I.Blahota; G.Gát
2008-01-01
The (N(o)rlund)logarithmic means of the Fburier series is:tnf=1/ln∑n-1k=1Skf/n-k,where ln=∑n-1k=11/k.In general,the Fejér(C,1)means have better propeaies than the logarithmic ones.We compare them and show that in the case of some unbounded Vilenkin systems the situation changes.
Indian Academy of Sciences (India)
P N Shankar
2006-08-01
The recently suggested embedding method to solve linear boundary value problems is here extended to cover situations where the domain of interest is unbounded or multiply connected. The extensions involve the use of complete sets of exterior and interior eigenfunctions on canonical domains. Applications to typical boundary value problems for Laplace’s equation, the Oseen equations and the biharmonic equation are given as examples.
A Boolean Approach to Unbounded, Fully Symbolic Model Checking of Timed Automata
2003-03-01
reachability properties (these can express safety and bounded-liveness properties [1]). Uppaal2k and Kronos are unbounded, symbolic model checkers that...explicitly enumerate the discrete component of the state space. Kronos uses Difference Bound Matrices (DBMs) as the symbolic representation [19] of the...difference. Note that while Kronos can check arbitrary TCTL formulas, Uppaal2k is limited to checking reachability properties and very restricted liveness
Gyroscope precession along unbound equatorial plane orbits around a Kerr black hole
Bini, Donato; Jantzen, Robert T
2016-01-01
The precession of a test gyroscope along unbound equatorial plane geodesic orbits around a Kerr black hole is analyzed with respect to a static reference frame whose axes point towards the "fixed stars." The accumulated precession angle after a complete scattering process is evaluated and compared with the corresponding change in the orbital angle. Limiting results for the non-rotating Schwarzschild black hole case are also discussed.
Directory of Open Access Journals (Sweden)
Xia Liu
2017-02-01
Full Text Available The discrete nonlinear Schrodinger equation is a nonlinear lattice system that appears in many areas of physics such as nonlinear optics, biomolecular chains and Bose-Einstein condensates. In this article, we consider a class of discrete nonlinear Schrodinger equations with unbounded potentials. We obtain some new sufficient conditions on the multiplicity results of ground state solutions for the equations by using the symmetric mountain pass lemma. Recent results in the literature are greatly improved.
Nagaya, Yoko; Nozaki, Yoshitane; Kobayashi, Kazumasa; Takenaka, Osamu; Nakatani, Yosuke; Kusano, Kazutomi; Yoshimura, Tsutomu; Kusuhara, Hiroyuki
2014-01-01
In central nervous system drug discovery, cerebrospinal fluid (CSF) drug concentration (C(CSF)) has been widely used as a surrogate for unbound brain concentrations (C(u,brain)). However, previous rodent studies demonstrated that when drugs undergo active efflux by transporters, such as P-glycoprotein (P-gp), at the blood-brain barrier, the C(CSF) overestimates the corresponding C(u,brain). To investigate the utility of C(CSF) as a surrogate for interstitial fluid (ISF) concentration (C(ISF)) in nonhuman primates, this study simultaneously determined the C(CSF) and C(ISF) of 12 compounds, including P-gp substrates, under steady-state conditions in cynomolgus monkeys using intracerebral microdialysis coupled with cisternal CSF sampling. Unbound plasma concentrations of non- or weak P-gp substrates were within 2.2-fold of the C(ISF) or C(CSF), whereas typical P-gp substrates (risperidone, verapamil, desloratadine, and quinidine) showed ISF-to-plasma unbound (K(p,uu,ISF)) and CSF-to-plasma unbound concentration ratios (K(p,uu,CSF)) that were appreciably lower than unity. Although the K(p,uu,CSF) of quinidine, verapamil, and desloratadine showed a trend of overestimating the K(p,uu,ISF), K(p,uu,CSF) showed a good agreement with K(p,uu,ISF) within 3-fold variations for all compounds examined. C(u,brain) of some basic compounds, as determined using brain homogenates, overestimated the C(ISF) and C(CSF). Therefore, C(CSF) could be used as a surrogate for C(ISF) in nonhuman primates.
Existence Result for a Class of Nonlinear Elliptic Systems on Punctured Unbounded Domains
Directory of Open Access Journals (Sweden)
Fabrice Colin
2010-01-01
Full Text Available We establish the existence of a nontrivial solution for systems with an arbitrary number of coupled Poisson equations with critical growth in punctured unbounded domains. The proof depends on a generalized linking theorem due to Krysewski and Szulkin, and on a concentration-compactness argument, proved by Frigon and the author. Applications to reaction-diffusion systems with skew gradient structure are also discussed in the last section.
An Extension of the Argument Principle and Nyquist Criterion to Systems with Unbounded Generators
2006-04-17
APRIL 17, 2006 1 An Extension of the Argument Principle and Nyquist Criterion to Systems with Unbounded Generators Makan Fardad and Bassam Bamieh...FA9550-04-1-0207 and NSF grant ECS-0323814. M. Fardad and B. Bamieh are with the Department of Mechanical and Environmental Engineering, University of...California, Santa Barbara, CA 93105-5070. email: fardad @engineering.ucsb.edu, bamieh@engineering.ucsb.edu Report Documentation Page Form ApprovedOMB No
VLDL hydrolysis by LPL activates PPAR-alpha through generation of unbound fatty acids.
Ruby, Maxwell A; Goldenson, Benjamin; Orasanu, Gabriela; Johnston, Thomas P; Plutzky, Jorge; Krauss, Ronald M
2010-08-01
Recent evidence suggests that lipoproteins serve as circulating reservoirs of peroxisomal proliferator activated receptor (PPAR) ligands that are accessible through lipolysis. The present study was conducted to determine the biochemical basis of PPAR-alpha activation by lipolysis products and their contribution to PPAR-alpha function in vivo. PPAR-alpha activation was measured in bovine aortic endothelial cells following treatment with human plasma, VLDL lipolysis products, or oleic acid. While plasma failed to activate PPAR-alpha, oleic acid performed similarly to VLDL lipolysis products. Therefore, fatty acids are likely to be the PPAR-alpha ligands generated by VLDL lipolysis. Indeed, unbound fatty acid concentration determined PPAR-alpha activation regardless of fatty acid source, with PPAR-alpha activation occurring only at unbound fatty acid concentrations that are unachievable under physiological conditions without lipase action. In mice, a synthetic lipase inhibitor (poloxamer-407) attenuated fasting-induced changes in expression of PPAR-alpha target genes. Apolipoprotein CIII (apoCIII), an endogenous inhibitor of lipoprotein and hepatic lipase, regulated access to the lipoprotein pool of PPAR-alpha ligands, because addition of exogenous apoCIII inhibited, and removal of endogenous apoCIII potentiated, lipolytic PPAR-alpha activation. These data suggest that the PPAR-alpha response is generated by unbound fatty acids released locally by lipase activity and not by circulating plasma fatty acids.
On one-dimensional compressible Navier-Stokes equations for a reacting mixture in unbounded domains
Li, Siran
2017-10-01
In this paper we consider the one-dimensional Navier-Stokes system for a heat-conducting, compressible reacting mixture which describes the dynamic combustion of fluids of mixed kinds on unbounded domains. This model has been discussed on bounded domains by Chen (SIAM J Math Anal 23:609-634, 1992) and Chen-Hoff-Trivisa (Arch Ration Mech Anal 166:321-358, 2003), among others, in which the reaction rate function is a discontinuous function obeying the Arrhenius' law of thermodynamics. We prove the global existence of weak solutions to this model on one-dimensional unbounded domains with large initial data in H^1. Moreover, the large-time behaviour of the weak solution is identified. In particular, the uniform-in-time bounds for the temperature and specific volume have been established via energy estimates. For this purpose we utilise techniques developed by Kazhikhov-Shelukhin (cf. Kazhikhov in Siber Math J 23:44-49, 1982; Solonnikov and Kazhikhov in Annu Rev Fluid Mech 13:79-95, 1981) and refined by Jiang (Commun Math Phys 200:181-193, 1999, Proc R Soc Edinb Sect A 132:627-638, 2002), as well as a crucial estimate in the recent work by Li-Liang (Arch Ration Mech Anal 220:1195-1208, 2016). Several new estimates are also established, in order to treat the unbounded domain and the reacting terms.
A multi-layered active target for the study of neutron-unbound nuclides at NSCL
Freeman, Jessica; Gueye, Paul; Redpath, Thomas; MoNA Collaboration
2017-01-01
The characteristics of neutron-unbound nuclides were investigated using a multi-layered Si/Be active target designed for use with the MoNA/LISA setup at the National Superconducting Cyclotron (NSCL). The setup consists of the MoNA/LISA arrays (for neutron detection) and a superconducting sweeper magnet (for charged separation) to identify products following the decay of neutron unbound states. The segmented target consisted of three 700 mg/cm2 beryllium targets and four 0.14 mm thick 62x62 mm2 silicon detectors. As a commissioning experiment for the target the decay of two-neutron unbound 26O populated in a one-proton removal reaction from a radioactive 27F beam was performed. The 27F secondary radioactive beam from the NSCL's Coupled Cyclotron Facility was produced from the fragmentation of a 140 MeV/u 48Ca beam incident on a thick beryllium target and then cleanly selected by the A1900 fragment separator. The energy loss and position spectra of the incoming beam and reaction products were used to calibrate the Silicon detectors to within 1.5% in both energy and position. A dedicated Geant4 model of the target was developed to simulate the energy loss within the target. A description of the experimental setup, simulation work, and energy and position calibration will be presented. DoE/NNSA - DE-NA0000979.
Ayala, A P; Levin, E M
1996-01-01
In this talk we present our detail study ( theory and numbers) [1] on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather contraversial 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 [2] and estimate the value of the shadowing corrections in this case. Than 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.
Xu, Renxin
2011-01-01
What is the real nature of pulsars? This is essentially a question of the fundamental strong interaction between quarks at low-energy scale and hence of the non-perturbative quantum chromo-dynamics, the solution of which would certainly be meaningful for us to understand one of the seven millennium prize problems (i.e., "Yang-Mills Theory") named by the Clay Mathematical Institute. After a historical note, it is argued here that a pulsar is very similar to an extremely big nucleus, but is a little bit different from the {\\em gigantic nucleus} speculated 80 years ago by L. Landau. The paper demonstrates the similarity between pulsars and gigantic nuclei from both points of view: the different manifestations of compact stars and the general behavior of the strong interaction.
Nucleomorphs: enslaved algal nuclei.
Cavalier-Smith, T
2002-12-01
Nucleomorphs of cryptomonad and chlorarachnean algae are the relict, miniaturised nuclei of formerly independent red and green algae enslaved by separate eukaryote hosts over 500 million years ago. The complete 551 kb genome sequence of a cryptomonad nucleomorph confirms that cryptomonads are eukaryote-eukaryote chimeras and greatly illuminates the symbiogenetic event that created the kingdom Chromista and their alveolate protozoan sisters. Nucleomorph membranes may, like plasma membranes, be more enduring after secondary symbiogenesis than are their genomes. Partial sequences of chlorarachnean nucleomorphs indicate that genomic streamlining is limited by the mutational difficulty of removing useless introns. Nucleomorph miniaturisation emphasises that selection can dramatically reduce eukaryote genome size and eliminate most non-functional nuclear non-coding DNA. Given the differential scaling of nuclear and nucleomorph genomes with cell size, it follows that most non-coding nuclear DNA must have a bulk-sequence-independent function related to cell volume.
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.
Directory of Open Access Journals (Sweden)
Kazushige Nakagawa
2009-11-01
Full Text Available The Phragmen-Lindelof theorem for Lp-viscosity solutions of fully nonlinear second order elliptic partial differential equations with unbounded coefficients and inhomogeneous terms is established.
Directory of Open Access Journals (Sweden)
Nele Noppe
2015-03-01
Full Text Available Review of Mizuko Ito, Daisuke Okabe and Izumi Tsuji, eds. Fandom unbound: Otaku culture in a connected world. New Haven, CT: Yale University Press, 2012, Kindle edition, $35; paperback, $38 (352p ISBN 978-0300158649.
te Brake, L H M; Ruslami, R; Later-Nijland, H; Mooren, F; Teulen, M; Apriani, L; Koenderink, J B; Russel, F G; Burger, D M; Alisjahbana, B; Wieringa, F; van Crevel, R; Aarnoutse, R E
2015-01-01
Nutritional status may have a profound impact on the pharmacokinetics of drugs, yet only few data are available for tuberculosis (TB) drugs. As malnutrition occurs frequently among TB patients, we assessed the effect of malnutrition on the steady-state pharmacokinetics of total and protein-unbound rifampin during the intensive phase of TB treatment. In a descriptive pharmacokinetic study in Bandung, Indonesia, patients received a fixed standard rifampin dose of 450 mg once daily during the intensive phase of TB treatment. A full pharmacokinetic curve for rifampin was recorded, and total and unbound concentrations of rifampin were analyzed in all samples. Rifampin pharmacokinetic parameters were compared between severely malnourished (BMI of effect on total and protein-unbound pharmacokinetic parameters of rifampin in Indonesian subjects. The large interindividual variability in the free fraction of rifampin suggests that protein-unbound rather than total rifampin concentrations should preferably be used to study exposure-response relationships.
Energy Technology Data Exchange (ETDEWEB)
Starkov, Konstantin E., E-mail: kstarkov@ipn.mx
2015-07-03
In this paper we study invariant domains with unbounded dynamics for one cosmological Hamiltonian system which is formed by the conformally coupled field; this system was introduced by Maciejewski et al. (2007). We find a few groups of conditions imposed on parameters of this system for which all trajectories are unbounded in both of time directions. Further, we present a few groups of other conditions imposed on system parameters under which we localize the invariant domain with unbounded dynamics; this domain is defined with help of bounds for values of the Hamiltonian level surface parameter. We describe one group of conditions when our system possesses two periodic orbits found explicitly. In some of rest cases we get localization bounds for compact invariant sets. - Highlights: • Equations for periodic orbits are got for many level sets. • Domains with unbounded dynamics are localized. • Localizations for compact invariant sets are obtained.
Cavitation inception from bubble nuclei
DEFF Research Database (Denmark)
Mørch, Knud Aage
2015-01-01
, and experimental investigations of bubbles and cavitation inception have been presented. These results suggest that cavitation nuclei in equilibrium are gaseous voids in the water, stabilized by a skin which allows diffusion balance between gas inside the void and gas in solution in the surrounding liquid....... 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......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...
New measurements of high-momentum nucleons and short-range structures in nuclei
Fomin, N; Asaturyan, R; Benmokhtar, F; Boeglin, W; Bosted, P; Bruell, A; Bukhari, M H S; Chudakov, E; Clasie, B; Connell, S H; Dalton, M M; Daniel, A; Day, D B; Dutta, D; Ent, R; Fassi, L El; Fenker, H; Filippone, B W; Garrow, K; Gaskell, D; Hill, C; Holt, R J; Horn, T; Jones, M K; Jourdan, J; Kalantarians, N; Keppel, C E; Kiselev, D; Kotulla, M; Lindgren, R; Lung, A F; Malace, S; Markowitz, P; McKee, P; Meekins, D G; Mkrtchyan, H; Navasardyan, T; Niculescu, G; Opper, A K; Perdrisat, C; Potterveld, D H; Punjabi, V; Qian, X; Reimer, P E; Roche, J; Rodriguez, V M; Rondon, O; Schulte, E; Seely, J; Segbefia, E; Slifer, K; Smith, G R; Solvignon, P; Tadevosyan, V; Tajima, S; Tang, L; Testa, G; Trojer, R; Tvaskis, V; Vulcan, W F; Wasko, C; Wesselmann, F R; Wood, S A; Wright, J; Zheng, X
2011-01-01
We present new, high-Q^2 measurements of inclusive electron scattering from high-momentum nucleons in nuclei. This yields an improved extraction of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data extend to the kinematic regime where three-nucleon correlations are expected to dominate and we observe significantly greater strength in this region than previous measurements.
Superheavy nuclei – cold synthesis and structure
Indian Academy of Sciences (India)
Raj K Gupta
2001-08-01
The quantum mechanical fragmentation theory (QMFT), given for the cold synthesis of new and superheavy elements, is reviewed and the use of radioactive nuclear beams (RNB) and targets (RNT) is discussed. The QMFT is a complete theory of cold nuclear phenomena, namely, the cold ﬁssion, cold fusion and cluster radioactivity. Also, the structure calculations based on the axially deformed relativistic mean ﬁeld (DRMF) approach are presented which predict new regions of spherical magicity, namely = 120 and = 172 or 184, for superheavy nuclei. This result is discussed in the light of recent experiments reporting the cold synthesis of = 118 element.
Reactions and structure of exotic nuclei
Energy Technology Data Exchange (ETDEWEB)
Esbensen, H.
1993-08-01
Radioactive beam experiments have made it possible to study the structure of light neutron rich nuclei. A characteristic feature is a large dipole strength near threshold. An excellent example is the loosely bound nucleus ``Li for which Coulomb dissociation plays a dominant role in breakup reactions on a high Z target. I will describe a three-body model and apply it to calculate the dipole response of {sup 11}Li and the momentum distributions for the three-body breakup reaction: {sup 11}Li {yields} {sup 9}Li+n+n, and comparisons will be made to recent three-body coincidence measurements.
The cochlear nuclei of snakes.
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
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.
Energy Technology Data Exchange (ETDEWEB)
Ayala, A.L. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica][Pelotas Univ., RS (Brazil). Inst. de Fisica e Matematica; Ducati, M.B.G. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Levin, E.M. [Fermi National Accelerator Lab., Batavia, IL (United States)][Nuclear Physics Inst., St. Petersburg (Russian Federation)
1996-10-01
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.
Benedetto, Andrea; D'Amico, Fabrizio; Tosti, Fabio
2013-04-01
It is well known that inter-particle friction and cohesion of soil particles and aggregates deeply affect the strength and deformation properties of soils, exerting critical effects on the bearing capacity of unbound pavement materials. In that respect, considering that strength characteristics of soil are highly dependent on particle interactions, and assuming a relationship between electric properties (e.g. electric permittivity) and bulk density of materials, a good correlation between mechanical and electric characteristics of soil is expected. In this work, Ground Penetrating Radar (GPR) techniques are used to investigate this topic. Two GPR equipment with same electronic characteristics and different survey configurations are used. Each radar operates with two ground-coupled antennae at 600 MHz and 1600 MHz central frequencies. Measurements are developed using 4 channels, 2 mono-static and 2 bi-static. The received signal is sampled in the time domain at dt = 7.8125 × 10-2 ns, and in the space domain every 2.4 × 10-2 m. A semi-empirical model is proposed for predicting the resilient modulus of sub-asphalt layers from GPR-derived data. Basically, the method requires to follow two steps. Firstly, laboratory tests are carried out for calibration, with the main focus to provide consistent empirical relationships between physical (e.g. bulk density) and electric properties. The second step is focused on the in-situ validation of results through soil strength measurements retrieved by CBR tests and Light Falling Weight Deflectometer (LFWD). On the basis of traditional empirical equations used for flexible pavement design, the following expression is proposed: -m Ei = αj?hj,i j=1 where Ei [MPa] is the ith expected resilient modulus of the surveyed soil under the line of scan, hj,i [m] is the ith thickness referred to the jth layer, and αj is a dielectric parameter calibrated as a function of the relative electric permittivity. The experimental setting requires
Description of Superdeformed Bands of the Nuclei in A ～ 60 Mass Region
Institute of Scientific and Technical Information of China (English)
刘玉鑫; 孟祥明
2003-01-01
Using the supersymmetry scheme including many-body interactions, we investigate the superdeformed (SD) bands of the nuclei in A ～ 60 mass region systematically. Quantitatively good results of the γ-ray energy spectra and the dynamical moments of inertia are obtained. It shows that the supersymmetry approach is powerful to describe the generic rotational property of SD states of light nuclei.
Status and Perspectives of the Search for Eta-Mesic Nuclei
Moskal, Pawel; Krzemien, Wojciech
2016-01-01
In this report the search for eta-mesic nuclei is reviewed. The brief description of the experimental studies is presented with a focus on the possible production of the eta-nucleus bound states for light nuclei like 4He and 3He.
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.
Spectroscopy of heavy fissionable nuclei
Indian Academy of Sciences (India)
S K Tandel
2015-09-01
Structural studies of heavy nuclei are quite challenging due to increased competition from fission, particularly at high spins. Nuclei in the actinide region exhibit a variety of interesting phenomena. Recent advances in instrumentation and analysis techniques have made feasible sensitive measurements of nuclei populated with quite low cross-sections. These include isomers and rotational band structures in isotopes of Pu ( = 94) to Rf ( = 104), and octupole correlations in the Th ( = 90) region. The obtained experimental data have provided insights on various aspects like moments of inertia and nucleon alignments at high spins, quasiparticle energies and evolution of quadrupole and octupole collectivity, among others. An overview of some of these results is presented.
Parshall, Karen Hunger
2002-01-01
Although today's mathematical research community takes its international character very much for granted, this "global nature" is relatively recent, having evolved over a period of roughly 150 years-from the beginning of the nineteenth century to the middle of the twentieth century. During this time, the practice of mathematics changed from being centered on a collection of disparate national communities to being characterized by an international group of scholars for whom the goal of mathematical research and cooperation transcended national boundaries. Yet, the development of an international community was far from smooth and involved obstacles such as war, political upheaval, and national rivalries. Until now, this evolution has been largely overlooked by historians and mathematicians alike. This book addresses the issue by bringing together essays by twenty experts in the history of mathematics who have investigated the genesis of today's international mathematical community. This includes not only develo...
Statistical Spectroscopy for Neutron-rich sd-Shell Nuclei
Kar, Kamales
2012-01-01
Statistical spectroscopic results using the spectral distribution theory are obtained for the structure of neutron-rich light nuclei going towards the drip line and compared to experimental values available. These results will be useful for nuclear astrophysics problems where often averaged nuclear properties are adequate.
Mukha, I; Grigorenko, L V; Xu, X; Acosta, L; Casarejos, E; Ciemny, A A; Dominik, W; Duénas-Díaz, J; Dunin, V; Espino, J M; Estradé, A; Farinon, F; Fomichev, A; Geissel, H; Golubkova, T A; Gorshkov, A; Janas, Z; Kamiński, G; Kiselev, O; Knöbel, R; Krupko, S; Kuich, M; Litvinov, Yu A; Marquinez-Durán, G; Martel, I; Mazzocchi, C; Nociforo, C; Ordúz, A K; Pfützner, M; Pietri, S; Pomorski, M; Prochazka, A; Rymzhanova, S; Sánchez-Benítez, A M; Scheidenberger, C; Sharov, P; Simon, H; Sitar, B; Slepnev, R; Stanoiu, M; Strmen, P; Szarka, I; Takechi, M; Tanaka, Y K; Weick, H; Winkler, M; Winfield, J S; Zhukov, M V
2015-11-13
Previously unknown isotopes (30)Ar and (29)Cl have been identified by measurement of the trajectories of their in-flight decay products (28)S+p+p and (28)S+p, respectively. The analysis of angular correlations of the fragments provided information on decay energies and the structure of the parent states. The ground states of (30)Ar and (29)Cl were found at 2.25(-0.10)(+0.15) and 1.8±0.1 MeV above the two- and one-proton thresholds, respectively. The lowest states in (30)Ar and (29)Cl point to a violation of isobaric symmetry in the structure of these unbound nuclei. The two-proton decay has been identified in a transition region between simultaneous two-proton and sequential proton emissions from the (30)Ar ground state, which is characterized by an interplay of three-body and two-body decay mechanisms. The first hint of a fine structure of the two-proton decay of (30)Ar*(2(+)) has been obtained by detecting two decay branches into the ground and first-excited states of the (28)S fragment.
Spreafico, Morena; Jacobson, Matthew P.
2014-01-01
The focus of CNS drug pharmacokinetics programs has recently shifted from determining the total concentrations in brain and blood to considering also unbound fractions and concentrations. Unfortunately, assessing unbound brain exposure experimentally requires demanding in vivo and in vitro studies. We propose a physical model, based on lipid binding and pH partitioning, to predict in silico the unbound volume of distribution in the brain. The model takes into account the partition of a drug into lipids, interstitial fluid and intracellular compartments of the brain. The results are in good agreement with the experimental data, suggesting that the contributions of lipid binding and pH partitioning are important in determining drug exposure in brain. The predicted values are used, together with predictions for plasma protein binding, as corrective terms in a second model to derive the unbound brain to plasma concentration ratio starting from experimental values of total concentration ratio. The calculated values of brain free fraction and passive permeability are also used to qualitatively determine the brain to plasma equilibration time in a model that shows promising results but is limited to a very small set of compounds. The models we propose are a step forward in understanding and predicting pharmacologically relevant exposure in brain starting from compounds’ chemical structure and neuropharmacokinetics, by using experimental total brain to plasma ratios, in silico calculated properties and simple physics-based approaches. The models can be used in central nervous system drug discovery programs for a fast and cheap assessment of unbound brain exposure. For existing compounds, the unbound ratios can be derived from experimental values of total brain to plasma ratios. For both existing and hypothetical compounds, the unbound volume of distribution due to lipid binding and pH partitioning can be calculated starting only from the chemical structure. PMID:23578025
Single-particle and collective motion in unbound deformed 39Mg
Fossez, K.; Rotureau, J.; Michel, N.; Liu, Quan; Nazarewicz, W.
2016-11-01
Background: Deformed neutron-rich magnesium isotopes constitute a fascinating territory where the interplay between collective rotation and single-particle motion is strongly affected by the neutron continuum. The unbound f p -shell nucleus 39Mg is an ideal candidate to study this interplay. Purpose: In this work, we predict the properties of low-lying resonant states of 39Mg, using a suite of realistic theoretical approaches rooted in the open quantum system framework. Method: To describe the spectrum and decay modes of 39Mg we use the conventional shell model, Gamow shell model, resonating group method, density matrix renormalization group method, and the nonadiabatic particle-plus-rotor model formulated in the Berggren basis. Results: The unbound ground state of 39Mg is predicted to be either a Jπ=7/2 - state or a 3/2 - state. A narrow Jπ=7/2 - ground-state candidate exhibits a resonant structure reminiscent of that of its one-neutron halo neighbor 37Mg, which is dominated by the f7 /2 partial wave at short distances and a p3 /2 component at large distances. A Jπ=3/2 - ground-state candidate is favored by the large deformation of the system. It can be associated with the 1/2 -[321 ] Nilsson orbital dominated by the ℓ =1 wave; hence its predicted width is large. The excited Jπ=1/2 - and 5 /2- states are expected to be broad resonances, while the Jπ=9/2 - and 11/2 - members of the ground-state rotational band are predicted to have very small neutron decay widths. Conclusion: We demonstrate that the subtle interplay between deformation, shell structure, and continuum coupling can result in a variety of excitations in an unbound nucleus just outside the neutron drip line.
Pseudospin Dynamical Symetry in Nuclei
Ginocchio, Joseph N
2014-01-01
Pseudospin symmetry has been useful in understanding atomic nuclei. We review the arguments that this symmetry is a relativistic symmetry. The condition for this symmetry is that the sum of the vector and scalar potentials in the Dirac Hamiltonian is a constant. We give the generators of pseudospin symmetry. We review some of the predictions that follow from this insight into the relativistic origins of pseudospin symmetry. Since in nuclei the sum of the scalar and vector potentials is not zero but is small, we discuss preliminary investigations into the conditions on the potentials to produce partial dynamic pseudospin symmetry. Finally we show that approximate pseudospin symmetry in nuclei predicts approximate spin symmetry in anti-nucleon scattering from nuclei.
Physics with loosely bound nuclei
Indian Academy of Sciences (India)
Chhanda Samanta
2001-08-01
The essential aspect of contemporary physics is to understand properties of nucleonic matter that constitutes the world around us. Over the years research in nuclear physics has provided strong guidance in understanding the basic principles of nuclear interactions. But, the scenario of nuclear physics changed drastically as the new generation of accelerators started providing more and more rare isotopes, which are away from the line of stability. These weakly bound nuclei are found to exhibit new forms of nuclear matter and unprecedented exotic behaviour. The low breakup thresholds of these rare nuclei are posing new challenges to both theory and experiments. Fortunately, nature has provided a few loosely bound stable nuclei that have been studied thoroughly for decades. Attempts are being made to ﬁnd a consistent picture for the unstable nuclei starting from their stable counterparts. Some signiﬁcant differences in the structure and reaction mechanisms are found.
A Fourier-based elliptic solver for vortical flows with periodic and unbounded directions
Chatelain, Philippe; Koumoutsakos, Petros
2010-04-01
We present a computationally efficient, adaptive solver for the solution of the Poisson and Helmholtz equation used in flow simulations in domains with combinations of unbounded and periodic directions. The method relies on using FFTs on an extended domain and it is based on the method proposed by Hockney and Eastwood for plasma simulations. The method is well-suited to problems with dynamically growing domains and in particular flow simulations using vortex particle methods. The efficiency of the method is demonstrated in simulations of trailing vortices.
Coupled-cluster computations of unbound states in neutron rich calcium isotopes
Hagen, Gaute
2014-09-01
In this talk I will present microscopic coupled-cluster computations of weakly bound and unbound states in the neutron rich calcium region. Starting from state-of-the-art nucleon-nucleon and schematic three-nucleon forces, the role of continuum on ordering of states close to and above the threshold is discussed. In particular several new level orderings are predicted that contrast the naïve shell-model ordering of states. We also discuss the possibility for Efimov physics around the very neutron rich calcium-62 by merging input from coupled-cluster calculations with halo effective-field-theory.
Directory of Open Access Journals (Sweden)
Т. Horsin
2014-01-01
Full Text Available We consider an optimal control problem associated to Dirichlet boundary valueproblem for linear elliptic equations on a bounded domain Ω. We take the matrixvalued coecients A(x of such system as a control in L1(Ω;RN RN. One of the important features of the admissible controls is the fact that the coecient matrices A(x are non-symmetric, unbounded on Ω, and eigenvalues of the symmetric part Asym = (A + At=2 may vanish in Ω.
Steady flow for shear thickening fluids in domains with unbounded sections
Dias, Gilberlandio J.
2017-02-01
We solve the stationary Stokes and Navier-Stokes equations for non-Newtonian incompressible fluids with shear dependent viscosity in domains with outlets containing unbounded cross sections, in the case of shear thickening viscosity. The flux assumes arbitrary given values and the growth of the cross sections are analyzed under different convergence hypotheses, inclusive the growth of Dirichlet's integral of the velocity field is deeply related the convergence hypotheses of such sections. We extend the results of the section 4 of [12, Ladyzhenskaya and Solonnikov] (for Newtonian fluids) to non-Newtonian fluids using the techniques found in [3, Dias and Santos].
Favorov, S
2012-01-01
We introduce a new geometric characteristic of compact sets on the plane called $r$-convexity, which fits nicely into the concept of generalized convexity and extends essentially the conventional convexity. For a class of subharmonic functions on unbounded domains with $r$-convex compact complement, with the growth governed by the distance to the boundary, we obtain the Blaschke--type condition for their Riesz' measures. The result is applied to the study of the convergence of the discrete spectrum for the Schatten-von Neumann perturbations.
II. Unbound versus total serum gold concentration: pharmacological actions on cellular function.
Lorber, A; Kunishima, D H; Harralson, A F; Simon, T M
1983-08-01
Unbound serum gold (UBSG) has received little attention, possibly because of rapid in vivo decay and in vivo concentration below the range of existing analytical procedures. We have recently developed a methodology enabling quantitation and study of UBSG during chrysotherapy to assess effects on cellular functions. UBSG after gold administration is labile, declining rapidly after attaining peak values at which lymphocyte mitogen response and polymorphonuclear phagocytosis were observed to be suppressed. Oral gold, i.e., auranofin, 3 mg BID as compared to systemic chrysotherapy 50 mg/wk, resulted in a higher percentage of UBSG to total serum gold.
On the vanishing electron-mass limit in plasma hydrodynamics in unbounded media
Donatelli, Donatella; Novotny, Antonin
2011-01-01
We consider the zero-electron-mass limit for the Navier-Stokes-Poisson system in unbounded spatial domains. Assuming smallness of the viscosity coefficient and ill-prepared initial data, we show that the asymptotic limit is represented by the incompressible Navier-Stokes system, with a Brinkman damping, in the case when viscosity is proportional to the electron-mass, and by the incompressible Euler system provided the viscosity is dominated by the electron mass. The proof is based on the RAGE theorem and dispersive estimates for acoustic waves, and on the concept of suitable weak solutions for the compressible Navier-Stokes system.
Single scale cluster expansions with applications to many Boson and unbounded spin systems
Energy Technology Data Exchange (ETDEWEB)
Lohmann, Martin, E-mail: mlohmann@math.ethz.ch [Departement Mathematik, ETH Zürich, Zürich (Switzerland)
2015-06-15
We develop a cluster expansion to show exponential decay of correlations for quite general single scale spin systems, as they arise in lattice quantum field theory and discretized functional integral representations for observables of quantum statistical mechanics. We apply our results to the small field approximation to the coherent state correlation functions of the grand canonical Bose gas at negative chemical potential, constructed by Balaban et al. [Ann. Henri Poincaré 11, 151–350 (2010c)], and to N component unbounded spin systems with repulsive two body interaction and massive, possibly complex, covariance. Our cluster expansion is derived by a single application of the Brydges-Kennedy-Abdesselam-Rivasseau interpolation formula.
Navier-Stokes calculations for vortex rings in an unbounded domain
Ishii, Katsuya; Kuwahara, Kunio; Liu, C. H.
1993-01-01
A computational code for the vorticity-potential method is developed for a three-dimensional bounded vorticity field. The evaluation of the boundary data for the vector potential in the code is improved so that the numerical solution simulates that in an unbounded domain to a high order. The time evolution of two vortex rings and that of an elliptic ring are investigated with this code. The cut-and-connect phenomena of vortex rings are successfully captured. The results are compared with those of asymptotic theory and the experiment. They also highlight the need for additional theoretical and numerical investigations.
Simple eigenvectors of unbounded operators of the type “normal plus compact”
Directory of Open Access Journals (Sweden)
Michael Gil'
2015-01-01
Full Text Available The paper deals with operators of the form \\(A=S+B\\, where \\(B\\ is a compact operator in a Hilbert space \\(H\\ and \\(S\\ is an unbounded normal one in \\(H\\, having a compact resolvent. We consider approximations of the eigenvectors of \\(A\\, corresponding to simple eigenvalues by the eigenvectors of the operators \\(A_n=S+B_n\\ (\\(n=1,2, \\ldots\\, where \\(B_n\\ is an \\(n\\-dimensional operator. In addition, we obtain the error estimate of the approximation.
Division of Free Nuclei in Rice Endosperm and Its Influencing Factors
Institute of Scientific and Technical Information of China (English)
LIU Man-xi; WANG Zhong; WU Xiao-mei; CHEN Yi-fang; GU Yun-jie
2009-01-01
The division process of endosperm in rice and its influencing factors were investigated. Total dissection, resin embedding and sectioning under light and transmission electron microscopes were used to observe the division patterns of free nuclei and cytological characters of an endosperm. The various division patterns of free nuclei in rice endosperm included mitosis, amitosis, and the mitosis to amitosis change without an interphase. The division velocity of free nuclei in rice endosperm varied with the internucleus distance. Comparing to a cluster, the division velocity increased when the free nuclei were separated from each other. Moderately higher temperatures also enhanced the proliferation and shortened the division cycle of free nuclei in rice endosperm. To a certain extent, nitrogenous fertilizer applied at the booting stage together with a moderate drought treatment accelerated the division of free nuclei as well.
Charge-changing interactions probing point-proton radii of nuclei
Directory of Open Access Journals (Sweden)
Yamaki S.
2014-03-01
Full Text Available The question of whether charge-changing interactions can be used to probe point-proton radii of nuclei remains unanswered. Charge-changing cross sections, σcc, were systematically investigated using stable and unstable nuclear beams of intermediateenergy. The ratios of the experimental σcc values to the calculated ones obtained from a phenomenological Glauber-type model analysis are found to be nearly constant in a broad range of Z/N for light neutron-rich nuclei. This enables the determination of density distributions, i.e., the radii of protons tightly bound in nuclei. To test the applicability of the present method to all nuclei in the nuclear chart, extensive measurements were performed for medium-mass nuclei ranging from Z = 18 to 32. The present study suggests the potential capability of a new experimental approach for exploring exotic nuclei.
Gamma Decay of Unbound Neutron-Hole States in 133Sn
Vaquero, V.; Jungclaus, A.; Doornenbal, P.; Wimmer, K.; Gargano, A.; Tostevin, J. A.; Chen, S.; Nácher, E.; Sahin, E.; Shiga, Y.; Steppenbeck, D.; Taniuchi, R.; Xu, Z. Y.; Ando, T.; Baba, H.; Garrote, F. L. Bello; Franchoo, S.; Hadynska-Klek, K.; Kusoglu, A.; Liu, J.; Lokotko, T.; Momiyama, S.; Motobayashi, T.; Nagamine, S.; Nakatsuka, N.; Niikura, M.; Orlandi, R.; Saito, T.; Sakurai, H.; Söderström, P. A.; Tveten, G. M.; Vajta, Zs.; Yalcinkaya, M.
2017-05-01
Excited states in the nucleus 133Sn, with one neutron outside the double magic 132Sn core, were populated following one-neutron knockout from a 134Sn beam on a carbon target at relativistic energies at the Radioactive Isotope Beam Factory at RIKEN. Besides the γ rays emitted in the decay of the known neutron single-particle states in 133Sn additional γ strength in the energy range 3.5-5.5 MeV was observed for the first time. Since the neutron-separation energy of 133Sn is low, Sn=2.402 (4 ) MeV , this observation provides direct evidence for the radiative decay of neutron-unbound states in this nucleus. The ability of electromagnetic decay to compete successfully with neutron emission at energies as high as 3 MeV above threshold is attributed to a mismatch between the wave functions of the initial and final states in the latter case. These findings suggest that in the region southeast of 132Sn nuclear structure effects may play a significant role in the neutron versus γ competition in the decay of unbound states. As a consequence, the common neglect of such effects in the evaluation of the neutron-emission probabilities in calculations of global β -decay properties for astrophysical simulations may have to be reconsidered.
Note on a modified return period scale for upper-truncated unbounded flood distributions
Bardsley, Earl
2017-01-01
Probability distributions unbounded to the right often give good fits to annual discharge maxima. However, all hydrological processes are in reality constrained by physical upper limits, though not necessarily well defined. A result of this contradiction is that for sufficiently small exceedance probabilities the unbounded distributions anticipate flood magnitudes which are impossibly large. This raises the question of whether displayed return period scales should, as is current practice, have some given number of years, such as 500 years, as the terminating rightmost tick-point. This carries the implication that the scale might be extended indefinitely to the right with a corresponding indefinite increase in flood magnitude. An alternative, suggested here, is to introduce a sufficiently high upper truncation point to the flood distribution and modify the return period scale accordingly. The rightmost tick-mark then becomes infinity, corresponding to the upper truncation point discharge. The truncation point is likely to be set as being above any physical upper bound and the return period scale will change only slightly over all practical return periods of operational interest. The rightmost infinity tick point is therefore proposed, not as an operational measure, but rather to signal in flood plots that the return period scale does not extend indefinitely to the right.
An Exact Equilibrium Model of an Unbound Stellar System in a Tidal Field
Fellhauer, M
2005-01-01
Star clusters and dwarf galaxies gradually dissolve as they move in the potential of their host galaxy. Once their density falls below a certain critical density (which is comparable with the background density of the galaxy) it is often assumed that their evolution is completed. In fact the remnant of such a system forms a distribution of stars which are unbound to each other and which move on similar orbits in their host potential. With this motivation we study the evolution of an idealised unbound system and follow its expansion and dissolution in the tidal field of a model galaxy. Initially the stars are uniformly distributed (with a density below the critical density) within an ellipsoidal volume. The system itself travels on a circular orbit within a galaxy modelled as an isothermal sphere. The initial velocities of the stars are chosen by assuming that they move on (three-dimensional) epicycles with guiding centre at the centre of the ellipsoid, though the usual epicyclic theory is altered to account f...
Guillochon, James; Chen, Xian; Johnson, Michael D; Berger, Edo
2015-01-01
The kinetic energy of a star in orbit about a supermassive black hole is a significant fraction of its rest mass energy when its periapse is comparable to its tidal radius. Upon its destruction, a fraction of this energy is extracted and injected into the stellar debris, half of which becomes unbound from the black hole, with the fastest material moving at $\\sim 0.03 c$. In this paper, we present a formalism for determining the fate of these unbound debris streams (UDSs) as they depart from the black hole and interact with the surrounding gas. As the density and velocity varies along the length of a UDS, we find that hydrodynamical drag quickly shapes UDSs into loop-like structures, with the densest portions of the streams leading portions of lower density. As UDSs travel outwards, their drag against the ISM increases quadratically with distance, which causes UDSs to deposit their momentum and energy into the ambient medium before the surrounding shocked ISM has a chance to cool. This sudden injection of $\\si...
Unbound Excited States of the N = 16 Closed Shell Nucleus 24O
Rogers, W. F.; MoNA Collaboration
2015-10-01
The energies of two low-lying neutron-unbound excited states of 24O, which were populated by proton-knockout reactions on 26F, have been measured using the MoNA and LISA arrays in combination with the Sweeper Magnet at the Coupled Cyclotron Facility at the NSCL using invariant mass spectroscopy. The current measurement confirms for the first time the separate identity of 2+ and (1+) neutron-unbound excited states in 24O with decay energies 0.51(5) MeV state and 1.20(7) MeV, respectively, to the 23O ground state. These measured decay energies are consistent with two previous lower resolution measurements to within 2 σ. The level energies for the two states are computed using the decay energies and the 1-neutron separation energy for 24O, resulting in 4.70(15) MeV for the 2+ state and 5.39(16) MeV for the (1+) state. Errors in the level energies are dominated by uncertainty in the 24O neutron separation energy, underscoring the need for a higher resolution 24O ground state mass measurement. Results will be compared with 3 phenomenological and 2 ab initio model calculations. Work Supported by NSF Grants PHY-0922335, PHY-0922409, PHY-0922446, PHY-0922462, PHY-0922473, PHY-0922537, PHY-0922559, PHY-0922622, PHY-0922794, PHY-0969173, PHY-1101745, PHY-1205357, PHY- 1205537.
Multiple μ-stability of neural networks with unbounded time-varying delays.
Wang, Lili; Chen, Tianping
2014-05-01
In this paper, we are concerned with a class of recurrent neural networks with unbounded time-varying delays. Based on the geometrical configuration of activation functions, the phase space R(n) can be divided into several Φη-type subsets. Accordingly, a new set of regions Ωη are proposed, and rigorous mathematical analysis is provided to derive the existence of equilibrium point and its local μ-stability in each Ωη. It concludes that the n-dimensional neural networks can exhibit at least 3(n) equilibrium points and 2(n) of them are μ-stable. Furthermore, due to the compatible property, a set of new conditions are presented to address the dynamics in the remaining 3(n)-2(n) subset regions. As direct applications of these results, we can get some criteria on the multiple exponential stability, multiple power stability, multiple log-stability, multiple log-log-stability and so on. In addition, the approach and results can also be extended to the neural networks with K-level nonlinear activation functions and unbounded time-varying delays, in which there can store (2K+1)(n) equilibrium points, (K+1)(n) of them are locally μ-stable. Numerical examples are given to illustrate the effectiveness of our results.
Single-particle and collective motion in unbound deformed $ ^{39}\\text{Mg} $
Fossez, K; Michel, N; Liu, Quan; Nazarewicz, W
2016-01-01
Background: Deformed neutron-rich magnesium isotopes constitute a fascinating territory where the interplay between collective rotation and single-particle motion is strongly affected by the neutron continuum. The unbound $fp$-shell nucleus $ ^{39}\\text{Mg} $ is an ideal candidate to study this interplay. Purpose: In this work, we predict the properties of low-lying resonant states of $ ^{39}\\text{Mg} $, using a suite of realistic theoretical approaches rooted in the open quantum system framework. Method: To describe the spectrum and decay modes of $ ^{39}\\text{Mg} $ we use the conventional Shell Model, Gamow Shell Model, Resonating Group Method, Density Matrix Renormalization Group method, and the non-adiabatic Particle-Plus-Rotor model formulated in the Berggren basis. Results: The unbound ground state of $ ^{39}\\text{Mg} $ is predicted to be either a $ J^{\\pi} = {7/2}^- $ state or a $ {3/2}^- $ state. A narrow $ J^{\\pi} = {7/2}^- $ ground-state candidate exhibits a resonant structure reminiscent of that of...
Chen, Wen-Yau; Lai, Jeng-You; Young, D. L.
2010-11-01
Asymptotic and transient stability analyses of unbounded uniform granular shear flow at high solids volume fractions were carried out in the paper, based on a model composed of the viscoplastic constitutive law [P. Jop, Y. Forterre, and O. Pouliquen, Nature (London) 441, 727 (2006)] and the dilatancy law [O. Pouliquen et al., J. Stat. Mech.: Theory Exp. (2006) P07020]. We refer to this model as the VPDL (meaning of the "viscoplastic and dilatancy laws") thereinafter. In this model, dense granular flows were treated as a viscoplastic fluid with a Drucker-Prager-like yielding criterion. We compared our results to those obtained using the frictional-kinetic model (FKM) [M. Alam and P. R. Nott, J. Fluid Mech. 343, 267 (1997)]. Our main result is that unbounded uniform dense granular shear flows are always asymptotically stable at large time based on the VPDL model, at least for two-dimensional perturbations. This is valid for disturbances of layering modes (i.e., the perturbations whose wavenumber vectors are aligned along the transverse coordinate) as well as for nonlayering modes (the streamwise component of the wavenumber vector is nonzero). By contrast, layering modes can be unstable based on the FKM constitutive laws. Interestingly, in the framework of the VPDL, the analysis shows that significant transient growth may occur owing to the non-normality of the linear system, although disturbances eventually decay at large time.
Directory of Open Access Journals (Sweden)
Xinsong Yang
2013-01-01
Full Text Available This paper investigates global synchronization in an array of coupled neural networks with time-varying delays and unbounded distributed delays. In the coupled neural networks, limited transmission efficiency between coupled nodes, which makes the model more practical, is considered. Based on a novel integral inequality and the Lyapunov functional method, sufficient synchronization criteria are derived. The derived synchronization criteria are formulated by linear matrix inequalities (LMIs and can be easily verified by using Matlab LMI Toolbox. It is displayed that, when some of the transmission efficiencies are limited, the dynamics of the synchronized state are different from those of the isolated node. Furthermore, the transmission efficiency and inner coupling matrices between nodes play important roles in the final synchronized state. The derivative of the time-varying delay can be any given value, and the time-varying delay can be unbounded. The outer-coupling matrices can be symmetric or asymmetric. Numerical simulations are finally given to demonstrate the effectiveness of the theoretical results.
Unbounded Immersed Interface solver, also for use in Vortex Particle-Mesh methods
Marichal, Yves; Chatelain, Philippe; Winckelmans, Gregoire
2012-11-01
We present a new and efficient algorithm to solve the 2-D Poisson equation in unbounded domain and with complex inner boundaries. It is based on an efficient combination of two components: the Immersed Interface method to enforce the boundary condition on each inner boundary (here using solely 1-D stencil corrections) and the James-Lackner algorithm to compute the outer boundary condition consistent with the unbounded domain solution. The algorithm is here implemented using second order finite differences and is particularized to the computation of potential flow past solid bodies. It is validated, by means of grid convergence studies, on the flow past multiple bodies (some also with circulation). The results confirm the second order accuracy everywhere. The algorithm is self consistent as ``all is done on the grid'' (thus without using a Vortex Panel boundary element method in addition to the grid). The next aim of this work is then to integrate this algorithm in the Vortex Particle-Mesh (VPM) method for the computation of unsteady viscous flows, with boundary layers, detached shear layers and wakes. Preliminary results of the combined methods will also be presented. Research Fellow (PhD student) of the F.R.S.-FNRS of Belgium.
Lim, Koeun; Wang, Wei; Merfeld, Daniel M
2017-07-26
Humans can subjectively yet quantitatively assess choice confidence based on perceptual precision even when a perceptual decision is made without an immediate reward or feedback. However, surprisingly little is known about choice confidence. Here we investigate the dynamics of choice confidence by merging two parallel conceptual frameworks of decision-making, signal detection theory and sequential analyses (i.e., drift diffusion modeling). Specifically, in order to capture end-point statistics of binary choice and confidence, we built on a previous study that defined choice confidence in terms of psychophysics derived from signal detection theory. At the same time, we augmented this mathematical model to include accumulator dynamics of a drift-diffusion model to characterize the time-dependency of the choice behaviors in a standard forced-choice paradigm in which stimulus duration is controlled by the operator. Human subjects performed a subjective visual vertical task, simultaneously reporting binary orientation choice and probabilistic confidence. Both binary choice and confidence experimental data displayed statistics and dynamics consistent with both signal detection theory and evidence accumulation, respectively. Specifically, the computational simulations showed that the unbounded evidence accumulator model fits the confidence data better than the classical bounded model, while bounded and unbounded models were indistinguishable for binary choice data. These results suggest that the brain can utilize mechanisms consistent with signal detection theory - especially when judging confidence without time pressure. Copyright © 2017, Journal of Neurophysiology.
Li, Dongfang; Zhang, Jiwei
2016-10-01
Anomalous diffusion behavior in many practical problems can be described by the nonlinear time-fractional parabolic problems on unbounded domain. The numerical simulation is a challenging problem due to the dependence of global information from time fractional operators, the nonlinearity of the problem and the unboundedness of the spacial domain. To overcome the unboundedness, conventional computational methods lead to extremely expensive costs, especially in high dimensions with a simple treatment of boundary conditions by making the computational domain large enough. In this paper, based on unified approach proposed in [25], we derive the efficient nonlinear absorbing boundary conditions (ABCs), which reformulates the problem on unbounded domain to an initial boundary value problem on bounded domain. To overcome nonlinearity, we construct a linearized finite difference scheme to solve the reduced nonlinear problem such that iterative methods become dispensable. And the stability and convergence of our linearized scheme are proved. Most important, we prove that the numerical solutions are bounded by the initial values with a constant coefficient, i.e., the constant coefficient is independent of the time. Overall, the computational cost can be significantly reduced comparing with the usual implicit schemes and a simple treatment of boundary conditions. Finally, numerical examples are given to demonstrate the efficiency of the artificial boundary conditions and theoretical results of the schemes.
The properties of bound and unbound molecular cloud populations formed in galactic disc simulations
Ward, Rachel L.; Benincasa, Samantha M.; Wadsley, James; Sills, Alison; Couchman, H. M. P.
2016-01-01
We explore the effect of galactic environment on properties of molecular clouds. Using clouds formed in a large-scale galactic disc simulation, we measure the observable properties from synthetic column density maps. We confirm that a significant fraction of unbound clouds forms naturally in a galactic disc environment and that a mixed population of bound and unbound clouds can match observed scaling relations and distributions for extragalactic molecular clouds. By dividing the clouds into inner and outer disc populations, we compare their distributions of properties and test whether there are statistically significant differences between them. We find that clouds in the outer disc have lower masses, sizes, and velocity dispersions as compared to those in the inner disc for reasonable choices of the inner/outer boundary. We attribute the differences to the strong impact of galactic shear on the disc stability at large galactocentric radii. In particular, our Toomre analysis of the disc shows a narrowing envelope of unstable masses as a function of radius, resulting in the formation of smaller, lower mass fragments in the outer disc. We also show that the star formation rate is affected by the environment of the parent cloud, and is particularly influenced by the underlying surface density profile of the gas throughout the disc. Our work highlights the strengths of using galaxy-scale simulations to understand the formation and evolution of cloud properties - and the star formation within them - in the context of their environment.
From heavy nuclei to super-heavy nuclei
Theisen, C
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.
Gao, Guang-hua; Sun, Zhi-zhong; Zhang, Ya-nan
2012-04-01
One-dimensional fractional anomalous sub-diffusion equations on an unbounded domain are considered in our work. Beginning with the derivation of the exact artificial boundary conditions, the original problem on an unbounded domain is converted into mainly solving an initial-boundary value problem on a finite computational domain. The main contribution of our work, as compared with the previous work, lies in the reduction of fractional differential equations on an unbounded domain by using artificial boundary conditions and construction of the corresponding finite difference scheme with the help of method of order reduction. The difficulty is the treatment of Neumann condition on the artificial boundary, which involves the time-fractional derivative operator. The stability and convergence of the scheme are proven using the discrete energy method. Two numerical examples clarify the effectiveness and accuracy of the proposed method.
Almost Everywhere Convergence of Fejér Means of L1 Functions on Rarely Unbounded Vilenkin Groups
Institute of Scientific and Technical Information of China (English)
Gy(o)rgy G(A)T
2007-01-01
A highly celebrated problem in dyadic harmonic analysis is the pointwise convergence ofthe author of this paper concerning this. That is, we know the a.e. convergence σnf→f (n→∞)for functions f ∈ Lp, where p＞1 (Journal of Approximation Theory, 101(1), 1-36, (1999)) and alsothe a.e. convergence σMnf→f (n→∞) for functions f ∈ L1 (Journal of Approximation Theory,124(1), 25-43, (2003)). The aim of this paper is to prove the a.e. relation limn→∞σnf = f for eachintegrable function f on any rarely unbounded Vilenkin group. The concept of the rarely unboundedVilenkin group is discussed in the paper. Basically, it means that the generating sequence m may bean unbounded one, but its "big elements" are not "too dense".
A high-throughput cell-based method to predict the unbound drug fraction in the brain.
Mateus, André; Matsson, Pär; Artursson, Per
2014-04-10
Optimization of drug efficacy in the brain requires understanding of the local exposure to unbound drug at the site of action. This relies on measurements of the unbound drug fraction (fu,brain), which currently requires access to brain tissue. Here, we present a novel methodology using homogenates of cultured cells for rapid estimation of fu,brain. In our setup, drug binding to human embryonic kidney cell (HEK293) homogenate was measured in a small-scale dialysis apparatus. To increase throughput, we combined drugs into cassettes for simultaneous measurement of multiple compounds. Our method estimated fu,brain with an average error of 1.9-fold. We propose that our simple method can be used as an inexpensive, easily available and high-throughput alternative to brain tissues excised from laboratory animals. Thereby, estimates of unbound drug exposure can now be implemented at a much earlier stage of the drug discovery process, when molecular property changes are easier to make.
Exotic decay of hot rotating nuclei near proton drip line
Ray, J.; Datta Pramanik, U.; Bhowmik, R. K.; Ray, I.; Rahaman, A.; Chakraborty, A.; Chakraborty, S.; Garg, R.; Goyal, S.; Ganguly, S.; Kumar, S.; Mandal, S.; Mukherjee, B.; Mukherjee, P.; Muralithar, S.; Negi, D.; Saxena, M.; Selvakumar, K.; Singh, P.; Singh, A. K.; Singh, R. P.
2014-03-01
Hot and rotating exotic 124Ce nucleus near proton drip line has been populated through fusion evaporation reaction of 32S and 92Mo. This exotic nucleus was de-excited by evaporating p, n, α and/or light nuclei etc and several exotic nuclei have been populated. The experimentally obtained relative population of those exotic nuclei have been compared with the statistical model calculation. Agreement between experimental and statistical model calculation have been observed for most of the evaporation channels. Huge enhancement in comparison to statistical model calculation have been observed fora few channels related to multiple proton evaporation which could not be explained by using default and modified input parameters in statistical calculation.
Coupled cluster calculations of neutron-rich nuclei
Hagen, Gaute
2016-09-01
In this talk I will present recent highlights from ab initio computations of atomic nuclei using coupled-cluster methods with state-of-the-art interactions from chiral effective field theory (EFT). The recent progress in computing nuclei from scratch is based on new optimizations of interactions from chiral EFT, and ab initio methods with a polynomial computational cost together with available super computing resources. The physics advancements I will discuss include: (i) accurate nuclear binding energies and radii of light and medium-mass nuclei, (ii) the neutron distribution and electric dipole polarizability of the nucleus 48Ca, (iii) and the structure of the rare nucleus 78Ni from first principles. All these quantities are currently targeted by precision measurements worldwide.
Nuclei at extreme conditions. A relativistic study
Energy Technology Data Exchange (ETDEWEB)
Afanasjev, Anatoli [Mississippi State Univ., Mississippi State, MS (United States)
2014-11-14
The major goals of the current project were further development of covariant density functional theory (CDFT), better understanding of its features, its application to different nuclear structure and nuclear astrophysics phenomena and training of graduate and undergraduate students. The investigations have proceeded in a number of directions which are discussed in detail in the part “Accomplishments” of this report. We have studied the role of isovector and isoscalar proton-neutron pairings in rotating nuclei; based on available experimental data it was concluded that there are no evidences for the existence of isoscalar proton-neutron pairing. Generalized theoretical approach has been developed for pycnonuclear reaction rates in the crust of neutron stars and interior of white dwarfs. Using this approach, extensive database for considerable number of pycnonuclear reactions involving stable and neutron-rich light nuclei has been created; it can be used in future for the study of various nuclear burning phenomena in different environments. Time-odd mean fields and their manifestations in terminating states, non-rotating and rotating nuclei have been studied in the framework of covariant density functional theory. Contrary to non-relativistic density functional theories these fields, which are important for a proper description of nuclear systems with broken time-reversal symmetry, are uniquely defined in the CDFT framework. Hyperdeformed nuclear shapes (with semi-axis ratio 2.5:1 and larger) have been studied in the Z = 40-58 part of nuclear chart. We strongly believe that such shapes could be studied experimentally in the future with full scale GRETA detector.
We intend to measure the structure of the unbound nucleus $^{21}$Al via resonance elastic and inelastic scattering with an active target. There are many goals: \\\\ a) to locate the 1/2$^{+}$ level in $^{21}$Al that brings information on the Thomas-Ehrman shift, \\\\ b) to measure the energy spectrum of $^{21}$Al which is a N=8 isotone with the resonance elastic scattering reaction, \\\\ c) to investigate via inelastic scattering the strength of core excitations in the existence of narrow unbound resonances beyond the proton drip-line.
Photodissociation of neutron deficient nuclei
Energy Technology Data Exchange (ETDEWEB)
Sonnabend, K.; Babilon, M.; Hasper, J.; Mueller, S.; Zarza, M.; Zilges, A. [TU Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany)
2006-03-15
The knowledge of the cross sections for photodissociation reactions like e.g. ({gamma}, n) of neutron deficient nuclei is of crucial interest for network calculations predicting the abundances of the so-called p nuclei. However, only single cross sections have been measured up to now, i.e., one has to rely nearly fully on theoretical predictions. While the cross sections of stable isotopes are accessible by experiments using real photons, the bulk of the involved reactions starts from unstable nuclei. Coulomb dissociation (CD) experiments in inverse kinematics might be a key to expand the experimental database for p-process network calculations. The approach to test the accuracy of the CD method is explained. (orig.)
A relativistic symmetry in nuclei
Energy Technology Data Exchange (ETDEWEB)
Ginocchio, J N [MS B283, Theoretical Division, Los Alamos National Laboratory Los Alamos, New Mexico 87545 (Mexico)
2007-11-15
We review some of the empirical and theoretical evidence supporting pseudospin symmetry in nuclei as a relativistic symmetry. We review the case that the eigenfunctions of realistic relativistic nuclear mean fields approximately conserve pseudospin symmetry in nuclei. We discuss the implications of pseudospin symmetry for magnetic dipole transitions and Gamow-Teller transitions between states in pseudospin doublets. We explore a more fundamental rationale for pseudospin symmetry in terms of quantum chromodynamics (QCD), the basic theory of the strong interactions. We show that pseudospin symmetry in nuclei implies spin symmetry for an anti-nucleon in a nuclear environment. We also discuss the future and what role pseudospin symmetry may be expected to play in an effective field theory of nucleons.
Spontaneous fission of superheavy nuclei
Indian Academy of Sciences (India)
R A Gherghescu; D N Poenaru
2015-09-01
The macroscopic–microscopic method is extended to calculate the deformation energy and penetrability for binary 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. The microscopic shell and pairing corrections are obtained using the Strutinsky and BCS approaches and the cranking formulae yield the inertia tensor. Finally, the WKB method is used to calculate penetrabilities and spontaneous fission half-lives. Calculations are performed for the decay of 282,292120 nuclei.
Octupole shapes in heavy nuclei
Energy Technology Data Exchange (ETDEWEB)
Ahmad, I.
1994-08-01
Theoretical calculations and measurements show the presence of strong octupole correlations in thecyround states and low-lying states of odd-mass and odd-odd nuclei in the RaPa region. Evidence for octupole correlations is provided by the observation of parity doublets and reductions in M1 matrix elements, decoupling parameters, and Coriolis matrix elements Involving high-j states. Enhancement of E1 transition rates has also been observed for some of the octupole deformed nuclei. The most convincing argument for octupole deformation is provided by the similarities of the reduced alpha decay rates to the two members of parity doublets.
International Symposium on Exotic Nuclei
Sobolev, Yu G; EXON-2014
2015-01-01
The production and the properties of nuclei in extreme conditions, such as high isospin, temperature, angular momenta, large deformations etc., have become the subject of detailed investigations in all scientific centers. The main topics discussed at the Symposium were: Synthesis and Properties of Exotic Nuclei; Superheavy Elements; Rare Processes, Nuclear Reactions, Fission and Decays; Experimental Facilities and Scientific Projects. This book provides a comprehensive overview of the newest results of the investigations in the main scientific centers such as GSI (Darmstadt, Germany), GANIL (Caen, France), RIKEN (Wako-shi, Japan), MSU (Michigan, USA), and JINR (Dubna, Russia).
Accardi, Alberto
2016-01-01
I review recent progress in the extraction of unpolarized parton distributions in the proton and in nuclei from a unified point of view that highlights how the interplay between high energy particle physics and lower energy nuclear physics can be of mutual benefit to either field. Areas of overlap range from the search for physics beyond the standard model at the LHC, to the study of the non perturbative structure of nucleons and the emergence of nuclei from quark and gluon degrees of freedom, to the interaction of colored probes in a cold nuclear medium.
UNBOUNDED BATCH SCHEDULING WITH A COMMON DUE WINDOW ON A SINGLE MACHINE
Institute of Scientific and Technical Information of China (English)
Hongluan ZHAO; Guojun LI
2008-01-01
The common due window scheduling problem with batching on a single machine is dealt with to minimize the total penalty of weighted earliness and tardiness. In this paper it is assumed that a job incurs no penalty as long as it is completed within the common due window. It is the first time for the due window scheduling to be extended to this situation so that jobs can be processed in batches. An unbounded version of batch scheduling is also considered. Hence, jobs, no matter how many there are, can be processed in a batch once the machine is free. For two cases that the location of due window is either a decision variable or a given parameter, polynomial algorithms are proposed based on several optimal properties.
A comparison of numerical methods for the Rayleigh equation in unbounded domains
Liou, W. W.; Morris, P. J.
1991-01-01
A second-order finite difference and two spectral methods, including a Chebyshev tau and a Chebyshev collocation method were implemented to determine the linear hydrodynamic stability of an unbounded shear flow. The velocity profile of the basic flow in the stability analysis mimicks that of a one-stream free mixing layer. Local and global eigenvalue solution methods are used to determine individual eigenvalues and the eigenvalue spectrum, respectively. The calculated eigenvalue spectrum includes a discrete mode, a continuous spectrum associated with the equation singularity and a continuous spectrum associated with the domain unboundedness. The efficiency and the accuracy of these discretization methods in the prediction of the eigensolutions of the discrete mode were evaluated by comparison with a conventional shooting procedure. Their capabilities in mapping out the continuous eigenvalue spectra are also discussed.
Probing transfer to unbound states of the ejectile with weakly bound 7Li on 93Nb
Pandit, S K; Mahata, K; Keeley, N; Parkar, V V; Rout, P C; Martel, I; Palshetkar, C S; Kumar, A; Ramachandran, K; Patale, P; Chatterjee, A; Kailas, S
2016-01-01
The two-step process of transfer followed by breakup is explored by measuring a rather complete set of exclusive data for reaction channels populating states in the ejectile continua of the $^7$Li+$^{93}$Nb system at energies close to the Coulomb barrier. The cross sections for $\\alpha+\\alpha$ events from one proton pickup were found to be smaller than those for $\\alpha+d$ events from one neutron stripping and $\\alpha+t$ events from direct breakup of $^7$Li. Coupled channels Born approximation and continuum discretized coupled channels calculations describe the data well and support the conclusion that the $\\alpha+d$ and $\\alpha+\\alpha$ events are produced by direct transfer to unbound states of the ejectile.
Numerical solution of the nonlinear Schrödinger equation with wave operator on unbounded domains.
Li, Hongwei; Wu, Xiaonan; Zhang, Jiwei
2014-09-01
In this paper, we generalize the unified approach proposed in Zhang et al. [J. Zhang, Z. Xu, and X. Wu, Phys. Rev. E 78, 026709 (2008)] to design the nonlinear local absorbing boundary conditions (LABCs) for the nonlinear Schrödinger equation with wave operator on unbounded domains. In fact, based on the methodology underlying the unified approach, we first split the original equation into two parts-the linear equation and the nonlinear equation-then achieve a one-way operator to approximate the linear equation to make the wave outgoing, and finally combine the one-way operator with the nonlinear equation to achieve the nonlinear LABCs. The stability of the equation with the nonlinear LABCs is also analyzed by introducing some auxiliary variables, and some numerical examples are presented to verify the accuracy and effectiveness of our proposed method.
DEFF Research Database (Denmark)
Daugaard, Line Møller
2016-01-01
stresses the importance of developing his Somali skills, he during Somali class works systematically to create space for English language use and resourcefully draws on a varied range of Englishes as well as a broad repertoire of stylised learner voices. Abdullahi’s playful use of linguistic resources......This paper presentation focuses on the unbounded and playful ways in which pupils put their linguistic resources to use across a highly regulated and compartmentalised language curriculum. The paper is based on a linguistic ethnographic study focusing on language teaching across the curriculum...... consisting of fieldnotes, photographs and video and audio recordings produced through participant observation in the language classroom and supplemented by interviews with pupils, language teachers and school management forms the empirical basis for the paper presentation.While translanguaging practices have...
Attractors of derivative complex Ginzburg-Landau equation in unbounded domains
Institute of Scientific and Technical Information of China (English)
GUO Boling; HAN Yongqian
2007-01-01
The Ginzburg-Landau-type complex equations are simplified mathematical models for various pattern formation systems in mechanics, physics, and chemistry. In this paper, the derivative complex Ginzburg- Landau (DCGL) equation in an unbounded domain ΩС R2 is studied. We extend the Gagliardo-Nirenberg inequality to the weighted Sobolev spaces introduced by S. V. Zelik. Applied this Gagliardo-Nirenberg inequality of the weighted Sobolev spaces and based on the technique for the semi-linear system of parabolic equations which has been developed by M. A. Efendiev and S. V. Zelik, the global attractor in the corresponding phase space is constructed, the upper bound of its Kolmogorov's ε-entropy is obtained, and the spatial chaos of the attractor for DCGL equation in R2 is detailed studied.
NUMERICAL SOLUTIONS OF PARABOLIC PROBLEMS ON UNBOUNDED 3-D SPATIAL DOMAIN
Institute of Scientific and Technical Information of China (English)
Hou-de Han; Dong-sheng Yin
2005-01-01
In this paper, the numerical solutions of heat equation on 3-D unbounded spatial domain are considered. An artificial boundary Γ is introduced to finite the computational domain. On the artificial boundary Γ, the exact boundary condition and a series of approximating boundary conditions are derived, which are called artificial boundary conditions.By the exact or approximating boundary condition on the artificial boundary, the original problem is reduced to an initial-boundary value problem on the bounded computational domain, which is equivalent or approximating to the original problem. The finite difference method and finite element method are used to solve the reduced problems on the finite computational domain. The numerical results demonstrate that the method given in this paper is effective and feasible.
The fastest unbound star in our Galaxy ejected by a thermonuclear supernova
Geier, S; Ziegerer, E; Kupfer, T; Heber, U; Irrgang, A; Wang, B; Liu, Z; Han, Z; Sesar, B; Levitan, D; Kotak, R; Magnier, E; Smith, K; Burgett, W S; Chambers, K; Flewelling, H; Kaiser, N; Wainscoat, R; Waters, C
2015-01-01
Hypervelocity stars (HVS) travel with velocities so high, that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we present a spectroscopic and kinematic analysis of US\\,708. Travelling with a velocity of $\\sim1200\\,{\\rm km\\,s^{-1}}$, it is the fastest unbound star in our Galaxy. In reconstructing its trajectory, the Galactic center becomes very unlikely as an origin, which is hardly consistent with the most favored ejection mechanism for the other HVS. Furthermore, we discovered US\\,708 to be a fast rotator. According to our binary evolution model it was spun-up by tidal interaction in a close binary and is likely to be the ejected donor remnant of a thermonuclear supernova.
Stellar dynamics. The fastest unbound star in our Galaxy ejected by a thermonuclear supernova.
Geier, S; Fürst, F; Ziegerer, E; Kupfer, T; Heber, U; Irrgang, A; Wang, B; Liu, Z; Han, Z; Sesar, B; Levitan, D; Kotak, R; Magnier, E; Smith, K; Burgett, W S; Chambers, K; Flewelling, H; Kaiser, N; Wainscoat, R; Waters, C
2015-03-06
Hypervelocity stars (HVSs) travel with velocities so high that they exceed the escape velocity of the Galaxy. Several acceleration mechanisms have been discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we present a spectroscopic and kinematic analysis of US 708. Traveling with a velocity of ~1200 kilometers per second, it is the fastest unbound star in our Galaxy. In reconstructing its trajectory, the Galactic center becomes very unlikely as an origin, which is hardly consistent with the most favored ejection mechanism for the other HVSs. Furthermore, we detected that US 708 is a fast rotator. According to our binary evolution model, it was spun-up by tidal interaction in a close binary and is likely to be the ejected donor remnant of a thermonuclear supernova.
The almost sure invariance principle for unbounded functions of expanding maps
Dedecker, Jerome; Merlevede, Florence
2011-01-01
We consider two classes of piecewise expanding maps $T$ of $[0,1]$: a class of uniformly expanding maps for which the Perron-Frobenius operator has a spectral gap in the space of bounded variation functions, and a class of expanding maps with a neutral fixed point at zero. In both cases, we give a large class of unbounded functions $f$ for which the partial sums of $f\\circ T^i$ satisfy an almost sure invariance principle. This class contains piecewise monotonic functions (with a finite number of branches) such that: - For uniformly expanding maps, they are square integrable with respect to the absolutely continuous invariant probability measure. - For maps having a neutral fixed point at zero, they satisfy an (optimal) tail condition with respect to the absolutely continuous invariant probability measure.
Unbounded Binary Search for a Fast and Accurate Maximum Power Point Tracking
Kim, Yong Sin; Winston, Roland
2011-12-01
This paper presents a technique for maximum power point tracking (MPPT) of a concentrating photovoltaic system using cell level power optimization. Perturb and observe (P&O) has been a standard for an MPPT, but it introduces a tradeoff between the tacking speed and the accuracy of the maximum power delivered. The P&O algorithm is not suitable for a rapid environmental condition change by partial shading and self-shading due to its tracking time being linear to the length of the voltage range. Some of researches have been worked on fast tracking but they come with internal ad hoc parameters. In this paper, by using the proposed unbounded binary search algorithm for the MPPT, tracking time becomes a logarithmic function of the voltage search range without ad hoc parameters.
Rutkowski, Adam; Buraczewski, Adam; Horodecki, Paweł; Stobińska, Magdalena
2017-01-01
Quantum steering is a relatively simple test for proving that the values of quantum-mechanical measurement outcomes come into being only in the act of measurement. By exploiting quantum correlations, Alice can influence—steer—Bob's physical system in a way that is impossible in classical mechanics, as shown by the violation of steering inequalities. Demonstrating this and similar quantum effects for systems of increasing size, approaching even the classical limit, is a long-standing challenging problem. Here, we prove an experimentally feasible unbounded violation of a steering inequality. We derive its universal form where tolerance for measurement-setting errors is explicitly built in by means of the Deutsch-Maassen-Uffink entropic uncertainty relation. Then, generalizing the mutual unbiasedness, we apply the inequality to the multisinglet and multiparticle bipartite Bell state. However, the method is general and opens the possibility of employing multiparticle bipartite steering for randomness certification and development of quantum technologies, e.g., random access codes.
A combined ADER-DG and PML approach for simulating wave propagation in unbounded domains
Amler, Thomas
2012-09-19
In this work, we present a numerical approach for simulating wave propagation in unbounded domains which combines discontinuous Galerkin methods with arbitrary high order time integration (ADER-DG) and a stabilized modification of perfectly matched layers (PML). Here, the ADER-DG method is applied to Bérenger’s formulation of PML. The instabilities caused by the original PML formulation are treated by a fractional step method that allows to monitor whether waves are damped in PML region. In grid cells where waves are amplified by the PML, the contribution of damping terms is neglected and auxiliary variables are reset. Results of 2D simulations in acoustic media with constant and discontinuous material parameters are presented to illustrate the performance of the method.
Attractors of the Derivative Complex Ginzburg-Landau Equation in Unbounded Domains
Institute of Scientific and Technical Information of China (English)
GUO Bo-ling; HAN Yong-qian
2005-01-01
@@ We consider the following initial boundary problem of derivative complex Ginzburg-Landau (DCGL) equation ut-(a1+ia2)△u-X0u+(b1+ib2)|u|2σu+|u|2λ·▽u+u2μ·▽u=g(x), (1) u(x,t = 0) = u0(x), u| Ω = 0 (2) in an unbounded domain Ω R2. Here u is a complex valued function of (x, t) ∈Ω× R +,a1 ＞ 0, b1 ＞ 0, σ＞ 0, a2, b2 ∈ R, λ = (λ1, λ2) and μ = (μ1,μ2) are complex constant vector.
Abbas, Ibrahim A.
2016-09-01
In the present paper, the theory of generalized photo-thermoelasticity under dual phase lag model has been applied to study the coupled thermal, plasma and elastic waves on unbounded semiconductor medium with cylindrical cavity. The bounding surface of the cavity is traction free and loaded thermally by exponentially decaying pulse boundary heat flux. By using Laplace transform and the eigenvalue approach methodology, the solutions of all variables have been obtained analytically. Numerical computations have been done for silicon-like semiconductor material, and the results are displayed graphically to show the difference between the dual phase lag (DPL) model, Lord and Shulman’s theory (LS) and the classical dynamical coupled theory (CT).
Loryan, Irena; Sinha, Vikash; Mackie, Claire; Van Peer, Achiel; Drinkenburg, Wilhelmus H; Vermeulen, An; Heald, Donald; Hammarlund-Udenaes, Margareta; Wassvik, Carola M
2015-02-01
In the present work we sought to gain a mechanistic understanding of the physicochemical properties that influence the transport of unbound drug across the blood-brain barrier (BBB) as well as the intra- and extracellular drug exposure in the brain. Interpretable molecular descriptors that significantly contribute to the three key neuropharmacokinetic properties related to BBB drug transport (Kp,uu,brain), intracellular accumulation (Kp,uu,cell), and binding and distribution in the brain (Vu,brain) for a set of 40 compounds were identified using partial least-squares (PLS) analysis. The tailoring of drug properties for improved brain exposure includes decreasing the polarity and/or hydrogen bonding capacity. The design of CNS drug candidates with intracellular targets may benefit from an increase in basicity and/or the number of hydrogen bond donors. Applying this knowledge in drug discovery chemistry programs will allow designing compounds with more desirable CNS pharmacokinetic properties.
Production of Polarized Vector Mesons off Nuclei
Kopeliovich, B Z; Schmidt, I; Schmidt, Ivan
2007-01-01
Using the light-cone QCD dipole formalism we investigate manifestations of color transparency (CT) and coherence length (CL) effects in electroproduction of longitudinally (L) and transversally (T) polarized vector mesons. Motivated by forthcoming data from the HERMES experiment we predict both the A and Q^2 dependence of the L/T- ratios, for rho^0 mesons produced coherently and incoherently off nuclei. For an incoherent reaction the CT and CL effects add up and result in a monotonic A dependence of the L/T-ratio at different values of Q^2. On the contrary, for a coherent process the contraction of the CL with Q^2 causes an effect opposite to that of CT and we expect quite a nontrivial A dependence, especially at Q^2 >> m_V^2.
Spectroscopy of neutron unbound states in 24O and 23N
Jones, Michael David
Unbound states in 24O and 23N were populated from an 24O beam at 83.4 MeV/u via inelastic excitation and proton knockout on a liquid deuterium target. Using the MoNA-LISA-Sweeper setup, the decay of each nucleus could be fully reconstructed. The two-body decay energy of 23N exhibits two prominent peaks at E = 100 +/- 20 keV and E = 960 +/- 30 keV with respect to the neutron separation energy. However, due to the lack of gamma-ray detection, a definitive statement on the structure of 23N could not be made. Shell model calculations with the WBP and WBT interactions lead to several interpretations of the spectrum. Both a single state at 2.9 MeV in 23N, or two states at 2.9 MeV and 2.75 MeV are consistent with the shell model and data. In addition, a two-neutron unbound excited state of 24O, populated by (d,d'), was observed with a three-body excitation of E = 715 +/- 110 (stat) +/-45 (sys) keV, placing it at E = 7.65 +/- 0.2 MeV with respect to the ground state. Three-body correlations for the decay of 24O → 22O + 2n show clear evidence for a sequential decay through an intermediate state in 23O. Neither a di-neutron nor phase-space model were able to describe the observed correlations. This measurement constitutes the first observation of a two-neutron sequential decay through three-body energy and angular correlations, and provides valuable insight into few-body physics at the neutron dripline.
Partial Dynamical Symmetries in Nuclei
Leviatan, A
2000-01-01
Partial dynamical symmetries (PDS) are shown to be relevant to the interpretation of the $K=0_2$ band and to the occurrence of F-spin multiplets of ground and scissors bands in deformed nuclei. Hamiltonians with bosonic and fermionic PDS are presented.
Multiphonon giant resonances in nuclei
Energy Technology Data Exchange (ETDEWEB)
Aumann, T. [Mainz Univ. (Germany). Inst. fuer Kernchemie; Bortignon, P.F. [Milan Univ. (Italy). Dipt. di Fisica]|[Istituto Nazionale di Fisica Nucleare, Milan (Italy); Emling, H. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)
1998-07-01
We review the present knowledge of multiphonon giant resonances in nuclei. Theoretical concepts approaching the intrinsic structure and excitation mechanisms of multi-phonon states are discussed. The available experimental results are summarized, including a brief description of applied techniques. This review emphasizes electromagnetic excitations of double dipole resonances. Open questions and possible routes toward a solution are addressed. (orig.)
Fission dynamics of hot nuclei
Indian Academy of Sciences (India)
Santanu Pal; Jhilam Sadhukhan
2014-04-01
Experimental evidence accumulated during the last two decades indicates that the fission of excited heavy nuclei involves a dissipative dynamical process. We shall briefly review the relevant dynamical model, namely the Langevin equations for fission. Statistical model predictions using the Kramers’ fission width will also be discussed.
Low energy + scattering on = nuclei
Indian Academy of Sciences (India)
Swapan Das; Arun K Jain
2003-11-01
The data for the total cross-section of + scattering on various nuclei have been analysed in the Glauber multiple scattering theory. Energy-dependent +-nucleus optical potential is generated using the forward +-nucleon scattering amplitude and the nuclear density distribution. Along with this, the calculated total +-nucleus cross-sections using the effective +-nucleon cross-section inside the nucleus are also presented.
Beyond the neutron drip line: The unbound oxygen isotopes ^{25}O and ^{26}O
DEFF Research Database (Denmark)
Caesar, C.; Simonis, J.; Adachi, T.
2013-01-01
The very neutron-rich oxygen isotopes 25O and 26O are investigated experimentally and theoretically. The unbound states are populated in an experiment performed at the R3B-LAND setup at GSI via proton-knockout reactions from 26F and 27F at relativistic energies around 442 and 414 MeV/nucleon, res...
Institute of Scientific and Technical Information of China (English)
Xing-qiu Zhang; Jing-xian Sun
2009-01-01
By constructing a special cone and using cone compression and expansion fixed point theorem,this paper presents some existence results of positive solutions of singular boundary value problem on unbounded domains for a class of first order differential equation.As applications of the main results,two examples are given at the end of this paper.
Hopkins, Ashley M; Moghaddami, Mahin; Foster, David J R; Proudman, Susanna M; Upton, Richard N; Wiese, Michael D
2017-01-01
Leflunomide's active metabolite teriflunomide inhibits dihydro-oroate dehydrogenase, an enzyme essential to proliferation of T lymphocytes. As teriflunomide must reach the target site to have this effect, this study assessed the distribution of teriflunomide into T lymphocytes, as intracellular concentrations may be a superior response biomarker to plasma concentrations. CD3 MicroBeads (Miltenyi Biotec, Bergisch Gladbach, Germany) were used to extract CD3(+) T cells from the peripheral blood of patients with rheumatoid arthritis who were taking a stable dose of leflunomide. Unbound plasma and intra-CD3(+) T cell teriflunomide concentrations were quantified using liquid chromatography-mass spectrometry. Concentration (log transformed) and partition differences were assessed through paired Student t tests. Sixteen patients provided plasma steady-state teriflunomide samples, and eight provided a sample 6-12 weeks later. At time-point one, the geometric mean teriflunomide concentration (range) in CD3(+) T cells was 18.12 μg/L (6.15-42.26 μg/L) compared with 69.75 μg/L (32.89-263.1 μg/L) unbound in plasma (P < 0.001). The mean partition coefficient (range) for unbound plasma teriflunomide into CD3(+) T cells was 0.295 (0.092-0.632), which was significantly different from unity (P < 0.001). The median (range) change in teriflunomide concentration between the two time points was 14% (-10% to 40%) in unbound plasma and -29% (-69 to 138%) for CD3(+) T cells. Because teriflunomide concentrations in CD3(+) T cells were lower and displayed a higher intraindividual variability than the unbound plasma concentrations, its applicability as a therapeutic drug-monitoring marker may be limited. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.
Fragmentation of relativistic oxygen nuclei in interactions with a proton
Glagolev, V V; Lipin, V D; Lutpullaev, S L; Olimov, K K; Yuldashev, A A; Yuldashev, B S; Olimov, Kh.K.
2001-01-01
The data on investigation of inelastic interactions of 16O nuclei with a proton at 3.25 A GeV/c momentum by the bubble chamber method are presented. The separate characteristics as fragments isotopic composition and as topo-logical cross sections of fragmentation channels are given. The processes of light fragments formation and breakup of 16O nucleus on multicharge fragments have been investigated. The comparison of experimental data with the calculations by statistical multifragmentation model was conducted.
Investigation of Properties of Exotic Nuclei in Non-relativistic and Relativistic Models
Institute of Scientific and Technical Information of China (English)
2001-01-01
Properties of exotic nuclei are described by non-relativistic and relativistic models. The relativistic mean field theory predicts one proton halo in 26,27,28P and two proton halos in 27,28,29S, recently, one proton halo in 26,27,28P has been found experimentally in MSU lab. The relativistic Hartree-Fock theory has been used to investigate the contribution of Fock term and isovector mesons to the properties of exotic nuclei. It turns out that the influence of the Fock term and isovector mesons on the properties of neutron extremely rich nuclei is very different from that of near stable nuclei. Meanwhile, the deformed Hartree-Fock-Bogoliubov theory has been employed to describe the ground state properties of the isotopes for some light nuclei.
Reactions with fast radioactive beams of neutron-rich nuclei
Energy Technology Data Exchange (ETDEWEB)
Aumann, T. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)
2005-11-01
The neutron dripline has presently been reached only for the lightest nuclei up to the element oxygen. In this region of light neutron-rich nuclei, scattering experiments are feasible even for dripline nuclei by utilizing high-energy secondary beams produced by fragmentation. In the present article, reactions of high-energy radioactive beams will be exemplified using recent experimental results mainly derived from measurements of breakup reactions performed at the LAND and FRS facilities at GSI and at the S800 spectrometer at the NSCL. Nuclear and electromagnetically induced reactions allow probing different aspects of nuclear structure at the limits of stability related to the neutron-proton asymmetry and the weak binding close to the dripline. Properties of the valence-neutron wave functions are studied in the one-neutron knockout reaction, revealing the changes of shell structure when going from the beta-stability line to more asymmetric loosely bound neutron-rich systems. The vanishing of the N=8 shell gap for neutron-rich systems like {sup 11}Li and {sup 12}Be, or the new closed N=14, 16 shells for the oxygen isotopes are examples. The continuum of weakly bound nuclei and halo states can be studied by inelastic scattering. The dipole response, for instance, is found to change dramatically when going away from the valley of stability. A redistribution of the dipole strength towards lower excitation energies is observed for neutron-rich nuclei, which partly might be due to a new collective excitation mode related to the neutron-proton asymmetry. Halo nuclei in particular show strong dipole transitions to the continuum at the threshold, being directly related to the ground-state properties of the projectile. Finally, an outlook on future experimental prospects is given. (orig.)
Directory of Open Access Journals (Sweden)
Wu C.Y.
2012-02-01
Full Text Available Spectra of γ rays following neutron capture at isolated resonances of 6 stable Gd isotopes were measured with highly segmented BaF2 detector DANCE at the Los Alamos LANSCE spallation neutron source. The main emphasis was put on studying the γ-cascade decay of neutron resonances to get unique information on photon strength. An analysis of the accumulated γ-ray spectra within the extreme statistical model leads to an inescapable conclusion that scissors mode resonances are built not only on the ground-state, but also on excited levels in all product nuclei studied. The results on summed B(M1↑ strength and energy of the scissors mode are compared with systematics of scissors mode parameters for the ground-state transitions deduced from nuclear resonance fluorescence measurements. A specific feature of our experiments is the investigation of scissors mode of odd nuclei, for which the nuclear resonance fluorescence provides only limited information.
Kroll, J.; Baramsai, B.; Becker, J. A.; Bečvář, F.; Bredeweg, T. A.; Couture, A.; Chyzh, A.; Dashdorj, D.; Haight, R. C.; Jandel, M.; Krtička, M.; Mitchell, G. E.; O'Donnell, J. M.; Parker, W.; Rundberg, R. S.; Ullmann, J. L.; Vieira, G. J.; Walker, C. L.; Wilhelmy, J. B.; Wouters, J. M.; Wu, C. Y.
2012-02-01
Spectra of γ rays following neutron capture at isolated resonances of 6 stable Gd isotopes were measured with highly segmented BaF2 detector DANCE at the Los Alamos LANSCE spallation neutron source. The main emphasis was put on studying the γ-cascade decay of neutron resonances to get unique information on photon strength. An analysis of the accumulated γ-ray spectra within the extreme statistical model leads to an inescapable conclusion that scissors mode resonances are built not only on the ground-state, but also on excited levels in all product nuclei studied. The results on summed B(M1)↑ strength and energy of the scissors mode are compared with systematics of scissors mode parameters for the ground-state transitions deduced from nuclear resonance fluorescence measurements. A specific feature of our experiments is the investigation of scissors mode of odd nuclei, for which the nuclear resonance fluorescence provides only limited information.
Proton scattering from unstable nuclei
Indian Academy of Sciences (India)
Y Blumenfeld; E Khan; F Maréchal; T Suomijärvi
2001-08-01
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 obtained are illustrated with recent results obtained at the GANIL facility for unstable oxygen, sulfur and argon isotopes. Methods to analyse the data using phenomenological and microscopic optical model potentials are discussed.
Strange neutral currents in nuclei
Ressell, M T; Aufderheide, M B; Bloom, S D; Resler, D A
1995-01-01
We examine the effects on the nuclear neutral current Gamow-Teller (GT) strength of a finite contribution from a polarized strange quark sea. We perform nuclear shell model calculations of the neutral current GT strength for a number of nuclei likely to be present during stellar core collapse. We compare the GT strength when a finite strange quark contribution is included to the strength without such a contribution. As an example, the process of neutral current nuclear de-excitation via \
Weak pion production from nuclei
Indian Academy of Sciences (India)
S K Singh; M Sajjad Athar; Shakeb Ahmad
2006-04-01
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 the nuclear medium. The pion absorption effects have also been taken into account.
Triaxial rotation in atomic nuclei
Institute of Scientific and Technical Information of China (English)
CHEN Yong-Shou; GAO Zao-Chun
2009-01-01
The Projected Shell Model has been developed to include the spontaneously broken axial symmetry so that the rapidly rotating triaxial nuclei can be described microscopically. The theory provides an useful tool to gain an insight into how a triaxial nucleus rotates, a fundamental question in nuclear structure. We shall address some current interests that are strongly associated with the triaxial rotation. A feasible method to explore the problem has been suggested.
Double pion photoproduction in nuclei
Vicente-Vacas, M J; Gómez-Tejedor, J A; Vicente-Vacas, M J; Oset, E; Gómez Tejedor, J A
1994-01-01
Abstract: The inclusive A(gamma,pi+ pi-)X reaction is studied theoretically. A sizeable enhancement of the cross section is found, in comparison with the scaling of the deuteron cross section (sigma_deuteron * A/2). This enhancement is due to the modifications in the nuclear medium of the gamma N ----> pi pi N amplitude and the pion dispersion relation. The enhancement is found to be bigger than the one already observed in the (pi,pi pi) reaction in nuclei.
No large population of unbound or wide-orbit Jupiter-mass planets
Mróz, Przemek; Udalski, Andrzej; Skowron, Jan; Poleski, Radosław; Kozłowski, Szymon; Szymański, Michał K.; Soszyński, Igor; Wyrzykowski, Łukasz; Pietrukowicz, Paweł; Ulaczyk, Krzysztof; Skowron, Dorota; Pawlak, Michał
2017-08-01
Planet formation theories predict that some planets may be ejected from their parent systems as result of dynamical interactions and other processes. Unbound planets can also be formed through gravitational collapse, in a way similar to that in which stars form. A handful of free-floating planetary-mass objects have been discovered by infrared surveys of young stellar clusters and star-forming regions as well as wide-field surveys, but these studies are incomplete for objects below five Jupiter masses. Gravitational microlensing is the only method capable of exploring the entire population of free-floating planets down to Mars-mass objects, because the microlensing signal does not depend on the brightness of the lensing object. A characteristic timescale of microlensing events depends on the mass of the lens: the less massive the lens, the shorter the microlensing event. A previous analysis of 474 microlensing events found an excess of ten very short events (1-2 days)—more than known stellar populations would suggest—indicating the existence of a large population of unbound or wide-orbit Jupiter-mass planets (reported to be almost twice as common as main-sequence stars). These results, however, do not match predictions of planet-formation theories and surveys of young clusters. Here we analyse a sample of microlensing events six times larger than that of ref. 11 discovered during the years 2010-15. Although our survey has very high sensitivity (detection efficiency) to short-timescale (1-2 days) microlensing events, we found no excess of events with timescales in this range, with a 95 per cent upper limit on the frequency of Jupiter-mass free-floating or wide-orbit planets of 0.25 planets per main-sequence star. We detected a few possible ultrashort-timescale events (with timescales of less than half a day), which may indicate the existence of Earth-mass and super-Earth-mass free-floating planets, as predicted by planet-formation theories.
A Statistical Approach to Describe Highly Excited Heavy and Superheavy Nuclei
Chen, Peng-Hui; Li, Jun-Qing; Zhang, Hong-Fei
2016-01-01
A statistical approach based on the Weisskopf evaporation theory has been developed to describe the de-excitation process of highly excited heavy and superheavy nuclei, in particular for the proton-rich nuclei. The excited nucleus is cooled by evaporating $\\gamma$-ray, light particles (neutrons, protons, $\\alpha$ etc) in competition with the binary fission, in which the structure effects (shell correction, fission barrier, particle separation energy) contribute to the processes. The formation of residual nuclei is evaluated via sequential emission of possible particles above the separation energies. The available data of fusion-evaporation excitation functions in the $^{28}$Si+$^{198}$Pt reaction can be reproduced nicely well within the approach.
Nuclei Measurements with the Alpha Magnetic Spectrometer on the International Space Station
Heil, Melanie
2017-03-01
The exact behavior of nuclei fluxes in cosmic rays and how they relate to each other is important for understanding the production, acceleration and propagation mechanisms of charged cosmic rays. Precise measurements with the Alpha Magnetic Spectrometer on the International Space Station of light nuclei fluxes and their ratios in primary cosmic rays with rigidities from GV to TV are presented. The high statistics of the measurements require detailed studies and in depth understanding of associated systematic uncertainties.
Nuclei Measurements with the Alpha Magnetic Spectrometer on the International Space Station
Directory of Open Access Journals (Sweden)
Heil Melanie
2017-01-01
Full Text Available The exact behavior of nuclei fluxes in cosmic rays and how they relate to each other is important for understanding the production, acceleration and propagation mechanisms of charged cosmic rays. Precise measurements with the Alpha Magnetic Spectrometer on the International Space Station of light nuclei fluxes and their ratios in primary cosmic rays with rigidities from GV to TV are presented. The high statistics of the measurements require detailed studies and in depth understanding of associated systematic uncertainties.
Neutron and Alpha Structure in Neutron Deficient Nuclei in Astrophysics
Institute of Scientific and Technical Information of China (English)
S. Kubono; T. Hashimoto; Y. Wakabayashi; N. Iwasa; S. Kato; T. Komatsubara; D. N. Binh; L. H. Khiem; N. N. Duy; T. Kawabata; C. Spitaleri; 何建军; G. G. Rapisarda; M. La Cognata; L. Lamia; R. G. Pizzone; S. Romano; A. Coc; N. de Sereville; F. Hammache; G. Kiss; S. Bishop; H. Yamaguchi; D. M. Kahl; S. Hayakawa; T. Teranishi; S. Cheribini; M. Gulino; Y. K. Kwon
2016-01-01
The paper includes discussions on the important role of neutron and alpha configurations in proton-rich nuclei in nuclear astrophysics in terms of nucleosynthesis under extremely high-temperature hydrogenburning conditions. The νp-process, which is supposed to take place at the very early epoch of type II supernovae, has considerable neutrons and alphas together with protons. The alpha-induced reactions on proton-rich unstable nuclei in the light mass regions is expected to play a crucial role, but very few of them were investigated well yet because of the experimental diﬃculties. Specifically, I report our recent experimental effort for the breakout process from the pp-chain region, 7Be(α,γ)11C(α,p)14N under the νp-process. The neutron-induced reactions on proton-rich nuclei, which is even more a challenging subject, were investigated previously for very few nuclei. One possible experimental method is the Trojan Horse Method (THM). We successfully have applied THM to the 18F(n,α)14N reaction study with an unstable beam of 18F.
Energy Technology Data Exchange (ETDEWEB)
Azuelos, G.; Gorringe, T.P.; Henderson, R.; Macdonald, J.A.; Poutissou, J.M. (TRIUMPH, Vancouver, BC (CA)); Azuelos, G.; Depommier, P.; Poutissou, R. (Montreal Univ., PQ (CA)); Ahmad, S.; Burnham, A.; Hasinoff, M.D.; Larabee, A.J.; Waltham, C.E.; Wright, D.H. (British Columbia Univ., Vancouver, BC (CA)); Armstrong, D.S.; Blecher, M.; Serna-Angel, A. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (US)); Bertl, W. (Paul Scherrer Inst. (PSI), Wuerenlingen (CH)); Chen, C.Q.; Zhang, N.S. (Academia Sinica, Beijing, BJ (CN). Inst. of High Energy Physics); Egidy, T. von (Technische Univ. Muenchen (DE)); McDonald, S.C.; Taylor, G.N. (Melbourne Univ., Parkville (AU)); Robertson, B.C. (Queen' s Univ., Belfast, Northern Ireland (UK))
1990-06-01
A brief review is made of the study of gp, the induced pseudoscalar coupling constant, in radiative muon capture on light nuclei, and of motivations for a measurement on hydrogen, with particular emphasis on recent and ongoing experiments at TRIUMF.
Directory of Open Access Journals (Sweden)
Zhi-Yong Yang
2016-09-01
Full Text Available Using the dynamic Monte Carlo method, we investigate dynamics of semiflexible polymer translocation through a nanopore into laterally unbounded region between two parallel flat membranes with separation R in presence of an electric field inside the pore. The average translocation time τ initially decreases rapidly with increase of R in the range of R < 10 and then almost keeps constant for R ≥ 10, and the decline range increases with increase of dimensionless bending stiffness κ. We mainly study the effect of chain length N, κ and electric field strength E on the translocation process for R = 5. The translocation dynamics is significantly altered in comparison to an unconfined environment. We find τ ~ Nα, where the exponent α increases with increase of E for small κ. α initially increases slowly with increase of E and then keeps constant for moderate κ. α decreases with increase of E for large κ. However, α decreases with increase of κ under various E. In addition, we find τ ~ κβ. β decreases with increase of N under various E. These behaviors are interpreted in terms of the probability distribution of translocation time and the waiting time of an individual monomer segment passing through the pore during translocation.
Self-similar fast-reaction limits for reaction-diffusion systems on unbounded domains
Crooks, E. C. M.; Hilhorst, D.
2016-08-01
We present a unified approach to characterising fast-reaction limits of systems of either two reaction-diffusion equations, or one reaction-diffusion equation and one ordinary differential equation, on unbounded domains, motivated by models of fast chemical reactions where either one or both reactant(s) is/are mobile. For appropriate initial data, solutions of four classes of problems each converge in the fast-reaction limit k → ∞ to a self-similar limit profile that has one of four forms, depending on how many components diffuse and whether the spatial domain is a half or whole line. For fixed k, long-time convergence to these same self-similar profiles is also established, thanks to a scaling argument of Kamin. Our results generalise earlier work of Hilhorst, van der Hout and Peletier to a much wider class of problems, and provide a quantitative description of the penetration of one substance into another in both the fast-reaction and long-time regimes.
Selective Population of Unbound Positive Parity States in 25F and 26F
Frank, Nathan; Herman, Jacob; Rabeh, Ali; Tuttle-Timm, Matthew; MoNA Collaboration
2017-01-01
Unbound Positive Parity States in 25F and 26F were populated in the one-proton removal reaction from a radioactive 27Ne beam. The experiment was performed at the National Superconducting Cyclotron Laboratory (NSCL), where a 101.3 MeV/u 27Ne ion beam impinged on a liquid deuterium target populating states in 26F. States above the one- and two- neutron separation energies lead to 24F and 25F, respectively. The MoNA/LISA setup at NSCL was used to detect the fragments in coincidence with neutrons and the decay energy spectra of 25F and 26F were reconstructed by invariant mass spectroscopy. Resonance energies of approximately 0.35 MeV and 0.5 MeV for 25F* and 26F*, respectively, were extracted. Based on the calculated spectroscopic strength distribution of negative and positive parity states in 26F and the selectivity of one proton-removal reactions both states were assigned positive parity. NSF Grant #1404236.
Clines with complete dominance and partial panmixia in an unbounded unidimensional habitat.
Nagylaki, Thomas; Zeng, Kai
2014-05-01
In spatially structured populations, global panmixia can be viewed as the limiting case of long-distance migration. The effect of incorporating partial panmixia into diallelic single-locus clines maintained by migration and selection with complete dominance in an unbounded unidimensional habitat is investigated. The population density is uniform. Migration and selection are both weak; the former is homogeneous and symmetric; the latter is frequency independent. The spatial factor g̃(x) in the selection term, where x denotes position, is a single step at the origin: g̃(x)=-α0. If α=1, there exists a globally asymptotically stable cline. For α1, a unique, asymptotically stable cline exists if and only if β is less than the critical value β(∗); then a smaller, unique, unstable equilibrium also exists whenever β0 and a cline exists, some polymorphism is maintained even at x=±∞. Both the preceding result and the existence of an unstable equilibrium when α>1 and 0<β<β(∗) differ qualitatively from the classical case (β=0).
Containment control of multi-agent systems with unbounded communication delays
Shen, Jun; Lam, James
2016-07-01
In this paper, we address the containment control problem for multi-agent systems under heterogeneous unbounded communication delays with emphasis on the convergence rate analysis. Different from most works on multi-agent systems, we resort to a viewpoint from the area of positive delay systems. We first cast the containment control problem into the stability analysis of an associated error system. In order to capture the convergence rate, we introduce a nondecreasing positive function whose reciprocal represents the decay rate of the associated error system. Under the assumption that each follower has access to at least one leader and some mild hypotheses on the communication delays, an explicit condition is given to characterise the decay rate of the associated error system in terms of linear programming. In addition, we provide several special cases when the communication delays are restricted by linear, sublinear and logarithmic growth rates, respectively. Finally, through numerical examples, it is shown that the convergence rate is dominated by the delays being the highest order infinitely large quantity.
Evaluation of unbound free heme in plant cells by differential acetone extraction.
Espinas, Nino A; Kobayashi, Koichi; Takahashi, Shigekazu; Mochizuki, Nobuyoshi; Masuda, Tatsuru
2012-07-01
Heme functions not only as a prosthetic group of hemoproteins but also as a regulatory molecule, suggesting the presence of 'free' heme. Classically, total non-covalently bound heme is extracted from plant samples with acidic acetone after removal of pigments with basic and neutral acetone. Earlier work proposed that free heme can be selectively extracted into basic acetone. Using authentic hemoproteins, we confirmed that acidic acetone can quantitatively extract heme, while no heme was extracted into neutral acetone. Meanwhile, a certain amount of heme was extracted into basic acetone from hemoglobin and myoglobin. Moreover, basic acetone extracted loosely bound heme from bovine serum albumin, implying that the nature of hemoproteins largely influences heme extraction into basic acetone. Using a highly sensitive heme assay, we found that basic and neutral acetone can extract low levels of heme from plant samples. In addition, neutral acetone quantitatively extracted free heme when it was externally added to plant homogenates. Furthermore, the level of neutral acetone-extractable heme remained unchanged by precursor (5-aminolevulinic acid) feeding, while increased by norflurazon treatment which abolishes chloroplast biogenesis. However, changes in these heme levels did not correlate to genomes uncoupled phenotypes, suggesting that the level of unbound free heme would not affect retrograde signaling from plastids to the nucleus. The present data demonstrate that the combination of single-step acetone extraction following a sensitive heme assay is the ideal method for determining total and free heme in plants.
Tunneling effects in resonant acoustic scattering of an air bubble in unbounded water
Directory of Open Access Journals (Sweden)
ANDRÉ G. SIMÃO
2016-06-01
Full Text Available Abstract The problem of acoustic scattering of a gaseous spherical bubble immersed within unbounded liquid surrounding is considered in this work. The theory of partial wave expansion related to this problem is revisited. A physical model based on the analogy between acoustic scattering and potential scattering in quantum mechanics is proposed to describe and interpret the acoustical natural oscillation modes of the bubble, namely, the resonances. In this context, a physical model is devised in order to describe the air water interface and the implications of the high density contrast on the various regimes of the scattering resonances. The main results are presented in terms of resonance lifetime periods and quality factors. The explicit numerical calculations are undertaken through an asymptotic analysis considering typical bubble dimensions and underwater sound wavelengths. It is shown that the resonance periods are scaled according to the Minnaert’s period, which is the short lived resonance mode, called breathing mode of the bubble. As expected, resonances with longer lifetimes lead to impressive cavity quality Q-factor ranging from 1010 to 105. The present theoretical findings lead to a better understanding of the energy storage mechanism in a bubbly medium.
Finite Element Modeling of Unbounded Grounding System Considering Soil Ionization Characteristic
Institute of Scientific and Technical Information of China (English)
CHEN Lin; LI Jingli; YANG Qing; SIMA Wenxia; SUN Caixin
2012-01-01
The aim of this paper is to calculate accurately the grounding performance of an unbounded grounding system under high-magnitude fault current.In this work,a finite element model is presented to compute the characteristic parameters of the grounding system in frequency domain.The ionization phenomenon in the soil surrounding the grounding electrode is taken into account by setting the resistivity of every soil element while the resistivity of each element is varying with the electric field intensity;not a priori hypothesis on the geometrical shape of the ionized region around the electrodes has to be enforced.Open boundaries of the grounding system are represented by introducing a spatial transformation formulation,which translates the semi-infinite space into the finite space without shortening the domain as in the traditional approach.The suggested modeling is validated by comparison of the calculated results,which are laid out for grounding rod and grounding grid,with experimental and simulation results found in literature.
HE 0437-5439 -- an unbound hyper-velocity main-sequence B-type star
Edelmann, H; Heber, U; Christlieb, N; Reimers, D; Edelmann, Heinz; Napiwotzki, Ralf; Heber, Uli; Christlieb, Norbert; Reimers, Dieter
2005-01-01
We report the discovery of a 16th magnitude star, HE0437-5439, with a heliocentric radial velocity of +723+-3km/s. A quantitative spectral analysis of high-resolution optical spectra obtained with the VLT and the UVES spectrograph shows that HE0437-5439 is a main sequence B-type star with Teff=20350K, log g=3.77, solar within a factor of a few helium abundance and metal content, rotating at v sin i=54km/s. Using appropriate evolutionary tracks we derive a mass of 8 Msun and a corresponding distance of 61 kpc. Its galactic rest frame velocity is at least 563km/s, almost twice the local Galactic escape velocity, indicating that the star is unbound to the Galaxy. Numerical kinematical experiments are carried out to constrain its place of birth. It has been suggested that such hyper-velocity stars can be formed by the tidal disruption of a binary through interaction with the super-massive black hole at the Galactic center (GC). HE0437-5439 needs about 100Myrs to travel from the GC to its presentposition, much lon...
Longitudinal patterning of twisted light
Dorrah, Ahmed H; Mojahedi, Mo
2016-01-01
Light beams with azimuthal phase dependence [$exp(i \\ell\\phi)$] carry orbital angular momentum (OAM) which differs fundamentally from spin angular momentum (SAM) associated with polarization. Striking difference between the two momenta is manifested in the allowable values: where SAM is limited to $\\hbar k_0$ per photon, the OAM has unbounded value of $\\ell\\hbar$ per photon ($\\ell$ is integer), thus dramatically exceeding the value of SAM \\cite{Ref1,Ref2, Ref3}. OAM has thus been utilized in optical trapping \\cite{Ref4}, imaging\\cite{Ref2}, and material processing \\cite{Ref5}. Furthermore, the unbounded degrees-of-freedom in OAM states have been deployed in data communications \\cite{Ref6}. Here, we report an \\textit{exceptional} behavior for a class of light beams---known as Frozen Waves (FWs)---whose intensity and azimuthal phase profiles can be controlled along the propagation direction, at will. Accordingly, we generate rotating light patterns that can change their sense of rotation and order of phase twis...
The Role of Nuclei-Nuclei Interactions in the Production of Gamma-ray Lines in Solar Flares
Institute of Scientific and Technical Information of China (English)
Boris M. Kuzhevskij; Wei-Qun Gan; Leonty I. Miroshnichenko
2005-01-01
Dramatic extensions of experimental possibilities (spacecraft RHESSI,CORONAS-F and others) in solar gamma-ray astronomy call for urgent, detailed theoretical consideration of a set of physical problems of solar activity and solarterrestrial relationships that earlier may have only been outlined. Here we undertake a theoretical analysis of issues related to the production of gamma-radiation in the processes of interactions of energetic (accelerated) heavy and middle nuclei with the nuclei of the solar atmosphere (the so-called i-j interactions). We also make an estimate of the contribution of these interactions to the formation of nuclear and isotopic abundances of the solar atmosphere in the range of light and rare elements. The analysis is carried out for solar flares in the wide range of their intensities. We compare our theoretical estimates with RHESSI observations for the flare of 2002 July 23. It was shown that the 24Mg gamma-ray emission in this event was produced by the newly generated Mg nuclei. With a high probability,the gamma-ray line emission of 28Si nuclei from this flare was generated by the same processes.
Feehan, Paul M N
2011-01-01
We solve four intertwined problems, motivated by mathematical finance, concerning degenerate-parabolic partial differential operators and degenerate diffusion processes. First, we consider a parabolic partial differential equation on a half-space whose coefficients are suitably Holder continuous and allowed to grow linearly in the spatial variable and which becomes degenerate along the boundary of the half-space. We establish existence and uniqueness of solutions in weighted Holder spaces which incorporate both the degeneracy at the boundary and the unboundedness of the coefficients. Second, we show that the martingale problem associated with a degenerate elliptic differential operator with unbounded, locally Holder continuous coefficients on a half-space is well-posed in the sense of Stroock and Varadhan. Third, we prove existence, uniqueness, and the strong Markov property for weak solutions to a stochastic differential equation with degenerate diffusion and unbounded coefficients with suitable H\\"older con...
Tensor Effect on Bubble Nuclei
Institute of Scientific and Technical Information of China (English)
WANG Yan-Zhao; GU Jian-Zhong; ZHANG Xi-Zhen; DONG Jian-Min
2011-01-01
In the framework of the Hartree-Fock-Bogoliubov (HFB) approach with Skyrme interactions SLy5+T, SLy5+Tw and several sets of TIJ parametrizations, I.e. The Skyrme interaction parametrizations including the tensor terms, the proton density distribution in 34Si and 46Ar nuclei is calculated with and without the tensor force. It is shown that the bubble effect in 34Si does not depend a great deal on the Skyrme parametrization and the proton density distribution in 34Si is hardly influenced by the tensor force. As to 46Ar, the SLy5+Tw parametrization favors the formation of the bubble structure due to the inversion between the 2s1/2 and 1d3/2 orbits (2s1/2-ld3/2 inversion). The inversion mechanism induced by the SLy5+Tw interaction is analyzed based on the proton single-particle spectra obtained from the SLy5 and SLy5+Tw interactions as well as the wave functions of the 2s1/2 and 1d3/2 states.%In the framework of the Hartree-Fock-Bogoliubov (HFB) approach with Skyrme interactions SLy5+ T,SLy5+ Tω and several sets of TIJ parametrizations,i.e.the Skyrme interaction pararmetrizations including the tensor terms,the proton density distribution in 34Si and 46 Ar nuclei is calculated with and without the tensor force.It is shown that the bubble effect in 34Si does not depend a great deal on the Skyrme parametrization and the proton density distribution in 34Si is hardly influenced by the tensor force.As to 46Ar,the SLy5+ Tω parametrization favors the formation of the bubble structure due to the inversion between the 2s1/2 and 1d3/2 orbits (2s1/2-1d3/2 inversion).The inversion mechanism induced by the SLy5+ Tω interaction is analyzed based on the proton single-particle spectra obtained from the SLy5 and SLy5+ Tω interactions as well as the wave functions of the 2s1/2 and 1d3/2 states.The study of exotic nuclear structures has been a hot topic in nuclear physics.[1-4] Exotic nuclei are unstabile,superheavy nuclei,halo nuclei and so forth,whose structures are quite different
Kratzer, Alexander; Kees, Frieder; Dorn, Christoph
2016-12-15
Ultrafiltration is a rapid and convenient method to determine the free concentrations of drugs in plasma. Several ultrafiltration devices based on Eppendorf cups are commercially available, but are not validated for such use by the manufacturer. Plasma pH, temperature and relative centrifugal force as well as membrane type can influence the results. In the present work, we developed an ultrafiltration method in order to determine the free concentrations of linezolid or fluconazole, both neutral and moderately lipophilic antiinfective drugs for parenteral as well as oral administration, in plasma of patients. Whereas both substances behaved relatively insensitive in human plasma regarding variations in pH (7.0-8.5), temperature (5-37°C) or relative centrifugal force (1000-10.000xg), losses of linezolid were observed with the Nanosep Omega device due to adsorption onto the polyethersulfone membrane (unbound fraction 75% at 100mg/L and 45% at 0.1mg/L, respectively). No losses were observed with Vivacon which is equipped with a membrane of regenerated cellulose. With fluconazole no differences between Nanosep and Vivacon were observed. Applying standard conditions (pH 7.4/37°C/1000xg/20min), the mean unbound fraction of linezolid in pooled plasma from healthy volunteers was 81.5±2.8% using Vivacon, that of fluconazole was 87.9±3.5% using Nanosep or 89.4±3.3% using Vivacon. The unbound fraction of linezolid was 85.4±3.7% in plasma samples from surgical patients and 92.1±6.2% in ICU patients, respectively. The unbound fraction of fluconazole was 93.9±3.3% in plasma samples from ICU patients.
Bolia, Ashini; Gerek, Z Nevin; Ozkan, S Banu
2014-03-24
Molecular docking serves as an important tool in modeling protein-ligand interactions. However, it is still challenging to incorporate overall receptor flexibility, especially backbone flexibility, in docking due to the large conformational space that needs to be sampled. To overcome this problem, we developed a novel flexible docking approach, BP-Dock (Backbone Perturbation-Dock) that can integrate both backbone and side chain conformational changes induced by ligand binding through a multi-scale approach. In the BP-Dock method, we mimic the nature of binding-induced events as a first-order approximation by perturbing the residues along the protein chain with a small Brownian kick one at a time. The response fluctuation profile of the chain upon these perturbations is computed using the perturbation response scanning method. These response fluctuation profiles are then used to generate binding-induced multiple receptor conformations for ensemble docking. To evaluate the performance of BP-Dock, we applied our approach on a large and diverse data set using unbound structures as receptors. We also compared the BP-Dock results with bound and unbound docking, where overall receptor flexibility was not taken into account. Our results highlight the importance of modeling backbone flexibility in docking for recapitulating the experimental binding affinities, especially when an unbound structure is used. With BP-Dock, we can generate a wide range of binding site conformations realized in nature even in the absence of a ligand that can help us to improve the accuracy of unbound docking. We expect that our fast and efficient flexible docking approach may further aid in our understanding of protein-ligand interactions as well as virtual screening of novel targets for rational drug design.
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
Breakup Densities of Hot Nuclei.
Viola, Vic
2006-04-01
Breakup densities of hot ^197Au-like residues have been deduced from the systematic trends of Coulomb parameters required to fit intermediate-mass-fragment kinetic-energy spectra. The results indicate emission from nuclei near normal nuclear density below an excitation energy E*/A .3ex˜x 5 MeV. Temperatures derived from these data with a density-dependent Fermi-gas model yield a nuclear caloric curve that is generally consistent with those derived from isotope ratios.
Double pion photoproduction in nuclei
Energy Technology Data Exchange (ETDEWEB)
Gomez Tejedor, J.A. [Departamento de Fisica Teorica, Valencia (Spain); Vicente-Vacas, M.J. [Departamento de Fisica Teorica, Valencia (Spain); Oset, E. [Departamento de Fisica Teorica, Valencia (Spain)
1995-06-19
The inclusive A({gamma},{pi}{sup +}{pi}{sup -})X reaction is studied theoretically. A sizable enhancement of the cross section is found, in comparison with the scaling of the deuteron cross section ({sigma}{sub d} A/2). This enhancement is due to the modifications in the nuclear medium of the {gamma}N {yields}{pi}{pi}N amplitude and the pion dispersion relation. The enhancement is found to be bigger than the one already observed in the ({pi},{pi}{pi}) reaction in nuclei. ((orig.)).
Pairing correlations in exotic nuclei
Sagawa, H
2012-01-01
The BCS and HFB theories which can accommodate the pairing correlations in the ground states of atomic nuclei are presented. As an application of the pairing theories, we investigate the spatial extension of weakly bound Ne and C isotopes by taking into account the pairing correlation with the Hartree-Fock-Bogoliubov (HFB) method and a 3-body model, respectively. We show that the odd-even staggering in the reaction cross sections of $^{30,31,32}$Ne and $^{14,15,16}$C are successfully reproduced, and thus the staggering can be attributed to the unique role of pairing correlations in nuclei far from the stability line. A correlation between a one-neutron separation energy and the anti-halo effect is demonstrated for $s$- and p-waves using the HFB wave functions. We also propose effective density-dependent pairing interactions which reproduce both the neutron-neutron ($nn$) scattering length at zero density and the neutron pairing gap in uniform matter. Then, we apply these interactions to study pairing gaps in ...