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Sample records for analog resonances strangeness

  1. Calculation of baryon chemical potential and strangeness chemical potential in resonance matter

    International Nuclear Information System (INIS)

    Fu Yuanyong; Hu Shouyang; Lu Zhongdao

    2006-01-01

    Based on the high energy heavy-ion collisions statistical model, the baryon chemical potential and strangeness chemical potential are calculated for resonance matter with net baryon density and net strangeness density under given temperature. Furthermore, the relationship between net baryon density, net strangeness density and baryon chemical potential, strangeness chemical potential are analyzed. The results show that baryon chemical potential and strangeness chemical potential increase with net baryon density and net strangeness density increasing, the change of net baryon density affects baryon chemical potential and strangeness chemical potential more strongly than the change of net strangeness density. (authors)

  2. Strangeness freeze-out: role of system size and missing resonances

    Directory of Open Access Journals (Sweden)

    Chatterjee Sandeep

    2018-01-01

    Full Text Available The conventional approach to treat strangeness freezeout has been to consider a unified freezeout scheme where strangeness freezes out along with the nonstrange hadrons (1CFO, with or without an additional parameter accounting for out-of-equilibrium strangeness production (γS. Several alternate scenarios have been formulated lately. Here, we will focus on flavor dependent freezeout with early freezeout of strangeness (2CFO in comparison to 1CFO and its variants with respect to the roles played by the system size and missing resonances predicted by different theoretical approaches but yet to be seen in experiments. In contrast to the performance of 1CFO with/without γS that is insensitive to system size, 2CFO exhibits a clear system size dependence-while for Pb+Pb the χ2/NDF is around 0-2, for smaller system size in p+Pb and p+p, the χ2/NDF> 5 and larger than 1CFO+γS. This clearly shows a system size dependence of the preference for the freezeout scheme, while 2CFO is preferred in Pb+Pb, 1CFO+γS is preferred in p+Pb and p+p. We have further investigated the role of the missing resonances on strangeness freezeout across SPS to LHC beam energies.

  3. The hydrogen bubble chamber and the strange resonances

    International Nuclear Information System (INIS)

    Alvarez, L.W.

    1989-01-01

    Work on observing strange particle resonances, already predicted by theory, was done at Berkeley by the author Luis Alvarez starting in 1953, thanks to the development of a bubble chamber filled with liquid hydrogen, which made the discovery on new particles and their mode of production easier. The first experiment, stopping K - mesons in hydrogen lead to copious production of the strangeness equal to minus one hyperons, the lambda, and sigma minus, plus and neutral, as well as enabling the first observation of muon-catalyzed fusion reactions. In 1955, funding was obtained for a seventy-two-inch bubble chamber, by far the largest ever constructed. Later computer analysis permitted calculation of track co-ordinates in real space. A neutral cascade particle, the xi, predicted by theory, had its mass measured first on the fifteen-inch chamber. The author closes with a description of the explosion in discoveries of resonance particles in the late fifties and speculates about future discoveries. (UK)

  4. Can doubly strange dibaryon resonances be discovered at RHIC?

    International Nuclear Information System (INIS)

    Paganis, S. D.; Hoffmann, G. W.; Ray, R. L.; Tang, J.-L.; Udagawa, T.; Longacre, R. S.

    2000-01-01

    The baryon-baryon continuum invariant mass spectrum generated from relativistic nucleus + nucleus collision data may reveal the existence of doubly strange dibaryons not stable against strong decay if they lie within a few MeV of threshold. Furthermore, since the dominant component of these states is a superposition of two color-octet clusters which can be produced intermediately in a color-deconfined quark-gluon plasma (QGP), an enhanced production of dibaryon resonances could be a signal of QGP formation. A total of eight, doubly strange dibaryon states are considered for experimental search using the STAR detector (solenoidal tracker at RHIC) at the new Relativistic Heavy Ion Collider (RHIC). These states may decay to ΛΛ and/or pΞ - , depending on the resonance energy. STAR's large acceptance, precision tracking and vertex reconstruction capabilities, and large data volume capacity, make it an ideal instrument to use for such a search. Detector performance and analysis sensitivity are studied as a function of resonance production rate and width for one particular dibaryon which can directly strong decay to pΞ - , but not ΛΛ. Results indicate that such resonances may be discovered using STAR if the resonance production rates are comparable to coalescence model predictions for dibaryon bound states. (c) 2000 The American Physical Society

  5. Production of multi-strange hyperons and strange resonances in the NA49 experiment

    CERN Document Server

    Barton, R A; Anticic, T; Bächler, J; Barna, D; Barnby, L S; Bartke, Jerzy; Betev, L; Bialkowska, H; Billmeier, A; Blume, C; Blyth, C O; Boimska, B; Botje, M; Bracinik, J; Brady, F P; Bramm, R; Brun, R; Buncic, P; Carr, L; Cebra, D; Cooper, G E; Cramer, J G; Csató, P; Eckhardt, F; Ferenc, D; Filip, P; Fischer, H G; Fodor, Z; Foka, P Y; Freund, P; Friese, V; Ftácnik, J; Gál, J; Gazdzicki, M; Georgopoulos, G; Gladysz-Dziadus, E; Hegyi, S; Hlinka, V; Höhne, C; Igo, G; Ivanov, M; Jacobs, P; Janik, R; Jones, P G; Kadija, K; Kolesnikov, V I; Kollegger, T; Kowalski, M; Van Leeuwen, M; Lévai, Peter; Malakhov, A I; Margetis, S; Markert, C; Mayes, B W; Melkumov, G L; Mischke, A; Molnár, J; Nelson, J M; Odyniec, Grazyna Janina; Pálla, G; Panagiotou, A D; Petridis, A; Pikna, M; Pinsky, L; Poskanzer, A M; Prindle, D J; Pühlhofer, F; Reid, J G; Renfordt, R E; Retyk, W; Ritter, H G; Röhrich, D; Roland, C; Roland, G; Rybicki, A; Sammer, T; Sandoval, A; Sann, H; Schäfer, E; Schmitz, N; Seyboth, P; Siklér, F; Sitár, B; Skrzypczak, E; Snellings, R; Squier, G T A; Stock, Reinhard; Strmen, P; Ströbele, H; Susa, T; Szarka, I; Szentpétery, I; Sziklai, J; Toy, M; Trainor, T A; Trentalange, S; Varga, D; Vassiliou, Maria; Veres, G I; Vesztergombi, G; Voloshin, S A; Vranic, D; Wang, F; Weerasundara, D D; Wenig, S; Wetzler, A; Whitten, C; Xu, N; Yates, T A; Yoo, I K; Zimányi, J

    2001-01-01

    The NA49 large-acceptance hadron spectrometer has measured strange and multi-strange hadrons from Pb+Pb and p+p collisions at the CERN SPS. Preliminary results for the transverse mass and rapidity distributions for X and Xi /sup +/ from central Pb+Pb collisions at 158 GeV c/sup -1//nudeon are presented. Fully integrated yields per event of 4.42+or-0.31 and 0.74+0.04 are found for Xi /sup -/ and Xi /sup +/, respectively, leading to a 4 pi Xi /sup +// Xi /sup -/ ratio of 0.17+or-0.02. The ratio Xi /sup +// Xi /sup -/ at mid-rapidity is found to be 0.22+or-0.04, agreeing with previously published values. In addition, preliminary data on the Lambda (1520) and phi (1020) resonances are presented. The Lambda (1520) multiplicity for p+p collisions is found to be 0.012+or-0.003. No signal is observed for Pb+Pb collisions and a production upper limit of 1.36 Lambda (1520) per event indicates an apparent suppression when comparing with scaled p+p data. Integrated phi (1020) yields per event are found to be 7.6+or-1.1 f...

  6. Electro and photoproduction of strangeness

    International Nuclear Information System (INIS)

    Bertini, R.

    1988-01-01

    Strangeness-production studies and the characteristics of the electron accelerators applied in the experiments are discussed. The strangeness of the nucleon, the polarization in hyperon production, strange dybaryons, hypernuclei and baryons resonance and strangeness are the main topics. The importance of the electromagnetic probe as a tool in hyperon polarization measurements, in order to understand why hyperons become polarized at large momentum transfer, is underlined. High beam energies (30 GeV or so) and targets are needed for the study of the nucleon spin functions, as well as transverse and longitudinal polarization of the beam must be provided. In the following studies the needed energy range has been determinated: for the study of the strangeness content of the nucleon a beam energy higher than 3-4 GeV, in the search of H and D baryons, energies higher than 4 GeV, for the production of hypernuclei, the hyperon polarization and the baryon resonances study, beam energies ranging in the 3-4 GeV gap are enough. The relation meson-nucleon sigma terms to the strange quark content of the nucleon is discussed. In the measurement of the K-N sigma term, low energy Kaon beams and, possibly, polarized targets are needed

  7. Strangeness Suppression and Color Deconfinement

    Science.gov (United States)

    Satz, Helmut

    2018-02-01

    The relative multiplicities for hadron production in different high energy collisions are in general well described by an ideal gas of all hadronic resonances, except that under certain conditions, strange particle rates are systematically reduced. We show that the suppression factor γs, accounting for reduced strange particle rates in pp, pA and AA collisions at different collision energies, becomes a universal function when expressed in terms of the initial entropy density s0 or the initial temperature T of the produced thermal medium. It is found that γs increases from about 0.5 to 1.0 in a narrow temperature range around the quark-hadron transition temperature Tc ≃ 160 MeV. Strangeness suppression thus disappears with the onset of color deconfinement; subsequently, full equilibrium resonance gas behavior is attained.

  8. Study of leading strange meson resonances and spin-orbit splittings in K-p → K-π+n at 11 GeV/c

    International Nuclear Information System (INIS)

    Honma, A.K.

    1980-11-01

    The results from a high-statistics study of Kπ elastic scattering in the reaction K - p → K - π + n are presented. The data for this analysis are taken from an 11-GeV/c K - p experiment performed on the Large Aperture Solenoidal Spectrometer (LASS) facility at the Stanford Linear Accelerator Center (SLAC). By selecting the very forward produced K - π + events, a sample consisting of data for the Kπ → Kπ elastic scattering reaction was extracted. The angular distribution for this meson-meson scattering is studied by use of both a spherical harmonic moments analysis and a partial-wave analysis (PWA). The previously established leading natural spin-parity strange meson resonances (the J/sup P/ = 1 - K*(895), the 2 + K*(1430), and the 3 - K*(1780)) are observed in the results from both the moments analysis and the PWA. In addition, evidence for a new spin 4 - K* resonance with a mass of 2080 MeV and a width of about 225 MeV is presented. The results from the PWA confirm the existence of a 0 + kappa (1490) and propose the existence of a second scalar meson resonance, the 0 + kappa' (1900). Structure in the P-wave amplitude indicates resonance behavior in the mass region near 1700 MeV. In two of the four ambiguous solutions for the mass region above 1800 MeV, there is strong evidence for another P-wave resonant structure near 2100 MeV. The observed strange meson resonances are found to have a natural interpretation in terms of states predicted by the quark model. In particular, the mass splittings of the leading trajectory natural spin-parity strange meson states and the mass splittings between the spin-orbit triplet states are discussed. 59 figures, 17 tables

  9. From strange stars to strange dwarfs

    International Nuclear Information System (INIS)

    Glendenning, N.K.; Kettner, C.; Weber, F.

    1995-01-01

    We determine all possible equilibrium sequences of compact strange-matter stars with nuclear crusts, which range from massive strange stars to strange white dwarf endash like objects (strange dwarfs). The properties of such stars are compared with those of their nonstrange counterparts emdash neutron stars and ordinary white dwarfs. The main emphasis of this paper is on strange dwarfs, which we divide into two distinct categories. The first one consists of a core of strange matter enveloped within ordinary white dwarf matter. Such stars are hydrostatically stable with or without the strange core and are therefore referred to as open-quote open-quote trivial close-quote close-quote strange dwarfs. This is different for the second category which forms an entirely new class of dwarf stars that contain nuclear material up to 4x10 4 times denser than in ordinary white dwarfs of average mass, M∼0.6 M circle-dot , and still about 400 times denser than in the densest white dwarfs. The entire family of such dwarfs, denoted dense strange dwarfs, owes its hydrostatic stability to the strange core. A striking features of strange dwarfs is that the entire sequence from the maximum-mass strange star to the maximum-mass strange dwarf is stable to radial oscillations. The minimum-mass star is only conditionally stable, and the sequences on both sides are stable. Such a stable, continuous connection does not exist between ordinary white dwarfs and neutron stars, which are known to be separated by a broad range of unstable stars. We find an expansive range of very low mass (planetary-like) strange-matter stars (masses even below 10 -4 M circle-dot are possible) that arise as natural dark-matter candidates, which if abundant enough in our Galaxy, should be seen in the gravitational microlensing searches that are presently being performed. copyright 1995 The American Astronomical Society

  10. Strangeness as a probe to baryon-rich QCD matter at NICA

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Kenji [The University of Tokyo, Department of Physics, Bunkyo-ku, Tokyo (Japan)

    2016-08-15

    We elucidate a prospect of strangeness fluctuation measurements in the heavy-ion collision at NICA energies. The strangeness fluctuation is sensitive to quark deconfinement. At the same time strangeness has a strong correlation with the baryon number under the condition of vanishing net strangeness, which leads to an enhancement of Λ{sup 0}, Ξ{sup 0}, Ξ{sup -}, and K{sup +} at high baryon density. The baryon density is maximized around the NICA energies, and strangeness should be an ideal probe to investigate quark deconfinement phenomena of baryon-rich QCD matter created at NICA. We also utilize the hadron resonance gas model to estimate a mixed fluctuation of strangeness and baryon number. (orig.)

  11. The 130Te (p,p') reaction on analog resonances

    International Nuclear Information System (INIS)

    Martinez Ruiz, M. del C.H.; Cescato, M.L.; Foster Junior, J.L.; Krmpotic, F.

    1983-07-01

    Angular distributions for elastic and inelastic scattering have been measured on six analog resonances in the 130 Te + p system and at two off resonance energies. Partial widths are deduced from the angular distributions. Formulae for the spectroscopic amplitudes within the framework of quasiparticle random phase approximation are presented. The experimental results are compared with the theoretical predictions. (Author) [pt

  12. Study of leading strange meson resonances and spin-orbit splittings in K/sup -/p. -->. K/sup -/. pi. /sup +/n at 11 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Honma, A.K.

    1980-11-01

    The results from a high-statistics study of K..pi.. elastic scattering in the reaction K/sup -/p ..-->.. K/sup -/..pi../sup +/n are presented. The data for this analysis are taken from an 11-GeV/c K/sup -/p experiment performed on the Large Aperture Solenoidal Spectrometer (LASS) facility at the Stanford Linear Accelerator Center (SLAC). By selecting the very forward produced K/sup -/..pi../sup +/ events, a sample consisting of data for the K..pi.. ..-->.. K..pi.. elastic scattering reaction was extracted. The angular distribution for this meson-meson scattering is studied by use of both a spherical harmonic moments analysis and a partial-wave analysis (PWA). The previously established leading natural spin-parity strange meson resonances (the J/sup P/ = 1/sup -/ K*(895), the 2/sup +/ K*(1430), and the 3/sup -/ K*(1780)) are observed in the results from both the moments analysis and the PWA. In addition, evidence for a new spin 4/sup -/ K* resonance with a mass of 2080 MeV and a width of about 225 MeV is presented. The results from the PWA confirm the existence of a 0/sup +/ kappa (1490) and propose the existence of a second scalar meson resonance, the 0/sup +/ kappa' (1900). Structure in the P-wave amplitude indicates resonance behavior in the mass region near 1700 MeV. In two of the four ambiguous solutions for the mass region above 1800 MeV, there is strong evidence for another P-wave resonant structure near 2100 MeV. The observed strange meson resonances are found to have a natural interpretation in terms of states predicted by the quark model. In particular, the mass splittings of the leading trajectory natural spin-parity strange meson states and the mass splittings between the spin-orbit triplet states are discussed. 59 figures, 17 tables.

  13. An analysis of stripping to isolated analog resonances

    International Nuclear Information System (INIS)

    Pessoa, E.F.; Toledo Piza, A.F.R. de.

    1983-04-01

    The Feshbach projection formalism is used to calculate the form factors for the (d,n) stripping process to isolated analog resonances. These are used in a standard DWBA stripping calculation in which the radial integration over all space is accomplished by including outerspace contributions evaluated along the complex contours of Vincent and Fortune. It turns out that the shape and magnitude of the predicted cross section is quite insensitive to the continuum proton wave emanating from the resonant residual state. (Author) [pt

  14. Particle-hole calculation of the isobaric analog and isovector monopole resonances

    International Nuclear Information System (INIS)

    Auerbach, N.; Nguyen Van Giai

    1977-06-01

    The correlated proton particle-neutron hole spectrum is calculated for N>Z nuclei using a Skyrme type interaction and the response function method. The basis of the calculation is a complete one particle-one hole space with the continuum included. As a result the distribution of the isovector monopole strength in the analog nucleus is obtained. This distribution has a narrow peak which corresponds to the isobaric analog resonance and at higher energies a broad peak which is the isovector monopole resonance. The coupling between these two states is inherent in the calculation

  15. Study of the multi-strange resonance $\\Xi(1530)^{0}$ production with ALICE at the LHC energies

    CERN Document Server

    AUTHOR|(CDS)2080748

    The primary goal of the relativistic heavy-ion physics program at Large Hadron Collider (LHC) at CERN, Geneva, Switzerland is to study the nuclear matter under extreme conditions. The measurement of resonances in ultra-relativistic heavy-ion collisions allows one to study the properties of the hadronic medium. Resonances with short lifetimes compared to the duration of the time span between chemical and kinetic freeze-out are good candidates to prove the interplay of particle re-scattering and regeneration in the hadronic phase, which result in a modification of their measured yields. The ALICE detector and its subsystem used for the analysis presented in this thesis are explained. Particle identification method and a coordinate system of ALICE are provided. Measurements of multi-strange resonance $\\Xi(1530)^{0}$ were performed with the ALICE detector in pp, p-Pb and Pb-Pb collisions at the LHC energies. The ${p_{\\mathrm{T}}}$-spectra of $\\Xi(1530)^{0}$ are obtained and compared with model predictions. The y...

  16. Analog implementation of an integral resonant control scheme

    International Nuclear Information System (INIS)

    Pereira, E; Moheimani, S O R; Aphale, S S

    2008-01-01

    Integral resonant control (IRC) has been introduced as a high performance controller design methodology for flexible structures with collocated actuator–sensor pairs. IRC has a simple structure and is capable of achieving significant damping, over several modes, while guaranteeing closed-loop stability of the system in the presence of unmodeled out-of-bandwidth dynamics. IRC can be an ideal controller for various industrial damping applications, if packaged in a simple easy-to-implement electronic module. This work proposes an analog implementation of the IRC scheme using a single Op-Amp circuit. The objective is to show that with simple analog realization of the modified IRC scheme, it is possible to damp a large number of vibration modes. A brief discussion about the modeling, circuit considerations, implementation and experimental results is presented in order to validate the usefulness and practicality of the proposed analog IRC implementation. (technical note)

  17. Study of high-spin analog resonances near the N=50 neutron shell

    International Nuclear Information System (INIS)

    Gales, S.; El Hage, Y.; Schapira, J.P.; Fortier, S.; Laurent, H.; Maison, J.M.

    1979-01-01

    The 96 Zr( 3 He,d) 97 Nb and the 92 Mo( 3 He,d) 93 Tc reactions, investigated at, respectively 39.0 and 28.5 MeV incident energies, were used to selectively populate high-spin analog resonances in the 97 Nb and 93 Tc nuclei. Angular distributions were measured for the dsub(3/2), gsub(7/2) and hsub(11/2) analog states of the low-lying levels in 97 Zr. A DWBA analysis of the data for these unbound levels (using Gamov functions as form factors) was carried out and spectroscopic strengths extracted. The 96 Zr( 3 He,dp) and 92 Mo( 3 He,dp) reactions were performed, respectively, at 37.5 and 30 MeV incident energies. The angular distributions of the emitted protons were measured in coincidence using method II of Litherland and Ferguson with 0 0 detection of deuteron groups. Spins, population parameters and proton branching ratios to the ground state and excited states of the targets were determined from the analysis of the angular correlation data. The position of the neutron threshold as compared with the excitation energies of the analog states in 97 Nb and 93 Tc is found to be an important parameter in the extraction of the structure informations on core-excited components in the parent levels wave functions. Neutron particle-hole multiplets are observed for the first time in 96 Zr through the decay of the gsub(7 /2) and hsub(11/2) analog resonances. The limitation of the present method due to the neutron threshold or to the energy resolution in the proton channel is discussed and compared with the results of inelastic resonant scattering through isobaric analog resonances

  18. Electromagnetic production of associated strangeness

    International Nuclear Information System (INIS)

    David, J.C.; CEA Centre d'Etudes de Saclay, 91 - Gif-sur-Yvette; Fayard, C.; Lamot, G.H.; Saghai, B.

    1996-04-01

    A formalism, based on an isobaric approach using Feynman diagram techniques, which includes the nucleonic (spin ≤ 5/2), hyperonic (spin 1/2) and kaonic resonances, is developed. Using this formalism, a thorough investigation of electromagnetic strangeness processes is performed. A reaction mechanism, describing well enough the data, is found to include a reasonable number of baryonic resonances among a very large number of potential candidates. Predictions for the upcoming photoproduction polarization and electroproduction observables are presented, and their sensitivity to the phenomenological models ingredients are emphasized. (K.A.)

  19. Echolocation The Strange Ways of Bats

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 5. Echolocation The Strange Ways of Bats. G Marimuthu. General Article Volume 1 Issue 5 May 1996 pp 40-48. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/05/0040-0048. Author Affiliations.

  20. Electromagnetic production of associated strangeness

    Energy Technology Data Exchange (ETDEWEB)

    David, J C [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; [CEA Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d` Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l` Instrumentation Associee; Fayard, C; Lamot, G H [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Saghai, B [CEA Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d` Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l` Instrumentation Associee

    1996-04-01

    A formalism, based on an isobaric approach using Feynman diagram techniques, which includes the nucleonic (spin {<=} 5/2), hyperonic (spin 1/2) and kaonic resonances, is developed. Using this formalism, a thorough investigation of electromagnetic strangeness processes is performed. A reaction mechanism, describing well enough the data, is found to include a reasonable number of baryonic resonances among a very large number of potential candidates. Predictions for the upcoming photoproduction polarization and electroproduction observables are presented, and their sensitivity to the phenomenological models ingredients are emphasized. (K.A.). 70 refs.; Submitted to Physical Review, C (US).

  1. Realizing a Circuit Analog of an Optomechanical System with Longitudinally Coupled Superconducting Resonators

    OpenAIRE

    Eichler, C.; Petta, J. R.

    2017-01-01

    We realize a superconducting circuit analog of the generic cavity-optomechanical Hamiltonian by longitudinally coupling two superconducting resonators, which are an order of magnitude different in frequency. We achieve longitudinal coupling by embedding a superconducting quantum interference device (SQUID) into a high frequency resonator, making its resonance frequency depend on the zero point current fluctuations of a nearby low frequency LC-resonator. By employing sideband drive fields we e...

  2. Neutron-skin thickness from the study of the anti-analog giant dipole resonance

    NARCIS (Netherlands)

    Krasznahorkay, A.; Stuhl, L.; Csatlós, M.; Algora, A.; Gulyás, J.; Timár, J.; Paar, N.; Vretenar, D.; Boretzky, K.; Heil, M.; Litvinov, Yu A.; Rossi, D.; Scheidenberger, C.; Simon, H.; Weick, H.; Bracco, A.; Brambilla, S.; Blasi, N.; Camera, F.; Giaz, A.; Million, B.; Pellegri, L.; Riboldi, S.; Wieland, O.; Altstadt, S.; Fonseca, M.; Glorius, J.; Göbel, K.; Heftrich, T.; Koloczek, A.; Kräckmann, S.; Langer, C.; Plag, R.; Pohl, M.; Rastrepina, G.; Reifarth, R.; Schmidt, S.; Sonnabend, K.; Weigand, M.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Rigollet, C.; Bagchi, S.; Najafi, M. A.; Aumann, T.; Atar, L.; Heine, M.; Holl, M.; Movsesyan, A.; Schrock, P.; Volkov, V.; Wamers, F.; Fiori, E.; Löher, B.; Marganiec, J.; Savran, D.; Johansson, H. T.; Fernández, P. Diaz; Garg, U.; Balabanski, D. L.

    2012-01-01

    The gamma-decay of the anti-analog of the giant dipole resonance (AGDR) has been measured to the isobaric analog state excited in the p(124Sn,n) reaction at a beam energy of 600 MeV/nucleon. The energy of the transition was also calculated with state-of-the-art self-consistent random-phase

  3. Production rates of strange vector mesons at the Z0 resonance

    International Nuclear Information System (INIS)

    Dima, M.O.

    1997-05-01

    This dissertation presents a study of strange vector meson production, open-quotes leading particleclose quotes effect and a first direct measurement of the strangeness suppression parameter in hadronic decays of the neutral electroweak boson, Z 0 . The measurements were performed in e + e - collisions at the Stanford Linear Accelerator Center (SLAC) with the SLC Large Detector (SLD) experiment. A new generation particle ID system, the SLD Cerenkov Ring Imaging Detector (CRID) is used to discriminate kaons from pions, enabling the reconstruction of the vector mesons over a wide momentum range. The inclusive production rates of φ and K* 0 and the differential rates versus momentum were measured and are compared with those of other experiments and theoretical predictions. The high longitudinal polarisation of the SLC electron beam is used in conjunction with the electroweak quark production asymmetries to separate quark jets from antiquark jets. K* 0 production is studied separately in these samples, and the results show evidence for the open-quotes leading particleclose quotes effect. The difference between K* 0 production rates at high momentum in quark and antiquark jets yields a first direct measurement of strangeness suppression in jet fragmentation

  4. Polarization observables for strangeness photoproduction on a frozen spin target with CLAS at Jefferson Lab

    International Nuclear Information System (INIS)

    Fegan, Stuart

    2012-01-01

    The FROST experiment at Jefferson Lab used the CLAS detector in Hall B with the intention of performing a complete measurement of polarization observables associated with strangeness photoproduction, in combination with data from previous JLab experiments. This was achieved by utilizing the FROST polarized target in conjunction with polarized photon beams, allowing direct measurement of beam-target double polarization observables. By studying strangeness reactions, such as γp → K + Λ 0 , it may be possible to find 'missing' baryon resonances, predicted by symmetric quark models but not observed in previous experiments, whose results are consistent with the di-quark model. It is thought these 'missing' resonances remain undiscovered because they have different coupling strengths for different reaction channels, such as the strangeness reactions, whereas the current data is dominated by studies of pN reactions. Observing these resonances therefore has important implications for our knowledge of the excited states of nucleons, and the models predicting the quark interactions within them. The G polarization observable is one of the beam-target double polarization observables, associated with a longitudinally polarized target and a linearly polarized photon beam, and its measurement for the strangeness reaction γp → K + Λ 0 is the focus of the work presented.

  5. Strangeness production in proton–proton and proton–nucleus ...

    Indian Academy of Sciences (India)

    Therefore, the strangeness production is expected to provide information about the resonances lying at higher excitation energies. For beam energies very close to the kaon production threshold the hyperon–proton final state interaction effects are quite important. Thus, these studies provide a check on the models of ...

  6. Strangeness production in AA and pp collisions

    Energy Technology Data Exchange (ETDEWEB)

    Castorina, Paolo [Universita di Catania, Dipartimento di Fisica ed Astronomia, Catania (Italy); INFN, Catania (Italy); Satz, Helmut [Universitaet Bielefeld, Fakultaet fuer Physik, Bielefeld (Germany)

    2016-07-15

    Boost-invariant hadron production in high-energy collisions occurs in causally disconnected regions of finite space-time size. As a result, globally conserved quantum numbers (charge, strangeness, baryon number) are conserved locally in spatially restricted correlation clusters. Their size is determined by two time scales: the equilibration time specifying the formation of a quark-gluon plasma, and the hadronization time, specifying the onset of confinement. The expected values for these scales provide the theoretical basis for the suppression observed for strangeness production in elementary interactions (pp, e{sup +}e{sup -}) below LHC energies. In contrast, the space-time superposition of individual collisions in high-energy heavy-ion interactions leads to higher energy densities, resulting in much later hadronization and hence much larger hadronization volumes. This largely removes the causality constraints and results in an ideal hadronic resonance gas in full chemical equilibrium. In the present paper, we determine the collision energies needed for that; we also estimate when pp collisions reach comparable hadronization volumes and thus determine when strangeness suppression should disappear there as well. (orig.)

  7. Strange Dibaryons

    International Nuclear Information System (INIS)

    Franklin, G.B.; Athanas, M.; Barnes, P.D.

    1993-01-01

    Strange Dibaryons, six valence-quark hadrons constructed from one or more strange quarks, are predicted to have greater binding than dibaryons in the non-strange sector. The flavor-singlet dibaryon with quark structure ''uuddss'' is of particular theoretical and experimental interest. A brief review of the status of H dibaryon studies is presented with emphasis on experiment E813 currently taking data at the AGS

  8. Nuclear magnetic resonance analogs of the Greenberger-Horne-Zeilinger experiment

    International Nuclear Information System (INIS)

    Lloyd, S.

    1998-01-01

    It has been recently shown that analogs of the Greenberger-Horne-Zeilinger experiment, which demonstrates the impossibility of certain types of local hidden variable theories in quantum mechanics, can be performed using nuclear magnetic resonance on spins in molecules at finite temperature. This paper examines the role of decoherence in the microscopic 'measurements' used to perform the NMR experiments. (author)

  9. Resonant Tunneling Analog-To-Digital Converter

    Science.gov (United States)

    Broekaert, T. P. E.; Seabaugh, A. C.; Hellums, J.; Taddiken, A.; Tang, H.; Teng, J.; vanderWagt, J. P. A.

    1995-01-01

    As sampling rates continue to increase, current analog-to-digital converter (ADC) device technologies will soon reach a practical resolution limit. This limit will most profoundly effect satellite and military systems used, for example, for electronic countermeasures, electronic and signal intelligence, and phased array radar. New device and circuit concepts will be essential for continued progress. We describe a novel, folded architecture ADC which could enable a technological discontinuity in ADC performance. The converter technology is based on the integration of multiple resonant tunneling diodes (RTD) and hetero-junction transistors on an indium phosphide substrate. The RTD consists of a layered semiconductor hetero-structure AlAs/InGaAs/AlAs(2/4/2 nm) clad on either side by heavily doped InGaAs contact layers. Compact quantizers based around the RTD offer a reduction in the number of components and a reduction in the input capacitance Because the component count and capacitance scale with the number of bits N, rather than by 2 (exp n) as in the flash ADC, speed can be significantly increased, A 4-bit 2-GSps quantizer circuit is under development to evaluate the performance potential. Circuit designs for ADC conversion with a resolution of 6-bits at 25GSps may be enabled by the resonant tunneling approach.

  10. Medium effects in strange quark matter and strange stars

    International Nuclear Information System (INIS)

    Schertler, K.; Greiner, C.; Thoma, M.H.

    1997-01-01

    We investigate the properties of strange quark matter at zero temperature including medium effects. The quarks are considered as quasiparticles which acquire an effective mass generated by the interaction with the other quarks of the dense system. The effective quark masses are derived from the zero momentum limit of the dispersion relations following from an effective quark propagator obtained from resumming one-loop self-energy diagrams in the hard dense loop approximation. This leads to a thermodynamic self-consistent description of strange quark matter as an ideal Fermi gas of quasiparticles. Within this approach we find that medium effects reduce the overall binding energy with respect to 56 Fe of strange quark matter. For typical values of the strong coupling constant (α s >or∼1) strange quark matter is not absolutely stable. The application to pure strange quark matter stars shows that medium effects have, nevertheless, no impact on the mass-radius relation of the stars. However, a phase transition to hadronic matter at the surface of the stars becomes more likely. (orig.)

  11. Overview of the electromagnetic production of strange mesons at MAMI

    Energy Technology Data Exchange (ETDEWEB)

    Achenbach, P., E-mail: patrick@kph.uni-mainz.de [Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Gómez Rodríguez, M. [Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Tsukada, K. [Department of Physics, Tohoku University, 980-8578 Sendai (Japan); Ayerbe Gayoso, C.; Böhm, R. [Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Borodina, O. [Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); GSI Helmholtz Centre for Heavy Ion Research, 64291 Darmstadt (Germany); Bosnar, D. [Department of Physics, University of Zagreb, 10002 Zagreb (Croatia); Bozkurt, V. [GSI Helmholtz Centre for Heavy Ion Research, 64291 Darmstadt (Germany); Bydžovský, P. [Nuclear Physics Institute, 25068 Řež near Prague (Czech Republic); Debenjak, L. [University of Ljubljana and Institut “Jožef Stefan”, 1000 Ljubljana (Slovenia); Distler, M.O.; Esser, A. [Institut für Kernphysik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Friščić, I. [Department of Physics, University of Zagreb, 10002 Zagreb (Croatia); Fujii, Y.; Gogami, T.; Hashimoto, O.; Hirose, S.; Kanda, H.; Kaneta, M. [Department of Physics, Tohoku University, 980-8578 Sendai (Japan); Kim, E. [GSI Helmholtz Centre for Heavy Ion Research, 64291 Darmstadt (Germany); and others

    2013-09-20

    The Mainz Microtron MAMI provides a continuous-wave unpolarized or spin-polarized electron beam with energies up to 1.6 GeV and high degrees of polarization. Electro-production of strange mesons is performed in the multi-spectrometer facility with the KAOS spectrometer for kaon detection and a high-resolution spectrometer for electron detection in plane or out of plane. Differential cross section measurements of exclusive p(e,e{sup ′}K{sup +})Λ,Σ{sup 0} reactions at low four-momentum transfers in the nucleon's third resonance region have been done, followed by a measurement of the beam helicity asymmetry for p(e{sup →},e{sup ′}K{sup +})Λ. These studies are important for the understanding of the effective coupling of photons to the hadrons and their resonances and electromagnetic form factors entering different effective Lagrangian models for photo- and electro-production of strangeness. The polarized structure function, extracted from the beam helicity asymmetry, shows an especially high sensitivity to model parameters.

  12. Theoretical perspective on strangeness production

    Directory of Open Access Journals (Sweden)

    Ko Che Ming

    2018-01-01

    Full Text Available A brief review of some highlights and puzzles on strangeness production in heavy ion collisions is given. These include strangeness production and the nuclear equation of state; deeply subthreshold strangeness production; mean-field potentials on strange hadrons; phi meson in dense matter; anomalous strange hadron to pion ratios; density fluctuations on particle production; A hyperon polarization and the vorticity field, and exotic hadrons.

  13. Chiral symmetry and strangeness at SIS energies

    International Nuclear Information System (INIS)

    Lutz, M.F.M.

    2003-11-01

    In this talk we review the consequences of the chiral SU(3) symmetry for strangeness propagation in nuclear matter. Objects of crucial importance are the meson-baryon scattering amplitudes obtained within the chiral coupled-channel effective field theory. Results for antikaon and hyperon-resonance spectral functions in cold nuclear matter are presented and discussed. The importance of the Σ(1385) resonance for the subthreshold antikaon production in heavy-ion reaction at SIS is pointed out. The in-medium properties of the latter together with an antikaon spectral function based on chiral SU(3) dynamics suggest a significant enhancement of the π Λ → anti Κ N reaction in nuclear matter. (orig.)

  14. Scalar resonances as two-quark states

    International Nuclear Information System (INIS)

    Shabalin, E.P.

    1984-01-01

    On the base of the theory with U(3)xU(3) symmetric chiral Lagrangian the properties of the two-quark scalar mesons are considered. It is shown, that the scalar resonances delta (980) and K(1240) may be treated as the p-wave states of anti qq system. The properties of the isovector and strange scalar mesons, obtained as a propetrties of the two-quark states, turn out to be very close to the properties of the isovector scalar resonance delta (980) and strange resonance K(1240)

  15. Production rates of strange vector mesons at the Z0 resonance

    Energy Technology Data Exchange (ETDEWEB)

    Dima, Mihai O. [Stanford Univ., CA (United States)

    1997-05-01

    This dissertation presents a study of strange vector meson production, "leading particle" effect and a first direct measurement of the strangeness suppression parameter in hadronic decays of the neutral electroweak boson, Z. The measurements were performed in e+e- collisions at the Stanford Linear Accelerator Center (SLAC) with the SLC Large Detector (SLD) experiment. A new generation particle ID system, the SLD Cerenkov Ring Imaging Detector (CRID) is used to discriminate kaons from pions, enabling the reconstruction of the vector mesons over a wide momentum range. The inclusive production rates of ρ and K*0 and the differential rates versus momentum were measured and are compared with those of other experiments and theoretical predictions. The high longitudinal polarisation of the SLC electron beam is used in conjunction with the electroweak quark production asymmetries to separate quark jets from antiquark jets. K*0 production is studied separately in these samples, and the results show evidence for the "leading particle" effect. The difference between K*0 production rates at high momentum in quark and antiquark jets yields a first direct measurement of strangeness suppression in jet fragmentation.

  16. Strange Assemblage

    Directory of Open Access Journals (Sweden)

    David Robert Cole

    2014-08-01

    Full Text Available This paper contends that the power of Deleuze & Guattari’s (1988 notion of assemblage as theorised in 1000 Plateaus can be normalised and reductive with reference to its application to any social-cultural context where an open system of dynamic and fluid elements are located. Rather than determining the assemblage in this way, this paper argues for an alternative conception of ‘strange assemblage’ that must be deliberately and consciously created through rigorous and focused intellectual, creative and philosophical work around what makes assemblages singular. The paper will proceed with examples of ‘strange assemblage’ taken from a film by Peter Greenaway (A Zed and 2 Noughts; the film ‘Performance’; educational research with Sudanese families in Australia; the book, Bomb Culture by Jeff Nuttall (1970; and the band Hawkwind. Fittingly, these elements are themselves chosen to demonstrate the concept of ‘strange assemblage’, and how it can be presented. How exactly the elements of a ‘strange assemblage’ come together and work in the world is unknown until they are specifically elaborated and created ‘in the moment’. Such spontaneous methodology reminds us of the 1960s ‘Happenings’, the Situationist International and Dada/Surrealism. The difference that will be opened up by this paper is that all elements of this ‘strange assemblage’ cohere in terms of a rendering of ‘the unacceptable.'

  17. Strange particles

    International Nuclear Information System (INIS)

    Chinowsky, W.

    1989-01-01

    Work done in the mid 1950s at Brookhaven National Laboratory on strange particles is described. Experiments were done on the Cosmotron. The author describes his own and others' work on neutral kaons, lambda and theta particles and points out the theoretical gap between predictions and experimental findings. By the end of the decade, the theory of strange particles was better understood. (UK)

  18. Strange quarks in nuclei

    International Nuclear Information System (INIS)

    Dover, C.B.

    1991-06-01

    We survey the field of strange particle nuclear physics, starting with the spectroscopy of strangeness S = -1 Λ hypernuclei, proceeding to an interpretation of recent data on S = -2 ΛΛ hypernuclear production and decay, and finishing with some speculations on the production of multi-strange nuclear composites (hypernuclei or ''strangelets'') in relativistic heavy ion collisions. 41 refs., 5 figs

  19. Survey of the (3He,t) reaction: Excitation of the isobaric analog of the giant dipole resonance

    International Nuclear Information System (INIS)

    Tabor, S.L.; Chang, C.C.; Collins, M.T.; Wagner, G.J.; Wu, J.R.; Halderson, D.W.; Petrovich, F.

    1982-01-01

    The ( 3 He,t) reaction at 130 and 170 MeV has been investigated on targets of 12 C, 16 O, 27 Al, 28 Si, 40 Ca, 46 Ti, and 90 Zr. Data for the ( 3 He, 3 He') reaction were measured simultaneously for reference purposes. Structure is observed in the spectra from the ( 3 He, 3 He') and ( 3 He,t) reaction at the expected positions of the giant quadrupole resonance and the isobaric analog of the giant dipole resonance, respectively. An angular distribution was measured for the suspected giant dipole resonance structure in the 40 Ca( 3 He,t) 40 Sc reaction at 130 MeV. The data are reasonably described by a collective model calculation based on the Goldhaber-Teller model for the giant dipole resonance. Several other strong peaks at excitation energies below the giant dipole resonance are observed in the ( 3 He,t) spectra. Most notable of these are the ones at the expected positions for analogs of well known 1 + states and 1hω stretched states in the targets

  20. Analogy of electromagnetically induced transparency in plasmonic nanodisk with a square ring resonator

    International Nuclear Information System (INIS)

    Li, Xianping; Wei, Zhongchao; Liu, Yuebo; Zhong, Nianfa; Tan, Xiaopei; Shi, Songsong; Liu, Hongzhan; Liang, Ruisheng

    2016-01-01

    We have demonstrated the analogy of electromagnetically induced transparency in plasmonic nanodisk with a square ring resonator. A reasonable analysis of the transmission feature based on the temporal coupled-mode theory is given and shows good agreement with the Finit-Difference Time-Domain simulation. The transparency window can be easily tuned by changing the geometrical parameters and the insulator filled in the resonator. The transmission of the resonator system is close to 80% and the full width at half maximum is less than 46 nm. The sensitivity of the structure is about 812 nm/RIU. These characteristics make the new system with potential to apply for optical storage, ultrafast plasmonic switch and slow-light devices.

  1. Analogy of electromagnetically induced transparency in plasmonic nanodisk with a square ring resonator

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xianping; Wei, Zhongchao, E-mail: wzc@scnu.edu.cn; Liu, Yuebo; Zhong, Nianfa; Tan, Xiaopei; Shi, Songsong; Liu, Hongzhan; Liang, Ruisheng

    2016-01-08

    We have demonstrated the analogy of electromagnetically induced transparency in plasmonic nanodisk with a square ring resonator. A reasonable analysis of the transmission feature based on the temporal coupled-mode theory is given and shows good agreement with the Finit-Difference Time-Domain simulation. The transparency window can be easily tuned by changing the geometrical parameters and the insulator filled in the resonator. The transmission of the resonator system is close to 80% and the full width at half maximum is less than 46 nm. The sensitivity of the structure is about 812 nm/RIU. These characteristics make the new system with potential to apply for optical storage, ultrafast plasmonic switch and slow-light devices.

  2. Strange and Multi-strange Particle Production in pPb and PbPb with CMS

    CERN Document Server

    Ni, Hong

    2017-01-01

    Identified particle spectra provide an important tool for understanding the particle production mechanism and the dynamical evolution of the medium created in relativistic heavy ion collisions. Studies involving strange and multi-strange hadrons, such as $K^0_S$, $\\Lambda$, and $\\Xi^-$, carry additional information since there is no net strangeness content in the initial colliding system. Strangeness enhancement in AA collisions with respect to pp and pA collisions has long been considered as one of the signatures for quark-gluon plasma (QGP) formation. Recent observations of collective effects in high-multiplicity pp and pA collisions raise the question of whether QGP can also be formed in the smaller systems. Systematic studies of strange particle abundance, particle ratios, and nuclear modification factors can shed light on this issue. The CMS experiment has excellent strange-particle reconstruction capabilities over a broad kinematic range, and dedicated high-multiplicity triggers in pp and pPb collision...

  3. Study of inelastic proton scattering at isobaric analog resonances

    International Nuclear Information System (INIS)

    Davis, S.L.

    1974-01-01

    Inelastic proton scattering at isobaric analog resonances (IAR's) was studied using the targets 138 Ba and 92 Mo. Differential cross sections and analyzing powers were measured at the 10.00, 10.63, 11.09, 11.45, and 11.70 MeV resonances in 138 Ba + p and at the 5.89, 6.09, and 6.55 MeV resonances in 92 Mo + p. In addition, a new measurement, the spin flip asymmetry, was developed. The experiment was performed by using a polarized beam to make spin flip measurements. Angular distributions for the spin flip probability and spin flip asymmetry were measured at all of the above energies except for the lowest three resonances in 138 Ba, where only the spin flip probability was measured. A DWBA code modified to include the coherent addition of resonance amplitudes was used to analyze the 138 Ba data. The partial widths extracted from this analysis were converted to expansion coefficients for parent states in 139 Ba. The coefficients were found to be in good agreement with unified model calculations. For 92 Mo, inelastic polarizations, deduced from the spin flip and spin flip asymmetry, were found to be large. Attempts using Hauser Feshbach theory to describe both the cross section and polarization data repeatedly failed for both the 6.55 and 5.87 MeV IAR's. This failure represents strong evidence that Hauser Feshbach theory is not valid when extended to describe scattering at an IAR. The 92 Mo data were analyzed using a reaction theory modified to include channel-channel correlations. This theory predicts that the enhanced compound scattering is identical to the resonance scattering. Good fits have been obtained with the use of this modified Hauser Feshbach theory. (U.S.)

  4. Ds1*(2860) and Ds3*(2860): candidates for 1D charmed-strange mesons

    International Nuclear Information System (INIS)

    Song, Qin-Tao; Chen, Dian-Yong; Liu, Xiang; Matsuki, Takayuki

    2015-01-01

    Newly observed two charmed-strange resonances, D s1 * (2860) and D s3 * (2860), are investigated by calculating their Okubo-Zweig-Iizuka-allowed strong decays, which shows that they are suitable candidates for the 1 3 D 1 and 1 3 D 3 states in the charmed-strange meson family. Our study also predicts other main decay modes of D s1 * (2860) and D s3 * (2860), which can be accessible at the future experiment. In addition, the decay behaviors of the spin partners of D s1 * (2860) and D s3 * (2860), i.e., 1D(2 - ) and 1D'(2 - ), are predicted in this work, which are still missing at present. The experimental search for the missing 1D(2 - ) and 1D'(2 - ) charmed-strange mesons is an intriguing and challenging task for further experiments. (orig.)

  5. Aspects of strangeness

    International Nuclear Information System (INIS)

    Dover, C.B.

    1995-01-01

    We review various aspects of strangeness production in relativistic heavy ion collisions from AGS to CERN energies. The experimental data are briefly summarized and various possible theoretical interpretations of these data are evaluated, such as quark-gluon- plasma (QGP), hadron gas (HG) thermal models, or event generators (cascade models). Some comments on the production of strange clusters are offered

  6. Missing baryonic resonances in the Hagedorn spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Man Lo, Pok [University of Wroclaw, Institute of Theoretical Physics, Wroclaw (Poland); GSI, Extreme Matter Institute EMMI, Darmstadt (Germany); Marczenko, Michal; Sasaki, Chihiro [University of Wroclaw, Institute of Theoretical Physics, Wroclaw (Poland); Redlich, Krzysztof [University of Wroclaw, Institute of Theoretical Physics, Wroclaw (Poland); GSI, Extreme Matter Institute EMMI, Darmstadt (Germany); Duke University, Department of Physics, Durham, NC (United States)

    2016-08-15

    The hadronic medium of QCD is modeled as a gas of point-like hadrons, with its composition determined by the Hagedorn mass spectrum. The spectrum consists of a discrete and a continuous part. The former is determined by the experimentally confirmed resonances tabulated by the Particle Data Group (PDG), while the latter can be extracted from the existing lattice data. This formulation of the hadron resonance gas (HRG) provides a transparent framework to relate the fluctuation of conserved charges as calculated in the lattice QCD approach to the particle content of the medium. A comparison of the two approaches shows that the equation of state is well described by the standard HRG model, which includes only a discrete spectrum of known hadrons. The corresponding description in the strange sector, however, shows clear discrepancies, thus a continuous spectrum is added to incorporate the effect of missing resonances. We propose a method to extract the strange-baryon spectrum from the lattice data. The result is consistent with the trend set by the unconfirmed strange baryons resonances listed by the PDG, suggesting that most of the missing interaction strength for the strange baryons reside in the S = 1 sector. This scenario is also supported by recent lattice calculations, and might be important in the energy region covered by the NICA accelerator in Dubna, where in the heavy-ion collisions, baryons are the dominating degrees of freedom in the final state. (orig.)

  7. Strangeness production at high baryon density

    Energy Technology Data Exchange (ETDEWEB)

    Satz, Helmut [Universitaet Bielefeld, Fakultaet fuer Physik, Bielefeld (Germany)

    2016-08-15

    We propose to measure strange and non-strange hadron abundances at NICA in both AA and pp collisions, in order to test the validity range and possible extension schemes for present explanations of the energy and collision dependence of strange particle suppression. (orig.)

  8. Strange and non-strange baryon production in ultrarelativistic sulphur-tungsten and sulphur-sulphur collisions

    International Nuclear Information System (INIS)

    Helstrup, H.

    1993-04-01

    Relativistic heavy ion collisions provide an opportunity to create a new phase of matter, the quark gluon plasma, in the laboratory. A possible quark gluon will be very short-lived, and only its decay products can be observed. There exists no unambiguous signal to identify plasma formation yet, although several candidates have been suggested. An enhanced production of strange particles is one of these proposed signals. The WA85 experiments measures strange particle production ratios in a narrow window in rapidity and transverse momentum. At present, WA85 is the only collaboration who have published results on multi strange particles. This thesis discusses the investigation of the production of strange particles in relativistic ion collisions done by the WA85 collaboration and its successors at CERN. An enhanced production of strange particles has been suggested as a signal for plasma production. Even if no plasma is produced, the experiment may reveal interesting information on the physics of the fireball produced by colliding heavy nuclei, the highest concentration of energy presently available on Earth. 80 refs., 57 figs., 11 tabs

  9. Is the nucleon strange?

    CERN Document Server

    Nowak, M A; Zahed, I

    1989-01-01

    The issue of the strangeness content of the proton in relation to a large σ π N term is examined using the instanton-antiinstanton description of the QCD ground state. Modulo plausible assumptions, our results indicate no strangeness admixture in the nucleon state at zero momentum transfer.

  10. Strange Hadronic Matter in a Chiral Model

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-Liang; SONG Hong-Qiu; WANG Ping; SU Ru-Keng

    2000-01-01

    The strange hadronic matter with nucleon, Λ-hyperon and E-hyperon is studied by using a chiral symmetry model in a mean-field approximation. The saturation properties and stabilities of the strange hadronic matter are discussed. The result indicates a quite large strangeness fraction (fs) region where the strange hadronic matter is stable against particle emission. In the large fs region, the component dominates, resulting in a deep minimum in the curve of the binding energy per baryon EB versus the strangeness fraction fs with (EB, fs) -~ (-26.0MeV, 1.23).

  11. Strangeness by Thermal Model Simulation at RHIC

    Institute of Scientific and Technical Information of China (English)

    SHI Xing-Hua; MA Yu-Gang; CAI Xiang-Zhou; CHEN Jin-Hui; MA Guo-Liang; ZHONG Chen

    2009-01-01

    The local temperature effect on strangeness enhancement in relativistic heavy ion collisions is discussed in the framework of the thermal model in which the K+ /h+ ratio becomes smaller with increasing freeze-out temperature.Considering that most strangeness particles of final-state particles are from the kaon meson,the temperature effect may play a role in strangeness production in hot dense matter where a slightly different temperature distribution in different areas could be produced by jet energy loss.This phenomenon is predicted by thermal model calculation at RHIC energy.The Ε-/φ ratio in central Au+Au collisions at 200 GeV from the thermal model depends on the freeze-out temperature obviously when γs is different.It should be one of the reasons why strangeness enhancements of Ε and φ are different though they include two strange quarks.These results indicate that thermodynamics is an important factor for strangeness production and the strangeness enhancement phenomenon.

  12. Magnetic monopoles and strange matter

    International Nuclear Information System (INIS)

    Sanudo, J.; Segui, A.

    1985-07-01

    We show that, if the density of grand unified monopoles at T approx. = 200 MeV is of the order of or greater than 4.4 * 10 21 cm -3 , they annihilate all of the strange matter produced in the quagmahadron phase transition which the Universe undergoes at this temperature. We also study gravitational capture of monopoles by lumps of strange matter. This yields upper limits on the density of monopoles for different sizes of strange ball. (author)

  13. Strange matter in compact stars

    Directory of Open Access Journals (Sweden)

    Klähn Thomas

    2018-01-01

    Full Text Available We discuss possible scenarios for the existence of strange matter in compact stars. The appearance of hyperons leads to a hyperon puzzle in ab-initio approaches based on effective baryon-baryon potentials but is not a severe problem in relativistic mean field models. In general, the puzzle can be resolved in a natural way if hadronic matter gets stiffened at supersaturation densities, an effect based on the quark Pauli quenching between hadrons. We explain the conflict between the necessity to implement dynamical chiral symmetry breaking into a model description and the conditions for the appearance of absolutely stable strange quark matter that require both, approximately masslessness of quarks and a mechanism of confinement. The role of strangeness in compact stars (hadronic or quark matter realizations remains unsettled. It is not excluded that strangeness plays no role in compact stars at all. To answer the question whether the case of absolutely stable strange quark matter can be excluded on theoretical grounds requires an understanding of dense matter that we have not yet reached.

  14. Strange matter in compact stars

    Science.gov (United States)

    Klähn, Thomas; Blaschke, David B.

    2018-02-01

    We discuss possible scenarios for the existence of strange matter in compact stars. The appearance of hyperons leads to a hyperon puzzle in ab-initio approaches based on effective baryon-baryon potentials but is not a severe problem in relativistic mean field models. In general, the puzzle can be resolved in a natural way if hadronic matter gets stiffened at supersaturation densities, an effect based on the quark Pauli quenching between hadrons. We explain the conflict between the necessity to implement dynamical chiral symmetry breaking into a model description and the conditions for the appearance of absolutely stable strange quark matter that require both, approximately masslessness of quarks and a mechanism of confinement. The role of strangeness in compact stars (hadronic or quark matter realizations) remains unsettled. It is not excluded that strangeness plays no role in compact stars at all. To answer the question whether the case of absolutely stable strange quark matter can be excluded on theoretical grounds requires an understanding of dense matter that we have not yet reached.

  15. Complete strangeness measurements in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Tomasik, Boris [Univerzita Mateja Bela, FPV, Banska Bystrica (Slovakia); Czech Technical University in Prague, FNSPE, Prague 1 (Czech Republic); Kolomeitsev, Evgeni E. [Univerzita Mateja Bela, FPV, Banska Bystrica (Slovakia)

    2016-08-15

    We discuss strangeness production in heavy-ion collisions within and around the energy range of the planned NICA facility. We describe a minimal statistical model, in which the total strangeness yield is fixed by the observed or calculated K{sup +} multiplicity. We show how the exact strangeness conservation can be taken into account on event-by-event basis in such a model. We argue that from strange particle yields one can reveal information about the collision dynamics and about possible modifications of particle properties in medium. This can be best achieved if the complete strangeness measurement is performed, i.e. kaons, antikaons, hyperons and multistrange hyperons are registered in the same experimental setup. In particular, production of hadrons containing two and more strange quarks, like Ξ and Ω baryons could be of interest. (orig.)

  16. Search for (exotic) strange matter in the Star and Alice experiments with the ultra-relativistic heavy ion colliders RHIC and LHC

    International Nuclear Information System (INIS)

    Vernet, R.

    2006-02-01

    Ultra-relativistic heavy ion collisions offer the possibility to create conditions of temperature and density that could lead nuclear matter to a state of deconfined partons, the quark-gluon plasma. Strange baryon production is one of the essential observables to understand the mechanisms involved in the medium. Furthermore, theories predict a possible production of strange dibaryons, still hypothetical particles, from which one could draw important inferences in nuclear physics and astrophysics. The experiments STAR at RHIC, and, soon, ALICE at LHC, allow one to search for strange baryons and dibaryons. The STAR sensitivity to the metastable dibaryon H 0 in the Λpπ - decay mode was calculated thanks to a dedicated simulation. The search for the H 0 , and for the Ξ - p resonance as well, was performed in the STAR Au+Au data at √(s NN ) = 62.4 and 200 GeV energies. Within the framework of the preparation of ALICE to the first Pb+Pb data, the detector ability to identify strange baryons Λ, Ξ and Ω, was estimated via several simulations. So as to favour the reconstruction efficiency in a large range of transverse momentum while keeping a reasonable S/B ratio, the influence of the geometrical selections and the size of the reconstruction zone was emphasized. The ALICE sensitivities to the metastable strange dibaryons H 0 and (Ξ 0 p) b and to the ΛΛ resonance were calculated as well. (author)

  17. Nucleon strangeness: present and future

    CERN Document Server

    Sapozhnikov, M G

    2010-01-01

    A review of experimental results for the measurement of the strange quark distributions in the nucleon, is given. Contributions of the strange quarks to the nucleon mass, electromagnetic form factors and spin, are discussed.

  18. Quark Condensate in the Strange Matter

    Institute of Scientific and Technical Information of China (English)

    LU Chang-Fang; LU" Xiao-Fu

    2003-01-01

    In a nonlinear chiral SU(3) framework, we investigate the quark condensate in the strange matter including N, Σ, Ξ, and Λ, making use of chiral symmetry spontaneous breaking Lagrangian and mean-field approximation. The results show that the chiral symmetry is restored partially when the strange matter density increases and that 〈π→2〉 plays a very important role in the strange matter which may approach the constituents of the neutron stars. In addition, we can find that the strange matter density where the π-condensate emerges leads to the ratio of the nucleon number to baryon number.

  19. Strange Light Nuclei

    Directory of Open Access Journals (Sweden)

    Nakamura Satoshi N.

    2014-04-01

    Full Text Available “Strange” means 1 unusual or surprising, especially in a way that is difficult to explain or understand or 2 having strangeness degree of freedom. Light nuclear systems with strangeness, light hypernuclei, are perfect playground to study baryon force which would be a bridge between well established nuclear force in low energy region and QCD, the first principle of the strong interaction. Overview of study of light hypernuclei is given and recent experimental findings are reviewed.

  20. Study of stellar objects with strange quark matter crust

    International Nuclear Information System (INIS)

    Hothi, N.; Bisht, S.

    2012-01-01

    The absolute stability of strange quark matter is a viable possibility and immensely effects physics at the astrophysical scale. Relativistic heavy-ion reactions offer a stage to produce this exotic state of matter and the enhanced production of strange particles during these reactions can be studied within the framework of quark-gluon plasma (QGP). We have tried to investigate the role of strangeness under the compact star phenomenology. Emphasis is laid upon the possibility of existence of a third family of strange quark stars and its study help in revealing a number of unexplored features of the cosmos. Bag model parameters have been used to determine some integral parameters for a sequence of strange stars with crust and strange dwarfs constructed out of strange quark matter crust. A comparative analysis is performed between the strange and neutron stars and the strange and white dwarfs based upon these intrinsic parameters and paramount differences are observed. The intimacy between astrophysics and strange quarks depends strongly upon the strange quark matter hypothesis. It states that for a collection of more than a few hundred u, d and s quarks, the energy per baryon E/A of strange quark matter (SQM) can be well below the energy per baryon of the most stable atomic nuclei

  1. Strangeness fluctuations and MEMO production at FAIR

    International Nuclear Information System (INIS)

    Steinheimer, Jan; Mitrovski, Michael; Schuster, Tim; Petersen, Hannah; Bleicher, Marcus; Stoecker, Horst

    2009-01-01

    We apply a coupled transport-hydrodynamics model to discuss the production of multi-strange meta-stable objects in Pb + Pb reactions at the FAIR facility. In addition to making predictions for yields of these particles we are able to calculate particle dependent rapidity and momentum distributions. We argue that the FAIR energy regime is the optimal place to search for multi-strange baryonic object (due to the high baryon density, favoring a distillation of strangeness). Additionally, we show results for strangeness and baryon density fluctuations. Using the UrQMD model we calculate the strangeness separation in phase space which might lead to an enhanced production of MEMOs compared to models that assume global thermalization.

  2. Production of strange particles in hadronization processes

    International Nuclear Information System (INIS)

    Hofmann, W.

    1987-08-01

    Strange particles provide an important tool for the study of the color confinement mechanisms involved in hadronization processes. We review data on inclusive strange-particle production and on correlations between strange particles in high-energy reactions, and discuss phenomenological models for parton fragmentation. 58 refs., 24 figs

  3. Strange mesonic transition form factor

    International Nuclear Information System (INIS)

    Goity, J.L.; Musolf, M.J.

    1996-01-01

    The strange-quark vector current ρ-to-π meson transition form factor is computed at one-loop order using strange meson intermediate states. A comparison is made with a φ-meson dominance model estimate. We find that one-loop contributions are comparable in magnitude to those predicted by φ-meson dominance. It is possible that the one-loop contribution can make the matrix element as large as those of the electromagnetic current mediating vector meson radiative decays. However, due to the quadratic dependence of the one-loop results on the hadronic form factor cutoff mass, a large uncertainty in the estimate of the loops is unavoidable. These results indicate that non-nucleonic strange quarks could contribute appreciable in moderate-parallel Q 2 parallel parity-violating electron-nucleus scattering measurements aimed at probing the strange-quark content of the nucleon. copyright 1996 The American Physical Society

  4. Measurement of the Strangeness Spectral Function and the Mass of the Strange Quark in Hadronic tau Decays with the OPAL Detector

    CERN Document Server

    Mader, Wolfgang Franz

    2004-01-01

    Tau lepton decays with open strangeness in the final state are measured with the Opal detector at LEP to determine the strange hadronic spectral function of the τ lepton and the mass of the strange quark. The decays τ −→ (Kπ) −ντ , (Kππ) −ντ and (Kπππ) −ντ with final states consisting of neutral and charged kaons and pions, have been studied. The invariant mass distribution of 93.4% of these final states have been experimentally determined. Monte Carlo simulations have been used for the remaining 6.6% and for the strange final states including η mesons. The reconstructed strange final states, corrected for resolution effects and detection efficiencies, yield the strange spectral function of the τ lepton. The moments of the spectral function and the ratio of strange to non-strange moments, which are important input parameters for theoretical analyses, are determined. Furthermore, the branching fractions B(τ − → K −π 0 ντ ) = (0.471 ± 0.064stat ± 0.021sys) % B(τ − → K ...

  5. Observation of enhanced production of strange and multi-strange hadrons in high-multiplicity pp and p-Pb collisions with the ALICE detector.

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    The production of strange hadrons has long been studied in heavy-ion collisions to investigate the formation of a deconfined medium. The interpretation of these data depends critically on the understanding of strange-particle production in smaller ‘baseline’ collision systems such as proton-proton and proton-ion. The ALICE experiment is well-suited to the measurement of identified charged hadrons and weakly-decaying strange and multi-strange baryons and has collected large samples of minimum-bias pp and p-Pb collisions. Characterising the collisions according to their final-state multiplicities reveals an enhancement in the production of strange and multi-strange particles, relative to light flavoured hadrons. This detailed information is valuable in understanding the mechanisms that control the production of strange particles.  

  6. Strange-quark-matter stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1989-11-01

    We investigate the implications of rapid rotation corresponding to the frequency of the new pulsar reported in the supernovae remnant SN1987A. It places very stringent conditions on the equation of state if the star is assumed to be bound by gravity alone. We find that the central energy density of the star must be greater than 13 times that of nuclear density to be stable against the most optimistic estimate of general relativistic instabilities. This is too high for the matter to consist of individual hadrons. We conclude that it is implausible that the newly discovered pulsar, if its half-millisecond signals are attributable to rotation, is a neutron star. We show that it can be a strange quark star, and that the entire family of strange stars can sustain high rotation if strange matter is stable at an energy density exceeding about 5.4 times that of nuclear matter. We discuss the conversion of a neutron star to strange star, the possible existence of a crust of heavy ions held in suspension by centrifugal and electric forces, the cooling and other features. 34 refs., 10 figs., 1 tab

  7. Observation of Fano resonance and classical analog of electromagnetically induced transparency in toroidal metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Han, Song; Yang, Helin [College of Physical Science and Technology, Central China Normal University, Wuhan (China); Cong, Lonqing; Singh, Ranjan [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore (Singapore); Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore (Singapore); Gao, Fei [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore (Singapore)

    2016-05-15

    Toroidal multipoles have recently been explored in various scientific communities, ranging from atomic and molecular physics, electrodynamics, and solid-state physics to biology. Here we experimentally and numerically demonstrate a three-dimensional toroidal metamaterial where two different toroidal dipoles along orthogonal directions have been observed. The chosen toroidal metamaterial also simultaneously supports Fano resonance and the classical analog of electromagnetically induced transparency (EIT) phenomena in the transmission spectra that originate from the electric-toroidal dipole and electric-magnetic dipole destructive interference. The intriguing properties of the toroidal resonances may open up avenues for applications in toroidal moments generator, sensing and slow-light devices. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Strange exotic states and compact stars

    International Nuclear Information System (INIS)

    Sagert, Irina; Wietoska, Mirjam; Schaffner-Bielich, Juergen

    2006-01-01

    We discuss the possible appearance of strange exotic multi-quark states in the interiors of neutron stars and signals for the existence of strange quark matter in the cores of compact stars. We show how the in-medium properties of possible pentaquark states are constrained by pulsar mass measurements. The possibility of generating the observed large pulsar kick velocities by asymmetric emission of neutrinos from strange quark matter in magnetic fields is outlined

  9. Measurement of the strangeness spectral function and the mass of the strange quark in hadronic τ decays with the OPAL detector

    International Nuclear Information System (INIS)

    Mader, W.

    2004-03-01

    Tau lepton decays with open strangeness in the final state are measured with the Opal detector at LEP to determine the strange hadronic spectral function of the τ lepton and the mass of the strange quark. The decays τ - → (Kπ) - ν τ , (Kππ) - ν τ and (Kπππ) - ν τ with final states consisting of neutral and charged kaons and pions, have been studied. The invariant mass distribution of 93.4% of these final states have been experimentally determined. Monte Carlo simulations have been used for the remaining 6.6% and for the strange final states including η mesons. The reconstructed strange final states, corrected for resolution effects and detection efficiencies, yield the strange spectral function of the τ lepton. The moments of the spectral function and the ratio of strange to non-strange moments, which are important input parameters for theoretical analyses, are determined. Furthermore, the branching fractions B(τ - → K - π 0 ν τ ) = (0.471 ± 0.064 stat ± 0.021 sys )%, B(τ - → K - π + π - ν τ ) = (0.415 ± 0.059 stat ± 0.031 sys )% have been measured. From the CKM weighted difference of strange and non-strange spectral moments, the mass of the strange quark at the τ mass scale has been determined: m s (m τ 2 ) = (84 ± 14 exp ± 6 V us ± 17 theo ) MeV. Evolving this result to customary scales yields m s (1 GeV 2 ) = (111 -35 +26 ) MeV, m s (4 GeV 2 ) = (82 -25 +19 ) MeV. (orig.)

  10. Strange sea quark effects for low lying baryons

    International Nuclear Information System (INIS)

    Upadhyay, A.; Batra, Meenakshi

    2013-01-01

    Assuming hadrons as an ensemble of quark-gluon Fock states, contributions from sea quarks and gluons can be studied in detail for ground state baryons. Spin crisis of nucleons say that only a small fraction of proton spin is carried by valence quarks. Rest part is distributed among gluons and sea which includes both strange and non-strange quark-anti-quark pairs. This necessitates the study of strange sea quark contribution for other baryons too due to higher mass and presence of strange quark in valence part. Recent studies have also studied strange sea contribution for baryons using different models. We implement the statistical modeling techniques to compute strange sea quark content for baryon octet. Statistical model has already been applied to study sea quark content for nucleons in the form of scalar, vector and tensor sea. In our present work the same idea has been extended for strange sea to probe the structure in more detail. (author)

  11. Strangeness chemical equilibration in a quark-gluon plasma

    International Nuclear Information System (INIS)

    Letessier, Jean; Rafelski, Johann

    2007-01-01

    We study, in the dynamically evolving quark-gluon plasma (QGP) fireball formed in relativistic heavy ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC), the growth of strangeness yield toward and beyond the chemical equilibrium. We account for the contribution of the direct strangeness production and evaluate the thermal-QCD strangeness production mechanisms. The specific yield of strangeness per entropy, s/S, is the primary target variable. We explore the effect of collision impact parameter, i.e., fireball size, on kinetic strangeness chemical equilibration in QGP. Insights gained in studying the RHIC data with regard to the dynamics of the fireball are applied to the study of strangeness production at the LHC. We use these results and consider the strange hadron relative particle yields at RHIC and LHC in a systematic fashion. We consider both the dependence on s/S and the direct dependence on the participant number

  12. Torsional oscillations of strange stars

    Directory of Open Access Journals (Sweden)

    Mannarelli Massimo

    2014-01-01

    Full Text Available Strange stars are one of the hypothetical compact stellar objects that can be formed after a supernova explosion. The existence of these objects relies on the absolute stability of strange collapsed quark matter with respect to standard nuclear matter. We discuss simple models of strange stars with a bare quark matter surface, thus standard nuclear matter is completely absent. In these models an electric dipole layer a few hundreds Fermi thick should exist close to the star surface. Studying the torsional oscillations of the electrically charged layer we estimate the emitted power, finding that it is of the order of 1045 erg/s, meaning that these objects would be among the brightest compact sources in the heavens. The associated relaxation times are very uncertain, with values ranging between microseconds and minutes, depending on the crust thickness. Although part of the radiated power should be absorbed by the electrosphere surrounding the strange star, a sizable fraction of photons should escape and be detectable.

  13. Measurement of the strangeness spectral function and the mass of the strange quark in hadronic {tau} decays with the OPAL detector

    Energy Technology Data Exchange (ETDEWEB)

    Mader, W.

    2004-03-01

    Tau lepton decays with open strangeness in the final state are measured with the Opal detector at LEP to determine the strange hadronic spectral function of the {tau} lepton and the mass of the strange quark. The decays {tau}{sup -} {yields} (K{pi}){sup -}{nu}{sub {tau}}, (K{pi}{pi}){sup -}{nu}{sub {tau}} and (K{pi}{pi}{pi}){sup -}{nu}{sub {tau}} with final states consisting of neutral and charged kaons and pions, have been studied. The invariant mass distribution of 93.4% of these final states have been experimentally determined. Monte Carlo simulations have been used for the remaining 6.6% and for the strange final states including {eta} mesons. The reconstructed strange final states, corrected for resolution effects and detection efficiencies, yield the strange spectral function of the {tau} lepton. The moments of the spectral function and the ratio of strange to non-strange moments, which are important input parameters for theoretical analyses, are determined. Furthermore, the branching fractions B({tau}{sup -} {yields} K{sup -}{pi}{sup 0}{nu}{sub {tau}}) = (0.471 {+-} 0.064{sub stat} {+-} 0.021{sub sys})%, B({tau}{sup -} {yields} K{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}}) = (0.415 {+-} 0.059{sub stat} {+-} 0.031{sub sys})% have been measured. From the CKM weighted difference of strange and non-strange spectral moments, the mass of the strange quark at the {tau} mass scale has been determined: m{sub s}(m{sub {tau}}{sup 2}) = (84 {+-} 14{sub exp} {+-} 6{sub V{sub us}} {+-} 17{sub theo}) MeV. Evolving this result to customary scales yields m{sub s}(1 GeV{sup 2}) = (111{sub -35}{sup +26}) MeV, m{sub s}(4 GeV{sup 2}) = (82{sub -25}{sup +19}) MeV. (orig.)

  14. Detecting analogies unconsciously

    Directory of Open Access Journals (Sweden)

    Thomas Peter Reber

    2014-01-01

    Full Text Available Analogies may arise from the conscious detection of similarities between a present and a past situation. In this functional magnetic resonance imaging study, we tested whether young volunteers would detect analogies unconsciously between a current supraliminal (visible and a past subliminal (invisible situation. The subliminal encoding of the past situation precludes awareness of analogy detection in the current situation. First, participants encoded subliminal pairs of unrelated words in either one or nine encoding trials. Later, they judged the semantic fit of supraliminally presented new words that either retained a previously encoded semantic relation (‘analog’ or not (‘broken analog’. Words in analogs versus broken analogs were judged closer semantically, which reflects unconscious analogy detection. Hippocampal activity associated with subliminal encoding correlated with the behavioral measure of unconscious analogy detection. Analogs versus broken analogs were processed with reduced prefrontal but enhanced medial temporal activity. We conclude that analogous episodes can be detected even unconsciously drawing on the episodic memory network.

  15. Strange matter and Big Bang helium synthesis

    International Nuclear Information System (INIS)

    Madsen, J.; Riisager, K.

    1985-01-01

    Stable strange quark matter produced in the QCD phase transition in the early universe will trap neutrons and repel protons, thus reducing primordial helium production, Ysub(p). For reasonable values of Ysub(p), the radius of strange droplets must exceed 10 -6 cm if strange matter shall solve the dark-matter problem without spoiling Big Bang helium synthesis. (orig.)

  16. COALESCENCE OF STRANGE-QUARK PLANETS WITH STRANGE STARS: A NEW KIND OF SOURCE FOR GRAVITATIONAL WAVE BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Geng, J. J.; Huang, Y. F. [School of Astronomy and Space Science, Nanjing University, Nanjing 210046 (China); Lu, T., E-mail: hyf@nju.edu.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2015-05-01

    Strange-quark matter (SQM) may be the true ground state of hadronic matter, indicating that the observed pulsars may actually be strange stars (SSs), but not neutron stars. According to the SQM hypothesis, the existence of a hydrostatically stable sequence of SQM stars has been predicted, ranging from 1 to 2 solar mass SSs, to smaller strange dwarfs and even strange planets. While gravitational wave (GW) astronomy is expected to open a new window to the universe, it will shed light on the search for SQM stars. Here we show that due to their extreme compactness, strange planets can spiral very close to their host SSs without being tidally disrupted. Like inspiraling neutron stars or black holes, these systems would serve as new sources of GW bursts, producing strong GWs at the final stage. The events occurring in our local universe can be detected by upcoming GW detectors, such as Advanced LIGO and the Einstein Telescope. This effect provides a unique probe to SQM objects and is hopefully a powerful tool for testing the SQM hypothesis.

  17. Strange-face illusions during inter-subjective gazing.

    Science.gov (United States)

    Caputo, Giovanni B

    2013-03-01

    In normal observers, gazing at one's own face in the mirror for a few minutes, at a low illumination level, triggers the perception of strange faces, a new visual illusion that has been named 'strange-face in the mirror'. Individuals see huge distortions of their own faces, but they often see monstrous beings, archetypal faces, faces of relatives and deceased, and animals. In the experiment described here, strange-face illusions were perceived when two individuals, in a dimly lit room, gazed at each other in the face. Inter-subjective gazing compared to mirror-gazing produced a higher number of different strange-faces. Inter-subjective strange-face illusions were always dissociative of the subject's self and supported moderate feeling of their reality, indicating a temporary lost of self-agency. Unconscious synchronization of event-related responses to illusions was found between members in some pairs. Synchrony of illusions may indicate that unconscious response-coordination is caused by the illusion-conjunction of crossed dissociative strange-faces, which are perceived as projections into each other's visual face of reciprocal embodied representations within the pair. Inter-subjective strange-face illusions may be explained by the subject's embodied representations (somaesthetic, kinaesthetic and motor facial pattern) and the other's visual face binding. Unconscious facial mimicry may promote inter-subjective illusion-conjunction, then unconscious joint-action and response-coordination. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Strangeness production in heavy ion collisions

    International Nuclear Information System (INIS)

    Redlich, K.

    2001-05-01

    Strangeness production in heavy ion collisions is discussed in a broad energy range from SIS to RHIC. In the whole energy range particle yields are showing high level of chemical equilibration which can be described by the unified freezeout conditions of fixed energy/particle ≅ 1GeV. The statistical model within the canonical formulation of strangeness conservation provides a framework to describe the observed enhancement of (multi)strange particles from p+A to A+A collisions measured at the SPS energy and predicts that this enhancement should be larger for decreasing collision energy. However, only at the SPS and RHIC chemical freezeout temperature is consistent within error with the critical value required for deconfinement and simultaneously strangeness is uncorrelated and distributed in the whole volume of the fireball. (orig.)

  19. Strange particle production in anti pp annihilation from 1.22 to 1.35 GeV/c

    International Nuclear Information System (INIS)

    Handler, T.; Plano, R.J.; Brucker, E.B.; Koller, E.L.; Taylor, S.; Stamer, P.E.

    1976-01-01

    Experimental results on antiproton-proton annihilations at 5 incident momenta in the range 1.22-1.35 GeV/c into final states with at least one visible K 1 0 meson are presented. Based on a total of 5855 events, cross sections and resonance fractions for all experimentally accessible final states are determined. The total cross section for annihilation into strange particles with at least one visible K 1 0 is 2069 +- 45 μb. Copious resonance production is observed but there is no significant evidence for the formation of a resonance in the s-channel. (Auth.)

  20. Determination of baryon and baryonic resonance masses from QCD sum rules. Strange baryons

    International Nuclear Information System (INIS)

    Belyaev, V.M.; Ioffe, B.L.

    1982-01-01

    The mass differences in baryonic octet Jsup(P)=1/2sup(+), decuplet Jsup(P)=3/2sup(+) and in octet Jsup(P)=3/2sup(-) are calculated basing on the QCD sum rules. The mass differences are expressed through two QCD parameters: the strange current qUark mass and the value of the quark condensate. At the properly chosen values of these parameters all of the mass differences are in a good agreement with experiment

  1. Multi-strangeness dynamics at PANDA

    Energy Technology Data Exchange (ETDEWEB)

    Gaitanos, Theodoros; Lenske, Horst; Mosel, Ulrich [Institut fuer Theoretische Physik, Universitaet Giessen (Germany)

    2014-07-01

    Multi-strange bound hadron systems are excellent candidates for studying in-medium hyperon-hyperon (YY) interactions. A better understanding of the strangeness sector of the hadronic equation of state is crucial for our understanding of astrophysical objects like neutron stars. Furthermore, these studies are being motivated by actual and planed experimental activities on hypernuclear physics (HypHI and PANDA Collaborations). In fact, HypHI has already studied single-strange hypernuclei in heavy-ion collisions, whereas studies on double- and multi-strange nuclear systems are being planed by PANDA. We have reported in the past first studies on single- and double-Λ hypernuclei production in reactions induced by heavy-ions and antiprotons, respectively. The YY-interaction is still little known and many controversial theoretical predictions exist in the literature. We therefore extend our previous works by investigating the influence of various hyperon-hyperon interactions on the production dynamics of multi-Λ hypernuclei in reactions relevant for FAIR. Particular attention is paid to the heavy Ω-baryon (S=-3) and its role to the formation of multi-Λ hypernuclei in reactions induced by antiprotons.

  2. Collider phenomenology of light strange-beauty squarks

    International Nuclear Information System (INIS)

    Cheung, Kingman; Hou Weizshu

    2004-01-01

    Strong mixing between right-handed strange and beauty squarks is a possible solution to the CP violation discrepancy in B→φK S decay as recently suggested by the Belle data. In this scenario, thanks to the strong mixing one of the strange-beauty squarks can be as light as 200 GeV, even though the generic supersymmetry scale is at TeV. In this work, we study the production of this light right-handed strange-beauty squark at hadronic colliders and discuss the detection in various decay scenarios. Detection prospect at the Tevatron run II is good for the strange-beauty squark mass up to about 300 GeV

  3. Strangeness in the nucleon on the light-cone

    International Nuclear Information System (INIS)

    Malheiro, Manuel; Melnitchouk, Wally

    1999-01-01

    Strange matrix elements of the nucleon are calculated within the light-cone formulation of the meson cloud model. The Q 2 dependence of the strange vector form factors is computed, and the strangeness radius and magnetic moment extracted, both of which are found to be very small. The strange magnetic moment μ S is seen to change sign once the spurious form factors arising from the violation of rotational invariance are subtracted. The resulting μ S is small and slightly positive, in agreement with the trend of the recent data from the SAMPLE experiment. Within the same framework one finds a small but non-zero excess of the antistrange distribution over the strange at large x. (author)

  4. Strange experiments at the AGS

    International Nuclear Information System (INIS)

    Chrien, R.

    1990-01-01

    The purpose of this review is to report recent progress in nuclear experiments involving strangeness which have been carried out at the Brookhaven Alternating Gradient Synchrotron over the past three years. These recent developments are noted in three areas: few body systems and dibaryons; strange probes of the nucleus; and associated production of hypernuclei. 9 refs., 3 figs

  5. Overview of strangeness nuclear physics

    International Nuclear Information System (INIS)

    Gibson, B.F.

    1998-01-01

    Novel as well as puzzling aspects of strangeness (S = -1 and S = -2) nuclear physics are highlighted. Opportunities to gain new insights into hypernuclear spectroscopy, structure, and weak decays and to contribute to the continuing effort to understand the fundamental baryon-baryon force are outlined. Connections to strangeness in heavy-ion reactions and astrophysics are noted

  6. Study of natural spin-parity strange meson radial excitations in K-p → K-π+n at 11 GeV/c

    International Nuclear Information System (INIS)

    Durkin, L.S.

    1980-12-01

    Results are presented from a high statistics study of the reaction K - p → K - π + n at 11 GeV/c. This data was selected offline from an approx. 1000 event/μb K - p experiment run on the Large Aperture Solenoid Spectrometer (LASS) at SLAC which triggered on essentially the total inelastic cross section. This K - π + n sample, after cuts, contained approx. 42,000 events in the Kπ invariant mass region from 0.65 GeV to 2.30 GeV, and absolute value t' 2 . A spherical harmonic angular moments analysis of this data is presented, as well as an energy independent partial wave analysis (PWA) of these angular moments. The nearly uniform acceptance characteristics of this data allowed a detailed analysis, which yielded information on natural spin-parity strange meson resonances in the Kπ invariant mass range from 0.65 GeV to 2.30 GeV. The well established K*(895), K*(1430), and K*(1780) are observed, and clear evidence is presented for a J/sup P/ = 4 + strange meson state at a mass of 2.08 GeV. The K - π + elastic scattering partial waves extracted in this PWA show unambiguous evidence for a relatively narrow S wave resonance near 1.42 GeV in the Kπ invariant mass. This state is a confirmation of the 0 + K(1500) seen in previous PWA's. A new higher S wave resonance is clearly seen unambiguously near 1.90 GeV. Unambiguous evidence is presented for a relatively wide P wave resonance in the 1.70 GeV region.A second new P wave resonance also is seen in two of four ambiguous partial wave solutions in the 2.10 GeV region. These resonance states are discussed within the framework of a simple harmonic oscillator quark model. In particular three of the underlying resonances are discussed as possible natural spin-parity strange meson radial excitations

  7. Towards a new generation of strangeness results

    CERN Document Server

    Bellwied, R

    2004-01-01

    I will review the latest strangeness result measured in fixed target heavy-ion collisions at SIS, AGS and SPS before describing the first round of RHIC results. I will show that the systematic studies performed at the lower energies give a very consistent picture of enhanced strangeness production at SPS energies and hints of medium modification effects at the lower energies, which are dominated by larger baryon densities. The RHIC results complement this picture by again indicating strangeness production from a thermally equilibrated source, albeit at slightly higher freeze-out temperatures and lower baryon densities. RHIC adds significant new physics results to the field, though, by enabling the measurement of strange particle production at high transverse momentum, presently out to about 6 GeV /c. The new regime between 2 and 6 GeV/c is dominated by an interplay between traditional soft particle production, which is well described by hydrodynamical and thermal models, and production of strangeness from jet...

  8. Multiquark resonant states

    International Nuclear Information System (INIS)

    Shahbazian, B.A.

    1982-01-01

    The invariant mass spectra of forty nine hadronic systems with hypercharge, strangeness and baryon number, varied in wide limits have been studied. Resonance peaks have been found in the invariant mass spectra of Y 2 and #betta#pπ 2495 MeV/c 2 resonant states. Three more candidates for anti qq 4 states were found #bettaπ# + π + : 1705, 2072, 2605 MeV/c 2 . The masses of all these candidates are in good agreement with Bag Model predictions. A hypercharge selection rule is suggested: ''The hypercharge of hadronic resonances in weak gravitational fields cannot exceed one Y <= 1

  9. Towards a new generation of strangeness results

    International Nuclear Information System (INIS)

    Bellwied, Rene

    2004-01-01

    I will review the latest strangeness result measured in fixed target heavy-ion collisions at SIS, AGS and SPS before describing the first round of RHIC results. I will show that the systematic studies performed at the lower energies give a very consistent picture of enhanced strangeness production at SPS energies and hints of medium modification effects at the lower energies, which are dominated by larger baryon densities. The RHIC results complement this picture by again indicating strangeness production from a thermally equilibrated source, albeit at slightly higher freeze-out temperatures and lower baryon densities. RHIC adds significant new physics results to the field, though, by enabling the measurement of strange particle production at high transverse momentum, presently out to about 6 GeV/c. The new regime between 2 and 6 GeV/c is dominated by an interplay between traditional soft particle production, which is well described by hydrodynamical and thermal models, and production of strangeness from jet fragmentation. Potential new QGP signatures, such as jet quenching and elliptic flow due to parton collectivity, can be probed by measuring particle identified strange particle spectra out to high p t . I will review the latest results and show that these measurements breathe new life into a well-established field

  10. Strangeness at SIS energies

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Volker

    2005-09-28

    In this contribution the authors discuss the physics of strange hadrons in low energy ({approx_equal} 1-2 AGeV) heavy ion collision. In this energy range the relevant strange particle are the kaons and anti-kaons. The most interesting aspect concerning these particles are so called in-medium modifications. They will attempt to review the current status of understanding of these in medium modifications. In addition they briefly discuss other issues related with kaon production, such as the nuclear equation of state and chemical equilibrium.

  11. Production of strange clusters in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Dover, C.B.; Baltz, A.J.; Pang, Yang; Schlagel, T.J.; Kahana, S.H.

    1993-02-01

    We address a number of issues related to the production of strangeness in high energy heavy ion collisions, including the possibility that stable states of multi-strange hyperonic or quark matter might exist, and the prospects that such objects may be created and detected in the laboratory. We make use of events generated by the cascade code ARC to estimate the rapidity distribution dN/dy of strange clusters produced in Si+Au and Au+Au collisions at AGS energies. These calculations are performed in a simple coalescence model, which yields a consistent description of the strange cluster (d, 3 HE, 3 H, 4 He) production at these energies. If a doubly strange, weakly bound ΛΛ dibaryon exists, we find that it is produced rather copiously in Au+Au collisions, with dN/dy ∼0.1 at raid-rapidity. If one adds another non-strange or strange baryon to a cluster, the production rate decreases by roughly one or two orders of magnitude, respectively. For instance, we predict that the hypernucleus ΛΛ 6 He should have dN/dy ∼5 x 10 -6 for Au+Au central collisions. It should be possible to measure the successive Λ → pπ- weak decays of this object. We comment on the possibility that conventional multi-strange hypernuclei may serve as ''doorway states'' for the production of stable configurations of strange quark matter, if such states exist

  12. Strange hadron production at low transverse momenta

    Science.gov (United States)

    Veres, Gábor I.; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Noell, A.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Roland, C.; Roland, G.; Sagerer, J.; Sarin, P.; Sawicki, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Teng, R.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wyslouch, B.; Zhang, J.

    2004-01-01

    Some of the latest results of the PHOBOS experiment from the \\sqrt{s_{NN}}= 200\\ GeV Au+Au data are discussed. Those relevant to strangeness production are emphasized. These observations relate to the nature of the matter created when heavy ions collide at the highest achieved energy. The invariant yields of strange and non-strange charged hadrons at very low transverse momentum have been measured, and used to differentiate between different dynamical scenarios. In the intermediate transverse momentum range, the measured ratios of strange and anti-strange kaons approach one, while the antibaryon to baryon ratio is still significantly less, independent of collision centrality and transverse momentum. At high transverse momenta, we find that central and peripheral Au+Au collisions produce similar numbers of charged hadrons per participant nucleon pair, rather than per binary nucleon-nucleon collision. Finally, we describe the upgrades of PHOBOS completed for the 2003 d+Au and p+p run, which extend the transverse momentum range over which particle identification is possible and, at the same time, implement a trigger system selective for high-pT particles.

  13. A Fat strange Repeller

    Institute of Scientific and Technical Information of China (English)

    申影; 何阅; 姜玉梅; 何大韧

    2004-01-01

    This article reports an observation on a fat strange repeller, which appears after a characteristic crisis observed in a kicked rotor subjected to a piecewise continuous force field. The discontinuity border in the definition range of the two-dimensional mapping, which describes the system, oscillates as the discrete time develops. At a threshold of a control parameter a fat chaotic attractor suddenly transfers to a fat transient set. The strange repeller, which appears after the crisis, is also a fat fractal. This is the reason why super-transience happens

  14. Search for a strangeness -2 dibaryon

    International Nuclear Information System (INIS)

    Franklin, G.B.

    1985-01-01

    The existing data on the strangeness -2 two-baryon mass spectrum is reviewed and a new experiment is proposed to explore this spectrum from 100 MeV below the mass of the lightest known two-baryon strangeness -2 system, ΛΛ, to 20 MeV above the ΛΛ mass. The proposed experiment is motivated by Jaffe's 1977 prediction of a six-quark object with strangeness -2 and J/sup π/ = 0 + at a mass of 2150. This particle, called the ''H'', has been predicted by later bag models as well. Calculations indicate the proposed experiment will be a sensitive test of the dibaryon theories. 12 refs

  15. Theoretical Issues in Strangeness Production

    International Nuclear Information System (INIS)

    Laget, Jean-Marc

    2000-01-01

    After pioneering works on hypernuclei, strangeness production mechanisms have been studied in hadron collisions and photoreactions in the sixties. Recent experiments at SATURNE and COSY, in the hadronic sector, as well as ELSA and JLab, in the electromagnetic sector, have confirmed our basic ideas on the reaction mechanisms. In the near future, strangeness production at JLab, HERMES and COMPASS may prove to be a powerful tool to study hadronic matter

  16. Electrochemistry and electron paramagnetic resonance spectroscopy of cytochrome c and its heme-disrupted analogs.

    Science.gov (United States)

    Novak, David; Mojovic, Milos; Pavicevic, Aleksandra; Zatloukalova, Martina; Hernychova, Lenka; Bartosik, Martin; Vacek, Jan

    2018-02-01

    Cytochrome c (cyt c) is one of the most studied conjugated proteins due to its electron-transfer properties and ability to regulate the processes involved in homeostasis or apoptosis. Here we report an electrochemical strategy for investigating the electroactivity of cyt c and its analogs with a disrupted heme moiety, i.e. apocytochrome c (acyt c) and porphyrin cytochrome c (pcyt c). The electrochemical data are supplemented with low-temperature and spin-probe electron paramagnetic resonance (EPR) spectroscopy. The main contribution of this report is a complex evaluation of cyt c reduction and oxidation at the level of surface-localized amino acid residues and the heme moiety in a single electrochemical scan. The electrochemical pattern of cyt c is substantially different to both analogs acyt c and pcyt c, which could be applicable in further studies on the redox properties and structural stability of cytochromes and other hemeproteins. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Strange Baryon Physics in Full Lattice QCD

    International Nuclear Information System (INIS)

    Huey-Wen Lin

    2007-01-01

    Strange baryon spectra and form factors are key probes to study excited nuclear matter. The use of lattice QCD allows us to test the strength of the Standard Model by calculating strange baryon quantities from first principles

  18. Seismic Search for Strange Quark Matter

    Science.gov (United States)

    Teplitz, Vigdor

    2004-01-01

    Two decades ago, Witten suggested that the ground state of matter might be material of nuclear density made from up, down and strange quarks. Since then, much effort has gone into exploring astrophysical and other implications of this possibility. For example, neutron stars would almost certainly be strange quark stars; dark matter might be strange quark matter. Searches for stable strange quark matter have been made in various mass ranges, with negative, but not conclusive results. Recently, we [D. Anderson, E. Herrin, V. Teplitz, and I. Tibuleac, Bull. Seis. Soc. of Am. 93, 2363 (2003)] reported a positive result for passage through the Earth of a multi-ton "nugget" of nuclear density in a search of about a million seismic reports, to the U.S. Geological Survey for the years 1990-93, not associated with known Earthquakes. I will present the evidence (timing of first signals to the 9 stations involved, first signal directions, and unique waveform characteristics) for our conclusion and discuss potential improvements that could be obtained from exploiting the seismologically quieter environments of the moon and Mars.

  19. PREFACE: Strangeness in Quark Matter (SQM2009) Strangeness in Quark Matter (SQM2009)

    Science.gov (United States)

    Fraga, Eduardo; Kodama, Takeshi; Padula, Sandra; Takahashi, Jun

    2010-09-01

    The 14th International Conference on Strangeness in Quark Matter (SQM2009) was held in Brazil from 27 September to 2 October 2009 at Hotel Atlântico, Búzios, Rio de Janeiro. The conference was jointly organized by Universidade Federal do Rio de Janeiro, Universidade Estadual de Campinas, Centro Brasileiro de Pesquisas Físicas, Universidade de São Paulo, Universidade Estadual Paulista and Universidade Federal do Rio Grande do Sul. Over 120 scientists from Argentina, Brazil, China, France, Germany, Hungary, Italy, Japan, Mexico, The Netherlands, Norway, Poland, Russia, Slovakia, South Africa, Switzerland, the UK and the USA gathered at the meeting to discuss the physics of hot and dense matter through the signals of strangeness and also the behavior of heavy quarks. Group photograph The topics covered were strange and heavy quark production in nuclear collisions, strange and heavy quark production in elementary processes, bulk matter phenomena associated with strange and heavy quarks, and strangeness in astrophysics. In view of the LHC era and many other upcoming new machines, together with recent theoretical developments, sessions focused on `New developments and new facilities' and 'Open questions' were also included. A stimulating round-table discussion on 'Physics opportunities in the next decade in the view of strangeness and heavy flavor in matter' was chaired in a relaxed atmosphere by Grazyna Odyniec and conducted by P Braun-Munzinger, W Florkowski, K Redlich, K Šafařík and H Stöcker, We thank these colleagues for pointing out to young participants new physics directions to be pursued. We also thank J Dunlop and K Redlich for excellent introductory lectures given on the Sunday evening pre-conference session. In spite of the not-so-helpful weather, the beauty and charm of the town of Búzios helped to make the meeting successful. Nevertheless, the most important contributions were the excellent talks, whose contents are part of these proceedings, given

  20. Weak strange particle production: advantages and difficulties

    International Nuclear Information System (INIS)

    Angelescu, Tatiana; Baker, O.K.

    2002-01-01

    Electromagnetic strange particle production developed at Jefferson Laboratory was an important source of information on strange particle electromagnetic formfactors and induced and transferred polarization. The high quality of the beam and the detection techniques involved could be an argument for detecting strange particles in weak interactions and answer questions about cross sections, weak formfactors, neutrino properties, which have not been investigated yet. The paper analyses some aspects related to the weak lambda production and detection with the Hall C facilities at Jefferson Laboratory and the limitations in measuring the weak interaction quantities. (authors)

  1. Multistrange Meson-Baryon Dynamics and Resonance Generation

    Science.gov (United States)

    Khemchandani, K. P.; Martínez Torres, A.; Hosaka, A.; Nagahiro, H.; Navarra, F. S.; Nielsen, M.

    2018-05-01

    In this talk I review our recent studies on meson-baryon systems with strangeness - 1 and - 2. The motivation of our works is to find resonances generated as a consequence of coupled channel meson-baryon interactions. The coupled channels are all meson-baryon systems formed by combining a pseudoscalar or a vector meson with an octet baryon such that the system has the strange quantum number equal to - 1 or - 2. The lowest order meson-baryon interaction amplitudes are obtained from Lagrangians based on the chiral and the hidden local symmetries related to the vector mesons working as the gauge bosons. These lowest order amplitudes are used as an input to solve the Bethe-Salpeter equation and a search for poles is made in the resulting amplitudes, in the complex plane. In case of systems with strangeness - 1, we find evidence for the existence of some hyperons such as: Λ(2000), Σ(1750), Σ(1940), Σ(2000). More recently, in the study of strangeness - 2 systems we have found two narrow resonances which can be related to Ξ (1690) and Ξ(2120). In this latter work, we have obtained the lowest order amplitudes relativistically as well as in the nonrelativistic approximation to solve the scattering equations. We find that the existence of the poles in the complex plane does not get affected by the computation of the scattering equation with the lowest order amplitudes obtained in the nonrelativistic approximation.

  2. Strangeness photoproduction

    International Nuclear Information System (INIS)

    Berthot, J.; Saghai, B.

    1989-01-01

    A non exhaustive review, about the strangeness photo-production is presented here in relation with the new electrons machines. Accent is put on the elementary reaction γp → K + Λ. The experiments on electroproduction and the study of hypernuclei with the electromagnetic probe are also discussed [fr

  3. Mass-radius relation for magnetized strange quark stars

    CERN Document Server

    Martinez, A Perez; Paret, D Manreza

    2010-01-01

    We review the stability of magnetized strange quark matter (MSQM) within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the strange quark mass, baryon density, magnetic field and bag parameter. A comparison with magnetized asymmetric quark matter in $\\beta$-equilibrium as well as with strange quark matter (SQM) is presented. We obtain that the energy per baryon for MSQM decreases as the magnetic field increases, and its minimum value at vanishing pressure is lower than the value found for SQM, which implies that MSQM is more stable than non-magnetized SQM. The mass-radius relation for magnetized strange quark stars is also obtained in this framework.

  4. Strangeness suppression in e+e- light flavour jets

    International Nuclear Information System (INIS)

    Liu Ximing; Sun Xubin

    2007-01-01

    From the simple physical picture of quark combination model, the authors obtain the generate probabilities of various particles and relative ration in e + e - →q 0 (q 0 )-bar→h's process, and find that the relationship between the ration of strange hadron to unstrange hadron γ and the strangeness suppression factor λ. Our results can be used to explain particle ration enhancement observed in experiments without assumption of strangeness suppression factor enhancement. (authors)

  5. Strangeness production with protons and pions

    International Nuclear Information System (INIS)

    Dover, C.B.

    1993-01-01

    We discuss the spectrum of physics questions related to strangeness which could be addressed with intense beams of protons and pions in the few GeV region. We focus on various aspects of strangeness production, including hyperon production in pp collisions, studies of hyperon-nucleon scattering, production of hypernuclei in proton and pion-nucleus collisions, and spin phenomena in hypernuclei

  6. Measurement of the Strange Spectral Function in Hadronic $\\tau$ Decays

    CERN Document Server

    Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barillari, T.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Buesser, K.; Burckhart, H.J.; Campana, S.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Ciocca, C.; Csilling, A.; Cuffiani, M.; Dado, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Gagnon, P.; Gary, John William; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harel, A.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hoffman, Kara Dion; Horvath, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kramer, T.; Krieger, P.; von Krogh, J.; Kruger, K.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Layter, J.G.; Lellouch, D.; Lettso, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, A.; Ludwig, J.; Mader, W.; Marcellini, S.; Martin, A.J.; Masetti, G.; Mashimo, T.; Mattig, Peter; McKenna, J.; McPherson, R.A.; Meijers, F.; Menges, W.; Menke, S.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J.M.; Rosati, S.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schorner-Sadenius, T.; Schroder, Matthias; Schumacher, M.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vollmer, C.F.; Vannerem, P.; Vertesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija

    2004-01-01

    Tau Lepton decays with open strangeness in the final state are measured with the OPAL detector at LEP to determine the strange hadronic spectral function of the tau lepton. The decays tau- -> (Kpi)-nu tau, (Kpipi)-nu tau and (Kpipipi)-nu tau with final states consisting of neutral and charged kaons and pions have been studied. The invariant mass distributions of 93.4% of these final states have been experimentally determined. Monte Carlo simulations have been used for the remaining 6.6% and for the strange final states including eta mesons. The reconstructed strange final states, corrected for resolution effects and detection efficiencies, yield the strange spectral function of the tau lepton. The moments of the spectral function and the ratio of strange to non-strange moments, which are important input parameters for theoretical analyses, are determined. Furthermore, the branching fractions B(tau- -> K-pi0nu tau) = (0.471+-0.059stat+-0.023sys)% and B(tau- -> K-pi+pi-nu tau) = (0.415+-0.053stat+-0.040sys)% ha...

  7. Strange quark content in the nucleon and the strange quark vector current form factors

    International Nuclear Information System (INIS)

    Dubnicka, S.; Dubnickova, A.Z.

    1996-12-01

    A behaviour of the form factors of the nucleon matrix element of the strange quark vector current in the momentum range of the planned measurements in MIT/Bates and CEBAF is predicted theoretically without using any of the experimental information on the nucleon electromagnetic structure. The corresponding leading nonvanishing moments of the nucleon vector strangeness distribution are comparable with the values obtained by other authors in the framework of the method based on the vector meson pole fit of the isoscalar electromagnetic form factors of the nucleon. (author). 16 refs, 2 figs

  8. Study of the diffractive production of baryon states and search for cryptoexotic baryons with hidden strangeness

    International Nuclear Information System (INIS)

    Balatz, M.Ya.; Belyaev, I.M.; Dorofeev, V.A.

    1993-01-01

    The reactions of baryon diffractive production p + N → (pK + K - ) + N, p + N → (pφ) + N, p + N → [Λ(1520)K + ] + N and p + N → [Σ(1385) 0 K + ] + N in the 70 GeV proton beam were studied. Very sensitive upper limits for the production cross sections of heavy narrow cryptoexotic baryon resonances with hidden strangeness were obtained

  9. Space-Time Geometry of Quark and Strange Quark Matter

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We study quark and strange quark matter in the context of general relativity. For this purpose, we solve Einstein's field equations for quark and strange quark matter in spherical symmetric space-times. We analyze strange quark matter for the different equations of state (EOS) in the spherical symmetric space-times, thus we are able to obtain the space-time geometries of quark and strange quark matter. Also, we discuss die features of the obtained solutions. The obtained solutions are consistent with the results of Brookhaven Laboratory, i.e. the quark-gluon plasma has a vanishing shear (i.e. quark-gluon plasma is perfect).

  10. Rapidity dependence of strangeness enhancement factor at FAIR energies

    International Nuclear Information System (INIS)

    Dey, Kalyan; Bhattacharjee, B.

    2014-01-01

    Strange particles are produced only at the time of collisions and thus expected to carry important information of collision dynamics. Strangeness enhancement is considered to be one of the traditional signatures of formation of Quark Gluon Plasma (QGP). Due to the limitation of the detector acceptance, the past and ongoing heavy ion experiments could measure the strangeness enhancement at midrapidity only. But the future heavy ion experiment CBM at FAIR will have the access to the entire forward rapidity hemisphere and thus the experimental determination of rapidity dependent strangeness enhancement is a possibility. In this work, an attempt has therefore been made to study the rapidity dependent strangeness enhancement at FAIR energies with the help of a string based hadronic model (UrQMD). A sum of 93 million minimum biased UrQMD events have been used for the present analysis

  11. D{sub s1}{sup *}(2860) and D{sub s3}{sup *}(2860): candidates for 1D charmed-strange mesons

    Energy Technology Data Exchange (ETDEWEB)

    Song, Qin-Tao [Chinese Academy of Sciences, Nuclear Theory Group, Institute of Modern Physics, Lanzhou (China); Lanzhou University and Institute of Modern Physics of CAS, Research Center for Hadron and CSR Physics, Lanzhou (China); University of Chinese Academy of Sciences, Beijing (China); Chen, Dian-Yong [Chinese Academy of Sciences, Nuclear Theory Group, Institute of Modern Physics, Lanzhou (China); Lanzhou University and Institute of Modern Physics of CAS, Research Center for Hadron and CSR Physics, Lanzhou (China); Liu, Xiang [Lanzhou University and Institute of Modern Physics of CAS, Research Center for Hadron and CSR Physics, Lanzhou (China); Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Matsuki, Takayuki [Tokyo Kasei University, Tokyo (Japan); RIKEN, Theoretical Research Division, Nishina Center, Saitama (Japan)

    2015-01-01

    Newly observed two charmed-strange resonances, D{sub s1}{sup *}(2860) and D{sub s3}{sup *}(2860), are investigated by calculating their Okubo-Zweig-Iizuka-allowed strong decays, which shows that they are suitable candidates for the 1{sup 3}D{sub 1} and 1{sup 3}D{sub 3} states in the charmed-strange meson family. Our study also predicts other main decay modes of D{sub s1}{sup *}(2860) and D{sub s3}{sup *}(2860), which can be accessible at the future experiment. In addition, the decay behaviors of the spin partners of D{sub s1}{sup *}(2860) and D{sub s3}{sup *}(2860), i.e., 1D(2{sup -}) and 1D'(2{sup -}), are predicted in this work, which are still missing at present. The experimental search for the missing 1D(2{sup -}) and 1D'(2{sup -}) charmed-strange mesons is an intriguing and challenging task for further experiments. (orig.)

  12. Performance analysis of pulse analog control schemes for LLC resonant DC/DC converters suitable in portable applications

    Directory of Open Access Journals (Sweden)

    P. Kowstubha

    2016-12-01

    Full Text Available Performance Analysis of Pulse Analog Control Schemes, predominantly Pulse-Width Modulation (PWM and Pulse-Position Modulation (PPM for LLC resonant DC/DC converter suitable in portable applications is addressed in this paper. The analysis is done for closed loop performance, frequency domain performance, primary and secondary side conduction losses and soft commutation using PSIM 6.0 software and observed that PPM scheme provides better performance at high input voltage with a good selectivity of frequency over a wide range of line and load variations. The performance of LLC resonant DC/DC converter is demonstrated using PPM scheme for a design specifications of 12 V, 5 A output.

  13. Experimental overview and challenge in strangeness nuclear physics — strangeness in the past and coming decades

    International Nuclear Information System (INIS)

    Imai, Kenichi

    2010-01-01

    A great progress has been made in strangeness nuclear physics in the past decade. Examples are; 1) The "hyperfine" structure of hypernuclei were measured with the Hyperball, and ΛN spin dependent interactions in p-shell hypernuclei were determined. 2) The "complete measurements" of the weak decay of hypernuclei were made and the np ratio puzzle in the non-mesonic decay was solved. 3) The discovery of a clean event of "Lambpha" and determination of its binding energy concluded that the Λ-Λ interaction is weak attractive. However, we still have important questions to be answered in this field, especially in relation with QCD and nuclear physics. For the future strangeness nuclear physics, we have and will have facilities such as JLab, SPring-8, Daphne, J-PARC, FAIR. We discuss experimental challenges in the strangeness nuclear physics and related fields in the next decade. (author)

  14. Study of the diffractive production of baryon states and search for cryptoexotic baryons with hidden strangeness

    Energy Technology Data Exchange (ETDEWEB)

    Balatz, M.Ya.; Belyaev, I.M.; Dorofeev, V.A.; Dzyubenko, G.B.; Filimonov, I.M.; Frolov, S.V.; Golovkin, S.V.; Grishkin, Yu.L.; Gritzuk, M.V.; Jilin, A.V.; Kamenskii, A.D.; Kliger, G.K.; Kolganov, V.Z.; Konstantinov, A.S.; Korchagin, Yu.V.; Kozhevnikov, A.P.; Kubarovskii, V.P.; Kulman, N.Yu.; Kulyavtsev, A.I.; Kurshetsov, V.F.; Kushnirenko, A.E.; Lakaev, V.S.; Landsberg, L.G.; Lebedev, A.A.; Lomkatzi, G.S.; Molchanov, V.V.; Mukhin, V.A.; Nilov, A.F.; Novoghilov, Yu.B.; Prutskoi, V.A.; Sitnikov, A.I.; Smolyankin, V.T.; Solyanik, V.I.; Vavilov, D.V.; Victorov, V.A.; Vishnyakov, V.E. (Inst. for High Energy Physics, Protvino (Russian Federation) Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation) Moscow State Univ. (Russian Federation)); SPHINX Collaboration

    1994-02-01

    The reactions of baryon diffractive production p + N [yields] (pK[sup +] K[sup -]) + N, p + N [yields] (p[Phi]) + N, p + N [yields] [Lambda](1520) K[sup +] + N and p + N [yields] [Sigma](1385) K[sup +] + N in the 70 GeV proton beam were studied. Very sensitive upper limits for the production cross sections of heavy narrow cryptoexotic baryon resonances with hidden strangeness were obtained. (orig.)

  15. Strangeness in nuclear collisions

    International Nuclear Information System (INIS)

    Gazdzicki, M.; Roehrich, D.

    1996-01-01

    Data on the mean multiplicity of strange hadrons produced in minimum bias proton-proton and central nucleus-nucleus collisions at momenta between 2.8 and 400 GeV/c per nucleon have been compiled. The multiplicities for nucleon-nucleon interactions were constructed. The ratios of strange particle multiplicity to participant nucleon as well as to pion multiplicity are larger for central nucleus-nucleus collisions than for nucleon-nucleon interactions at all studied energies. The data at AGS energies suggest that the latter ratio saturates with increasing masses of the colliding nuclei. The strangeness to pion multiplicity ratio observed in nucleon-nucleon interactions increases with collision energy in the whole energy range studied. A qualitatively different behaviour is observed for central nucleus-nucleus collisions: the ratio rapidly increases when going from Dubna to AGS energies and changes little between AGS and SPS energies. This change in the behaviour can be related to the increase in the entropy production observed in central nucleus-nucleus collisions at the same energy range. The results are interpreted within a statistical approach. They are consistent with the hypothesis that the quark gluon plasma is created at SPS energies, the critical collision energy being between AGS and SPS energies. (orig.)

  16. Stars of strange matter

    International Nuclear Information System (INIS)

    Bethe, H.A.; Brown, G.E.; Cooperstein, J.

    1987-01-01

    We investigate suggestions that quark matter with strangeness per baryon of order unity may be stable. We model this matter at nuclear matter densities as a gas of close packed Λ-particles. From the known mass of the Λ-particle we obtain an estimate of the energy and chemical potential of strange matter at nuclear densities. These are sufficiently high to preclude any phase transition from neutron matter to strange matter in the region near nucleon matter density. Including effects from gluon exchange phenomenologically, we investigate higher densities, consistently making approximations which underestimate the density of transition. In this way we find a transition density ρ tr > or approx.7ρ 0 , where ρ 0 is nuclear matter density. This is not far from the maximum density in the center of the most massive neutron stars that can be constructed. Since we have underestimated ρ tr and still find it to be ∝7ρ 0 , we do not believe that the transition from neutron to quark matter is likely in neutron stars. Moreover, measured masses of observed neutron stars are ≅1.4 M sun , where M sun is the solar mass. For such masses, the central (maximum) density is ρ c 0 . Transition to quark matter is certainly excluded for these densities. (orig.)

  17. Properties of Strange Matter in a Model with Effective Lagrangian

    Institute of Scientific and Technical Information of China (English)

    WANG Ping; SU Ru-Keng; SONG Hong-Qiu; ZHANG Li-Liang

    2001-01-01

    The strange hadronic matter with nucleons, A-hyperons and E-hyperons is studied by using an effective nuclear model in a mean-field approximation. The density and strangeness fraction dependence of the effective baryon masses as well as the saturation properties and stabilities of the strange hadronic matter are discussed.``

  18. On meson resonances and chiral symmetry

    International Nuclear Information System (INIS)

    Lutz, M.F.M.

    2003-07-01

    We study meson resonances with quantum numbers J P = 1 + in terms of the chiral SU(3) Lagrangian. At leading order a parameter-free prediction is obtained for the scattering of Goldstone bosons off vector mesons with J P = 1 - once we insist on approximate crossing symmetry of the unitarized scattering amplitude. A resonance spectrum arises that is remarkably close to the empirical pattern. In particular, we find that the strangeness-zero resonances h 1 (1380), f 1 (1285) and b 1 (1235) are formed due to strong K anti K μ and K K μ channels. This leads to large coupling constants of those resonances to the latter states. (orig.)

  19. Resonances in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, Matthias F.M., E-mail: m.lutz@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Technische Universität Darmstadt, D-64289 Darmstadt (Germany); Lange, Jens Sören, E-mail: Soeren.Lange@exp2.physik.uni-giessen.de [II. Physikalisches Institut, Justus-Liebig-Universität Giessen, D-35392 Giessen (Germany); Pennington, Michael, E-mail: michaelp@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Bettoni, Diego [Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, 44122 Ferrara (Italy); Brambilla, Nora [Physik Department, Technische Universität München, D-85747 Garching (Germany); Crede, Volker [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Eidelman, Simon [Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Budker Istitute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); Gillitzer, Albrecht [Institut für Kernphysik, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany); Gradl, Wolfgang [Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55128 Mainz (Germany); Lang, Christian B. [Institut für Physik, Universität Graz, A-8010 Graz (Austria); Metag, Volker [II. Physikalisches Institut, Justus-Liebig-Universität Giessen, D-35392 Giessen (Germany); Nakano, Takashi [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); and others

    2016-04-15

    We report on the EMMI Rapid Reaction Task Force meeting ‘Resonances in QCD’, which took place at GSI October 12–14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: • What is needed to understand the physics of resonances in QCD? • Where does QCD lead us to expect resonances with exotic quantum numbers? • What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy–light and heavy–heavy meson systems, those with charm quarks were the focus. This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.

  20. Resonances in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, Matthias F. M.; Lange, Jens Sören; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B.; Metag, Volker; Nakano, Takashi; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Stephen L.; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram

    2016-04-01

    We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015 (Fig.~1). A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions; what is needed to understand the physics of resonances in QCD?; where does QCD lead us to expect resonances with exotic quantum numbers?; and what experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy-light and heavy-heavy meson systems, those with charm quarks were the focus.This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.

  1. Strange sea determination from collider data

    Science.gov (United States)

    Alekhin, S.; Blümlein, J.; Moch, S.

    2018-02-01

    We consider determinations of the strange sea in the nucleon based on QCD analyses of data collected at the LHC with focus on the recent high-statistics ATLAS measurement of the W±- and Z-boson production. We study the effect of different functional forms for parameterization of the parton distribution functions and the combination of various data sets in the analysis. We compare to earlier strange sea determinations and discuss ways to improve them in the future.

  2. Strange Attractors in Drift Wave Turbulence

    International Nuclear Information System (INIS)

    Lewandowski, J.L.V.

    2003-01-01

    A multi-grid part-in-cell algorithm for a shearless slab drift wave model with kinetic electrons is presented. The algorithm, which is based on an exact separation of adiabatic and nonadiabatic electron responses, is used to investigate the presence of strange attractors in drift wave turbulence. Although the simulation model has a large number of degrees of freedom, it is found that the strange attractor is low-dimensional and that it is strongly affected by dissipative (collisional) effects

  3. Strange sea determination from collider data

    International Nuclear Information System (INIS)

    Alekhin, S.; Bluemlein, J.; Moch, S.

    2017-08-01

    We consider determinations of the strange sea in the nucleon based on QCD analyses of data collected at the LHC with focus on the recent high-statistics ATLAS measurement of the W ± - and Z-boson production. We study the effect of different functional forms for parameterization of the parton distribution functions and the combination of various data sets in the analysis. We compare to earlier strange sea determinations and discuss ways to improve them in the future.

  4. Strange sea determination from collider data

    Energy Technology Data Exchange (ETDEWEB)

    Alekhin, S. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Institut Fiziki Vysokikh Ehnergij, Protvino (Russian Federation); Bluemlein, J. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Moch, S. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2017-08-15

    We consider determinations of the strange sea in the nucleon based on QCD analyses of data collected at the LHC with focus on the recent high-statistics ATLAS measurement of the W{sup ±}- and Z-boson production. We study the effect of different functional forms for parameterization of the parton distribution functions and the combination of various data sets in the analysis. We compare to earlier strange sea determinations and discuss ways to improve them in the future.

  5. On the Stability of Strange Dwarf Hybrid Stars

    Energy Technology Data Exchange (ETDEWEB)

    Alford, Mark G.; Harris, Steven P. [Physics Department, Washington University, St. Louis, MO 63130 (United States); Sachdeva, Pratik S., E-mail: harrissp@wustl.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States)

    2017-10-01

    We investigate the stability of “strange dwarfs”: white-dwarf-sized stars with a density discontinuity between a small dense core of quark matter and a thick low-density mantle of degenerate electrons. Previous work on strange dwarfs suggested that such a discontinuity could stabilize stars that would have been classified as unstable by the conventional criteria based on extrema in the mass–radius relation. We investigate the stability of such stars by numerically solving the Sturm–Liouville equations for the lowest-energy modes of the star. We find that the conventional criteria are correct, and strange dwarfs are not stable.

  6. Status and prospects for strange physics at LHCb

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Rare decays are fundamental probes of physics beyond the Standard Model. We present the current status of rare decays studies at the LHCb experiment and discuss a possible picture emerging from these measurements. The expanding LHCb program of strange physics, in particular of their rare decays, provides a unique and complementary probe to test the SM with respect to the beauty and charm. We present recent results on rare strange hadrons decays exploiting the LHCb Run I data. We then present prospects for strange physics with the LHCb Run II data and after the improvements in the trigger for the LHCb Upgrade.

  7. On the properties of strange quark matter

    International Nuclear Information System (INIS)

    Zhou Leming; Peng Guangxiong; Ning Pingzhi

    1999-01-01

    According to authors' recent studies, the authors derive a new mass formula for strange quarks at zero temperature. The authors apply it to investigating the properties of strange quark matter and obtain similar results to those in the MIT bag model. A different point in authors' results is that the variation of sound velocity with energy density becomes a little slower

  8. Enhanced production of multi-strange hadrons in high-multiplicity proton–proton collisions

    CERN Document Server

    Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahmad, Shakeel; Ahn, Sang Un; Aiola, Salvatore; Akindinov, Alexander; Alam, Sk Noor; Silva De Albuquerque, Danilo; 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; An, Mangmang; Andrei, Cristian; Andrews, Harry Arthur; Andronic, Anton; Anguelov, Venelin; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Arnaldi, Roberta; Arnold, Oliver Werner; Arsene, Ionut Cristian; Arslandok, Mesut; Audurier, Benjamin; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Balasubramanian, Supraja; Baldisseri, Alberto; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Barth, Klaus; 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; Espinoza Beltran, Lucina Gabriela; 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; Biro, Gabor; Biswas, Rathijit; Biswas, Saikat; Bjelogrlic, Sandro; Blair, Justin Thomas; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Bombara, Marek; Bonora, Matthias; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Borri, Marcello; Bossu, Francesco; Botta, Elena; Bourjau, Christian; 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; Bashir Butt, Jamila; Buxton, Jesse Thomas; Cabala, Jan; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calero Diaz, Liliet; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Carena, Francesco; Carena, Wisla; Carnesecchi, Francesca; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Cerkala, Jakub; Chang, Beomsu; Chapeland, Sylvain; Chartier, Marielle; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chauvin, Alex; Chelnokov, Volodymyr; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Cho, Soyeon; 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; Crkovska, Jana; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Danisch, Meike Charlotte; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; De Conti, Camila; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; Derradi De Souza, Rafael; Deisting, Alexander; Deloff, Andrzej; Denes, Ervin Sandor; Deplano, Caterina; Dhankher, Preeti; Di Bari, Domenico; Di Mauro, Antonio; Di Nezza, Pasquale; Di Ruzza, Benedetto; Diaz Corchero, Miguel Angel; Dietel, Thomas; Dillenseger, Pascal; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Drozhzhova, Tatiana; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dupieux, Pascal; Ehlers Iii, Raymond James; Elia, Domenico; Endress, Eric; Engel, Heiko; Epple, Eliane; Erazmus, Barbara Ewa; Erdemir, Irem; Erhardt, Filip; 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; Feliciello, Alessandro; Feofilov, Grigorii; Ferencei, Jozef; Fernandez Tellez, Arturo; Gonzalez Ferreiro, Elena; Ferretti, Alessandro; Festanti, Andrea; Feuillard, Victor Jose Gaston; Figiel, Jan; Araujo Silva Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Francisco, Audrey; Frankenfeld, Ulrich Michael; Fronze, Gabriele Gaetano; Fuchs, Ulrich; Furget, Christophe; Furs, Artur; Fusco Girard, Mario; Gaardhoeje, Jens Joergen; Gagliardi, Martino; Gago Medina, Alberto Martin; Gajdosova, Katarina; Gallio, Mauro; Duarte Galvan, Carlos; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Gao, Chaosong; Garabatos Cuadrado, Jose; Garcia-Solis, Edmundo Javier; Garg, Kunal; Gargiulo, Corrado; Gasik, Piotr Jan; Gauger, Erin Frances; Germain, Marie; 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; Sanchez Gonzalez, Andres; Gonzalez, Victor; Gonzalez Zamora, Pedro; Gorbunov, Sergey; Gorlich, Lidia Maria; Gotovac, Sven; Grabski, Varlen; Grachov, Oleg Anatolievich; Graczykowski, Lukasz Kamil; Graham, Katie Leanne; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoryev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grynyov, Borys; Grion, Nevio; Gronefeld, Julius Maximilian; Grosse-Oetringhaus, Jan Fiete; Grosso, Raffaele; Gruber, Lukas; Guber, Fedor; Guernane, Rachid; Guerzoni, Barbara; Gulbrandsen, Kristjan Herlache; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Haake, Rudiger; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Hamon, Julien Charles; Harris, John William; Harton, Austin Vincent; Hatzifotiadou, Despina; Hayashi, Shinichi; Heckel, Stefan Thomas; Hellbar, Ernst; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Herrmann, Florian; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hillemanns, Hartmut; Hippolyte, Boris; Horak, David; Hosokawa, Ritsuya; Hristov, Peter Zahariev; Hughes, Charles; Humanic, Thomas; Hussain, Nur; Hussain, Tahir; Hutter, Dirk; Hwang, Dae Sung; Ilkaev, Radiy; Inaba, Motoi; Incani, Elisa; Ippolitov, Mikhail; Irfan, Muhammad; Isakov, Vladimir; Ivanov, Marian; Ivanov, Vladimir; Izucheev, Vladimir; Jacak, Barbara; Jacazio, Nicolo; Jacobs, Peter Martin; Jadhav, Manoj Bhanudas; Jadlovska, Slavka; Jadlovsky, Jan; Jahnke, Cristiane; Jakubowska, Monika Joanna; Janik, Malgorzata Anna; Pahula Hewage, Sandun; Jena, Chitrasen; Jena, Satyajit; Jimenez Bustamante, Raul Tonatiuh; Jones, Peter Graham; Jusko, Anton; Kalinak, Peter; Kalweit, Alexander Philipp; Kang, Ju Hwan; Kaplin, Vladimir; Kar, Somnath; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karayan, Lilit; Karpechev, Evgeny; Kebschull, Udo Wolfgang; Keidel, Ralf; Keijdener, Darius Laurens; Keil, Markus; Khan, Mohammed Mohisin; Khan, Palash; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Khatun, Anisa; Kileng, Bjarte; Kim, Do Won; Kim, Dong Jo; Kim, Daehyeok; Kim, Hyeonjoong; Kim, Jinsook; Kim, Jiyoung; 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; Klewin, Sebastian; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Kobdaj, Chinorat; Kofarago, Monika; Kollegger, Thorsten; Kolozhvari, Anatoly; Kondratev, Valerii; Kondratyeva, Natalia; Kondratyuk, Evgeny; Konevskikh, Artem; Kopcik, Michal; Kour, Mandeep; Kouzinopoulos, Charalampos; Kovalenko, Oleksandr; Kovalenko, Vladimir; Kowalski, Marek; Koyithatta Meethaleveedu, Greeshma; Kralik, Ivan; Kravcakova, Adela; Krivda, Marian; Krizek, Filip; Kryshen, Evgeny; Krzewicki, Mikolaj; Kubera, Andrew Michael; Kucera, Vit; Kuhn, Christian Claude; Kuijer, Paulus Gerardus; Kumar, Ajay; Kumar, Jitendra; Kumar, Lokesh; Kumar, Shyam; Kurashvili, Podist; Kurepin, Alexander; Kurepin, Alexey; Kuryakin, Alexey; Kweon, Min Jung; Kwon, Youngil; La Pointe, Sarah Louise; La Rocca, Paola; Ladron De Guevara, Pedro; Lagana Fernandes, Caio; Lakomov, Igor; Langoy, Rune; Lapidus, Kirill; Lara Martinez, Camilo Ernesto; Lardeux, Antoine Xavier; Lattuca, Alessandra; Laudi, Elisa; Lea, Ramona; Leardini, Lucia; Lee, Seongjoo; Lehas, Fatiha; Lehner, Sebastian; Lemmon, Roy Crawford; Lenti, Vito; Leogrande, Emilia; Leon Monzon, Ildefonso; Leon Vargas, Hermes; 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; Loginov, Vitaly; Loizides, Constantinos; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lowe, Andrew John; Luettig, Philipp Johannes; Lunardon, Marcello; Luparello, Grazia; Lupi, Matteo; Lutz, Tyler Harrison; 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; Manko, Vladislav; Manso, Franck; Manzari, Vito; Mao, Yaxian; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Margutti, Jacopo; Marin, Ana Maria; Markert, Christina; Marquard, Marco; Martin, Nicole Alice; Martinengo, Paolo; Martinez Hernandez, Mario Ivan; Martinez-Garcia, Gines; Martinez Pedreira, Miguel; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Mastroserio, Annalisa; Matyja, Adam Tomasz; Mayer, Christoph; Mazer, Joel Anthony; Mazzilli, Marianna; Mazzoni, Alessandra Maria; Mcdonald, Daniel; Meddi, Franco; Melikyan, Yuri; Menchaca-Rocha, Arturo Alejandro; Meninno, Elisa; Mercado-Perez, Jorge; Meres, Michal; Mhlanga, Sibaliso; Miake, Yasuo; Mieskolainen, Matti Mikael; Mikhaylov, Konstantin; Milano, Leonardo; Milosevic, Jovan; Mischke, Andre; Mishra, Aditya Nath; Mishra, Tribeni; Miskowiec, Dariusz Czeslaw; Mitra, Jubin; Mitu, Ciprian Mihai; Mohammadi, Naghmeh; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Montes Prado, Esther; 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; Mulligan, James Declan; Gameiro Munhoz, Marcelo; Munning, Konstantin; Munzer, Robert Helmut; Murakami, Hikari; Murray, Sean; Musa, Luciano; Musinsky, Jan; Naik, Bharati; Nair, Rahul; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Naru, Muhammad Umair; Ferreira Natal Da Luz, Pedro Hugo; Nattrass, Christine; Rosado Navarro, Sebastian; Nayak, Kishora; Nayak, Ranjit; Nayak, Tapan Kumar; Nazarenko, Sergey; Nedosekin, Alexander; Negrao De Oliveira, Renato Aparecido; 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; Cabanillas Noris, Juan Carlos; Norman, Jaime; Nyanin, Alexander; Nystrand, Joakim Ingemar; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Ohlson, Alice Elisabeth; Okatan, Ali; Okubo, Tsubasa; Oleniacz, Janusz; Oliveira Da Silva, Antonio Carlos; Oliver, Michael Henry; Onderwaater, Jacobus; Oppedisano, Chiara; Orava, Risto; Oravec, Matej; Ortiz Velasquez, Antonio; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Ozdemir, Mahmut; Pachmayer, Yvonne Chiara; Pagano, Davide; Pagano, Paola; Paic, Guy; Pal, Susanta Kumar; Palni, Prabhakar; Pan, Jinjin; Pandey, Ashutosh Kumar; Papikyan, Vardanush; Pappalardo, Giuseppe; Pareek, Pooja; Park, Woojin; Parmar, Sonia; Passfeld, Annika; Paticchio, Vincenzo; Patra, Rajendra Nath; Paul, Biswarup; Pei, Hua; Peitzmann, Thomas; Peng, Xinye; Pereira Da Costa, Hugo Denis Antonio; Peresunko, Dmitry Yurevich; Perez Lezama, Edgar; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petrov, Viacheslav; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Pikna, Miroslav; Pillot, Philippe; Ozelin De Lima Pimentel, Lais; 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; Poppenborg, Hendrik; 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; Rami, Fouad; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Ravasenga, Ivan; Read, Kenneth Francis; Redlich, Krzysztof; Reed, Rosi Jan; Rehman, Attiq Ur; Reichelt, Patrick Simon; Reidt, Felix; Ren, Xiaowen; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Reygers, Klaus Johannes; Riabov, Viktor; Ricci, Renato Angelo; Richert, Tuva Ora Herenui; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Ristea, Catalin-Lucian; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roeed, Ketil; Rogochaya, Elena; Rohr, David Michael; Roehrich, Dieter; 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; Saarinen, Sampo; Sadhu, Samrangy; Sadovskiy, Sergey; Safarik, Karel; Sahlmuller, Baldo; Sahoo, Pragati; Sahoo, Raghunath; Sahoo, Sarita; Sahu, Pradip Kumar; Saini, Jogender; Sakai, Shingo; Saleh, Mohammad Ahmad; Salzwedel, Jai Samuel Nielsen; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Sarkar, Debojit; Sarkar, Nachiketa; Sarma, Pranjal; Scapparone, Eugenio; Scarlassara, Fernando; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schmidt, Martin; Schuchmann, Simone; Schukraft, Jurgen; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Rebecca Michelle; Sefcik, Michal; Seger, Janet Elizabeth; Sekiguchi, Yuko; Sekihata, Daiki; Selyuzhenkov, Ilya; Senosi, Kgotlaesele; Senyukov, Serhiy; Serradilla Rodriguez, Eulogio; Sevcenco, Adrian; Shabanov, Arseniy; Shabetai, Alexandre; Shadura, Oksana; Shahoyan, Ruben; Shangaraev, Artem; Sharma, Ankita; Sharma, Mona; Sharma, Monika; Sharma, Natasha; Sheikh, Ashik Ikbal; Shigaki, Kenta; Shou, Qiye; 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; Singhal, Vikas; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Slupecki, Maciej; Smirnov, Nikolai; Snellings, Raimond; Snellman, Tomas Wilhelm; Song, Jihye; Song, Myunggeun; Song, Zixuan; Soramel, Francesca; Sorensen, Soren Pontoppidan; Sozzi, Federica; Spiriti, Eleuterio; Sputowska, Iwona Anna; Spyropoulou-Stassinaki, Martha; Stachel, Johanna; Stan, Ionel; Stankus, Paul; 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; Suljic, Miljenko; Sultanov, Rishat; Sumbera, Michal; Sumowidagdo, Suharyo; Swain, Sagarika; Szabo, Alexander; Szarka, Imrich; Szczepankiewicz, Adam; Szymanski, Maciej Pawel; Tabassam, Uzma; Takahashi, Jun; Tambave, Ganesh Jagannath; Tanaka, Naoto; Tarhini, Mohamad; Tariq, Mohammad; Tarzila, Madalina-Gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terasaki, Kohei; Terrevoli, Cristina; Teyssier, Boris; Thaeder, Jochen Mathias; Thakur, Dhananjaya; Thomas, Deepa; Tieulent, Raphael Noel; Tikhonov, Anatoly; Timmins, Anthony Robert; Toia, Alberica; Trogolo, Stefano; Trombetta, Giuseppe; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vala, Martin; Valencia Palomo, Lizardo; 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; Vazquez Doce, Oton; Vechernin, Vladimir; Veen, Annelies Marianne; Velure, Arild; Vercellin, Ermanno; Vergara Limon, Sergio; Vernet, Renaud; Vickovic, Linda; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Villatoro Tello, Abraham; Vinogradov, Alexander; Vinogradov, Leonid; 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; Wagner, Boris; Wagner, Jan; Wang, Hongkai; Wang, Mengliang; Watanabe, Daisuke; Watanabe, Yosuke; Weber, Michael; Weber, Steffen Georg; Weiser, Dennis Franz; Wessels, Johannes Peter; Westerhoff, Uwe; Whitehead, Andile Mothegi; Wiechula, Jens; Wikne, Jon; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Willems, Guido Alexander; Williams, Crispin; Windelband, Bernd Stefan; Winn, Michael Andreas; Yalcin, Serpil; Yang, Ping; Yano, Satoshi; Yin, Zhongbao; Yokoyama, Hiroki; Yoo, In-Kwon; Yoon, Jin Hee; Yurchenko, Volodymyr; Zaborowska, Anna; Zaccolo, Valentina; Zaman, Ali; Zampolli, Chiara; Correia Zanoli, Henrique Jose; Zaporozhets, Sergey; Zardoshti, Nima; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhang, Yonghong; Chunhui, Zhang; Zhang, Zuman; Zhao, Chengxin; Zhigareva, Natalia; Zhou, Daicui; Zhou, You; Zhou, Zhuo; Zhu, Hongsheng; Zhu, Jianhui; Zichichi, Antonino; Zimmermann, Alice; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zyzak, Maksym

    2017-01-01

    At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark–gluon plasma (QGP). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed. Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions, is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton–proton (pp) collisions, but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton–proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The me...

  9. A new deterministic model of strange stars

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, Farook; Shit, G.C. [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); Chakraborty, Koushik [Government Training College, Department of Physics, Hooghly, West Bengal (India); Kuhfittig, P.K.F. [Milwaukee School of Engineering, Department of Mathematics, Milwaukee, WI (United States); Rahman, Mosiur [Meghnad Saha Institute of Technology, Department of Mathematics, Kolkata (India)

    2014-10-15

    The observed evidence for the existence of strange stars and the concomitant observed masses and radii are used to derive an interpolation formula for the mass as a function of the radial coordinate. The resulting general mass function becomes an effective model for a strange star. The analysis is based on the MIT bag model and yields the energy density, as well as the radial and transverse pressures. Using the interpolation function for the mass, it is shown that a mass-radius relation due to Buchdahl is satisfied in our model. We find the surface redshift (Z) corresponding to the compactness of the stars. Finally, from our results, we predict some characteristics of a strange star of radius 9.9 km. (orig.)

  10. CP asymmetries in Strange Baryon Decays

    Science.gov (United States)

    Bigi, I. I.; Kang, Xian-Wei; Li, Hai-Bo

    2018-01-01

    While indirect and direct CP violation (CPV) has been established in the decays of strange and beauty mesons, no CPV has yet been found for baryons. There are different paths to finding CP asymmetry in the decays of strange baryons; they are all highly non-trivial. The HyperCP Collaboration has probed CPV in the decays of single Ξ and Λ [1]. We discuss future lessons from {{{e}}}+{{{e}}}- collisions at BESIII/BEPCII: probing decays of pairs of strange baryons, namely Λ, Σ and Ξ. Realistic goals are to learn about non-perturbative QCD. One can hope to find CPV in the decays of strange baryons; one can also dream of finding the impact of New Dynamics. We point out that an important new era will start with the BESIII/BEPCII data accumulated by the end of 2018. This also supports new ideas to trigger {{J}}/{{\\psi }}\\to \\bar{{{Λ }}}{{Λ }} at the LHCb collaboration. Supported by National Science Foundation (PHY-1520966), National Natural Science Foundation of China (11335009, 11125525), Joint Large-Scale Scientific Facility Funds of the NSFC and CAS (U1532257), the National Key Basic Research Program of China (2015CB856700), Key Research Program of Frontier Sciences, CAS, (QYZDJ-SSW-SLH003), XWK’s work is also supported by MOST (Taiwan) (104-2112-M-001-022)

  11. Effects of Density-Dependent Bag Constant and Strange Star Rotation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qiao-Er; GUO Hua

    2003-01-01

    With the emphasis on the effects of the density-dependent bag constant and the rotation of strange star the limiting mass of strange star is calculated. The obtained results show that the limiting mass and the corresponding radius of strange star increase as the rotation frequency increases, and tend to be lowered when the density-dependent bag constant is considered.

  12. Universal scaling of strange particle pT spectra in pp collisions

    Science.gov (United States)

    Yang, Liwen; Wang, Yanyun; Hao, Wenhui; Liu, Na; Du, Xiaoling; Zhang, Wenchao

    2018-04-01

    As a complementary study to that performed on the transverse momentum (pT) spectra of charged pions, kaons and protons in proton-proton (pp) collisions at LHC energies 0.9, 2.76 and 7TeV, we present a scaling behaviour in the pT spectra of strange particles (KS0, Λ, Ξ and φ) at these three energies. This scaling behaviour is exhibited when the spectra are expressed in a suitable scaling variable z=pT/K, where the scaling parameter K is determined by the quality factor method and increases with the center of mass energy (√{s}). The rates at which K increases with ln √{s} for these strange particles are found to be identical within errors. In the framework of the colour string percolation model, we argue that these strange particles are produced through the decay of clusters that are formed by the colour strings overlapping. We observe that the strange mesons and baryons are produced from clusters with different size distributions, while the strange mesons (baryons) KS0 and φ ( Λ and Ξ) originate from clusters with the same size distributions. The cluster's size distributions for strange mesons are more dispersed than those for strange baryons. The scaling behaviour of the pT spectra for these strange particles can be explained by the colour string percolation model in a quantitative way.

  13. Is EG 50 a White or Strange Dwarf?

    Science.gov (United States)

    Hajyan, G. S.; Vartanyan, Yu. L.

    2017-12-01

    The time dependences of the luminosity of a white dwarf and four strange dwarfs with masses of 0.5 M (the mass of the white dwarf EG 50 with a surface temperature of 2.1·104 K) are determined taking neutrino energy losses into account. It was assumed that these configurations radiate only at the expense of thermal energy reserves. It is shown that the sources of thermal energy owing to nonequilibrium b-processes and the phenomenon of crystallization of electron-nuclear matter are insignificant in determining the cooling time of white and strange dwarfs with masses of 0.5 M⨀. It is shown that in this approximation the time dependences of the luminosity of white and strange dwarfs with masses of 0.5 M⨀ differ significantly only for surface temperatures TR≥7·104 K, so it is impossible to determine whether EG 50 is a white or strange dwarf based on the cooling time.

  14. 'Strange money': risk, finance and socialized debt.

    Science.gov (United States)

    Dodd, Nigel

    2011-03-01

    This paper explores an essential but neglected aspect of recent discussions of the banking and financial system, namely money itself. Specifically, I take up a distinction drawn by Susan Strange which has never been fully elaborated: between a financial system that is global, and an international monetary system that remains largely territorial. I propose a sociological elaboration of this distinction by examining each category, 'finance' and 'money', in terms of its distinctive orientation to risk and debt. Money is distinguished by its high degree of liquidity and low degree of risk, corresponding to expectations that derive from its status as a 'claim upon society'- a form of socialized debt. But as Strange argued, these features of money are being undermined by the proliferation of sophisticated instruments of financial risk management -'strange money'- that, as monetary substitutes, both weaken states' capacity to manage money, and more broadly, contribute to 'overbanking'. The ultimate danger, according to Strange, is the 'death of money'. The paper concludes by exploring the implications of the distinction for sociological arguments about the changing nature of money. © London School of Economics and Political Science 2011.

  15. Strangeness photoproduction and hadronic resonances

    International Nuclear Information System (INIS)

    David, J.C.

    1994-09-01

    The purpose of this thesis is to study the kaon photoproduction off a proton (γp → K + Λ,γp → K + Σ 0 , γp → K 0 Σ + ), with a photon energy between 0.9 and 2.1 GeV. We use an isobaric model where the amplitudes are computed with Feynman diagrams. The insertion of nucleonic resonances with spin 3/2 and 5/2 is necessary to improve the existing models beyond 1.5 GeV. This step is also necessary to extend the elementary process of photoproduction to electroproduction where the data have been taken with photon energies above 2.0 GeV. The parameters of our models are the coupling constants which appear at each Feynman diagram vertex. They are determined by fitting our models to the experimental data (cross sections, polarization asymmetries). Before performing the minimization we drew some informations about coupling constants from mesonic and electromagnetic decays, and from SU(3) and SU(6) symmetries. In conclusion, the models developed here reproduce the experimental data (E γ ≤ 2.0 GeV) and the two main coupling constants are in good agreement with broken SU(3)-symmetry predictions. (author)

  16. Determination of strange sea distributions from {nu}N deep inelastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Alekhin, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)]|[Inst. for High Energy Physics, Protvino (Russian Federation); Kulagin, S. [Academy of Sciences of Russia, Moscow (Russian Federation). Inst. for Nuclear Research; Petti, R. [South Carolina Univ., Columbia, SC (United States). Dept. of Physics and Astronomy

    2008-12-15

    We present an analysis of the nucleon strange sea extracted from a global Parton Distribution Function fit including the neutrino and anti-neutrino dimuon data by the CCFR and NuTeV collaborations, the inclusive charged lepton-nucleon Deep Inelastic Scattering and Drell-Yan data. The (anti-)neutrino induced dimuon analysis is constrained by the semi-leptonic charmed-hadron branching ratio B{sub {mu}}=(8.8{+-}0.5)%, determined from the inclusive charmed hadron measurements performed by the FNAL-E531 and CHORUS neutrino emulsion experiments. Our analysis yields a strange sea suppression factor {kappa}(Q{sup 2}=20 GeV{sup 2})=0.62{+-}0.04, the most precise value available, an x-distribution of total strange sea that is slightly softer than the non-strange sea, and an asymmetry between strange and anti-strange quark distributions consistent with zero (integrated over x it is equal to 0.0013{+-}0.0009 at Q{sup 2}=20 GeV{sup 2}). (orig.)

  17. Conserved number fluctuations in a hadron resonance gas model

    International Nuclear Information System (INIS)

    Garg, P.; Mishra, D.K.; Netrakanti, P.K.; Mohanty, B.; Mohanty, A.K.; Singh, B.K.; Xu, N.

    2013-01-01

    Net-baryon, net-charge and net-strangeness number fluctuations in high energy heavy-ion collisions are discussed within the framework of a hadron resonance gas (HRG) model. Ratios of the conserved number susceptibilities calculated in HRG are being compared to the corresponding experimental measurements to extract information about the freeze-out condition and the phase structure of systems with strong interactions. We emphasize the importance of considering the actual experimental acceptances in terms of kinematics (pseudorapidity (η) and transverse momentum (p T )), the detected charge state, effect of collective motion of particles in the system and the resonance decay contributions before comparisons are made to the theoretical calculations. In this work, based on HRG model, we report that the net-baryon number fluctuations are least affected by experimental acceptances compared to the net-charge and net-strangeness number fluctuations

  18. Assessment of the biological effects of 'strange' radiation

    International Nuclear Information System (INIS)

    Pryakhin, E.A.; Tryapitsina, G.A.; Urutskoyev, L.I.; Akleyev, A.V.

    2006-01-01

    The results from studies of the effects produced by electrical explosions of foils made from super pure materials in water point to the emergence of new chemical elements. An additional finding was the discharge of 'strange' radiation accompanying the transformation of chemical elements. However, currently, the mechanism involved in the interaction between 'strange' radiation and a substance or a biological entity remains obscure. Therefore, the aim of the present research is to investigate the biological effects of the 'strange' radiation. Pilot studies were performed at the RECOM RRC 'Kurchatov Institute' in April-May of 2004. The animals used in the experiment were female mice of C57Bl/6 line aged 80 days with body weight 16-18 g. The animals were exposed to radiation discharged during explosions of Ti foils in water and aqueous solutions. The cages with animals were placed at 1 m from the epicenter of the explosion. Explosions were carried out on the 19. (3 explosions), 20. (4 explosions) and 22. (3 explosions) of April, 2004 (explosions No1373 - No1382, respectively). The animals were assigned to 4 experimental groups comprised of 17-20 mice per group. The animals received experimental exposure within 1, 2 and 3 days of the experiment. In total, the experimental groups were exposed to 3, 7 and 10 explosions, respectively. In order to identify the biological reactions, the following parameters were estimated: number of nucleated cells in the bone marrow, number of CFU in the spleen after additional gamma-irradiation (6 Gy), cell composition of the bone marrow, the rate of erythrocytes with the different level of maturation in the bone marrow, the rate of erythrocytes with the micronuclei in the bone marrow, the reaction of bone marrow cells to additional gamma-irradiation (2 Gy), number of leucocytes in the peripheral blood, and cell composition of the peripheral blood. The following conclusions were drawn from these studies: 1. 'strange' radiation resulting

  19. Low-lying charmed and charmed-strange baryon states

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bing [Anyang Normal University, Department of Physics, Anyang (China); Institute of Modern Physics of CAS and Lanzhou University, Research Center for Hadron and CSR Physics, Lanzhou (China); Wei, Ke-Wei [Anyang Normal University, Department of Physics, Anyang (China); Liu, Xiang [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Institute of Modern Physics of CAS and Lanzhou University, Research Center for Hadron and CSR Physics, Lanzhou (China); Matsuki, Takayuki [Tokyo Kasei University, Tokyo (Japan); Nishina Center, RIKEN, Theoretical Research Division, Saitama (Japan)

    2017-03-15

    In this work, we systematically study the mass spectra and strong decays of 1P and 2S charmed and charmed-strange baryons in the framework of non-relativistic constituent quark models. With the light quark cluster-heavy quark picture, the masses are simply calculated by a potential model. The strong decays are studied by the Eichten-Hill-Quigg decay formula. Masses and decay properties of the well-established 1S and 1P states can be reproduced by our method. Σ{sub c}(2800){sup 0,+,++} can be assigned as a Σ{sub c2}(3/2{sup -}) or Σ{sub c2}(5/2{sup -}) state. We prefer to interpret the signal Σ{sub c}(2850){sup 0} as a 2S(1/2{sup +}) state although at present we cannot thoroughly exclude the possibility that this is the same state as Σ{sub c}(2800){sup 0}. Λ{sub c}(2765){sup +} or Σ{sub c}(2765){sup +} could be explained as the Λ{sub c}{sup +}(2S) state or Σ{sup +}{sub c1}(1/2{sup -}) state, respectively. We propose to measure the branching ratio of B(Σ{sub c}(2455)π)/B(Σ{sub c}(2520)π) in the future, which may disentangle the puzzle of this state. Our results support Ξ{sub c}(2980){sup 0,+} as the first radial excited state of Ξ{sub c}(2470){sup 0,+} with J{sup P} = 1/2{sup +}. The assignment of Ξ{sub c}(2930){sup 0} is analogous to Σ{sub c}(2800){sup 0,+,++}, i.e., a Ξ{sup '}{sub c2}(3/2{sup -}) or Ξ{sup '}{sub c2}(5/2{sup -}) state. In addition, we predict some typical ratios among partial decay widths, which are valuable for experimental search for these missing charmed and charmed-strange baryons. (orig.)

  20. Strangeness production in pA and AA collisions at 158 A GeV

    Institute of Scientific and Technical Information of China (English)

    王晓荣[1; 萨本豪[2; 周代翠[3; 刘涵[4; 蔡勖[5

    2000-01-01

    LUCIAE, a hadronic and string cascade model and its corresponding event generator are used to analyse strangeness production singly and multiply in p-Pb and Pb-Pb collisions at 158 A GeV. Spectra of multiplicity and transverse mass for single (Α ,Α ) and multiple (Ε Ε ) strangeness are given. in LUCIAE model it suggests a physical mechanism, i.e. the dependence of the strange quark suppression factor on incident energy, projectile mass and centrality of colliding sys-tem might result in increase of yield of strange particles with increasing the above three parameters. Calculations from the model reconstruct well the WA97 experimental data: increase of yield of strange particles with increasing centrality and increase of strangeness enhancement with increasing number of strange quarks, in relativistic nucleus-nucleus collisions.

  1. Strangeness production in pA and AA collisions at 158 A GeV

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    LUCIAE, a hadronic and string cascade model and its corresponding event generator are used to analyse strangeness production singly and multiply in p-Pb and Pb-Pb collisions at 158 A GeV. Spectra of multiplicity and transverse mass for single (Λ, Λ) and multiple (Ξ-, Ξ-, Ω-, Ω-) strangeness are given. In LUCIAE model it suggests a physical mechanism, i.e. the dependence of the strange quark suppression factor on incident energy, projectile mass and centrality of colliding system might result in increase of yield of strange particles with increasing the above three parameters. Calculations from the model reconstruct well the WA97 experimental data: increase of yield of strange particles with increasing centrality and increase of strangeness enhancement with increasing number of strange quarks, in relativistic nucleus-nucleus collisions.

  2. Studies on inclusive meson resonance and particle production

    International Nuclear Information System (INIS)

    Saarikko, Heimo

    1978-01-01

    Production and decay of meson resonances are studied in medium energy meson-proton collisions. Strong evidence is found that hadronic collisions are dominated by resonance production. Especially the vector mesons have often large inclusive cross sections, typically of the order of few millibarns at the present energies. In all, a majority of pions and kaons appear to be decay products of resonances or other unstable particles. The detailed kinematics of the parent resonance's decays is found to play an important role in determining inclusive pion spectra. The squared transverse momentum distributions of hadrons heavier than the pion appear to have in common an exponential behaviour, with a universal slope for the esponential fall-off. The observed vector meson yields suggest that only a small fraction of the direct lepton production observed at large transverse momentum in nucleon-nucleon interactions is accounted for by the ''old'' vector mesons. An attempt has been made to separate out the central production and fragmentation components of the meson production. Both the central production and the fragmentation of the incoming meson are found to be important mechanisms in the non-strange meson production whereas the central production of strange meson resonances is rare at our energies. The ratios of the observed meson yields are found to be generally in good agreement with a simple quark-counting model. (author)

  3. Double-strangeness five-body system

    Energy Technology Data Exchange (ETDEWEB)

    Myint, K S [Mandalay Univ. (Myanmar). Dept. of Physics; Akaishi, Yoshinori

    1995-03-01

    We perform theoretical analysis on the structure and decay of a double-strangeness five-body system which consists of {sub {Lambda}{Lambda}}{sup 5}H and {sub {Xi}}{sup 5}H states. In this S=-2 five-body system the thresholds of the t{Lambda}{Lambda} channel and the {alpha}{Xi}{sup -} channel come closer with only 8.51 MeV difference. We treat both bound and resonant states of the three-body channels t{Lambda}{Lambda} and tp{Xi}{sup -} by applying a complex rotation method. It is found that there is a bound {sub {Lambda}{Lambda}}{sup 5}H state with 6.3 MeV below the threshold of t+{Lambda}+{Lambda}. In the {Xi}{sup -} channel a resonant {sub {Xi}}{sup 5}H state appears at 1.7 MeV below the threshold of {alpha}+{Xi}{sup -}. Though the existence of this state is ensured by the Coulomb interaction, it is a `halo` nuclear state rather than an atomic state as judged from its size. The conversion width of this state is 0.2 MeV which is extremely narrow. It is also found that {Xi} mixing into the {sub {Lambda}{Lambda}}{sup 5}H ground state is small with 1.0%. For the {sub {Lambda}{Lambda}}{sup 5}H state, the weak decay to the {alpha}+{Sigma}{sup -} final state produces a high mono-energetic {Sigma}{sup -} with branching ratio of 5.5%. Thus the {Sigma}{sup -} with discrete energy would become a clear signature of the forming of the {Lambda}{Lambda} hypernucleus. (author).

  4. The Fastest Rotating Pulsar: a Strange Star?

    Institute of Scientific and Technical Information of China (English)

    徐仁新; 徐轩彬; 吴鑫基

    2001-01-01

    According to the observational limits on the radius and mass, the fastest rotating pulsar (PSR 1937+21) is probably a strange star, or at least some neutron star equations of state should be ruled out, if we suggest that a dipole magnetic field is relevant to its radio emission. We presume that the millisecond pulsar is a strange star with much low mass, small radius and weak magnetic moment.

  5. A dark business, full of shadows: analogy and theology in William Harvey.

    Science.gov (United States)

    Goldberg, Benjamin

    2013-09-01

    In a short work called De conceptione appended to the end of his Exercitationes de generatione animalium (1651), William Harvey developed a rather strange analogy. To explain how such marvelous productions as living beings were generated from the rather inauspicious ingredients of animal reproduction, Harvey argued that conception in the womb was like conception in the brain. It was mostly rejected at the time; it now seems a ludicrous theory based upon homonymy. However, this analogy offers insight into the structure and function of analogies in early modern natural philosophy. In this essay I hope to not only describe the complex nature of Harvey's analogy, but also offer a novel interpretation of his use of analogical reasoning, substantially revising the account offered by Guido Giglioni (1993). I discuss two points of conceptual change and negotiation in connection with Harvey's analogy, understanding it as both a confrontation between the border of the natural and the supernatural, as well as a moment in the history of psychology. My interpretation touches upon a number of important aspects, including why the analogy was rejected, how Harvey systematically deployed analogies according to his notions of natural philosophical method, how the analogy fits into contemporary discussions of analogies in science, and finally, how the analogy must be seen in the context of changing Renaissance notions of the science of the soul, ultimately confronting the problem of how to understand final causality in Aristotelian science. In connection with the last, I conclude the essay by turning to how Harvey embeds the analogy within a natural theological cosmology. Copyright © 2013. Published by Elsevier Ltd.

  6. Measurement of strange particle production in the NICA fixed-target programme

    Energy Technology Data Exchange (ETDEWEB)

    Friese, Volker [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

    2016-08-15

    Strange particles provide a sensitive tool to study the dense and hot matter created in relativistic nuclear collisions. Although strangeness production in such collisions has been a topic of experimental and theoretical research for many years, its understanding is far from being complete. This holds in particular for multi-strange hyperons and for lower collision energies as relevant for NICA and FAIR. Multi-strange particles, being sensitive to both the mechanism of strangeness production and the net-baryon density, are expected to shed light on the state of the created matter and to indicate possible transitions to new phases of strongly interacting matter. We thus advocate the measurement of hyperons and φ mesons in a fixed-target experiment at NICA (BM rate at N), which can be achieved by a relatively compact detector system. (orig.)

  7. Connecting coherent structures and strange attractors

    Science.gov (United States)

    Keefe, Laurence R.

    1990-01-01

    A concept of turbulence derived from nonlinear dynamical systems theory suggests that turbulent solutions to the Navier-Stokes equations are restricted to strange attractors, and, by implication, that turbulent phenomenology must find some expression or source in the structure of these mathematical objects. Examples and discussions are presented to link coherent structures to some of the commonly known characteristics of strange attractors. Basic to this link is a geometric interpretation of conditional sampling techniques employed to educe coherent structures that offers an explanation for their appearance in measurements as well as their size.

  8. K/sup -/p interactions at 11 GeV/c: new results on strange meson systems

    Energy Technology Data Exchange (ETDEWEB)

    Ratcliff, B.N.

    1980-06-01

    The status of our programmatic study of states containing a strange quark is briefly reviewed. An 11 GeV/c K/sup -/p experiment run on the LASS spectrometer at SLAC is discussed and preliminary results presented for several inelastic channels based on approximately one half of the available data sample. In addition, new results utilizing the full statistics of the experiment are presented for the elastic K/sup -/..pi../sup +/ channel from the K/sup -/..pi../sup +/n final state. The well established leading K*(890), K*(1435), and K*(1780) resonances are observed, and clear evidence is presented for a new J/sup p/ = 4/sup +/ resonance at approx. 2070 MeV. Preliminary results from an energy independent partial wave analysis of these data are presented which display unambiguous evidence for resonant structure in the non-leading 0/sup +/ and 1/sup -/ waves.

  9. Form factors and other measures of strangeness in the nucleon

    International Nuclear Information System (INIS)

    Diehl, M.; Feldmann, T.; Kroll, P.

    2007-11-01

    We discuss the phenomenology of strange-quark dynamics in the nucleon, based on experimental and theoretical results for electroweak form factors and for parton densities. In particular, we construct a model for the generalized parton distribution that relates the asymmetry s(x)- anti s(x) between the longitudinal momentum distributions of strange quarks and antiquarks with the form factor F s 1 (t), which describes the distribution of strangeness in transverse position space. (orig.)

  10. Discriminating strange star mergers from neutron star mergers by gravitational-wave measurements

    International Nuclear Information System (INIS)

    Bauswein, A.; Oechslin, R.; Janka, H.-T.

    2010-01-01

    We perform three-dimensional relativistic hydrodynamical simulations of the coalescence of strange stars and explore the possibility to decide on the strange matter hypothesis by means of gravitational-wave measurements. Self-binding of strange quark matter and the generally more compact stars yield features that clearly distinguish strange star from neutron star mergers, e.g. hampering tidal disruption during the plunge of quark stars. Furthermore, instead of forming dilute halo structures around the remnant as in the case of neutron star mergers, the coalescence of strange stars results in a differentially rotating hypermassive object with a sharp surface layer surrounded by a geometrically thin, clumpy high-density strange quark matter disk. We also investigate the importance of including nonzero temperature equations of state in neutron star and strange star merger simulations. In both cases we find a crucial sensitivity of the dynamics and outcome of the coalescence to thermal effects, e.g. the outer remnant structure and the delay time of the dense remnant core to black hole collapse depend on the inclusion of nonzero temperature effects. For comparing and classifying the gravitational-wave signals, we use a number of characteristic quantities like the maximum frequency during inspiral or the dominant frequency of oscillations of the postmerger remnant. In general, these frequencies are higher for strange star mergers. Only for particular choices of the equation of state the frequencies of neutron star and strange star mergers are similar. In such cases additional features of the gravitational-wave luminosity spectrum like the ratio of energy emitted during the inspiral phase to the energy radiated away in the postmerger stage may help to discriminate coalescence events of the different types. If such characteristic quantities could be extracted from gravitational-wave signals, for instance with the upcoming gravitational-wave detectors, a decision on the

  11. Study of Strange and Multistrange Particles in Ultrarelativistic Nucleus-Nucleus Collisions

    CERN Multimedia

    Vande vyvre, P; Feofilov, G; Snoeys, W; Hetland, K F; Campbell, M; Klempt, W

    2002-01-01

    % NA57\\\\ \\\\ The goal of the experiment is to study the production of strange and multi-strange particles in nucleus-nucleus collisions. This study was initiated at the OMEGA spectrometer, where three ion experiments have been performed: WA85 (S-W and p-W collisions at 200 A GeV/c), WA94 (S-S and p-S collisions at 200 A GeV/c) and WA97 (Pb-Pb, p-Pb and p-Be collisions at 160 A GeV/c).\\\\ \\\\ The experiment aims at extending the scope of WA97 by:\\\\ \\\\ - investigating the beam energy dependence of the enhancements of multi-strange particle production reported by the previous experiments, and by\\\\ \\\\\\\\ \\\\- measuring the yields of strange and multi-strange particles over an extended centrality range compared with the previous experiments.\\\\ \\\\ The apparatus consists mainly of silicon pixel detector planes.

  12. Searching for Strange Quark Matter Objects in Exoplanets

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y. F.; Yu, Y. B., E-mail: hyf@nju.edu.cn [Department of Astronomy, School of Astronomy and Space Science, Nanjing University, Nanjing 210023 (China)

    2017-10-20

    The true ground state of hadronic matter may be strange quark matter (SQM). Consequently, observed pulsars may actually be strange quark stars, but not neutron stars. However, proving or disproving the SQM hypothesis still remains a difficult problem to solve due to the similarity between the macroscopical characteristics of strange quark stars and neutron stars. Here, we propose a hopeful method to probe the existence of SQM. In the framework of the SQM hypothesis, strange quark dwarfs and even strange quark planets can also stably exist. Noting that SQM planets will not be tidally disrupted even when they get very close to their host stars due to their extreme compactness, we argue that we could identify SQM planets by searching for very close-in planets among extrasolar planetary systems. Especially, we should keep our eyes on possible pulsar planets with orbital radius less than ∼5.6 × 10{sup 10} cm and period less than ∼6100 s. A thorough search in the currently detected ∼2950 exoplanets around normal main-sequence stars has failed to identify any stable close-in objects that meet the SQM criteria, i.e., lying in the tidal disruption region for normal matter planets. However, the pulsar planet PSR J1719-1438B, with an orbital radius of ∼6 × 10{sup 10} cm and orbital period of 7837 s, is, encouragingly, found to be a good candidate.

  13. Strange particles from dense hadronic matter

    International Nuclear Information System (INIS)

    Rafelski, J.; Letessier, J.; Tounsi, A.

    1996-01-01

    After a brief survey of the remarkable accomplishments of the current heavy ion collision experiments up to 200A GeV, we address in depth the role of strange particle production in the search for new phases of matter in these collisions. In particular, we show that the observed enhancement pattern of otherwise rarely produced multistrange antibaryons can be consistently explained assuming color deconfinement in a localized, rapidly disintegrating hadronic source. We develop the theoretical description of this source, and in particular study QCD based processes of strangeness production in the deconfined, thermal quark-gluon plasma phase, allowing for approach to chemical equilibrium and dynamical evolution. We also address thermal charm production. Using a rapid hadronization model we obtain final state particle yields, providing detailed theoretical predictions about strange particle spectra and yields as functions of heavy ion energy. Our presentation is comprehensive and self contained: we introduce the procedures used in data interpretation in considerable detail, discuss the particular importance of selected experimental results, and show how they impact the theoretical developments. (author)

  14. Form factors and other measures of strangeness in the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Feldmann, T. [Siegen Univ. (Germany). Theoretische Physik I; Kroll, P. [Bergische Univ., Wuppertal (Germany). Fachbereich Physik

    2007-11-15

    We discuss the phenomenology of strange-quark dynamics in the nucleon, based on experimental and theoretical results for electroweak form factors and for parton densities. In particular, we construct a model for the generalized parton distribution that relates the asymmetry s(x)- anti s(x) between the longitudinal momentum distributions of strange quarks and antiquarks with the form factor F{sup s}{sub 1}(t), which describes the distribution of strangeness in transverse position space. (orig.)

  15. Discovery Mondays - “Relativity Theory... strange! Did you say strange?”

    CERN Multimedia

    2005-01-01

    We all know that famous equation E=mc2, but do you know its true significance? Relativity theory: what is the meaning of this strange concept which plunged the physics world into turmoil 100 years ago? What effects can be observed today? Did you know that the GPS system would not work if relativity was not taken into account? The next Discovery Monday will take you on a journey into a strange world. You will be able to witness for yourselves the consequences of Einstein's theories. How, for example, can relativity theory be tested by eclipses? What consequences does it have for the accelerators at CERN? How can it be used to measure the mass of enormous black holes? And finally, how is it linked to the puzzle surrounding the missing mass of the Universe? As part of the World Year of Physics, the next Discovery Monday will be dedicated to one of the theories that Einstein published in 1905, his “annus mirabilis”. Join us at the Microcosm (Reception Building 33, Meyrin site), on Monday 5th September ...

  16. Discovery Mondays - “Relativity Theory... strange! Did you say strange?”

    CERN Multimedia

    2005-01-01

    We all know that famous equation E=mc2, but do you know its true significance? Relativity theory: what is the meaning of this strange concept which plunged the physics world into turmoil 100 years ago? What effects can be observed today? Did you know that the GPS system would not work if relativity was not taken into account? The next Discovery Monday will take you on a journey into a strange world. You will be able to witness for yourselves the consequences of Einstein's theories. How, for example, can relativity theory be tested by eclipses? What consequences does it have for the accelerators at CERN? How can it be used to measure the mass of enormous black holes? And finally, how is it linked to the puzzle surrounding the missing mass of the Universe? As part of the World Year of Physics, the next Discovery Monday will be dedicated to one of the theories that Einstein published in 1905, his “annus mirabilis”. Join us at the Microcosm (Reception Building 33, Meyrin site), on Monday 5th Septemb...

  17. Hot Strange Hadronic Matter in an Effective Model

    Institute of Scientific and Technical Information of China (English)

    QIAN Wei-Liang; SU Ru-Keng; SONG Hong-Qiu

    2003-01-01

    An effective model used to describe the strange hadronic matter with nucleons, Λ-hyperons, and Ξ-hyperonsis extended to finite temperature. The extended model is used to study the density, temperature, and strangeness fractiondependence of the effective masses of baryons in the matter. The thermodynamical quantities, such as free energy andpressure, as well as the equation of state of the matter, are given.

  18. Mini-Proceedings of ECT Workshop Strangeness in Nuclei

    CERN Document Server

    Zmeskal, J

    2011-01-01

    This workshop brought together international experts in the research area of strangeness in nuclei physics, working on theory as well as on experiments, to discuss the present status, to develop new methods of analysis and to have the opportunity for brainstorming towards future studies, going towards a deeper understanding of the hot topics in the low-energy QCD in the strangeness sector.

  19. Strange Quark Magnetic Moment of the Nucleon at the Physical Point.

    Science.gov (United States)

    Sufian, Raza Sabbir; Yang, Yi-Bo; Alexandru, Andrei; Draper, Terrence; Liang, Jian; Liu, Keh-Fei

    2017-01-27

    We report a lattice QCD calculation of the strange quark contribution to the nucleon's magnetic moment and charge radius. This analysis presents the first direct determination of strange electromagnetic form factors including at the physical pion mass. We perform a model-independent extraction of the strange magnetic moment and the strange charge radius from the electromagnetic form factors in the momentum transfer range of 0.051  GeV^{2}≲Q^{2}≲1.31  GeV^{2}. The finite lattice spacing and finite volume corrections are included in a global fit with 24 valence quark masses on four lattices with different lattice spacings, different volumes, and four sea quark masses including one at the physical pion mass. We obtain the strange magnetic moment G_{M}^{s}(0)=-0.064(14)(09)μ_{N}. The four-sigma precision in statistics is achieved partly due to low-mode averaging of the quark loop and low-mode substitution to improve the statistics of the nucleon propagator. We also obtain the strange charge radius ⟨r_{s}^{2}⟩_{E}=-0.0043(16)(14)  fm^{2}.

  20. Flipped neutrino emissivity from strange matter

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, A.; Dutta, S. (Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India))

    1994-04-15

    Energy loss due to wrong helicity sterile neutrinos through spin flip processes leads to rapid cooling of nascent neutron stars. The observed cooling of neutron stars associated with SN 1987A seems to preclude the existence of Dirac neutrinos with a mass in excess of 20 keV. Assuming that nuclear matter in the core of the neutron star undergoes a phase transition to quark matter leading to a strange star or a neutron star with a strange matter core, we examine the emission of flipped Dirac neutrinos for two dominant processes: quark-neutrino scattering [[ital q]+[nu][sub [minus

  1. Virtual meson cloud of the nucleon and intrinsic strangeness and charm

    International Nuclear Information System (INIS)

    Navarra, F.S.; Nielsen, M.; Duraes, F.O.; Barz, L.L.; Paiva, S.

    1996-09-01

    We have applied the Meson Cloud Model (MCM) to calculate the charm and strange antiquark distribution in the nucleon. The resulting distribution, in the case of charm, is very similar to the intrinsic charm momentum distribution in the nucleon. This seems to corroborate the hypothesis that the intrinsic charm is in the cloud and, at the same time, explains why other calculations with the MCM involving strange quark distributions fail in reproducing the low x region data. From the intrinsic strange distribution in the nucleon we have extracted the strangeness radius of the nucleon, which is in agreement with other meson cloud calculations. (author). 28 refs., 4 figs

  2. D{sub s1}{sup ∗}(2860) and D{sub s3}{sup ∗}(2860): candidates for 1D charmed-strange mesons

    Energy Technology Data Exchange (ETDEWEB)

    Song, Qin-Tao [Nuclear Theory Group, Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou (China); Research Center for Hadron and CSR Physics, Lanzhou University & Institute of Modern Physics of CAS, 730000, Lanzhou (China); University of Chinese Academy of Sciences, 100049, Beijing (China); Chen, Dian-Yong, E-mail: chendy@impcas.ac.cn [Nuclear Theory Group, Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou (China); Research Center for Hadron and CSR Physics, Lanzhou University & Institute of Modern Physics of CAS, 730000, Lanzhou (China); Liu, Xiang, E-mail: xiangliu@lzu.edu.cn [Research Center for Hadron and CSR Physics, Lanzhou University & Institute of Modern Physics of CAS, 730000, Lanzhou (China); School of Physical Science and Technology, Lanzhou University, 730000, Lanzhou (China); Matsuki, Takayuki, E-mail: matsuki@tokyo-kasei.ac.jp [Tokyo Kasei University, 1-18-1 Kaga, Itabashi, 173-8602, Tokyo (Japan); Theoretical Research Division, Nishina Center, RIKEN, 351-0198, Saitama (Japan)

    2015-01-27

    Newly observed two charmed-strange resonances, D{sub s1}{sup ∗}(2860) and D{sub s3}{sup ∗}(2860), are investigated by calculating their Okubo–Zweig–Iizuka-allowed strong decays, which shows that they are suitable candidates for the 1{sup 3}D{sub 1} and 1{sup 3}D{sub 3} states in the charmed-strange meson family. Our study also predicts other main decay modes of D{sub s1}{sup ∗}(2860) and D{sub s3}{sup ∗}(2860), which can be accessible at the future experiment. In addition, the decay behaviors of the spin partners of D{sub s1}{sup ∗}(2860) and D{sub s3}{sup ∗}(2860), i.e., 1D(2{sup -}) and 1D{sup ′}(2{sup -}), are predicted in this work, which are still missing at present. The experimental search for the missing 1D(2{sup -}) and 1D{sup ′}(2{sup -}) charmed-strange mesons is an intriguing and challenging task for further experiments.

  3. Effect of the Curved Spacetime on the Electrostatic Potential Energy Distribution of Strange Stars

    Institute of Scientific and Technical Information of China (English)

    陈次星; 张家铝

    2001-01-01

    The effect of the strong gravitational field of the strange core of a strange star on its surface electrostatic potential energy distribution is discussed. We present the general-relativistic hydrodynamics equations of fluids in the presence of the electric fields and investigate the surface electrostatic potential distribution of the strange core of a strange star in hydrostatic equilibrium to correct Alcock and coworker's result [Astrophys. J. 310 (1986) 261]. Also, we discuss the temperature distribution of the bare strange star surface and give the related formulae, which may be useful if we are concerned further about the physical processes near the quark atter surfaces of strange stars.

  4. Hot Strange Hadronic Matter in an Effective Model

    Institute of Scientific and Technical Information of China (English)

    QIANWei-Liang; SURu-Keng; SONGHong-Qiu

    2003-01-01

    An effective model used to describe the strange hadronic matter with nucleons, A-hyperons, and [I]-hyperons is extended to finite temperature. The extended model is used to study the density, temperature, and strangeness fraction dependence of the effective masses of baryons in the matter. The thermodynamical quantities, such as free energy and pressure, as well as the equation of state of the matter, are given.

  5. Relativistic simulations of compact object mergers for nucleonic matter and strange quark matter

    International Nuclear Information System (INIS)

    Bauswein, Andreas Ottmar

    2010-01-01

    Under the assumption that the energy of the ground state of 3-flavor quark matter is lower than the one of nucleonic matter, the compact stellar remnants of supernova explosions are composed of this quark matter. Because of the appearance of strange quarks, such objects are called strange stars. Considering their observational features, strange stars are very similar to neutron stars made of nucleonic matter, and therefore observations cannot exclude the existence of strange stars. This thesis introduces a new method for simulating mergers of compact stars and black holes within a general relativistic framework. The main goal of the present work is the investigation of the question, whether the coalescence of two strange stars in a binary system yields observational signatures that allow one to distinguish them from colliding neutron stars. In this context the gravitational-wave signals are analyzed. It is found that in general the characteristic frequencies in the gravitational-wave spectra are higher for strange stars. Moreover, the amount of matter that becomes gravitationally unbound during the merging is determined. The detection of ejecta of strange star mergers as potential component of cosmic ray flux could serve as a proof of the existence of strange quark matter. (orig.)

  6. Relativistic simulations of compact object mergers for nucleonic matter and strange quark matter

    Energy Technology Data Exchange (ETDEWEB)

    Bauswein, Andreas Ottmar

    2010-01-29

    Under the assumption that the energy of the ground state of 3-flavor quark matter is lower than the one of nucleonic matter, the compact stellar remnants of supernova explosions are composed of this quark matter. Because of the appearance of strange quarks, such objects are called strange stars. Considering their observational features, strange stars are very similar to neutron stars made of nucleonic matter, and therefore observations cannot exclude the existence of strange stars. This thesis introduces a new method for simulating mergers of compact stars and black holes within a general relativistic framework. The main goal of the present work is the investigation of the question, whether the coalescence of two strange stars in a binary system yields observational signatures that allow one to distinguish them from colliding neutron stars. In this context the gravitational-wave signals are analyzed. It is found that in general the characteristic frequencies in the gravitational-wave spectra are higher for strange stars. Moreover, the amount of matter that becomes gravitationally unbound during the merging is determined. The detection of ejecta of strange star mergers as potential component of cosmic ray flux could serve as a proof of the existence of strange quark matter. (orig.)

  7. Double-strangeness five-body system

    Energy Technology Data Exchange (ETDEWEB)

    Myint, K S [Mandalay Univ. (Myanmar). Dept. of Physics; Akaishi, Yoshinori

    1994-09-01

    We perform theoretical analysis on the structure and decay of a double-strangeness five-body system which consists of {sub {Lambda}{Lambda}}{sup 5}H and {sub {identical_to}}{sup 5}H states. In this S=-2 five-body system the thresholds of the t{Lambda}{Lambda} channel and the {alpha}{identical_to}{sup -} channel come closer with only 8.51 MeV difference. We treat both bound and resonant states of the three-body channels t{Lambda}{Lambda} and tp{identical_to}{sup -} by applying a complex rotation method. It is found that there is a bound {sub {Lambda}{Lambda}}{sup 5}H state with 6.3 MeV below the threshold of t+{Lambda}+{Lambda}. In the {identical_to}{sup -} channel a resonant {sub {identical_to}}{sup 5}H state appears at 1.7 MeV below the threshold of {alpha}+{identical_to}{sup -}. Though the existence of this state is ensured by the Coulomb interaction, it is a `halo` nuclear state rather than an atomic state as judged from its size. The conversion width of this state is 0.2 MeV which is extremely narrow. It is also found that {identical_to} mixing into the {sub {Lambda}{Lambda}}{sup 5}H ground state is small with 1.0 %. For the {sub {Lambda}{Lambda}}{sup 5}H state, the weak decay to the {alpha}+{Sigma}{sup -} final state produces a high mono-energetic {Sigma}{sup -} with branching ratio of 5.5 %. Thus the {Sigma}{sup -} with discrete energy would become a clear signature of the forming of the {Lambda}{Lambda} hypernucleus. (author).

  8. Strange Particle Production from SIS to LHC

    CERN Document Server

    Oeschler, H; Redlich, Krzysztof

    2003-01-01

    A review of meson emission in heavy ion collisions at incident energies from SIS up to collider energies is presented. A statistical model assuming chemical equilibrium and local strangeness conservation (i.e. strangeness conservation per collision) explains most of the observed features. Emphasis is put onto the study of $K^+$ and $K^-$ emission at low incident energies. In the framework of this statistical model it is shown that the experimentally observed equality of $K^+$ and $K^-$ rates at ``threshold-corrected'' energies $\\sqrt{s} - \\sqrt{s_{th}}$ is due to a crossing of two excitation functions. Furthermore, the independence of the $K^+$ to $K^-$ ratio on the number of participating nucleons observed between SIS and RHIC is consistent with this model. It is demonstrated that the $K^-$ production at SIS energies occurs predominantly via strangeness exchange and this channel is approaching chemical equilibrium. The observed maximum in the $K^+/\\pi^+$ excitation function is also seen in the ratio of stran...

  9. Towards Strange Metallic Holography

    International Nuclear Information System (INIS)

    2010-01-01

    We initiate a holographic model building approach to 'strange metallic' phenomenology. Our model couples a neutral Lifshitz-invariant quantum critical theory, dual to a bulk gravitational background, to a finite density of gapped probe charge carriers, dually described by D-branes. In the physical regime of temperature much lower than the charge density and gap, we exhibit anomalous scalings of the temperature and frequency dependent conductivity. Choosing the dynamical critical exponent z appropriately we can match the non-Fermi liquid scalings, such as linear resistivity, observed in strange metal regimes. As part of our investigation we outline three distinct string theory realizations of Lifshitz geometries: from F theory, from polarized branes, and from a gravitating charged Fermi gas. We also identify general features of renormalization group flow in Lifshitz theories, such as the appearance of relevant charge-charge interactions when z (ge) 2. We outline a program to extend this model building approach to other anomalous observables of interest such as the Hall conductivity.

  10. Neural correlates of creativity in analogical reasoning.

    Science.gov (United States)

    Green, Adam E; Kraemer, David J M; Fugelsang, Jonathan A; Gray, Jeremy R; Dunbar, Kevin N

    2012-03-01

    Brain-based evidence has implicated the frontal pole of the brain as important for analogical mapping. Separately, cognitive research has identified semantic distance as a key determinant of the creativity of analogical mapping (i.e., more distant analogies are generally more creative). Here, we used functional magnetic resonance imaging to assess brain activity during an analogy generation task in which we varied the semantic distance of analogical mapping (as derived quantitatively from a latent semantic analysis). Data indicated that activity within an a priori region of interest in left frontopolar cortex covaried parametrically with increasing semantic distance, even after removing effects of task difficulty. Results implicate increased recruitment of frontopolar cortex as a mechanism for integrating semantically distant information to generate solutions in creative analogical reasoning. 2012 APA, all rights reserved

  11. Charm and strangeness of ultrarelativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Gerschel, C.

    1994-01-01

    Charmonium and strangeness production in collisions induced by ultrarelativistic sulfur or silicon ions is reviewed. A suppression of charmonium production and a strangeness enhancement are observed. Predicted as potential signatures of the quark gluon plasma formation, their interpretation is still very much debated. The status of the discussion will be given as well as the expected evolutions with the forthcoming Pb beams. (author). 45 refs., 11 figs., 1 tab

  12. Non-Spherical Gravitational Collapse of Strange Quark Matter

    Institute of Scientific and Technical Information of China (English)

    Zade S S; Patil K D; Mulkalwar P N

    2008-01-01

    We study the non-spherical gravitational collapse of the strange quark null fluid.The interesting feature which emerges is that the non-spherical collapse of charged strange quark matter leads to a naked singularity whereas the gravitational collapse of neutral quark matter proceeds to form a black hole.We extend the earlier work of Harko and Cheng[Phys.Lett.A 266 (2000) 249]to the non-spherical case.

  13. Strangeness in nuclei

    International Nuclear Information System (INIS)

    Dover, C.B.

    1988-01-01

    We review some of the motivations for the study of strange particle nuclear physics. A status report on recent progress in the spectroscopy of Λ and Σ hypernuclei is provided, as well as a discussion of future prospects for the study of S = /minus/1 and /minus/2 systems. The importance of the nuclear physics program at future high intensity hadron facilities is emphasized. 45 refs

  14. Strangeness Production in Jets with ALICE at the LHC

    Science.gov (United States)

    Smith, Chrismond; Harton, Austin; Garcia, Edmundo; Alice Collaboration

    2016-03-01

    The study of strange particle production is an important tool for understanding the properties of the hot and dense QCD medium created in heavy-ion collisions at ultra-relativistic energies. The study of strange particles in these collisions provides information on parton fragmentation, a fundamental QCD process. While measurements at low and intermediate pT, are already in progress at the LHC, the study of high momentum observables is equally important for a complete understanding of the QCD matter, this can be achieved by studying jet interactions. We propose the measurement of the characteristics of the jets containing strange particles. Starting with proton-proton collisions, we have calculated the inclusive pTJet spectra and the spectra for jets containing strange particles (K-short or lambda), and we are extending this analysis to lead-lead collisions. In this talk the ALICE experiment will be described, the methodology used for the data analysis and the available results will be discussed. This material is based upon work supported by the National Science Foundation under Grants PHY-1305280 and PHY-1407051.

  15. Controlling Strange Attractor in Dynamics

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A nonlinear system which exhibits a strange attractor is considered, with the goal of illustrating how to control the chaotic dynamical system and to obtain a desired attracting periodic orbit by the OGY control algorithm.

  16. Strange and non-strange baryon and antibaryon production in sulphur-tungsten and sulphur-sulphur interactions at 200 A Gev/c

    Energy Technology Data Exchange (ETDEWEB)

    Holme, A.K.

    1995-11-01

    The author has studied production of strange and multistrange baryons and antibaryons in central sulphur-tungsten, sulphur-sulphur, and lead-lead interactions at relativistic energies. The spectra of strange baryons and antibaryons provide information about the dynamics of hadronic matter under the extreme conditions realised in these collisions. The particle ratios allow the degree and the nature of the flavour equilibrium to be studied, while the transverse mass distributions provide independent information of the temperatures achieved. 143 refs.

  17. Strange and non-strange baryon and antibaryon production in sulphur-tungsten and sulphur-sulphur interactions at 200 A Gev/c

    International Nuclear Information System (INIS)

    Holme, A.K.

    1995-11-01

    The author has studied production of strange and multistrange baryons and antibaryons in central sulphur-tungsten, sulphur-sulphur, and lead-lead interactions at relativistic energies. The spectra of strange baryons and antibaryons provide information about the dynamics of hadronic matter under the extreme conditions realised in these collisions. The particle ratios allow the degree and the nature of the flavour equilibrium to be studied, while the transverse mass distributions provide independent information of the temperatures achieved. 143 refs

  18. The Geometric Structure of Strange Attractors in the Lozi Map

    Institute of Scientific and Technical Information of China (English)

    YongluoCAO; ZengrongLIU

    1998-01-01

    In this paper,the structure of the strange attractors in the Lozi map is investigated on basis of the results gotten by the authors in 1991-1993,The new results of the strange atrtractors of the Lozi map show that our viewpoint is correct.

  19. Strangeness and quark gluon plasma: Aspects of theory and experiment

    International Nuclear Information System (INIS)

    Eggers, H.C.; Rafelski, J.

    1990-07-01

    A survey of our current understanding of the strange particle signature of quark gluon plasma is presented. Emphasis is placed on the theory of strangeness production in the plasma and recent pertinent experimental results. Useful results on spectra of thermal particles are given. (orig.)

  20. Strange-face Illusions During Interpersonal-Gazing and Personality Differences of Spirituality.

    Science.gov (United States)

    Caputo, Giovanni B

    Strange-face illusions are produced when two individuals gaze at each other in the eyes in low illumination for more than a few minutes. Usually, the members of the dyad perceive numinous apparitions, like the other's face deformations and perception of a stranger or a monster in place of the other, and feel a short lasting dissociation. In the present experiment, the influence of the spirituality personality trait on strength and number of strange-face illusions was investigated. Thirty participants were preliminarily tested for superstition (Paranormal Belief Scale, PBS) and spirituality (Spiritual Transcendence Scale, STS); then, they were randomly assigned to 15 dyads. Dyads performed the intersubjective gazing task for 10 minutes and, finally, strange-face illusions (measured through the Strange-Face Questionnaire, SFQ) were evaluated. The first finding was that SFQ was independent of PBS; hence, strange-face illusions during intersubjective gazing are authentically perceptual, hallucination-like phenomena, and not due to superstition. The second finding was that SFQ depended on the spiritual-universality scale of STS (a belief in the unitive nature of life; e.g., "there is a higher plane of consciousness or spirituality that binds all people") and the two variables were negatively correlated. Thus, strange-face illusions, in particular monstrous apparitions, could potentially disrupt binding among human beings. Strange-face illusions can be considered as 'projections' of the subject's unconscious into the other's face. In conclusion, intersubjective gazing at low illumination can be a tool for conscious integration of unconscious 'shadows of the Self' in order to reach completeness of the Self. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Strange Men

    OpenAIRE

    Snider, William Stephen

    2017-01-01

    Haamid lives a modest life running a restaurant in a small market town in Uganda. A member of the minority Indian population, he is estranged from his family for reasons he prefers not to discuss. At night he cooks elaborate dinners that he eats alone. When an openly gay Peace Corps volunteer comes to town looking for more than a good meal, Haamid's comfortable routine is broken, and his life is put in danger. STRANGE MEN explores the limits of good intentions and the uneven stakes for Americ...

  2. Results from CERN experiment NA36 on strangeness production

    International Nuclear Information System (INIS)

    1991-12-01

    Measurements of the production of strange particles in the reactions S + Pb and S + S at beam momentum 200GeV/c per nucleon are presented. A short description of CERN experiment NA36 and the methods of raw data analysis, is followed by physics results concentrating on the dependence of strange particle production on multiplicity. Transverse momentum distributions are also presented

  3. Strange functions in real analysis

    CERN Document Server

    Kharazishvili, AB

    2005-01-01

    Weierstrass and Blancmange nowhere differentiable functions, Lebesgue integrable functions with everywhere divergent Fourier series, and various nonintegrable Lebesgue measurable functions. While dubbed strange or "pathological," these functions are ubiquitous throughout mathematics and play an important role in analysis, not only as counterexamples of seemingly true and natural statements, but also to stimulate and inspire the further development of real analysis.Strange Functions in Real Analysis explores a number of important examples and constructions of pathological functions. After introducing the basic concepts, the author begins with Cantor and Peano-type functions, then moves to functions whose constructions require essentially noneffective methods. These include functions without the Baire property, functions associated with a Hamel basis of the real line, and Sierpinski-Zygmund functions that are discontinuous on each subset of the real line having the cardinality continuum. Finally, he considers e...

  4. Nucleation of strange matter in dense stellar cores

    International Nuclear Information System (INIS)

    Horvath, J.E.; Benvenuto, O.G.; Vucetich, H.

    1992-01-01

    We investigate the nucleation of strange quark matter inside hot, dense nuclear matter. Applying Zel'dovich's kinetic theory of nucleation we find a lower limit of the temperature T for strange-matter bubbles to appear, which happens to be satisfied inside the Kelvin-Helmholtz cooling era of a compact star life but not much after it. Our bounds thus suggest that a prompt conversion could be achieved, giving support to earlier expectations for nonstandard type-II supernova scenarios

  5. Cross-Curricular Teaching Going Forward: A View from "Strange Fruit"

    Science.gov (United States)

    Esteve-Faubel, José-María; Martin, Tania Josephine; Junda, Mary Ellen

    2018-01-01

    "Strange Fruit," a song popularized by Billie Holiday in 1939, paints a gruesome picture of racial violence suffered by former African-American slaves following Reconstruction, 1863-1877 (Foner, 2011). While many scholars have analyzed the lyrics of "Strange Fruit", research that focuses on young people's reaction to the song…

  6. Effects of strangeness on the mass-radius of neutron stars in MQMC

    International Nuclear Information System (INIS)

    Sahoo, H.S.; Mishra, R.N.; Panda, P.K.; Barik, N.

    2017-01-01

    With the increase of baryon density towards centers of neutron stars, chemical potentials of neutrons become high so that neutrons at Fermi surfaces are changed to hyperons via strangeness non-conserving weak interactions overcoming rest masses of hyperons. In the present attempt we incorporate an additional pair of hidden strange mesons σ∗ and ϕ which couple only to the strange quark and the hyperons of the nuclear matter

  7. Evidences for existence of a strange meson with the 1627 MeV/c2 mass

    International Nuclear Information System (INIS)

    Karnaukhov, V.M.; Moroz, V.I.; Coca, C.

    1995-01-01

    The narrow structure with Μ=(1627±4) MeV/c 2 and Γ=(12 -12 +14 ) MeV/c 2 is observable in π - p interactions at 16 GeV/c in 6 effective mass spectra of the Kmπ systems. In the summed spectrum the number of standard deviations in the structure region over the background is 10. A performed compilative analysis of paper results on the study of strange meson resonances in various experiments does not contradict indication for the existence of K(1627)-meson, a narrow enhancement is observed in the same mass region. (author). 21 refs., 4 figs

  8. Strange Quark Stars in Binaries: Formation Rates, Mergers, and Explosive Phenomena

    Science.gov (United States)

    Wiktorowicz, G.; Drago, A.; Pagliara, G.; Popov, S. B.

    2017-09-01

    Recently, the possible coexistence of a first family composed of “normal” neutron stars (NSs) with a second family of strange quark stars (QSs) has been proposed as a solution of problems related to the maximum mass and to the minimal radius of these compact stellar objects. In this paper, we study the mass distribution of compact objects formed in binary systems and the relative fractions of quark and NSs in different subpopulations. We incorporate the strange QS formation model provided by the two-families scenario, and we perform a large-scale population synthesis study in order to obtain the population characteristics. According to our results, the main channel for strange QS formation in binary systems is accretion from a secondary companion on an NS. Therefore, a rather large number of strange QSs form by accretion in low-mass X-ray binaries and this opens the possibility of having explosive GRB-like phenomena not related to supernovae and not due to the merger of two NSs. The number of double strange QS systems is rather small, with only a tiny fraction that merge within a Hubble time. This drastically limits the flux of strangelets produced by the merger, which turns out to be compatible with all limits stemming from Earth and lunar experiments. Moreover, this value of the flux rules out at least one relevant channel for the transformation of all NSs into strange QSs by strangelets’ absorption.

  9. Strange Quark Stars in Binaries: Formation Rates, Mergers, and Explosive Phenomena

    International Nuclear Information System (INIS)

    Wiktorowicz, G.; Drago, A.; Pagliara, G.; Popov, S. B.

    2017-01-01

    Recently, the possible coexistence of a first family composed of “normal” neutron stars (NSs) with a second family of strange quark stars (QSs) has been proposed as a solution of problems related to the maximum mass and to the minimal radius of these compact stellar objects. In this paper, we study the mass distribution of compact objects formed in binary systems and the relative fractions of quark and NSs in different subpopulations. We incorporate the strange QS formation model provided by the two-families scenario, and we perform a large-scale population synthesis study in order to obtain the population characteristics. According to our results, the main channel for strange QS formation in binary systems is accretion from a secondary companion on an NS. Therefore, a rather large number of strange QSs form by accretion in low-mass X-ray binaries and this opens the possibility of having explosive GRB-like phenomena not related to supernovae and not due to the merger of two NSs. The number of double strange QS systems is rather small, with only a tiny fraction that merge within a Hubble time. This drastically limits the flux of strangelets produced by the merger, which turns out to be compatible with all limits stemming from Earth and lunar experiments. Moreover, this value of the flux rules out at least one relevant channel for the transformation of all NSs into strange QSs by strangelets’ absorption.

  10. Strange Quark Stars in Binaries: Formation Rates, Mergers, and Explosive Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Wiktorowicz, G. [Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw (Poland); Drago, A.; Pagliara, G. [Dipartimento di Fisica e Scienze della Terra dell’Università di Ferrara and INFN Sezione di Ferrara, Via Saragat 1, I-44100 Ferrara (Italy); Popov, S. B., E-mail: gwiktoro@astrouw.edu.pl [Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetsky prospekt 13, 119234, Moscow (Russian Federation)

    2017-09-10

    Recently, the possible coexistence of a first family composed of “normal” neutron stars (NSs) with a second family of strange quark stars (QSs) has been proposed as a solution of problems related to the maximum mass and to the minimal radius of these compact stellar objects. In this paper, we study the mass distribution of compact objects formed in binary systems and the relative fractions of quark and NSs in different subpopulations. We incorporate the strange QS formation model provided by the two-families scenario, and we perform a large-scale population synthesis study in order to obtain the population characteristics. According to our results, the main channel for strange QS formation in binary systems is accretion from a secondary companion on an NS. Therefore, a rather large number of strange QSs form by accretion in low-mass X-ray binaries and this opens the possibility of having explosive GRB-like phenomena not related to supernovae and not due to the merger of two NSs. The number of double strange QS systems is rather small, with only a tiny fraction that merge within a Hubble time. This drastically limits the flux of strangelets produced by the merger, which turns out to be compatible with all limits stemming from Earth and lunar experiments. Moreover, this value of the flux rules out at least one relevant channel for the transformation of all NSs into strange QSs by strangelets’ absorption.

  11. Associated strangeness production at intermediate energies

    International Nuclear Information System (INIS)

    Saghai, B.

    1996-04-01

    Elementary strangeness production reactions with hadronic and electromagnetic probes are briefly reviewed. Some recent theoretical and experimental findings are underlined and a few open questions are singled out. (author)

  12. Strangeness in nuclei and neutron stars

    Science.gov (United States)

    Lonardoni, Diego

    2017-01-01

    The presence of exotic particles in the core of neutron stars (NS) has been questioned for a long time. At present, it is still an unsolved problem that drives intense research efforts, both theoretical and experimental. The appearance of strange baryons in the inner regions of a NS, where the density can exceed several times the nuclear saturation density, is likely to happen due to energetic considerations. The onset of strange degrees of freedom is considered as an effective mechanism to soften the equation of state (EoS). This softening affects the entire structure of the star, reducing the pressure and therefore the maximum mass that the star can stably support. The observation of two very massive NS with masses of the order of 2M⊙ seems instead to rule out soft EoS, apparently excluding the possibility of hyperon formation in the core of the star. This inconsistency, usually referred to as the hyperon puzzle, is based on what we currently know about the interaction between strange particles and normal nucleons. The combination of a poor knowledge of the hypernuclear interactions and the difficulty of obtaining clear astrophysical evidence of the presence of hyperons in NS makes the understanding of the behavior of strange degrees of freedom in NS an intriguing theoretical challenge. We give our contribution to the discussion by studying the general problem of the hyperon-nucleon interaction. We attack this issue by employing a quantum Monte Carlo (QMC) technique, that has proven to be successful in the description of strongly correlated Fermion systems, to the study of finite size nuclear systems including strange degrees of freedom, i.e. hypernuclei. We show that many-body hypernuclear forces are fundamental to properly reproduce the ground state physics of Λ hypernuclei from light- to medium-heavy. However, the poor abundance of experimental data on strange nuclei leaves room for a good deal of indetermination in the construction of hypernuclear

  13. Life Is Strange : a mediated game reception analysis

    OpenAIRE

    Mänder, Leili

    2017-01-01

    In this essay a mediated video game reception of the game Life Is Strange is made, with the purpose of examining the players' meaning-making processes from a gender perspective. The materials of this essay consist of videos from six different YouTube channels where each player film themselves whilst playing through Life Is Strange as a way to review and share the gaming experience. The results show how the meaning-making processes are littered with gender discourses and affects. The affects o...

  14. Non-Equilibrium Heavy Flavored Hadron Yields from Chemical Equilibrium Strangeness-Rich QGP

    OpenAIRE

    Kuznetsova, Inga; Rafelski, Johann

    2008-01-01

    The yields of heavy flavored hadrons emitted from strangeness-rich QGP are evaluated within chemical non-equilibrium statistical hadronization model, conserving strangeness, charm, and entropy yields at hadronization.

  15. Strangeness and charm production in high energy heavy ion collisions

    International Nuclear Information System (INIS)

    Xu, Nu

    2001-01-01

    We discuss the dynamical effects of strangeness and charm production in high energy nuclear collisions. In order to understand the early stage dynamical evolution, it is necessary to study the transverse momentum distributions of multi-strange hadrons like Ξ and Ω and charm mesons like J/Ψ as a function of collision centrality

  16. Strange Meson Radiative Capture on the Proton in Low Energy QCD Lagrangian

    Institute of Scientific and Technical Information of China (English)

    ZHOU Li-Juan; MA Wei-Xing

    2002-01-01

    Based on our low energy QCD Lagrangian description of strange meson photoproduction off the protonand the crossing symmetry, the strange meson radiative capture on the proton, K- + p →γ + A, is investigated in the[SUsF (6) O(3)]sym. SUc (3) quark model of baryon structure with the same input parameter, the only strong couplingconstant aM, as that in the strange meson photoproduction off the proton γ + p → K+ + A, a crossing channel of thecapture reaction. A good agreement on the branching ratio between the predictions and data is obtained successfully.This excellent fit indicates that our low energy QCD Lagrangian theory with only one free parameter is an advancedand unified description of strange meson photoproduction and its associated radiative capture.

  17. Relativistic model for anisotropic strange stars

    Science.gov (United States)

    Deb, Debabrata; Chowdhury, Sourav Roy; Ray, Saibal; Rahaman, Farook; Guha, B. K.

    2017-12-01

    In this article, we attempt to find a singularity free solution of Einstein's field equations for compact stellar objects, precisely strange (quark) stars, considering Schwarzschild metric as the exterior spacetime. To this end, we consider that the stellar object is spherically symmetric, static and anisotropic in nature and follows the density profile given by Mak and Harko (2002) , which satisfies all the physical conditions. To investigate different properties of the ultra-dense strange stars we have employed the MIT bag model for the quark matter. Our investigation displays an interesting feature that the anisotropy of compact stars increases with the radial coordinate and attains its maximum value at the surface which seems an inherent property for the singularity free anisotropic compact stellar objects. In this connection we also perform several tests for physical features of the proposed model and show that these are reasonably acceptable within certain range. Further, we find that the model is consistent with the energy conditions and the compact stellar structure is stable with the validity of the TOV equation and Herrera cracking concept. For the masses below the maximum mass point in mass vs radius curve the typical behavior achieved within the framework of general relativity. We have calculated the maximum mass and radius of the strange stars for the three finite values of bag constant Bg.

  18. How strange a non-strange heavy baryon?

    International Nuclear Information System (INIS)

    Zhitnitsky, A.R.

    1997-01-01

    We give some general arguments in favor of the large magnitude of matrix elements of an operator associated with nonvalence quarks in heavy hadrons. In particular, we estimate matrix element left angle Λ b vertical stroke ss vertical stroke Λ b right angle to be of order of 1 for Λ b baryon whose valence content is b, u, d quarks. The arguments are based on the QCD sum rules and low energy theorems. The physical picture behind the phenomenon is somewhat similar to the one associated with the large strange content of the nucleon, i.e. with the large magnitude of the matrix element left angle p vertical stroke ss vertical stroke p right angle ∼ 1. We discuss some possible applications of the result. (orig.)

  19. Examination of the strangeness contribution to the nucleon magnetic moment

    NARCIS (Netherlands)

    Chen, XS; Timmermans, RGE; Sun, WM; Zong, HS; Wang, F

    We examine the nucleon strangeness magnetic moment mu(s) with a lowest order meson cloud model. We observe that (1) strangeness in the nucleon is a natural requirement of the empirical relation mu(p)/mu(n)similar or equal to-3/2, which favors an SU(3) octet meson cloud instead of merely the SU(2)

  20. Strangeness Production in a Chemically Equilibrating Quark-Gluon Plasma

    Institute of Scientific and Technical Information of China (English)

    HE Ze-Jun; LONG Jia-Li; MA Yu-Gang; MA Guo-Liang

    2004-01-01

    @@ We study the strangeness of a chemically equilibrating quark-gluon plasma at finite baryon density based on the and will accelerate with the change of the initial system from a chemically non-equilibrated to an equilibrated system. We also find that the calculated strangeness is very different from the one in the thermodynamic equilibrium system. This study may be helpful to understand the formation of quark-gluon plasma via a chemically non-equilibrated evolution framework.

  1. Quark core stars, quark stars and strange stars

    International Nuclear Information System (INIS)

    Grassi, F.

    1988-01-01

    A recent one flavor quark matter equation of state is generalized to several flavors. It is shown that quarks undergo a first order phase transition. In addition, this equation of state depends on just one parameter in the two flavor case, two parameters in the three flavor case, and these parameters are constrained by phenomenology. This equation of state is then applied to the hadron-quark transition in neutron stars and the determination of quark star stability, the investigation of strange matter stability and possible strange star existence. 43 refs., 6 figs

  2. Strange Meson Radiative Capture on the Proton in Low Energy QCD Lagrangian

    Institute of Scientific and Technical Information of China (English)

    ZHOULi-Juan; MAWei-Xing; 等

    2002-01-01

    Based on our low energy QCD Lagrangian description of strange meson photoproduction off the proton and the crossing symmetry,the strange meson radiative capture on the proton,K-+p→γ+A,is investigated in the [SU SF(6)×O(3)]sym,SUc(3) quark model of baryon structure with the same input parameter,the only strong coupling constant αM,as that in the strange meson photoproduction off the proton γ+p-→K+ Α,a crossing channel of the capture reaction,A good agreement on the branching ratio between the predictions and data is obtained successfully.This excellent fit indicates that our low energy QCD Lagrangian theory with only one free parameter is an advanced and unified description of strange meson photoproduction and its associated radiative capture.

  3. Frontopolar cortex mediates abstract integration in analogy.

    Science.gov (United States)

    Green, Adam E; Fugelsang, Jonathan A; Kraemer, David J M; Shamosh, Noah A; Dunbar, Kevin N

    2006-06-22

    Integration of abstractly similar relations during analogical reasoning was investigated using functional magnetic resonance imaging. Activation elicited by an analogical reasoning task that required both complex working memory and integration of abstractly similar relations was compared to activation elicited by a non-analogical task that required complex working memory in the absence of abstract relational integration. A left-sided region of the frontal pole of the brain (BA 9/10) was selectively active for the abstract relational integration component of analogical reasoning. Analogical reasoning also engaged a left-sided network of parieto-frontal regions. Activity in this network during analogical reasoning is hypothesized to reflect categorical alignment of individual component terms that make up analogies. This parieto-frontal network was also engaged by the complex control task, which involved explicit categorization, but not by a simpler control task, which did not involve categorization. We hypothesize that frontopolar cortex mediates abstract relational integration in complex reasoning while parieto-frontal regions mediate working memory processes, including manipulation of terms for the purpose of categorical alignment, that facilitate this integration.

  4. Search for (exotic) strange matter in the Star and Alice experiments with the ultra-relativistic heavy ion colliders RHIC and LHC; Recherche de matiere etrange (exotique) dans les experiences STAR et ALICE aupres des collisionneurs d'ions lourds ultra-relativistes RHIC et LHC

    Energy Technology Data Exchange (ETDEWEB)

    Vernet, R

    2006-02-15

    Ultra-relativistic heavy ion collisions offer the possibility to create conditions of temperature and density that could lead nuclear matter to a state of deconfined partons, the quark-gluon plasma. Strange baryon production is one of the essential observables to understand the mechanisms involved in the medium. Furthermore, theories predict a possible production of strange dibaryons, still hypothetical particles, from which one could draw important inferences in nuclear physics and astrophysics. The experiments STAR at RHIC, and, soon, ALICE at LHC, allow one to search for strange baryons and dibaryons. The STAR sensitivity to the metastable dibaryon H{sup 0} in the {lambda}p{pi}{sup -} decay mode was calculated thanks to a dedicated simulation. The search for the H{sup 0}, and for the {xi}{sup -}p resonance as well, was performed in the STAR Au+Au data at {radical}(s{sub NN}) = 62.4 and 200 GeV energies. Within the framework of the preparation of ALICE to the first Pb+Pb data, the detector ability to identify strange baryons {lambda}, {xi} and {omega}, was estimated via several simulations. So as to favour the reconstruction efficiency in a large range of transverse momentum while keeping a reasonable S/B ratio, the influence of the geometrical selections and the size of the reconstruction zone was emphasized. The ALICE sensitivities to the metastable strange dibaryons H{sup 0} and ({xi}{sup 0}p){sub b} and to the {lambda}{lambda} resonance were calculated as well. (author)

  5. Thermodynamics of strange quark matter with the density-dependent bag constant

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The thermodynamics of strange quark matter with density dependent bag constant are studied self-consistently in the framework of the general ensemble theory and the MIT bag model.In our treatment,an additional term is found in the expression of pressure.With the additional term,the zero pressure locates exactly at the lowest energy state,indicating that our treatment is a self-consistently thermodynamic treatment.The self-consistent equations of state of strange quark matter in both the normal and color-flavor-locked phase are derived.They are both softer than the inconsistent ones.Strange stars in both the normal and color-flavor locked phase have smaller masses and radii in our treatment.It is also interesting to find that the energy density at a star surface in our treatment is much higher than that in the inconsistent treatment for both phases.Consequently,the surface properties and the corresponding observational properties of strange stars in our treatment are different from those in the inconsistent treatment.

  6. Thermodynamics of strange quark matter with the density-dependent bag constant

    Institute of Scientific and Technical Information of China (English)

    ZHU MingFeng; LIU GuangZhou; YU Zi; XU Yan; SONG WenTao

    2009-01-01

    The thermodynamics of strange quark matter with density dependent bag constant are studied selfconsistently in the framework of the general ensemble theory and the MIT bag model.In our treatment,an additional term Is found in the expression of pressure.With the additional term,the zero pressure locates exactly at the lowest energy state,Indicating that our treatment is a self-consistently thermodynamic treatment.The self-consistent equations of state of strange quark matter in both the normal and color-flavor-locked phase are derived.They are both softer than the inconsistent ones.Strange stars in both the normal and color-flavor locked phase have smaller masses and radii in our treatment.It is also interesting to find that the energy density at a star surface in our treatment is much higher than that In the inconsistent treatment for both phases.Consequently,the surface properties and the corresponding observational properties of strange stars in our treatment are different from those in the inconsistent treatment.

  7. Using the Moon As A Low-Noise Seismic Detector For Strange Quark Nuggets

    Science.gov (United States)

    Banerdt, W. Bruce; Chui, Talso; Griggs, Cornelius E.; Herrin, Eugene T.; Nakamura, Yosio; Paik, Ho Jung; Penanen, Konstantin; Rosenbaum, Doris; Teplitz, Vigdor L.; Young, Joseph

    2006-01-01

    Strange quark matter made of up, down and strange quarks has been postulated by Witten [1]. Strange quark matter would be nearly charge neutral and would have density of nuclear matter (10(exp 14) gm/cu cm). Witten also suggested that nuggets of strange quark matter, or strange quark nuggets (SQNs), could have formed shortly after the Big Bang, and that they would be viable candidates for cold dark matter. As suggested by de Rujula and Glashow [2], an SQN may pass through a celestial body releasing detectable seismic energy along a straight line. The Moon, being much quieter seismically than the Earth, would be a favorable place to search for such events. We review previous searches for SQNs to illustrate the parameter space explored by using the Moon as a low-noise detector of SQNs. We also discuss possible detection schemes using a single seismometer, and using an International Lunar Seismic Network.

  8. Softness of Nuclear Matter and the Production of Strange Particles in Neutron Stars

    Institute of Scientific and Technical Information of China (English)

    陈伟; 文德华; 刘良钢

    2003-01-01

    In the various models, we study the influences of the softness of nuclear matter, the vacuum fluctuation ofnucleons and σ mesons on the production of strange particles in neutron stars. Wefind that the stiffer the nuclear matter is, the more easily the strange particles is produced in neutron stars. The vacuum fluctuation of nucleons has large effect on strange particle production while that of σ meson has little effect on it.

  9. Oscillations of neutral K mesons in the theory of dynamical expansion of the weak interaction theory or in the theory of dynamical analogy of the Cabibbo-Kobayashi-Maskawa matrices

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    1998-01-01

    The elements of the theory of dynamical expansion of the weak interaction theory working on the tree level, i.e., the theory of dynamical analogy of Cabibbo-Kobayashi-Maskawa matrices, are given. The equation for mass difference of K 1 0 , K 2 0 mesons or the length of K 0 -, K bar 0 - meson oscillations is calculated. In the framework of this theory the oscillations of K 0 , K 0 mesons which arise at violation of strangeness by B bosons are considered. The general conclusion is: the length of K 0 -, K 0 -meson oscillations is proportional to the mass of B boson (which changes strangeness) in the fourth degree

  10. Strange star candidates revised within a quark model with chiral mass scaling

    Institute of Scientific and Technical Information of China (English)

    Ang Li; Guang-Xiong Peng; Ju-Fu Lu

    2011-01-01

    We calculate the properties of static strange stars using a quark model with chiral mass scaling. The results are characterized by a large maximum mass (~ 1.6 M⊙) and radius (~ 10 km). Together with a broad collection of modern neutron star models, we discuss some recent astrophysical observational data that could shed new light on the possible presence of strange quark matter in compact stars. We conclude that none of the present astrophysical observations can prove or confute the existence of strange stars.

  11. Strange matter and dihyperon physics

    International Nuclear Information System (INIS)

    Barnes, P.D.

    1986-01-01

    A short review of the properties of Strange Matter is followed by a discussion of dihyperon physics. Calculations of the mass, lifetime and decay modes of the H particle are discussed, along with a review of experiments designed to search for the H Dibaryon. 32 refs., 15 figs

  12. New experimental results on strangeness production

    International Nuclear Information System (INIS)

    Sapozhnikov, M.G.

    1998-01-01

    New experimental results on the production of φ and f 2 ' (1525) mesons in the annihilation of stopped antiprotons are discussed. The explanation of these facts in the framework of the polarized strangeness model is considered

  13. Cooling Curve of Strange Star in Strong Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Qin; LUO Zhi-Quan

    2008-01-01

    In this paper, firstly, we investigate the neutrino emissivity from quark Urca process in strong magnetic field. Then, we discuss the heat capacity of strange stars in strong magnetic field. Finally, we give the cooling curve in strong magnetic field. In order to make a comparison, we also give the corresponding cooling curve in the case of null magnetic field. It turns out that strange stars cool faster in strong magnetic field than that without magnetic field.

  14. Properties of bare strange stars associated with surface electric fields

    International Nuclear Information System (INIS)

    Picanco Negreiros, Rodrigo; Mishustin, Igor N.; Schramm, Stefan; Weber, Fridolin

    2010-01-01

    In this paper we investigate the electrodynamic surface properties of bare strange quark stars. The surfaces of such objects are characterized by the formation of ultrahigh electric surface fields which might be as high as ∼10 19 V/cm. These fields result from the formation of electric dipole layers at the stellar surfaces. We calculate the increase in gravitational mass associated with the energy stored in the electric dipole field, which turns out to be only significant if the star possesses a sufficiently strong net electric charge distribution. In the second part of the paper, we explore the intriguing possibility of what happens when the electron layer (sphere) rotates with respect to the stellar strange matter body. We find that in this event magnetic fields can be generated which, for moderate effective rotational frequencies between the electron layer and the stellar body, agree with the magnetic fields inferred for several central compact objects. These objects could thus be comfortably interpreted as strange stars whose electron atmospheres rotate at frequencies that are moderately different (∼10 Hz) from the rotational frequencies of the strange star itself.

  15. Strangeness in nuclear matter at DAΦNE

    International Nuclear Information System (INIS)

    Gianotti, P.

    1998-01-01

    The low energy kaons from the φ meson produced at DAΦNE offer a unique opportunity to study strangeness in nuclear matter. The interaction of kaons with hadronic matter can be investigated at DAΦNE using three main approaches: study of hypernuclei production and decay, kaons scattering on nucleons, kaonic atoms formation. These studies explore kaon-nucleon and hyperon-nucleon forces at very low energy, the nuclear shell model in presence of strangeness quantum number and eventual quarks deconfinement phenomena. The experiments devoted to study this physical program at DAΦNE are FINUDA and DEAR. The physics topics of both experiments are illustrated together with a detailed descriptions of the two detectors

  16. Will strangeness win the prize?

    Energy Technology Data Exchange (ETDEWEB)

    Kapusta, Joseph I. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States). E-mail: kapusta at physics.spa.umn.edu

    2001-03-01

    Five groups have made predictions involving the production of strange hadrons and entered them in a competition set up by Barbara Jacak, Xin-Nian Wang and myself in the spring of 1998 for the purpose of comparing with first-year physics results from RHIC. These predictions are summarized and evaluated. (author)

  17. Strangeness in nuclei

    International Nuclear Information System (INIS)

    Buettgen, R.; Holinde, K.; Holzenkamp, B.; Speth, J.

    1986-01-01

    We present further results of our general program, which is to construct meson-exchange potentials for hadronic systems involving strange particles. In this contribution we investigate the relationship between the free ΛN-interaction and the effective interactions inside of a nucleus. These polarization effects are taken into account within a generalized Brueckner G-matrix. Within this approximation we calculate the binding energy and effective mass of a Λ-particle in nuclear matter as well as the Landau-parameters of the ΛN-system

  18. Dark matter, neutron stars, and strange quark matter.

    Science.gov (United States)

    Perez-Garcia, M Angeles; Silk, Joseph; Stone, Jirina R

    2010-10-01

    We show that self-annihilating weakly interacting massive particle (WIMP) dark matter accreted onto neutron stars may provide a mechanism to seed compact objects with long-lived lumps of strange quark matter, or strangelets, for WIMP masses above a few GeV. This effect may trigger a conversion of most of the star into a strange star. We use an energy estimate for the long-lived strangelet based on the Fermi-gas model combined with the MIT bag model to set a new limit on the possible values of the WIMP mass that can be especially relevant for subdominant species of massive neutralinos.

  19. Inclusive production of strange particles in 360 GeV/c PP interactions

    International Nuclear Information System (INIS)

    Rodrigo Anoro, T.

    1985-01-01

    Results on cross sections, longitudinal and transverse momentum distributions for ksub(s)sup(o), Λ and anti Λ production in 360 GeV/c PP interactions are presented as obtained from EHS equipped with the Rapid Cycling Bubble Chamber (RCBC). The Λ and anti Λ polarization are measured. The cross sections for the diffractive components are given using the recoil spectrum. The data are discussed with respect to charm production. The study on inclusive production of strange meson and baryon resonances is presented. Results on cross sections for K**(892), K* - (892), Σ + (1385) and Σ - (1285). Longitudinal and transverse momentum distributions for K*(892) and Σ(1385) are presented as well as for their induced Ksup(o's) and Λsup('s). An estimation is given on the K*(1430) and Σ* - (1915) productions. (author)

  20. A strange cat in Dublin

    Science.gov (United States)

    O'Raifeartaigh, Cormac

    2012-11-01

    Not many life stories in physics involve Nazis, illicit sex, a strange cat and the genetic code. Thus, a new biography of the great Austrian physicist Erwin Schrödinger is always of interest, and with Erwin Schrödinger and the Quantum Revolution, veteran science writer John Gribbin does not disappoint.

  1. Resonance production in p+p, p+A and A+A collisions measured with HADES

    Directory of Open Access Journals (Sweden)

    Reshetin A.

    2012-11-01

    Full Text Available The knowledge of baryonic resonance properties and production cross sections plays an important role for the extraction and understanding of medium modifications of mesons in hot and/or dense nuclear matter. We present and discuss systematics on dielectron and strangeness production obtained with HADES on p+p, p+A and A+A collisions in the few GeV energy regime with respect to these resonances.

  2. Strangeness nuclear physics

    International Nuclear Information System (INIS)

    Imai, Kenichi

    1999-01-01

    A simple review of strangeness nuclear physics is stated in the order of introduction, generation, structure and decay of hyper-nucleus and S=-2 nuclear physics. Strangeness nuclear physics investigate the structure and nuclear force of new created nucleus by introducing strangeness to the nuclear matter. The fundamental problems are hyperon-nucleon and hyperon-hyperon interaction. There are many methods to generate hyper nucleus. The stopped K - reaction is the best one. Λ and S hyper and S=-2 nucleus were generated by (K - , π) and (π + , K + ) reaction, (K - , π) reaction and (K - , K + ) reaction, respectively. The elementary decay process in the nucleus is Λ - > pπ (Q=38 MeV), nπ 0 and Λp - > np (Q=176 MeV), Λn- > nn. In emulsion, mass of light nucleus less than 160 were determined. Two measurement units are stated. One of them is a double focusing type K beam line in BNL to investigate H dibaryon by (K - , K + ) reaction. The other is KEK-SKS, which is superconducting kaon spectrometer to study hyper nucleus by (π + , K + ) reaction. The various kinds of binding energy of Λ single-particle states are displayed as a function of A -2/3 . These experimental data fit well with DWIA calculation using Woods-Saxon type one-body potential. A spectrum of 12C (π + , K + ) reaction showed small peak without main two peaks, which was a hyperfine structure between the exited state of 11 C core and couple of s 1/2 Λ. Although γ-ray was detected by three nucleuses such as 4 HΛ, 7 Li Λ and 9 Be Λ , γ-ray spectrometry of hyper nucleus remains unexplored. E hyper nucleus is detected by 4He(K-, t) and not by 4 He (K - , π + ). The binding energy of 4He Σ is 4.4 + 1 MeV and the width 7.0 + 0.7 MeV. Λ hyper nucleus decay is occurred by weak interaction. The elementary processes are a mesonic decay of Λ - > pπ - and Λ - > nπ 0 and a nonmesonic decay of Λn - > nn and Λp- > np. The lifetime of hyper nucleus is shorter than free Λ. Subject of S=-2 nuclear

  3. PSR1987A: the case for strange-quark stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1989-01-01

    The new fast pulsar observed in the remnant of SN1987A, together with other considerations, provide evidence that there are two types of collapsed stars: neutron stars, having moderate central densities and subject to the usual mass constraint, and strange-quark-matter stars. We show that (i) all known pulsar masses and frequencies, with the exception of the new one, can be accounted for by plausible neutron star models; (ii) no known neutron star model can withstand the fast rotation of the new pulsar unless the central energy density is ∼ 15 that of normal nuclei, at which densities hadrons cannot plausibly exist as constituents; and (iii) if strange-quark matter is the true ground state of the strong interactions, strange-quark stars can sustain the high rotation imputed to the new pulsar. In the absence of another plausible structure that can withstand the fast rotation, we provisionally infer that the new pulsar is such a star. (author)

  4. Not strange but bizarre physics from the sample experiment

    International Nuclear Information System (INIS)

    Leinweber, D. B.

    1999-01-01

    Since the report of the SAMPLE Collaboration suggesting the strange-quark contribution to the nucleon, G M s (0), may be greater than zero, numerous models have appeared supporting positive values for G M s (0) In this paper the bizarre physics associated with G M s (0) > 0 is illustrated. Two equations are presented describing the strange quark contribution to the nucleon magnetic moment in terms of the ratio of strange to light sea-quark-loop contributions and valence-quark ratios, probing the subtle effects of environment sensitivity. The evaluations involve no approximations outside of the usual assumption of equal current quark masses. Using the new lattice QCD results, our best estimate for G M s (0) shifts slightly from G M s (0) =-0.75 ± 0.30 μ N , to G M s (0) = -0.62 ± 0.26 μ N . Copyright (1999) World Scientific Publishing Co. Pte. Ltd

  5. Strange (and incompatible) bedfellows: The relationship between ...

    African Journals Online (AJOL)

    Strange (and incompatible) bedfellows: The relationship between the National Health Act and the regulations relating to artificial fertilisation of persons, and its impact on individuals engaged in assisted reproduction.

  6. Strangeness production in Pb-Pb collisions at LHC energies with ALICE

    Directory of Open Access Journals (Sweden)

    Šefčík Michal

    2018-01-01

    Full Text Available The results on the production of strange and multi-strange hadrons (K0S, Λ, Ξ and Ω measured with ALICE in Pb-Pb collisions at the top LHC energy of SNN = 5.02 TeV are reported. Thanks to its excellent tracking and particle identification capabilities, ALICE is able to measure weakly decaying particles through the topological reconstruction of the identified hadronic decay products. Results are presented as a function of centrality and include transverse momentum spectra measured at central rapidity, pT-dependent Λ/K0S ratios and integrated yields. A systematic study of strangeness production is of fundamental importance for determining the thermal properties of the system created in ultrarelativistic heavy ion collisions. In order to study strangeness enhancement, the yields of studied particles are normalised to the corresponding measurement of pion production in the various centrality classes. The results are compared to measurements performed at lower energies, as well as to different systems and to predictions from statistical hadronization models.

  7. Theoretical study of nuclear physics with strangeness at Nankai University

    International Nuclear Information System (INIS)

    Ning Pingzhi

    2007-01-01

    Theoretical study of nuclear physics with strangeness from the nuclear physics group at Nankai university is briefly introduced. Theoretical calculations on hyperon mean free paths in nuclear medium have been done. The other 4 topics in the area of strangeness nuclear physics are the effect of different baryon impurities in nucleus, the heavy flavored baryon hypernuclei, the eta-mesons in nuclear matter and the properties of kaonic nuclei. (authors)

  8. Constituent quarks and enhancement of multi-strange baryons in heavy-ion collisions

    International Nuclear Information System (INIS)

    Behera, Nirbhay Kumar; Nandi, Basanta Kumar; Sahoo, Raghunath

    2011-01-01

    Heavy-ion collisions at relativistic energies aim to produce a state of matter which is governed by partonic degrees of freedom, known as Quark-Gluon Plasma (QGP). In the central rapidity region, strangeness enhancement has been proposed as a potential signature of QGP. It has been observed that a quark participant scaling of the multi-strange baryon production and also a strangeness scaling of the enhancement. This confirms that the partonic degrees of freedom is playing a major role in the particle production mechanism and may therefore significantly determine the formation of QGP in heavy ion collisions

  9. Aspects of strangeness production with 15 -- 30 GeV proton beams

    International Nuclear Information System (INIS)

    Dover, C.B.

    1992-04-01

    We discuss the spectrum of physics questions related to strangeness which could be addressed with a 15--30 GeV proton storage ring. We focus on various aspects of strangeness production, including hyperon production in pp collisions, studies of hyperon-nucleon scattering, production of hyper-fragments in p-nucleus collisions, and hyperon spin observables in inclusive production

  10. Strange culinary cncounters:

    DEFF Research Database (Denmark)

    Leer, Jonatan; Kjær, Katrine Meldgaard

    Strange Culinary Encounters: Stranger Fetishism in Cooking Shows In this paper, we will examine the ways in which the encountering of 'other' food cultures is played out in the two travelogue cooking shows Gordon's Great Escape and Jamie's Italian Escape, arguing that despite their ‘noble......’ intentions and ‘enlightened’ cosmopolitan approach to meeting the other (culinary culture), ultimately, Jamie and Gordon's respective culinary adventures work to create a social hierarchy in their own favor. Inspired by Sara Ahmed’s work on stranger fetishism, we will investigate how the two protagonist...

  11. Strangeness production and propagation in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Herrmann, N.

    1997-01-01

    Strangeness production is studied with the FOPI detector at GSI in the reaction 58 Ni + 58 Ni at 1.93 AGeV. K + and Λ momentum space distributions are compatible with the assumption of kinetic equilibrium with the baryons. The extrapolated production yields are in variance with chemical equilibrium. Effects of possible in-medium modification of the strange meson masses on the experimental observables are discussed. The directed sideward flow of kaons is used as an additional probe of the in-medium properties. (authors)

  12. Charm and strange quark contributions to the proton structure

    International Nuclear Information System (INIS)

    Torokoff, K.

    1999-02-01

    The possibility to have charm and strange quarks as quantum mechanical fluctuations in the proton wave function is investigated based on a model for non-perturbative QCD dynamics. Both hadron and parton basis are examined. A scheme for energy fluctuations is constructed and compared with explicit energy-momentum conservation. Resulting momentum distributions for charm and strange quarks in the proton are derived at the starting scale Q 0 for the perturbative QCD evolution. Kinematical constraints are found to be important when comparing to the 'intrinsic charm' model

  13. Torus-doubling process via strange nonchaotic attractors

    International Nuclear Information System (INIS)

    Mitsui, Takahito; Uenohara, Seiji; Morie, Takashi; Horio, Yoshihiko; Aihara, Kazuyuki

    2012-01-01

    Torus-doubling bifurcations typically occur only a finite number of times. It has been assumed that torus-doubling bifurcations in quasiperiodically forced systems are interrupted by the appearance of strange nonchaotic attractors (SNAs). In the present Letter, we study a quasiperiodically forced noninvertible map and report the occurrence of a torus-doubling process via SNAs. The mechanism of this process is numerically clarified. Furthermore, this process is experimentally demonstrated in a switched-capacitor integrated circuit. -- Highlights: ► We report the occurrence of a torus-doubling process via strange nonchaotic attractors (SNAs). ► The process consists of the gradual fractalization of a torus and the Heagy–Hammel transition. ► The torus-doubling process via SNAs is also experimentally demonstrated in an electronic circuit.

  14. The analog resonance of 208Pb

    International Nuclear Information System (INIS)

    Brinati, J.R.; Bund, G.W.

    1973-01-01

    Elastic and inelastic partial proton widths and Coulomb displacement energies for the IAR of the Ground State of 208 Pb are calculated in the Blair-Bund model. Exchange terms are included and different optical potentials are considered. Comparison with the experimental widths is made taking into account the off-resonance cross sections predicted by the optical potentials [pt

  15. Strange baryons in a chiral quark-meson model. Pt. 2

    International Nuclear Information System (INIS)

    McGovern, J.A.; Birse, M.C.

    1990-01-01

    The chrial-quark meson model is used to study baryon properties with realistic breaking of SU(3). The symmetry breaking is assumed to be strong, so that a random phase approximation (RPA) can be used. In this the strange baryons are described as excitations built on the hedgehog soliton and have an excitation energy of 315 MeV. Other properties of strange baryons are obtained by an approximate spin-isospin projection from the RPA wave function. The magnetic moments agree reasonably well with experiment, but the deviations from the experimental values suggest that the method is valid for the case of rather stronger symmetry breaking than is realistic. The dependence of the RPA energy on the magnitude of the symmetry breaking is examined, and found to be strongly nonlinear for realistic values. This supports the idea that a large πN sigma commutator need not imply a large strange-quark content in the proton. For reasonable values of the scalar meson masses the strange-quark condensate is found to be less than 5% of the total, at the mean-field level. We also estimate the contribution to the condensate from RPA correlations. Within a one-mode approximation we find these to be very small, ≅ 2%. (orig.)

  16. Neutrino dimuon production and the strangeness asymmetry of the nucleon

    International Nuclear Information System (INIS)

    Olness, F.; Nadolsky, P.; Pumplin, J.; Stump, D.; Huston, J.; Tung, W.K.; Lai, H.L.; Kretzer, S.; Owens, J.F.

    2005-01-01

    We have performed the first global QCD analysis to include the CCFR and NuTeV dimuon data, which provide direct constraints on the strange and antistrange parton distributions, s(x) and anti s(x). To explore the strangeness sector, we adopt a general parametrization of the non-perturbative s(x), anti s(x) functions satisfying basic QCD requirements. We find that the strangeness asymmetry, as represented by the momentum integral [S - ]≡∫ 0 1 x [s(x)- anti s(x)] dx, is sensitive to the dimuon data provided the theoretical QCD constraints are enforced. We use the Lagrange multiplier method to probe the quality of the global fit as a function of [S - ] and find -0.001 - ] < 0.004. Representative parton distribution sets spanning this range are given. Comparisons with previous work are made. (orig.)

  17. Fast reconstruction of multi-strange hyperons in the CBM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Vassiliev, Iouri [GSI, Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Collaboration: CBM-Collaboration

    2015-07-01

    The main goal of the CBM experiment is to study the behaviour of nuclear matter at very high baryonic density in which the transition to a deconfined and chirally restored phase is expected to happen. One of the promissing signatures of this new state is the enhanced production of multi-strange particles, therefore the reconstruction of multi-strange hyperons is essential for the understanding of the heavy ion collision dynamics. Another experimental challenge of the CBM experiment is online selection of open charm particles via the displaced vertex of the hadronic decay, Charmonium and low mass vector mesons in the environment of a heavy-ion collision. This task requires fast and efficient track reconstruction algorithms, primary vertex finder and particles finder. Results of feasibility studies of the multi-strange hyperons in the CBM experiment are presented.

  18. Beauty-conserving strangeness-changing rare semileptonic decays of Bs meson

    International Nuclear Information System (INIS)

    Harpreet Kaur

    1999-01-01

    The beauty-conserving strangeness-changing decays of B s meson are examined. In the charm sector, charm-conserving strangeness changing (Δc = 0, Δs ≠ 0) decays are Cabibbo suppressed and are governed by the CKM element V us which is much smaller than the CKM diagonal element V cs , so may be of little interest. On the other hand, in the b-sector, beauty-conserving strangeness changing (Δb = 0, Δs ≠ 0) decays are CKM allowed as the CKM matrix element V us governing such decays is much larger than V bc or V bu which govern respectively the b→c or b→u transitions. The phase space available, however, is too small for the decays considered here. The numerical estimates for the decay widths of two such modes of B s meson are presented. (author)

  19. Role of the strange quark in the rho(770) meson

    Energy Technology Data Exchange (ETDEWEB)

    Molina Peralta, Raquel [George Washington Univ., Washington, DC (United States); Guo, Dehua [George Washington Univ., Washington, DC (United States); Hu, B. [George Washington Univ., Washington, DC (United States); Alexandru, Andrei; Doering, Michael [George Washington Univ., Washington, DC (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2017-03-01

    Recently, the GWU lattice group has evaluated high-precision phase-shift data for $\\pi\\pi$ scattering in the $I = 1$, $J = 1$ channel. Unitary Chiral Perturbation Theory describes these data well around the resonance region and for different pion masses. Moreover, it allows to extrapolate to the physical point and estimate the effect of the missing $K\\bar{K}$ channel in the two-flavor lattice calculation. The absence of the strange quark in the lattice data leads to a lower $\\rho$ mass, and the analysis with U$\\chi$PT shows that the $K \\bar{K}$ channel indeed pushes the $\\pi\\pi$-scattering phase shift upward, having a surprisingly large effect on the $\\rho$-mass. The inelasticity is shown to be compatible with the experimental data. The analysis is then extended to all available two-flavor lattice simulations and similar mass shifts are observed. Chiral extrapolations of $N_f = 2 + 1$ lattice simulations for the $\\rho(770)$ are also reported.

  20. Strangeness production in nuclear collisions: Color rope formations?

    International Nuclear Information System (INIS)

    Toneev, V.D.; Amelin, N.S.; Csernai, L.P.; Gudima, K.K.; Sivoklokov, S.Yu.

    1992-12-01

    Strangeness production at SPS-CERN energies is studied within the Quark Gluon String Model. This analysis indicates that the observed shape of rapidity and transverse mass distributions are reproduced fairly well for both peripheral and central heavy ion collisions. However, for central collisions the model underpredicts strange particles abundance by a factor of about 2:2:4 for K S 0 , Λ and anti Λ, respectively. This discrepancy can be considered as a possible manifestation of string-string interactions of a collective type similar to the formation of a color rope. The model predictions for coming experiments with the Pb beam at CERN are given. (orig.)

  1. Charm and strange quark contributions to the proton structure

    Energy Technology Data Exchange (ETDEWEB)

    Torokoff, K

    1999-02-01

    The possibility to have charm and strange quarks as quantum mechanical fluctuations in the proton wave function is investigated based on a model for non-perturbative QCD dynamics. Both hadron and parton basis are examined. A scheme for energy fluctuations is constructed and compared with explicit energy-momentum conservation. Resulting momentum distributions for charm and strange quarks in the proton are derived at the starting scale Q{sub 0} for the perturbative QCD evolution. Kinematical constraints are found to be important when comparing to the `intrinsic charm` model 20 refs, 30 figs, 9 tabs

  2. Study of strange particle production by neutral currents induced by 1 and 12 GeV neutrinos and antineutrinos

    International Nuclear Information System (INIS)

    Francois, T.L.B.

    1977-01-01

    Strange particles production by weak neutral currents was experimentally studied. The first result is a direct confirmation that neutral currents conserve strangeness (by an upper limit on ΔS=-1 production). The two other results, production rate of strange neutral particles and ratio of strange particles production for antineutrinos and neutrinos, prove that these particles are mainly produced in the final hadronic state rather than on strange sea-quarks and give an upper limit on the rate of this type of quark in the nucleon [fr

  3. Odd-parity light baryon resonances

    International Nuclear Information System (INIS)

    Gamermann, D.; Garcia-Recio, C.; Salcedo, L. L.; Nieves, J.

    2011-01-01

    We use a consistent SU(6) extension of the meson-baryon chiral Lagrangian within a coupled channel unitary approach in order to calculate the T matrix for meson-baryon scattering in the s wave. The building blocks of the scheme are the π and N octets, the ρ nonet and the Δ decuplet. We identify poles in this unitary T matrix and interpret them as resonances. We study here the nonexotic sectors with strangeness S=0, -1, -2, -3 and spin J=(1/2), (3/2) and (5/2). Many of the poles generated can be associated with known N, Δ, Σ, Λ, Ξ and Ω resonances with negative parity. We show that most of the low-lying three and four star odd-parity baryon resonances with spin (1/2) and (3/2) can be related to multiplets of the spin-flavor symmetry group SU(6). This study allows us to predict the spin-parity of the Ξ(1620), Ξ(1690), Ξ(1950), Ξ(2250), Ω(2250) and Ω(2380) resonances, which have not been determined experimentally yet.

  4. The strange 0++ and 2++ radial excitations: A review of LASS data

    International Nuclear Information System (INIS)

    Aston, D.; Bienz, T.; Bird, F.; Dunwoodie, W.; Johnson, W.B.; Kunz, P.; Kwon, Y.; Leith, D.W.G.S.; Levinson, L.; Ratcliff, B.N.; Rensing, P.; Schultz, D.; Shapiro, S.; Sinervo, P.K.; Tarnopolsky, G.; Toge, N.; Waite, A.; Williams, S.; Awaji, N.; Fujii, K.; Hayashii, H.; Iwata, S.; Kajikawa, R.; Matsui, T.; Miyamoto, A.; Ozaki, H.; Pak, C.O.; Shimomura, T.; Sugiyama, A.; Suzuki, S.; Tauchi, T.; D'Amore, J.; Endorf, R.; Martinez, J.; Meadows, B.T.; Nussbaum, M.; Ukai, K.

    1991-10-01

    The experimental status of the strange 0 ++ and 2 ++ mesons is briefly reviewed and compared with expectations from the quark model. The results are taken from a high statistics study of strange mesons produced in LASS by an 11 GeV/c K - beam. 13 refs., 8 figs., 1 tab

  5. Higher dimensional strange quark matter solutions in self creation cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Şen, R., E-mail: ramazansen-1991@hotmail.com [Institute for Natural and Applied Sciences, Çanakkale Onsekiz Mart University, 17020, Çanakkale (Turkey); Aygün, S., E-mail: saygun@comu.edu.tr [Department of Physics, Art and Science Faculty, Çanakkale Onsekiz Mart University, Çanakkale 17020 (Turkey)

    2016-03-25

    In this study, we have generalized the higher dimensional flat Friedmann-Robertson-Walker (FRW) universe solutions for a cloud of string with perfect fluid attached strange quark matter (SQM) in Self Creation Cosmology (SCC). We have obtained that the cloud of string with perfect fluid does not survive and the string tension density vanishes for this model. However, we get dark energy model for strange quark matter with positive density and negative pressure in self creation cosmology.

  6. Flipped neutrino emissivity from strange matter

    International Nuclear Information System (INIS)

    Goyal, A.; Dutta, S.

    1994-01-01

    Energy loss due to wrong helicity sterile neutrinos through spin flip processes leads to rapid cooling of nascent neutron stars. The observed cooling of neutron stars associated with SN 1987A seems to preclude the existence of Dirac neutrinos with a mass in excess of 20 keV. Assuming that nuclear matter in the core of the neutron star undergoes a phase transition to quark matter leading to a strange star or a neutron star with a strange matter core, we examine the emission of flipped Dirac neutrinos for two dominant processes: quark-neutrino scattering [q+ν - (bar ν + )→q+ν + (bar ν - )] and the quark neutrino pair bremsstrahlung process [q+q→q+q+ν - bar ν - (ν+bar ν + )]. We determine the composition of quark matter just after core bounce and examine the effect of neutrino degeneracy on the emission rate and mean free path of the wrong helicity neutrinos

  7. A generalized Bethe-Weizaecker mass formula for strange hadronic matter

    International Nuclear Information System (INIS)

    Dover, C.B.; Gal, A.

    1993-01-01

    We extend the Bethe- Weizsaecker nuclear mass formula to strange hadronic matter composed of nucleons, lambdas and cascade hyperons. The generalized formula contains several volume and symmetry terms constrained by phenomenologically determined Λ-nuclear, Ξ-nuclear and ΛΛ interaction parameters and by hyperon-hyperon (ΛΛ, ΛΞ, ΞΞ) interaction parameters suggested by one-boson-exchange models. We confirm that multi-Λ hypernuclei are generally unstable to ΛΛ→ΞN conversion. For strange hadronic matter we determine, as function of the baryon number A, the line of strong-interaction stability, along which a large strangeness fraction vertical stroke /Svertical stroke /A∝0.5-1.1 and a low charge fraction q/A< or ∼0.2 hold, and no fission occurs. The binding energy per baryon increases monotonically to its bulk limit, B/A→38 MeV, vertical stroke /Svertical stroke /A→ 1.1 and q/A→0 for the parameters adopted here assuming that the hyperon species saturate at densities similar to those of protons and neutrons in nuclei. Even in the extreme limit of vanishingly small hyperon-hyperon interaction strengths, strange hadronic matter with B/A→15 MeV, vertical stroke /Svertical stroke /A→0.7 and q/A→0 in the bulk limit should exist and our mass formula reproduces semi-quantitatively recent mean-field calculations which implicitly assumed weak hyperon-hyperon interactions. (orig.)

  8. A generalized Bethe-Weizsaecker mass formula for strange hadronic matter

    International Nuclear Information System (INIS)

    Dover, C.B.; Washington Univ., Seattle, WA; Gal, A.; Washington Univ., Seattle, WA

    1992-12-01

    The Bethe-Weizsaecker nuclear mass formula is extended to strange hadronic matter composed of nucleons, lambdas and cascade hyperons. The generalized formula contains several volume and symmetry terms constrained by phenomenologically determined λ-nuclear, ξ-nuclear and λλ interaction parameters and by hyperon-hyperon (λλ, λξ, ξξ) interaction parameters suggested by One-Boson-Exchange models. We find that hypernuclei are generally unstable to λλ → ξN conversion. For strange hadronic matter, as function of the baryon number A, the line of strong-interaction stability, along which a large strangeness fraction |S|/A ∼ 0.5 - 1.1 and a low charge fraction q/A approx-lt 0.2 hold, and no fission occurs, is determined. The binding energy per baryon increases monotonically to its bulk limit, B/A → 38 MeV, |S|/A → 1.1 and q/A → 0 for the parameters adopted here assuming that the hyperon species saturate at densities similar to those of protons and neutrons in nuclei. Even in the extreme limit of vanishingly small hyperon-hyperon interaction strengths, strange hadronic matter with B/A → 15 MeV, |S|/A → 0.7 and q/A → 0 in the bulk limit should exist; the mass formula reproduces semi-quantitatively recent mean-field calculations which implicitly assumed weak hyperon-hyperon interactions

  9. Role of strangeness to the neutron star mass and cooling

    Science.gov (United States)

    Lee, Chang-Hwan; Lim, Yeunhwan; Hyun, Chang Ho; Kwak, Kyujin

    2018-01-01

    Neutron star provides unique environments for the investigation of the physics of extreme dense matter beyond normal nuclear saturation density. In such high density environments, hadrons with strange quarks are expected to play very important role in stabilizing the system. Kaons and hyperons are the lowest mass states with strangeness among meson and bayron families, respectively. In this work, we investigate the role of kaons and hyperons to the neutron star mass, and discuss their role in the neutron star cooling.

  10. Charges on Strange Quark Nuggets in Space

    Science.gov (United States)

    Teplitz, V.; Bhatia, A.; Abers, E.; Dicus, D.; Repko, W.; Rosenbaum, D.

    2008-01-01

    This viewgraph presentation reviews the work done in calculations to find ZN such that the rate of ambient photons ionize the strange quark nuggets (SQNs) Electrons are equal to the rate of ambient e's to replace them.

  11. A strange horn between Paolo Mantegazza and Charles Darwin.

    Science.gov (United States)

    Garbarino, Carla; Mazzarello, Paolo

    2013-09-01

    During the preparation of an exhibition in Pavia dedicated to the centennial anniversary of the death of the Italian Pathologist Paolo Mantegazza, a strange cheratinic horn was found at the Museum for the History of the University of Pavia labelled as 'spur of a cock transplanted into an ear of a cow.' After some historical investigation, we found this strange object was at the centre of a scientific correspondence between Mantegazza and Charles Darwin, who made reference to it in his book The Variation of Animals and Plants under Domestication. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Low-lying 1/2-hidden strange pentaquark states in the constituent quark model

    Institute of Scientific and Technical Information of China (English)

    Hui Li; Zong-Xiu Wu; Chun-Sheng An; Hong Chen

    2017-01-01

    We investigate the spectrum of the low-lying 1/2-hidden strange pentaquark states,employing the constituent quark model,and looking at two ways within that model of mediating the hyperfine interaction between quarks-Goldstone boson exchange and one gluon exchange.Numerical results show that the lowest 1/2-hidden strange pentaquark state in the Goldstone boson exchange model lies at ~ 1570 MeV,so this pentaquark configuration may form a notable component in S11(1535) if the Goldstone boson exchange model is applied.This is consistent with the prediction that S11 (1535) couples very strongly to strangeness channels.

  13. Strange and charm baryon masses with two flavors of dynamical twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrou, C. [Univ. of Cyprus, Nicosia (Cyprus). Dept. of Physics; Cyprus Institute, Nicosia (Cyprus). Computation-Based Science and Technology Research Center; Carbonell, J. [CEA-Saclay, Gif-sur-Yvette (France). IRFU/Service de Physique Nucleaire; Christaras, D.; Gravina, M. [Univ. of Cyprus, Nicosia (Cyprus). Dept. of Physics; Drach, V. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Papinutto, M. [UFJ/CNRS/IN2P3, Grenoble (France). Laboratoire de Physique Subatomique et Cosmologie; Universidad Autonoma de Madrid (Spain). Dept. de Fisica Teorica; Universidad Autonoma de Madrid UAM/CSIC (Spain). Inst. de Fisica Teorica

    2012-10-15

    The masses of the low-lying strange and charm baryons are evaluated using two degenerate flavors of twisted mass sea quarks for pion masses in the range of about 260 MeV to 450 MeV. The strange and charm valence quark masses are tuned to reproduce the mass of the kaon and D-meson at the physical point. The tree-level Symanzik improved gauge action is employed. We use three values of the lattice spacing, corresponding to {beta}=3.9, {beta}=4.05 and {beta}=4.2 with r{sub 0}/a=5.22(2), r{sub 0}/a=6.61(3) and r{sub 0}/a=8.31(5) respectively. We examine the dependence of the strange and charm baryons on the lattice spacing and strange and charm quark masses. The pion mass dependence is studied and physical results are obtained using heavy baryon chiral perturbation theory to extrapolate to the physical point.

  14. Neutral strange particle production in neutrino and antineutrino charged current interactions on protons

    Science.gov (United States)

    Jones, G. T.; Jones, R. W. L.; Kennedy, B. W.; O'Neale, S. W.; Villalobos-Baillie, O.; Klein, H.; Morrison, D. R. O.; Schmid, P.; Wachsmuth, H.; Miller, D. B.; Mobayyen, M. M.; Wainstein, S.; Aderholz, M.; Hantke, D.; Katz, U. F.; Kern, J.; Schmitz, N.; Wittek, W.; Borner, H. P.; Myatt, G.; Radojicic, D.; Bullock, F. W.; Burke, S.

    1993-06-01

    The production of the neutral strange particles K 0, Λ andbar Λ in vp andbar vp charged current interactions is studied in an experiment with the Big European Bubble Chamber. Mean multiplicities are measured as a function of the event variables E v, W 2 and Q 2 and of the hadron variables x F, z and p {T/2}. K *± (892) and ∑ *± (1385) signals are observed, whereas there is no evidence for ∑ *- (1385) production in vp scattering. Forward, backward and total mean multiplicities are found to compare well with the predictions of an empirical model for deep-inelastic reactions in the case of the strange mesons K 0 and K *± (892) but less so for the strange baryons Λ,bar Λ and ∑ *± (1385). The strange baryon multiplicities are used to obtain the decuplet to octet baryon production ratio and to assess the probabilities of a uu or ud system to break up.

  15. Neutral strange particle production in neutrino and antineutrino charged current interactions on protons

    International Nuclear Information System (INIS)

    Jones, G.T.; Jones, R.W.L.; Kennedy, B.W.; O'Neale, S.W.; Villalobos-Baillie, O.; Klein, H.; Morrison, D.R.O.; Schmid, P.; Wachsmuth, H.; Miller, D.B.; Mobayyen, M.M.; Wainstein, S.; Aderholz, M.; Hantke, D.; Katz, U.F.; Kern, J.; Schmitz, N.; Wittek, W.; Borner, H.P.; Myatt, G.; Radojicic, D.; Bullock, F.W.; Burke, S.

    1992-08-01

    The production of the neutral strange particles K 0 , Λ and anti Λ in νp and anti νp charged current interactions is studied in an experiment with the Big European Bubble Chamber. Mean multiplicities are measured as a function of the event variables. E ν , W 2 and Q 2 and of the hadron variables χ F , z and p T 2 . K* ± (892) and Σ* ± (1385) signals are observed, whereas there is no evidence for Σ* - (1385) production in νp scattering. Forward, backward and total mean multiplicities are found to compare well with the predictions of an empirical model for deep-inelastic reactions in the case of the strange mesons K 0 and K* ± (892) but less so for the strange baryons Λ, anti Λ and Σ* ± (1385). The strange baryon multiplicities are used to obtain the decuplet to octet baryon production ratio and to assess the probabilities of a uu or ud system to break up. (orig.)

  16. Neutral strange particle production in neutrino and antineutrino charged current interactions on protons

    International Nuclear Information System (INIS)

    Jones, G.T.; Jones, R.W.L.; Kennedy, B.W.; O'Neale, S.W.; Villalobos-Baillie, O.; Klein, H.; Morrison, D.R.O.; Schmid, P.; Wachsmuth, H.; Miller, D.B.; Mobayyen, M.M.; Wainstein, S.; Borner, H.P.; Myatt, G.; Radojicic, D.; Bullock, F.W.; Burke, S.

    1993-01-01

    The production of the neutral strange particles K 0 , Λ and anti Λ in νp and anti νp charged current interactions is studied in an experiment with the Big European Bubble Chamber. Mean multiplicities are measured as a function of the event variables E ν , W 2 and Q 2 and of the hadron variables x F , z and p T 2 . K* ± (892) and Σ* ± (1385) signals are observed, whereas there is no evidence for Σ* - (1385) production in νp scattering. Forward, backward and total mean multiplicities are found to compare well with the predictions of an empirical model for deep-inelastic reactions in the case of the strange mesons K 0 and K* ± (892) but less so for the strange baryons Λ, anti Λ and Σ* ± (1385). The strange baryon multiplicites are used to obtain the decuplet to octet baryon production ratio and to assess the probabilities of a uu or ud system to break up. (orig.)

  17. Account of proton channels coupling in optical-shell description of partial proton widths of isobaric analog resonances

    International Nuclear Information System (INIS)

    Guba, V.G.; Urin, M.G.

    1983-01-01

    Quantitative analysis of partial proton width of isobaric analog resonances (IAR) for magic and near-magic (by neutrons) nuclei (at proton scattering on sup(207, 208Pb, 140 Ce, 138 Ba, 90 Zr) is conducted. Optical-shell model of nuclear reactions has been used. Quantitative interpretation of width is suggested on the base of numerical solution of integral equations for effective Coulomb field with account relation of 0 + -configurations proton-neutron hole both with continuum and with multiparticle configurations. Accountancy of relation of proton channels results in systematic 1.3-2.0 fold decrease of calculated values of widths. It permits to coordinate experimental and calculated values of width at reasonable values of parameters of optical potential. The results of calculation of reduced width are stable to variation of parameters of the model

  18. Role of strangeness to the neutron star mass and cooling

    Directory of Open Access Journals (Sweden)

    Lee Chang-Hwan

    2018-01-01

    Full Text Available Neutron star provides unique environments for the investigation of the physics of extreme dense matter beyond normal nuclear saturation density. In such high density environments, hadrons with strange quarks are expected to play very important role in stabilizing the system. Kaons and hyperons are the lowest mass states with strangeness among meson and bayron families, respectively. In this work, we investigate the role of kaons and hyperons to the neutron star mass, and discuss their role in the neutron star cooling.

  19. Study of giant resonances with pions

    International Nuclear Information System (INIS)

    Baer, H.W.

    1984-01-01

    Recent results on giant resonances obtained with pion-inelastic scattering and with single- and double-charge-exchange scattering are reviewed. The states discussed are isobaric analog states, double-isobaric analog states, and isovector L = 0, 1, and 2 collective states. 36 references

  20. The neural substrate of analogical reasoning: an fMRI study.

    Science.gov (United States)

    Luo, Qian; Perry, Conrad; Peng, Danling; Jin, Zhen; Xu, Duo; Ding, Guosheng; Xu, Shiyong

    2003-10-01

    This study investigated the anatomical substrate of analogical reasoning using functional magnetic resonance imaging. In the study, subjects performed a verbal analogy task (e.g., soldier is to army as drummer is to band) and, to control for activation caused by purely semantic access, a semantic judgment task. Significant activation differences between the verbal analogy and the semantic judgment task were found bilaterally in the prefrontal cortex (right BA 11/BA 47 and left BA45), the fusiform gyrus, and the basal ganglia; left lateralized in the postero-superior temporal gyrus (BA 22) and the (para) hippocampal region; and right lateralized in the anterior cingulate. The role of these areas in analogical reasoning is discussed.

  1. Neutral strange particle production at top SPS energy measured by the CERES experiment

    International Nuclear Information System (INIS)

    Radomski, S.

    2006-01-01

    Systematics of strange particle production in collisions of ultrarelativistic nuclei provides an insight into the properties of the strongly interacting matter. Hadrochemistry, the study of the relative yields, provides information about chemical freeze-out and the position of the system in the phase diagram. Strangeness production at Super Proton Synchrotron (SPS) energies is not fully explained by the thermal model of hadron gas. Data reported by one experiment show sharp structures as a function of energy which are interpreted as a signature for a phase transition, but due to discrepancies in the results between two different experiments, a conclusion can not be drawn. This thesis is part of an effort to build a database of the strangeness production at SPS energy. The particular subject of this work is a precise measurement of the production of K S 0 . The results are compared with two other experiments and the prediction of the thermal model. The high precision data shed light on the systematics of strangeness production and allow clarification of the experimental status. The study of transverse momentum spectra provides information about the temperature and the radial expansion of the system. Here, as in the case of particle yields, interesting structures are visible as a function of energy. A rapid increase in the number of degrees of freedom is visible in the SPS region. A large part of the strangeness is carried by the neutral strange baryon Λ. Here the experimental situation is even more complicated because the reconstruction of the Λ yield requires large extrapolation to low transverse momentum. In this work first results on Λ production will be presented. (orig.)

  2. Neutral strange particle production at top SPS energy measured by the CERES experiment

    Energy Technology Data Exchange (ETDEWEB)

    Radomski, S.

    2006-07-05

    Systematics of strange particle production in collisions of ultrarelativistic nuclei provides an insight into the properties of the strongly interacting matter. Hadrochemistry, the study of the relative yields, provides information about chemical freeze-out and the position of the system in the phase diagram. Strangeness production at Super Proton Synchrotron (SPS) energies is not fully explained by the thermal model of hadron gas. Data reported by one experiment show sharp structures as a function of energy which are interpreted as a signature for a phase transition, but due to discrepancies in the results between two different experiments, a conclusion can not be drawn. This thesis is part of an effort to build a database of the strangeness production at SPS energy. The particular subject of this work is a precise measurement of the production of K{sub S}{sup 0}. The results are compared with two other experiments and the prediction of the thermal model. The high precision data shed light on the systematics of strangeness production and allow clarification of the experimental status. The study of transverse momentum spectra provides information about the temperature and the radial expansion of the system. Here, as in the case of particle yields, interesting structures are visible as a function of energy. A rapid increase in the number of degrees of freedom is visible in the SPS region. A large part of the strangeness is carried by the neutral strange baryon {lambda}. Here the experimental situation is even more complicated because the reconstruction of the {lambda} yield requires large extrapolation to low transverse momentum. In this work first results on {lambda} production will be presented. (orig.)

  3. Hot Strange Hadronic Matter in an Effective Model

    Science.gov (United States)

    Qian, Wei-Liang; Su, Ru-Keng; Song, Hong-Qiu

    2003-10-01

    An effective model used to describe the strange hadronic matter with nucleons, Λ-hyperons, and Ξ-hyperons is extended to finite temperature. The extended model is used to study the density, temperature, and strangeness fraction dependence of the effective masses of baryons in the matter. The thermodynamical quantities, such as free energy and pressure, as well as the equation of state of the matter, are given. The project supported in part by National Natural Science Foundation of China under Grant Nos. 10075071, 10047005, 19947001, 19975010, and 10235030, and the CAS Knowledge Innovation Project No. KJCX2-N11. Also supported by the State Key Basic Research Development Program under Grant No. G200077400 and the Exploration Project of Knowledge Innovation Program of the Chinese Academy of Sciences

  4. Strange attractor of Henon map and its basin

    Institute of Scientific and Technical Information of China (English)

    曹永罗

    1995-01-01

    In this paper, Henon map is considered. For a positive measure set of parameters (a, b), we construct a trapping region G of topologically transitive strange attractor Aa,b for Ta,b, and prove that Aa,b= ∩n≥0Ta,bnG, and the basin B(Aa,b) of Aa,b is exactly the union of domain whose boundary is contained in w5(p) ∪wu(p) and ws(p). Therefore, that the conjecture posed by Benedicks and Carleson about the basin of strange attactor is true is proved. Furthermore, B(Aa,b) is simply connected and path-connected, w4(p2) is contained in the attainable boundary set of B(Aa,b) (where p2 is another hyperbolic fixed point of Ta,b).

  5. Statistical properties of chaotic dynamical systems which exhibit strange attractors

    International Nuclear Information System (INIS)

    Jensen, R.V.; Oberman, C.R.

    1981-07-01

    A path integral method is developed for the calculation of the statistical properties of turbulent dynamical systems. The method is applicable to conservative systems which exhibit a transition to stochasticity as well as dissipative systems which exhibit strange attractors. A specific dissipative mapping is considered in detail which models the dynamics of a Brownian particle in a wave field with a broad frequency spectrum. Results are presented for the low order statistical moments for three turbulent regimes which exhibit strange attractors corresponding to strong, intermediate, and weak collisional damping

  6. Strange magnetism and the anapole structure of the proton

    International Nuclear Information System (INIS)

    Hasty, R.; Beck, D.H.; Danagoulian, A.; Blake, A.; Carr, R.; Covrig, S.; Filipoone, B.W.; Ito, T.M.; Gao, J.; Jones, C.E.; Lee, P.; McKeown, R.D.; Savu, V.; Beise, E.J.; Breuer, H.; Spayde, D.T.; Tieulent, R.; Herda, M.C.; Barkhuff, D.; Dodson, G.; Dow, K.; Farkhondeh, M.; Kowalski, S.; Tsentalovich, E.; Yang, B.; Zwart, T.; Hawthorne-Allen, A.M.; Pitt, M.; Ritter, J.; Korsch, W.; Mueller, B.; Wells, S.P.; Averett, T.; Roche, J.; Kramer, K.

    2000-01-01

    The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The measurement reported here provides an unambiguous constraint on strange quark contributions to the proton's magnetic moment through the electron-proton weak interaction. We also report evidence for the existence of a parity-violating electromagnetic effect known as the anapole moment of the proton. The proton's anapole moment is not yet well understood theoretically, but it could have important implications for precision weak interaction studies in atomic systems such as cesium.

  7. The strange quark contribution to the neutron electric dipole moment in multi-Higgs doublet models

    International Nuclear Information System (INIS)

    He, Xiao Gang; McKeller, H.J.; Pakvasa, S.

    1990-09-01

    The strange quark contribution to the neutron electric dipole moment was studied and compared with other contributions in multi-Higgs doublet models. It was found that the strange quark contribution is significant because the strange quark color dipole moment is larger than that of the down (up) quark by a factor m s /m d (m s /m u ). In the case of neutral Higgs it can be the dominant contribution to the neutron electric dipole moment. 18 refs

  8. Using the Moon and Mars as Giant Detectors for Strange Quark Nuggets

    Science.gov (United States)

    Chui, Talso; Penanen, Konstantin; Strayer, Don; Banerdt, Bruce; Tepliz, Vigdor; Herrin, Eugene

    2004-01-01

    On the Earth, the detectability of small seismic signals is limited by pervasive seismic background noise, caused primarily by interactions of the atmosphere and oceans with the solid surface. Mars, with a very thin atmosphere and no ocean is expected to have a noise level at least an order of magnitude lower than the Earth, and the airless Moon is even quieter still. These pristine low-vibration environments are ideal for searching for nuggets of "strange quark matter." Strange quark matter was postulated by Edward Witten [Phys. Rev. D30, 272, 1984] as the lowest possible energy state of matter. It would be made of up, down, and strange quarks, instead of protons and neutrons made only of up and down quarks. It would have nuclear densities, and hence be difficult to detect. Micron-sized nuggets would weigh in the ton range. As suggested by de Rujula and Glashow [Nature 312 (5996): 734, 1984], a massive strange quark nugget can generate a trail of seismic waves, as it traverses a celestial body. We discuss the mission concept for deploying a network of sensitive seismometers on Mars and on the Moon for such a search.

  9. Strange diquarks and orbital excitations of hyperons

    International Nuclear Information System (INIS)

    Kondratyuk, L.A.; Ralchenko, Yu.V.; Vasilets, A.V.

    1987-01-01

    Using the model of the QCD string with spin-orbital interaction the masses of strange diquarks are determined. The spectra of orbital excitations of the Λ and Σ hyperons are calculated and discussed. Also the decay modes for Λ's and Σ's are considered

  10. Consideration of the vacuum of QCD in a composite quark model. Strange hadrons

    International Nuclear Information System (INIS)

    Dorokhov, A.E.; Kochelev, N.I.

    1986-01-01

    The method of inclusion of QCD vacuum condensates within the quark composite model is generalized to the case of hadrons containing strange quarks. The mass formula for such hadrons is obtained. The mass of strange quark is defined by analysing the energy spectrum of hadron ground states. The mixing angles of pseudoscalar mesons are estimated

  11. The effect of dynamical quark mass on the calculation of a strange quark star's structure

    Institute of Scientific and Technical Information of China (English)

    Gholam Hossein Bordbar; Babak Ziaei

    2012-01-01

    We discuss the dynamical behavior of strange quark matter components,in particular the effects of density dependent quark mass on the equation of state of strange quark matter.The dynamical masses of quarks are computed within the Nambu-Jona-Lasinio model,then we perform strange quark matter calculations employing the MIT bag model with these dynamical masses.For the sake of comparing dynamical mass interaction with QCD quark-quark interaction,we consider the one-gluon-exchange term as the effective interaction between quarks for the MIT bag model.Our dynamical approach illustrates an improvement in the obtained equation of state values.We also investigate the structure of the strange quark star using TolmanOppenheimer-Volkoff equations for all applied models.Our results show that dynamical mass interaction leads to lower values for gravitational mass.

  12. Strange attractors in weakly turbulent Couette-Taylor flow

    Science.gov (United States)

    Brandstater, A.; Swinney, Harry L.

    1987-01-01

    An experiment is conducted on the transition from quasi-periodic to weakly turbulent flow of a fluid contained between concentric cylinders with the inner cylinder rotating and the outer cylinder at rest. Power spectra, phase-space portraits, and circle maps obtained from velocity time-series data indicate that the nonperiodic behavior observed is deterministic, that is, it is described by strange attractors. Various problems that arise in computing the dimension of strange attractors constructed from experimental data are discussed and it is shown that these problems impose severe requirements on the quantity and accuracy of data necessary for determining dimensions greater than about 5. In the present experiment the attractor dimension increases from 2 at the onset of turbulence to about 4 at a Reynolds number 50-percent above the onset of turbulence.

  13. 1-3 Nuclear In-medium Effects of Strange Particles in Proton-nucleus Collisions

    Institute of Scientific and Technical Information of China (English)

    Feng; Zhaoqing[1

    2014-01-01

    Extraction of the in-medium properties of strange particles from heavy-ion collisions is very complicated, since he nuclear density varies in the evolution of nucleus-nucleus collisions. To avoid the uncertainties of the baryon ensities during the stage of strange particle production, one can investigate proton-nucleus collisions where the uclear density is definite around the saturation density. Dynamics of strange particles produced in the protoninduced uclear the reactions near the threshold energies has been investigated within the Lanzhou quantum olecular dynamics (LQMD) transport model. The in-medium modifications on particle production in densenuclear matter are considered through the corrections to the elementary cross sections via the effective mass and he mean-field potentials[1].

  14. New strangeness results from HADES

    Czech Academy of Sciences Publication Activity Database

    Fabbietti, L.; Agakishiev, G.; Agodi, C.; Balanda, A.; Bellia, G.; Belver, D.; Belyaev, A.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Braun-Munzinger, P.; Cabanelas, P.; Castro, E.; Chernenko, S.; Christ, T.; Destefanis, M.; Díaz, J.; Dohrmann, F.; Dybczak, A.; Eberl, T.; Fateev, O.; Friese, J.; Frohlich, I.; Galatyuk, T.; Garzón, J.A.; Gernhäuser, R.; Gil, A.; Gilardi, C.; Golubeva, M.; Gonzalez-Diaz, D.; Grosse, E.; Guber, F.; Heilmann, M.; Hennino, T.; Holzman, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Kanaki, K.; Karavicheva, T.; Kirschner, D.; Koenig, I.; Koenig, W.; Kolb, B.W.; Kotte, R.; Kozuch, A.; Krása, Antonín; Křížek, Filip; Krücken, R.; Kühn, W.; Kugler, Andrej; Kurepin, A.; Lamas-Valverde, J.; Lang, S.; Lange, J.S.; Lapidus, K.; Lopes, L.; Maier, L.; Mangiarotti, A.; Marín, J.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Mishra, D.; Moriniére, E.; Mousa, J.; Muntz, C.; Naumann, L.; Novotný, R.; Otwinowski, J.; Pachmayer, Y.C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Cavalcanti, T.P.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Roy-Stephan, M.; Rustamov, A.; Sadovsky, A.; Sailer, B.; Salabura, P.; Schmah, A.; Simon, R. S.; Sobolev, Yuri, G.; Spataro, S.; Spruck, B.; Strobele, H.; Stroth, J.; Sturm, C.; Sudol, M.; Tarantola, A.; Teilab, K.; Tlustý, Pavel; Traxler, M.; Trebacz, R.; Tsertos, H.; Veretenkin, I.; Wagner, Vladimír; Wen, H.; Wisniowski, M.; Wojcik, T.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y.V.; Zhou, P.; Zumbruch, P.

    2009-01-01

    Roč. 36, č. 6 (2009), 064005/1-064005/12 ISSN 0954-3899. [12th International Conference on Strangeness in Quark Matter. Beijing, 05.10.2008-10.10.2008] R&D Projects: GA AV ČR IAA100480803; GA MŠk LC07050 Institutional research plan: CEZ:AV0Z10480505 Keywords : heavy-ion collisions * kaon production * sis energies Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 2.124, year: 2009

  15. Strangeness photoproduction and hadronic resonances; Photoproduction d`etrangete et resonances hadroniques

    Energy Technology Data Exchange (ETDEWEB)

    David, J C

    1994-09-01

    The purpose of this thesis is to study the kaon photoproduction off a proton ({gamma}p {yields} K{sup +}{Lambda},{gamma}p {yields} K{sup +}{Sigma}{sup 0}, {gamma}p {yields} K{sup 0}{Sigma}{sup +}), with a photon energy between 0.9 and 2.1 GeV. We use an isobaric model where the amplitudes are computed with Feynman diagrams. The insertion of nucleonic resonances with spin 3/2 and 5/2 is necessary to improve the existing models beyond 1.5 GeV. This step is also necessary to extend the elementary process of photoproduction to electroproduction where the data have been taken with photon energies above 2.0 GeV. The parameters of our models are the coupling constants which appear at each Feynman diagram vertex. They are determined by fitting our models to the experimental data (cross sections, polarization asymmetries). Before performing the minimization we drew some informations about coupling constants from mesonic and electromagnetic decays, and from SU(3) and SU(6) symmetries. In conclusion, the models developed here reproduce the experimental data (E{sub {gamma}} {<=} 2.0 GeV) and the two main coupling constants are in good agreement with broken SU(3)-symmetry predictions. (author). 47 refs.

  16. Despina Hatzifotiadou: ALICE Master Class 1 - Theory: strange particles, V0 decays, invariant mass

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    This is the 1st of 4 short online videos. It contains an introduction to the first part of the exercise : what are strange particles, V0 decays, invariant mass. More details and related links on this indico event page. In more detail: What is Physics Master Classes Students after morning lectures, run programmes in the afternoon to do measurements. These tutorials are about how to use the software required to do these measurements. Background info and examples  Looking for strange particles with ALICE http://aliceinfo.cern.ch/Public/MasterCL/MasterClassWebpage.html Introduction to first part of the exercise : what are strange particles, V0 decays, invariant mass. Demonstration of the software for the 1st part of the exercise - visual identification of V0s Introduction to second part of the exercise : strangeness enhancement; centrality of lead-lead collisions; explanation of efficiency, yield, background etc Demonstration of the software for the 2nd part of the exercise - invariant mass spec...

  17. Strange attractor in the Potts spin glass on hierarchical lattices

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Washington de [Universidade Federal de Pernambuco, Centro Acadêmico do Agreste, Pernambuco (Brazil); Camelo-Neto, G. [Universidade Federal de Alagoas, Núcleo de Ciências Exatas, Laboratório de Física Teórica e Computacional, CEP 57309-005 Arapiraca, Alagoas (Brazil); Coutinho, S., E-mail: sergio@ufpe.br [Universidade Federal de Pernambuco, Departamento de Física, Laboratório de Física Teórica e Computacional, Cidade Universitária, CEP 50670-901 Recife, Pernambuco (Brazil)

    2013-11-29

    The spin-glass q-state Potts model on d-dimensional diamond hierarchical lattices is investigated by an exact real space renormalization group scheme. Above a critical dimension d{sub l}(q) for q>2, the coupling constants probability distribution flows to a low-temperature strange attractor or to the high-temperature paramagnetic fixed point, according to the temperature is below or above the critical temperature T{sub c}(q,d). The strange attractor was investigated considering four initial different distributions for q=3 and d=5 presenting strong robustness in shape and temperature interval suggesting a condensed phase with algebraic decay.

  18. Neutral strange particle production in antineutrino-neon charged current interactions

    Science.gov (United States)

    Willocq, S.; Marage, P.; Aderholz, M.; Allport, P.; Baton, J. P.; Berggren, M.; Clayton, E. F.; Cooper-Sarkar, A. M.; Erriquez, O.; Faulkner, P. J. W.; Guy, J.; Hulth, P. O.; Jones, G. T.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; O'Neale, S.; Sacton, J.; Sansum, R. A.; Varvell, K.; Venus, W.; Wells, J.; Wittek, W.

    1992-06-01

    Neutral strange particle production inbar v Ne charged current interactions is studied using the bubble chamber BEBC, exposed to the CERN SPS antineutrino wide band beam. From a sample of 1191 neutral strange particles, the inclusive production rates are determined to be (15.7±0.8)% for K 0 mesons, (8.2±0.5)% for Λ, (0.4±0.2)% forbar Λ and (0.6±0.3)% for Σ0 hyperons. The inclusive production properties of K 0 mesons and Λ hyperons are investigated. The Λ hyperons are found to be polarized in the production plane.

  19. Unlocking color and flavor in superconducting strange quark matter

    International Nuclear Information System (INIS)

    Alford, Mark; Berges, Juergen; Rajagopal, Krishna

    1999-01-01

    We explore the phase diagram of strongly interacting matter with massless u and d quarks as a function of the strange quark mass m s and the chemical potential μ for baryon number. Neglecting electromagnetism, we describe the different baryonic and quark matter phases at zero temperature. For quark matter, we support our model-independent arguments with a quantitative analysis of a model which uses a four-fermion interaction abstracted from single-gluon exchange. For any finite m s , at sufficiently large μ we find quark matter in a color-flavor-locked state which leaves a global vector-like SU(2) color+L+R symmetry unbroken. As a consequence, chiral symmetry is always broken in sufficiently dense quark matter. As the density is reduced, for sufficiently large m s we observe a first-order transition from the color-flavor-locked phase to color superconducting phase analogous to that in two-flavor QCD. At this unlocking transition chiral symmetry is restored. For realistic values of m s our analysis indicates that chiral symmetry breaking may be present for all densities down to those characteristic of baryonic matter. This supports the idea that quark matter and baryonic matter may be continuously connected in nature. We map the gaps at the quark Fermi surfaces in the high density color-flavor-locked phase onto gaps at the baryon Fermi surfaces at low densities

  20. Strange resonance poles from Kπ scattering below 1.8 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez, J.R.; Rodas, A. [Universidad Complutense de Madrid, Departamento de Fisica Teorica II, Madrid (Spain); Ruiz de Elvira, J. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Bonn (Germany); University of Bern, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland)

    2017-02-15

    In this work we present a determination of the mass, width, and coupling of the resonances that appear in kaon-pion scattering below 1.8 GeV. These are: the much debated scalar κ-meson, nowadays known as K{sub 0}{sup *}(800), the scalar K{sub 0}{sup *}(1430), the K*(892) and K{sub 1}{sup *}(1410) vectors, the spin-two K{sub 2}{sup *}(1430) as well as the spin-three K{sup *}{sub 3}(1780). The parameters will be determined from the pole associated to each resonance by means of an analytic continuation of the Kπ scattering amplitudes obtained in a recent and precise data analysis constrained with dispersion relations, which were not well satisfied in previous analyses. This analytic continuation will be performed by means of Pade approximants, thus avoiding a particular model for the pole parameterization. We also pay particular attention to the evaluation of uncertainties. (orig.)

  1. Study of diffractive dissociation especially into strange and charmed particles with EHS

    CERN Multimedia

    2002-01-01

    The diffractive production of heavy quark-antiquark pairs leading to strangeness-antistrangeness and charm-anticharm systems is intended to be measured in this experiment. The use of the rapid cycling bubble chamber (RCBC) with a volume of 100 x 40 x 40 cm$^{3}$ and a picture taking rate of 15 Hz as vertex detector and EHS as forward spectrometer is suitable for the first step of this physics programme. Inclusive cross-sections for diffraction dissociation into $s\\bar{s}$ are lacking whereas diffractive $c\\bar{c}$ production is already better known. The gain of more insight into the mechanism of heavy quark-antiquark production, exclusive diffractive reactions with $\\pi^{0}$'s, diffractive resonance production and also the extraction of data for the double Pomeron exchange mechanism are envisaged. \\\\\\\\ This experiment will be run in two parts, the first one recording the entire unbiased sample of $pp$ and $\\pi^{-}p$ interactions, the second however using triggering for beam and high mass target diffraction di...

  2. Decays of negative parity non-strange baryons in the 1/Nc expansion

    International Nuclear Information System (INIS)

    Goity, Jose L.; Schat, Carlos L.; Norberto Scoccola

    2004-01-01

    The decays of non-strange negative parity baryons via the emission of single π and η mesons are analyzed in the framework of the 1/N c expansion. A basis of spin-flavor operators is established to that order, and with this basis the different partial wave decay amplitudes are obtained. The unknown effective coefficients are determined by fitting to the S- and D-wave partial widths as provided by the PDG. A full set of relations between widths that result at the leading order, i.e. order N c0 , is given and tested with the data. The rather large errors of the input partial widths, that result from the often discrepant results for the resonance parameters from different analyses of the data, lead to a rather good fit at the leading order N c0 . The next to leading order fit fails for that reason to pin down with satisfactory accuracy the effective sub leading effective constants

  3. Strange VLF bursts in northern Scandinavia: case study of the afternoon "mushroom-like" hiss on 8 December 2013

    Directory of Open Access Journals (Sweden)

    J. Manninen

    2015-08-01

    Full Text Available We investigate a non-typical very low frequency (VLF 1–4 kHz hiss representing a sequence of separated noise bursts with a strange "mushroom-like" shape in the frequency–time domain, each one lasting several minutes. These strange afternoon VLF emissions were recorded at Kannuslehto (KAN, ϕ = 67.74° N, λ = 26.27° E; L ∼ 5.5 in northern Finland during the late recovery phase of the small magnetic storm on 8 December 2013. The left-hand (LH polarized 2–3 kHz "mushroom caps" were clearly separated from the right-hand (RH polarized "mushroom stems" at the frequency of about 1.8–1.9 kHz, which could match the lower ionosphere waveguide cutoff (the first transverse resonance of the Earth–ionosphere cavity. We hypothesize that this VLF burst sequence could be a result of the modulation of the VLF hiss electron–cyclotron instability from the strong Pc5 geomagnetic pulsations observed simultaneously at ground-based stations as well as in the inner magnetosphere by the Time History of Events and Macroscale Interactions during Substorms mission probe (THEMIS-E; ThE. This assumption is confirmed by a similar modulation of the intensity of the energetic (1–10 keV electrons simultaneously observed by the same ThE spacecraft. In addition, the data of the European Incoherent Scatter Scientific Association (EISCAT radar at Tromsø show a similar quasi-periodicity in the ratio of the Hall-to-Pedersen conductance, which may be used as a proxy for the energetic particle precipitation enhancement. Our findings suggest that this strange mushroom-like shape of the considered VLF hiss could be a combined mutual effect of the magnetospheric ULF–VLF (ultra low frequency–very low frequency wave interaction and the ionosphere waveguide propagation.

  4. Baryons and baryon resonances in nuclear matter

    Science.gov (United States)

    Lenske, Horst; Dhar, Madhumita; Gaitanos, Theodoros; Cao, Xu

    2018-01-01

    Theoretical approaches to the production of hyperons and baryon resonances in elementary hadronic reactions and heavy ion collisions are reviewed. The focus is on the production and interactions of baryons in the lowest SU(3) flavor octet and states from the next higher SU(3) flavor decuplet. Approaches using the SU(3) formalism for interactions of mesons and baryons and effective field theory for hyperons are discussed. An overview of application to free space and in-medium baryon-baryon interactions is given and the relation to a density functional theory is indicated. The intimate connection between baryon resonances and strangeness production is shown first for reactions on the nucleon. Pion-induced hypernuclear reactions are shown to proceed essentially through the excitation of intermediate nucleon resonances. Transport theory in conjunction with a statistical fragmentation model is an appropriate description of hypernuclear production in antiproton and heavy ion induced fragmentation reactions. The excitation of subnuclear degrees of freedom in peripheral heavy ion collisions at relativistic energies is reviewed. The status of in-medium resonance physics is discussed.

  5. Measurement of the strange - antistrange asymmetry at NLO in QCD from NuTeV dimuon data

    Energy Technology Data Exchange (ETDEWEB)

    Mason, David Alexander [Univ. of Oregon, Eugene, OR (United States)

    2006-03-01

    A measurement of the asymmetry between the strange and antistrange quark distributions, from a next to leading order QCD analysis of dimuon events measured by the NuTeV experiment at Fermilab is presented. Neutrino charged current events with two muons in the final state provide a direct means for studying charm production and measuring the strange sea. NuTeV's sign selected beam allows independent measurement of the strange and antistrange seas. An improved measurement of the neutrino and antineutrino forward dimuon cross section tables, using the complete charged current event sample for normalization is performed. These tables are then analyzed at NLO to measure the strange and antistrange seas. Detector acceptance is modeled using an NLO charm cross section differential in all variables required. The strange quark distribution is found to have an integrated momentum weighted asymmetry of +0.00196 ± 0.00046(stat) ± 0.00045(syst) ± 0.00182(external). The charm mass is found to be 1.41 ± 0.10(stat) ± 0.08(syst) ± 0.12(external) GeV.

  6. Study of $\\tau$ decays involving kaons, spectral functions and determination of the strange quark mass

    CERN Document Server

    Barate, R.; Ghez, Philippe; Goy, C.; Lees, J.P.; Merle, E.; Minard, M.N.; Pietrzyk, B.; Alemany, R.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Grauges, E.; Juste, A.; Martinez, M.; Merino, G.; Miquel, R.; Mir, L.M.; Pacheco, A.; Park, I.C.; Riu, I.; Colaleo, A.; Creanza, D.; De Palma, M.; Gelao, G.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Becker, U.; Boix, G.; Cattaneo, M.; Ciulli, V.; Dissertori, G.; Drevermann, H.; Forty, R.W.; Frank, M.; Halley, A.W.; Hansen, J.B.; Harvey, John; Janot, P.; Jost, B.; Lehraus, I.; Leroy, O.; Mato, P.; Minten, A.; Moutoussi, A.; Ranjard, F.; Rolandi, Gigi; Rousseau, D.; Schlatter, D.; Schmitt, M.; Schneider, O.; Tejessy, W.; Teubert, F.; Tomalin, I.R.; Tournefier, E.; Wright, A.E.; Ajaltouni, Z.; Badaud, F.; Chazelle, G.; Deschamps, O.; Falvard, A.; Ferdi, C.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.C.; Pallin, D.; Perret, P.; Podlyski, F.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Rensch, B.; Waananen, A.; Daskalakis, G.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Blondel, A.; Bonneaud, G.; Brient, J.C.; Rouge, A.; Rumpf, M.; Swynghedauw, M.; Verderi, M.; Videau, H.; Focardi, E.; Parrini, G.; Zachariadou, K.; Cavanaugh, R.; Corden, M.; Georgiopoulos, C.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Lynch, J.G.; Negus, P.; O'Shea, V.; Raine, C.; Teixeira-Dias, P.; Thompson, A.S.; Buchmuller, O.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Girone, M.; Goodsir, S.; Martin, E.B.; Marinelli, N.; Sedgbeer, J.K.; Spagnolo, P.; Thomson, Evelyn J.; Williams, M.D.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Betteridge, A.P.; Bowdery, C.K.; Buck, P.G.; Colrain, P.; Crawford, G.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Robertson, N.A.; Williams, M.I.; Giehl, I.; Hoffmann, C.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.G.; van Gemmeren, P.; Wachsmuth, H.; Zeitnitz, C.; Aubert, J.J.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Etienne, F.; Motsch, F.; Payre, P.; Talby, M.; Thulasidas, M.; Aleppo, M.; Antonelli, M.; Ragusa, F.; Berlich, R.; Buescher, Volker; Dietl, H.; Ganis, G.; Huttmann, K.; Lutjens, G.; Mannert, C.; Manner, W.; Moser, H.G.; Schael, S.; Settles, R.; Seywerd, H.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Azzurri, P.; Boucrot, J.; Callot, O.; Chen, S.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, P.; Hocker, Andreas; Jacholkowska, A.; Kim, D.W.; Le Diberder, F.; Lefrancois, J.; Lutz, A.M.; Schune, M.H.; Veillet, J.J.; Videau, I.; Zerwas, D.; Bagliesi, Giuseppe; Bettarini, S.; Boccali, T.; Bozzi, C.; Calderini, G.; Dell'Orso, R.; Ferrante, I.; Foa, L.; Giassi, A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P.S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Sciaba, A.; Sguazzoni, G.; Tenchini, R.; Vannini, C.; Venturi, A.; Verdini, P.G.; Blair, G.A.; Cowan, G.; Green, M.G.; Medcalf, T.; Strong, J.A.; von Wimmersperg-Toeller, J.H.; Botterill, D.R.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Thompson, J.C.; Bloch-Devaux, Brigitte; Colas, P.; Emery, S.; Kozanecki, W.; Lancon, E.; Lemaire, M.C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.F.; Roussarie, A.; Schuller, J.P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S.N.; Dann, J.H.; Johnson, R.P.; Kim, H.Y.; Konstantinidis, N.; Litke, A.M.; McNeil, M.A.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Kelly, M.S.; Lehto, M.; Thompson, L.F.; Affholderbach, K.; Boehrer, Armin; Brandt, S.; Grupen, C.; Prange, G.; Giannini, G.; Gobbo, B.; Rothberg, J.; Wasserbaech, S.; Armstrong, S.R.; Charles, E.; Elmer, P.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Greening, T.C.; Hayes, O.J.; Hu, H.; Jin, S.; McNamara, P.A., III; Nachtman, J.M.; Nielsen, J.; Orejudos, W.; Pan, Y.B.; Saadi, Y.; Scott, I.J.; Walsh, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.

    1999-01-01

    All ALEPH measurements of branching ratios of tau decays involving kaons are summarized including a combination of results obtained with K^0_S and K^0_L detection. The decay dynamics are studied, leading to the determination of contributions from vector K^*(892) and K^{*}(1410), and axial-vector K_1(1270) and K_1(1400) resonances. Agreement with isospin symmetry is observed among the different final states. Under the hypothesis of the conserved vector current, the spectral function for the K\\bar{K}\\pi mode is compared with the corresponding cross section for low energy e^+e^- annihilation, yielding an axial-vector fraction of (94^{+6}_{-8})% for this mode. The branching ratio for tau decay into all strange final states is determined to be B(\\tau^-\\to X^-(S=-1)\

  7. Fast pulsars, strange stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1990-02-01

    The initial motivation for this work was the reported discovery in January 1989 of a 1/2 millisecond pulsar in the remnant of the spectacular supernova, 1987A. The status of this discovery has come into grave doubt as of data taken by the same group in February, 1990. At this time we must consider that the millisecond signal does not belong to the pulsar. The existence of a neutron star in remnant of the supernova is suspected because of recent observations on the light curve of the remnant, and of course by the neutrino burst that announced the supernova. However its frequency is unknown. I can make a strong case that a pulsar rotation period of about 1 ms divides those that can be understood quite comfortably as neutron stars, and those that cannot. What we will soon learn is whether there is an invisible boundary below which pulsar periods do not fall, in which case, all are presumable neutron stars, or whether there exist sub- millisecond pulsars, which almost certainly cannot be neutron stars. Their most plausible structure is that of a self-bound star, a strange-quark-matter star. The existence of such stars would imply that the ground state of the strong interaction is not, as we usually assume, hadronic matter, but rather strange quark matter. Let us look respectively at stars that are bound only by gravity, and hypothetical stars that are self-bound, for which gravity is so to speak, icing on the cake

  8. Strange Particles and Heavy Ion Physics

    Energy Technology Data Exchange (ETDEWEB)

    Bassalleck, Bernd [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy; Fields, Douglas [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy

    2016-04-28

    This very long-running grant has supported many experiments in nuclear and particle physics by a group from the University of New Mexico. The gamut of these experiments runs from many aspects of Strangeness Nuclear Physics, to rare Kaon decays, to searches for exotic Hadrons such as Pentaquark or H-Dibaryon, and finally to Spin Physics within the PHENIX collaboration at RHIC. These experiments were performed at a number of laboratories worldwide: first and foremost at Brookhaven National Lab (BNL), but also at CERN, KEK, and most recently at J-PARC. In this Final Technical Report we summarize progress and achievements for this award since our last Progress Report, i.e. for the period of fall 2013 until the award’s termination on November 30, 2015. The report consists of two parts, representing our two most recent experimental efforts, participation in the Nucleon Spin Physics program of the PHENIX experiment at RHIC, the Relativistic Heavy Ion Collider at BNL – Task 1, led by Douglas Fields; and participation in several Strangeness Nuclear Physics experiments at J-PARC, the Japan Proton Accelerator Research Center in Tokai-mura, Japan – Task 2, led by Bernd Bassalleck.

  9. Enhancement of strangeness in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Grassi, F.; Heiselberg, H.

    1990-01-01

    The theoretical and experimental conditions to obtain strange particle production in heavy ion collisions at high energies are discussed, by analysis of results obtained from Super Proton Synchrotron - CERN and Alternating Gradient Synchrotron in United States. (M.C.K.)

  10. Strange quark condensate in the nucleon in 2 + 1 flavor QCD.

    Science.gov (United States)

    Toussaint, D; Freeman, W

    2009-09-18

    We calculate the "strange quark content of the nucleon," , which is important for interpreting the results of some dark matter detection experiments. The method is to evaluate quark-line disconnected correlations on the MILC lattice ensembles, which include the effects of dynamical light and strange quarks. After continuum and chiral extrapolations, the result is = 0.69(7)_{stat}(9)_{syst}, in the modified minimal subtraction scheme (2 GeV) regularization, or for the renormalization scheme invariant form, m_{s} partial differentialM_{N}/ partial differentialm_{s} = 59(6)(8) MeV.

  11. Search for Exotic Strange Dibaryon in Relativistic Heavy Ion Collisions

    Institute of Scientific and Technical Information of China (English)

    GAO Chong-Shou

    2003-01-01

    The exotic strange dibaryon particle (ΩΩ)0+ with S = -6 can be produced in relativistic heavyioncollisions. The yields of this kind of exotic strange dibaryon particles can increase significantly soon as the formation ofQGP does exhibit after the collision. If there is no phase transition after the collision, the upper bound of the productionof this diomega can be estimated from the free hadronic gas model for nuclear matter. The relative yield ratio of diomegato deuteron is less than 0.000205, this means that if there is no QGP creation it is difficult to observe the production ofdiomega in relativistic heavy ion collisions.

  12. Search for Exotic Strange Dibaryon in Relativistic Heavy Ion Collisions

    Institute of Scientific and Technical Information of China (English)

    GAOChong-Shou

    2003-01-01

    The exotic strange dibaryon particle (ΩΩ)0+ with S = -6 can be produced in relativistic heavy ion collisions. The yields of this kind of exotic strange dibaryon particles can increase signitlcantly soon as the formation of QGP does exhibit after the collision. If there is no phase transition after the collision, the upper bound of the production of this diomega can be estimated from the free hadronic gas model for nuclear matter. The relative yield ratio of diomega to deuteron is less than 0.000205, this means that if there is no QGP creation it is difficult to observe the production of diomega in relativistic heavy ion collisions.

  13. Correction of asymmetric quark-antiquark strange sea to Weinberg angle

    International Nuclear Information System (INIS)

    Ding Yong; Lv Zhun; Ma Boqiang

    2004-01-01

    The authors derive a new Paschos-Wolfenstein relationship which should bring an important correction to Weinberg angle sin 2 θ w when considering the quark-antiquark asymmetry in the nucleon sea. The authors also obtain the distributions of asymmetric strange antistrange sea by using the light-cone meson-baryon fluctuation model with two kinds of wave functions, respectively. The most important issue is that the correction of asymmetric strange-antistrange sea can reduce approximately 30%-80% of the difference with three standard deviations between the measured value of the Weinberg angle sin 2 θ w by the NuTeV Collaboration and the predicted value by the standard model. (author)

  14. Rho resonance parameters from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Dehua; Alexandru, Andrei; Molina, Raquel; Döring, Michael

    2016-08-01

    We perform a high-precision calculation of the phase shifts for $\\pi$-$\\pi$ scattering in the I = 1, J = 1 channel in the elastic region using elongated lattices with two mass-degenerate quark favors ($N_f = 2$). We extract the $\\rho$ resonance parameters using a Breit-Wigner fit at two different quark masses, corresponding to $m_{\\pi} = 226$MeV and $m_{\\pi} = 315$MeV, and perform an extrapolation to the physical point. The extrapolation is based on a unitarized chiral perturbation theory model that describes well the phase-shifts around the resonance for both quark masses. We find that the extrapolated value, $m_{\\rho} = 720(1)(15)$MeV, is significantly lower that the physical rho mass and we argue that this shift could be due to the absence of the strange quark in our calculation.

  15. Low-lying 1/2- hidden strange pentaquark states in the constituent quark model

    Science.gov (United States)

    Li, Hui; Wu, Zong-Xiu; An, Chun-Sheng; Chen, Hong

    2017-12-01

    We investigate the spectrum of the low-lying 1/2- hidden strange pentaquark states, employing the constituent quark model, and looking at two ways within that model of mediating the hyperfine interaction between quarks - Goldstone boson exchange and one gluon exchange. Numerical results show that the lowest 1/2- hidden strange pentaquark state in the Goldstone boson exchange model lies at ˜1570 MeV, so this pentaquark configuration may form a notable component in S 11(1535) if the Goldstone boson exchange model is applied. This is consistent with the prediction that S 11(1535) couples very strongly to strangeness channels. Supported by National Natural Science Foundation of China (11675131, 11645002), Chongqing Natural Science Foundation (cstc2015jcyjA00032) and Fundamental Research Funds for the Central Universities (SWU115020)

  16. Ratios of strange hadrons to pions in collisions of large and small nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Oeschler, H. [Ruprecht-Karls-Universitaet Heidelberg, Physikalisches Institut, Heidelberg (Germany); Cleymans, J. [University of Cape Town, UCT-CERN Research Centre and Department of Physics, Rondebosch (South Africa); Hippolyte, B. [Universite de Strasbourg, CNRS-IN2P3, Institut Pluridisciplinaire Hubert Curien (IPHC), Strasbourg (France); Redlich, K. [University of Wroclaw, Institute of Theoretical Physics, Wroclaw (Poland); ExtreMe Matter Institute EMMI, GSI, Darmstadt (Germany); Sharma, N. [Panjab University, Department of Physics, Chandigarh (India)

    2017-09-15

    The dependence of particle production on the size of the colliding nuclei is analyzed in terms of the thermal model using the canonical ensemble. The concept of strangeness correlation in clusters of sub-volume V{sub c} is used to account for the suppression of strangeness. A systematic analysis is presented of the predictions of the thermal model for particle production in collisions of small nuclei. The pattern of the maxima of strange-particles-to-pion ratios as a function of beam energy is quite special, as they do not occur at the same beam energy and are sensitive to the system size. In particular, the Λ/π{sup +} ratio shows a clear maximum even for small systems while the maximum in the K{sup +}/π{sup +} ratio is less pronounced in small systems. (orig.)

  17. Strange fireball as an explanation of the muon excess in Auger data

    Science.gov (United States)

    Anchordoqui, Luis A.; Goldberg, Haim; Weiler, Thomas J.

    2017-03-01

    We argue that ultrahigh-energy cosmic-ray collisions in Earth's atmosphere can probe the strange quark density of the nucleon. These collisions have center-of-mass energies ≳1 04.6A GeV , where A ≥14 is the nuclear baryon number. We hypothesize the formation of a deconfined thermal fireball which undergoes a sudden hadronization. At production the fireball has a very high matter density and consists of gluons and two flavors of light quarks (u , d ). Because the fireball is formed in the baryon-rich projectile fragmentation region, the high baryochemical potential damps the production of u u ¯ and d d ¯ pairs, resulting in gluon fragmentation mainly into s s ¯. The strange quarks then become much more abundant and upon hadronization the relative density of strange hadrons is significantly enhanced over that resulting from a hadron gas. Assuming the momentum distribution functions can be approximated by Fermi-Dirac and Bose-Einstein statistics, we estimate a kaon-to-pion ratio of about 3 and expect a similar (total) baryon-to-pion ratio. We show that, if this were the case, the excess of strange hadrons would suppress the fraction of energy which is transferred to decaying π0's by about 20%, yielding an ˜40 % enhancement of the muon content in atmospheric cascades, in agreement with recent data reported by the Pierre Auger Collaboration.

  18. Resonance formation in γγ-collisions - as observed with the Crystal Ball detector

    International Nuclear Information System (INIS)

    Bienlein, J.K.

    1991-01-01

    Analysis of two-photon reactions with the Crystal Ball detector at the DORIS-II e + e - storage ring (E beam = 5 GeV) resulted in a complete set of data on γγ-formation of mesons. The data are best represented by their helicity matrix elements. For isoscalar mesons the mixing of non-strange and strange quark constituents can be derived. A highly efficient selection of the channel γγ → π 0 π 0 yielded 7000 events with (M(π 0 π 0 ) > 800 MeV/c 2 . A partial wave decomposition became possible and showed under the f 2 (1270) a scalar meson resonance f 0 (1250) with 4.0 standard deviations. In the same analysis 23 events of γγ → ηη have been found. (orig.)

  19. Pattern of (Multi)strange (Anti)baryon Production and Search for Deconfinement

    Science.gov (United States)

    Rafelski, Johann

    1998-04-01

    We study (multi)strange particle abundances obtained recently in relativistic heavy ion collisions and determine thermal and chemical source parameters(J. Letessier et al., Phys. Lett. B410 (1997) 315--322 hep-ph/9710310 and: Acta Physica Polonica in press, hep- ph/9710340). These are primarily constrained by (multi)strange (anti)baryon relative abundances, which have been measured for Pb--Pb 158 A GeV interactions(I. Kralik, for WA97 collaboration, QM97 Tsukuba, to appear in Nucl. Phys. A) and S-S/W/Pb 200 A GeV interactions(See: proceedings of S'96-Budapest, APH N.S., Heavy Ion Physics 4 (1996) vii--x). We have extended our analysis and have now determined the properties of the particle source using the fitted macro canonical parameters, allowing as required for non-equilibrium dynamics of the locally thermal fireball. We find that in the 158 A GeV Pb--Pb collisions the entropy per baryon, energy per baryon, strangeness per baryon implied by particle spectra are all in the range of values associated commonly with the deconfined QGP phase.

  20. Gravitoelectromagnetic resonances

    International Nuclear Information System (INIS)

    Tsagas, Christos G.

    2011-01-01

    The interaction between gravitational and electromagnetic radiation has a rather long research history. It is well known, in particular, that gravity-wave distortions can drive propagating electromagnetic signals. Since forced oscillations provide the natural stage for resonances to occur, gravitoelectromagnetic resonances have been investigated as a means of more efficient gravity-wave detection methods. In this report, we consider the coupling between the Weyl and the Maxwell fields on a Minkowski background, which also applies to astrophysical environments where gravity is weak, at the second perturbative level. We use covariant methods that describe gravitational waves via the transverse component of the shear, instead of pure-tensor metric perturbations. The aim is to calculate the properties of the electromagnetic signal, which emerges from the interaction of its linear counterpart with an incoming gravitational wave. Our analysis shows how the wavelength and the amplitude of the gravitationally driven electromagnetic wave vary with the initial conditions. More specifically, for certain initial data, the amplitude of the induced electromagnetic signal is found to diverge. Analogous, diverging, gravitoelectromagnetic resonances were also reported in cosmology. Given that, we extend our Minkowski space study to cosmology and discuss analogies and differences in the physics and in the phenomenology of the Weyl-Maxwell coupling between the aforementioned two physical environments.

  1. Strangeness photoproduction at the BGO-OD experiment

    Energy Technology Data Exchange (ETDEWEB)

    Jude, Thomas [Physikalisches Institut, Bonn University (Germany); Collaboration: BGO-OD-Collaboration

    2016-07-01

    The BGO-OD experiment at the ELSA accelerator facility uses an energy tagged bremstrahlung photon beam to investigate the internal structure of the nucleon. The setup consists of a highly segmented BGO calorimeter surrounding the target, with a particle tracking magnetic spectrometer at forward angles. Compared to constituent quark models (CQMs), models including psuedoscalar meson-baryon interactions have had improved success in describing baryon excitation spectra. For example, the Λ(1405) appears to be dynamically generated from meson-baryon interactions at least to some extent. Vector-meson baryon interactions have also been predicted to dynamically generate states, which may have been observed in photoproduction reactions. BGO-OD is ideal for investigating low momentum transfer processes due to the acceptance and high momentum resolution at forward angles. This enables the investigation of degrees of freedom not derived from CQMs, and in particular, strangeness photoproduction where t-channel exchange mechanisms play a dominant role. With the first major data taking periods for BGO-OD complete, an extensive programme for the investigation of associated strangeness photoproduction has begun.

  2. Strange hadron decays involving e+e- pairs

    International Nuclear Information System (INIS)

    Soyeur, M.

    1996-01-01

    A high resolution, large acceptance e + e - detector like HADES coupled to intense secondary kaon beams could offer a remarkable opportunity to study at GSI both the electromagnetic and electroweak decays of strange hadrons. Such data can be very consistently interpreted using effective chiral Lagrangians based on the SU(3) x SU(3) symmetry. Of particular interest are a complete set of data on the electromagnetic form factors for the ρ,ω, φ and K* Dalitz decays, which would put very strong constraints on departures from ideal SU(3) mixings, and measurements of Dalitz decays of hyperons, whose electromagnetic structure is very much unknown. Better data on the nonleptonic radiative (e + e - ) decays of kaons would be most useful to study the strangeness changing weak currents and effects related to CP violation. A major progress in the understanding of these decays came recently from their description in chiral perturbation theory, where the chiral dynamics of Goldstone bosons is coupled to the weak and electromagnetic gauge fields. Those studies could be extended to the electroweak decays of hyperons. (author)

  3. Properties of resonance wave functions.

    Science.gov (United States)

    More, R. M.; Gerjuoy, E.

    1973-01-01

    Construction and study of resonance wave functions corresponding to poles of the Green's function for several illustrative models of theoretical interest. Resonance wave functions obtained from the Siegert and Kapur-Peierls definitions of the resonance energies are compared. The comparison especially clarifies the meaning of the normalization constant of the resonance wave functions. It is shown that the wave functions may be considered renormalized in a sense analogous to that of quantum field theory. However, this renormalization is entirely automatic, and the theory has neither ad hoc procedures nor infinite quantities.

  4. Strange Encounter: Depicting An “Other” Reality for Young Readers

    Directory of Open Access Journals (Sweden)

    YOU Chengcheng

    2015-04-01

    Full Text Available This article explores fantastic encounters between humans and non-humans inChinese and Japanese Children’s literature. Naoko Awa’s collection of short storiesThe Fox’s Window and Other Stories is closely read to elucidate narrative features ofwhat I call as “strange encounter”, the magic realistic human-animal encounter inChinese and Japanese cultural context. Chinese supernatural literature and culturaltradition of yaoguai, which have been assimilated into Japanese culture (Japaneseyōkai, are referred to throughout my discussion.  Todorov’s approach to thefantastic, Judith Zeitlin’s study of Strange Tales of Liaozhai Studio, and RosemaryJackson’s study of fantasy are drawn upon to illuminate the meaning of encountersbetween men and animals. I argue that magic realism as a relatively new genrefor young readers, not only reflects the author’s individual creative experienceof the fantastic but also partakes in the sense of an “other” reality that resonatesthroughout a cultural community. Perjumpaan Ganjil: Gambaran suatu Realitas “Liyan” bagi Pembaca Muda.Artikel ini membahas perjumpaan fantastis antara ‘manusia’ dan ‘non-manusia’ didalam sastra anak Cina dan Jepang. Antologi cerita pendek karangan Naoko Awa TheFox’s Window and Other Stories akan dikupas untuk memaparkan fitur naratif yangdisebut sebagai ‘perjumpaan aneh’ (strange encounter, perjumpaan magis-realis antaramanusia dengan binatang dalam konteks kebudayaan Cina dan Jepang. Karya sastrasupernatural Cina dan keberadaan yaoguai yang telah diasimilasi dalam kebudayaanJepang (disebut youkai menjadi sebuah referensi penting dalam artikel ini. Pendekatanfantasi dari Todorov, studi Judith Zeitlin tentang Strange Tales of Liaozhai Studio,dan studi fantasi dari Rosemary Jackson digunakan untuk memperjelas arti dariperjumpaan antara manusia dan binatang. Magis-realis sebagai sesuatu yang baru bagi pembaca muda tidak hanya merefleksikan pengalaman

  5. The impact of s- anti s asymmetry on the strange electromagnetic form factor

    Energy Technology Data Exchange (ETDEWEB)

    Ghasempour Nesheli, Ali [Islamic Azad University, Department of Physics, Shiraz Branch, Shiraz (Iran, Islamic Republic of)

    2016-09-15

    The existence of the strange quark asymmetry in the nucleon sea has been indicated by both the experimental and theoretical analyses. Although it is well known that the s- anti s asymmetry is important for some processes in high-energy hadron collisions, it has also been indicated that it can be related to the strange Dirac form factor F{sub 1}{sup s}. In this work, we have studied the impact of s- anti s asymmetry and its uncertainty from various modern parton distribution functions (PDFs) on F{sub 1} {sup s} and compared the obtained results with the available experimental information. As a result, we found that the uncertainty in F{sub 1}{sup s}(t) due to the s(x) - anti s (x) distribution is rather large so that it dominates the model uncertainty at all values of the squared momentum transfer t. However, taking into account the uncertainties, the theoretical predictions of F{sub 1}{sup s}(t) are fully compatible with the estimate extracted from experiment. We concluded that the future accurate experimental data of the strange Dirac form factor might be used to put direct constraints on the strange content of the proton and reduce its uncertainty that has always been a challenge. (orig.)

  6. Strange baryon production in Z hadronic decays

    CERN Document Server

    Abreu, P; Adye, T; Agasi, E; Ajinenko, I; Aleksan, Roy; Alekseev, G D; Allport, P P; Almehed, S; Alvsvaag, S J; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Anykeyev, V B; Apel, W D; Arnoud, Y; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barate, R; Bardin, Dimitri Yuri; Barker, G J; Baroncelli, A; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Benvenuti, Alberto C; Berggren, M; Bertrand, D; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Blyth, S; Bocci, V; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Bosworth, S; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenner, R A; Bricman, C; Brillault, L; Brown, R C A; Brunet, J M; Brückman, P; Bugge, L; Buran, T; Buys, A; Bärring, O; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carrilho, P; Carroll, L; Caso, Carlo; Cassio, V; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerrito, L; Chabaud, V; Charpentier, P; Chaussard, L; Chauveau, J; Checchia, P; Chelkov, G A; Chikilev, O G; Chliapnikov, P V; Chochula, P; Chorowicz, V; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; D'Almagne, B; Da Silva, W; Dahl-Jensen, Erik; Dahm, J; Dam, M; Damgaard, G; Daum, A; Dauncey, P D; Davenport, Martyn; De Angelis, A; De Boeck, H; De Brabandere, S; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Defoix, C; Della Ricca, G; Delpierre, P A; Demaria, N; Di Ciaccio, Lucia; Dijkstra, H; Djama, F; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Dufour, Y; Dupont, F; Dönszelmann, M; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Ershaidat, N; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Ferrer, A; Filippas-Tassos, A; Firestone, A; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Föth, H; Fürstenau, H; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gillespie, D; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Gracco, Valerio; Grard, F; Graziani, E; Grosdidier, G; Gunnarsson, P; Guy, J; Guz, Yu; Górski, M; Günther, M; Haedinger, U; Hahn, F; Hahn, M; Hahn, S; Haider, S; Hajduk, Z; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Ioannou, P; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Joram, Christian; Juillot, P; Jönsson, L B; Jönsson, P E; Kaiser, M; Kalmus, George Ernest; Kapusta, F; Karlsson, M; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klein, H; Klovning, A; Kluit, P M; Kokkinias, P; Koratzinos, M; Korcyl, K; Kostyukhin, V; Kourkoumelis, C; Kramer, P H; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Królikowski, J; Kubinec, P; Kucewicz, W; Kurvinen, K L; Kuznetsov, O; Köhne, J H; Köne, B; La Vaissière, C de; Lacasta, C; Laktineh, I; Lamblot, S; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Lapin, V; Last, I; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemoigne, Y; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lokajícek, M; Loken, J G; Loukas, D; Lutz, P; Lyons, L; López, J M; López-Aguera, M A; López-Fernandez, A; Lörstad, B; MacNaughton, J N; Maehlum, G; Maio, A; Malychev, V; Mandl, F; Marco, J; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Maron, T; Martí i García, S; Martínez-Rivero, C; Martínez-Vidal, F; Maréchal, B; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Meroni, C; Meyer, W T; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Monge, M R; Morettini, P; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Mönig, K; Møller, R; Müller, H; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Negri, P; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Némécek, S; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Palka, H; Papadopoulou, T D; Pape, L; Parodi, F; Passeri, A; Pegoraro, M; Pennanen, J; Peralta, L; Pernegger, H; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Prest, M; Privitera, P; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Ruhlmann-Kleider, V; Ruiz, A; Rídky, J; Rückstuhl, W; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sannino, M; Schneider, H; Schyns, M A E; Sciolla, G; Scuri, F; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Shellard, R C; Siccama, I; Siegrist, P; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stepaniak, K; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Stäck, H; Szczekowski, M; Szeptycka, M; Sánchez, J; Tabarelli de Fatis, T; Tavernet, J P; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Toet, D Z; Tomaradze, A G; Tomé, B; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tuuva, T; Tyapkin, I A; Tyndel, M; Tzamarias, S; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van Doninck, W K; Van Eldik, J; Van der Velde, C; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Voutilainen, M; Vrba, V; Wahlen, H; Walck, C; Waldner, F; Wehr, A; Weierstall, M; Weilhammer, Peter; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Wormser, G; Woschnagg, K; Yip, K; Yu, L; Yushchenko, O P; Zach, F; Zacharatou-Jarlskog, C; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zhigunov, V P; Zimin, N I; Zito, M; Zontar, D; Zuberi, R; Zucchelli, G C; Zumerle, G; de Boer, Wim; van Apeldoorn, G W; van Dam, P; Åsman, B; Österberg, K; Überschär, B; Überschär, S

    1995-01-01

    A study of the production of strange octet and decuplet baryons in hadronic decays of the Z recorded by the DELPHI detector at LEP is presented. This includes the first measurement of the \\Sigma^\\pm average multiplicity. The total and differential cross sections, the event topology and the baryon-antibaryon correlations are compared with current hadronization models.

  7. Strangeness and the quark-gluon plasma: An experimenter's perspective

    International Nuclear Information System (INIS)

    Odyniec, G.

    1994-02-01

    Current status of experimental results on strange particle production in relativistic nucleus-nucleus collisions is reviewed. Emphasis is placed on the relevance to the hypothetical quark-gluon plasma formation and the origin of the Universe

  8. Hawking-Unruh hadronization and strangeness production in high energy collisions

    Directory of Open Access Journals (Sweden)

    Castorina Paolo

    2015-01-01

    Full Text Available The interpretation of quark (q- antiquark (q̄ pairs production and the sequential string breaking as tunneling through the event horizon of colour confinement leads to a thermal hadronic spectrum with a universal Unruh temperature, T ≃ 165 Mev, related to the quark acceleration, a, by T = a/2π. The resulting temperature depends on the quark mass and then on the content of the produced hadrons, causing a deviation from full equilibrium and hence a suppression of strange particle production in elementary collisions. In nucleus-nucleus collisions, where the quark density is much bigger, one has to introduce an average temperature (acceleration which dilutes the quark mass effect and the strangeness suppression almost disappears.

  9. Strange Stars: Can Their Crust Reach the Neutron Drip Density?

    Institute of Scientific and Technical Information of China (English)

    Hai Fu; Yong-Feng Huang

    2003-01-01

    The electrostatic potential of electrons near the surface of static strange stars at zero temperature is studied within the frame of the MIT bag model. We find that for QCD parameters within rather wide ranges, if the nuclear crust on the strange star is at a density leading to neutron drip, then the electrostatic potential will be insufficient to establish an outwardly directed electric field, which is crucial for the survival of such a crust. If a minimum gap width of 200 fm is brought in as a more stringent constraint, then our calculations will completely rule out the possibility of such crusts. Therefore, our results argue against the existence of neutron-drip crusts in nature.

  10. Regge-plus-resonance predictions for charged-kaon photoproduction from the deuteron

    Directory of Open Access Journals (Sweden)

    Van Cauteren T.

    2010-04-01

    Full Text Available We present a Regge-inspired effective-Lagrangian framework for charged-kaon photoproduction from the deuteron. Quasi-free kaon production is investigated using the Regge-plus-resonance elementary operator within the non-relativistic plane-wave impulse approximation. The Regge-plus-resonance model was developed to describe photoinduced and electroinduced kaon production off protons and can be extended to strangeness production off neutrons. The non-resonant contributions to the amplitude are modelled in terms of K+ (494 and K*+ (892 Regge-trajectory exchange in the t-channel. This amplitude is supplemented with a selection of s-channel resonance-exchange diagrams. We investigate several sources of theoretical uncertainties on the semi-inclusive charged-kaon production cross section. The experimental error bars on the photocoupling helicity amplitudes turn out to put severe limits on the predictive power when considering quasi-free kaon production on a bound neutron.

  11. Observation of new resonance structure in the natural spin parity strange meson system

    International Nuclear Information System (INIS)

    Ratcliff, B.N.

    1981-04-01

    New data from the LASS spectrometer are presented on the reaction K - p → K - π + n. An energy independent partial wave analysis of this data yields unique K - π + elastic scattering partial wave amplitudes in the invariant mass region from 0.7 GeV to 1.8 GeV, and two distinguishable sets of amplitudes between 1.8 GeV and 2.3 GeV. These amplitudes confirm all of the well known Kπ resonances, and display clear evidence for new resonance structure in the S, P and G waves in the mass region above 1.6 GeV

  12. Plane Symmetric Cosmological Model with Quark and Strange ...

    Indian Academy of Sciences (India)

    Keywords. f(R,T) theory of gravity—plane symmetric space-time—quark and strange quark matter—constant deceleration parameter. 1. Introduction. Modern astrophysical observations point out that present expansion of the Universe is an accelerated epoch. The most fascinating evidence for this is found in measurements ...

  13. Strange nucleon electromagnetic form factors from lattice QCD

    Science.gov (United States)

    Alexandrou, C.; Constantinou, M.; Hadjiyiannakou, K.; Jansen, K.; Kallidonis, C.; Koutsou, G.; Avilés-Casco, A. Vaquero

    2018-05-01

    We evaluate the strange nucleon electromagnetic form factors using an ensemble of gauge configurations generated with two degenerate maximally twisted mass clover-improved fermions with mass tuned to approximately reproduce the physical pion mass. In addition, we present results for the disconnected light quark contributions to the nucleon electromagnetic form factors. Improved stochastic methods are employed leading to high-precision results. The momentum dependence of the disconnected contributions is fitted using the model-independent z-expansion. We extract the magnetic moment and the electric and magnetic radii of the proton and neutron by including both connected and disconnected contributions. We find that the disconnected light quark contributions to both electric and magnetic form factors are nonzero and at the few percent level as compared to the connected. The strange form factors are also at the percent level but more noisy yielding statistical errors that are typically within one standard deviation from a zero value.

  14. Multiplicity dependence of non-extensive parameters for strange and multi-strange particles in proton-proton collisions at √(s) = 7 TeV at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Khuntia, Arvind; Tripathy, Sushanta; Sahoo, Raghunath [Indian Institute of Technology Indore, Discipline of Physics, School of Basic Sciences, Indore (India); Cleymans, Jean [University of Cape Town, UCT-CERN Research Centre and Department of Physics, Rondebosch (South Africa)

    2017-05-15

    The transverse momentum (p{sub T}) spectra in proton-proton collisions at √(s) = 7 TeV, measured by the ALICE experiment at the LHC are analyzed with a thermodynamically consistent Tsallis distribution. The information about the freeze-out surface in terms of freeze-out volume, temperature and the non-extensivity parameter, q, for K{sup 0}{sub S}, Λ + anti Λ, Ξ{sup -} + anti Ξ{sup +} and Ω{sup -} + anti Ω{sup +} are extracted by fitting the p{sub T} spectra with the Tsallis distribution function. The freeze-out parameters of these particles are studied as a function of the charged particle multiplicity density (dN{sub ch}/dη). In addition, we also study these parameters as a function of the particle mass to see any possible mass ordering. The strange and multi-strange particles show mass ordering in volume, temperature, non-extensive parameter and also a strong dependence on multiplicity classes. It is observed that with increase in particle multiplicity, the non-extensivity parameter, q decreases, which indicates the tendency of the produced system towards thermodynamic equilibration. The increase in strange particle multiplicity is observed to be due to the increase of temperature and may not be due to the size of the freeze-out volume. (orig.)

  15. Multiplicity dependence of non-extensive parameters for strange and multi-strange particles in proton-proton collisions at √(s) = 7 TeV at the LHC

    International Nuclear Information System (INIS)

    Khuntia, Arvind; Tripathy, Sushanta; Sahoo, Raghunath; Cleymans, Jean

    2017-01-01

    The transverse momentum (p T ) spectra in proton-proton collisions at √(s) = 7 TeV, measured by the ALICE experiment at the LHC are analyzed with a thermodynamically consistent Tsallis distribution. The information about the freeze-out surface in terms of freeze-out volume, temperature and the non-extensivity parameter, q, for K 0 S , Λ + anti Λ, Ξ - + anti Ξ + and Ω - + anti Ω + are extracted by fitting the p T spectra with the Tsallis distribution function. The freeze-out parameters of these particles are studied as a function of the charged particle multiplicity density (dN ch /dη). In addition, we also study these parameters as a function of the particle mass to see any possible mass ordering. The strange and multi-strange particles show mass ordering in volume, temperature, non-extensive parameter and also a strong dependence on multiplicity classes. It is observed that with increase in particle multiplicity, the non-extensivity parameter, q decreases, which indicates the tendency of the produced system towards thermodynamic equilibration. The increase in strange particle multiplicity is observed to be due to the increase of temperature and may not be due to the size of the freeze-out volume. (orig.)

  16. STRANGE BARYONIC MATTER AND KAON CONDENSATION

    Czech Academy of Sciences Publication Activity Database

    Gazda, Daniel; Friedman, E.; Gal, A.; Mareš, Jiří

    2011-01-01

    Roč. 26, 3-4 (2011), s. 567-569 ISSN 0217-751X. [11th International Workshop on Meson Production, Properties and Interaction. Krakow, 10.06.2010-15.06.2010] R&D Projects: GA ČR GA202/09/1441 Institutional research plan: CEZ:AV0Z10480505 Keywords : (K)over-bar-nuclear bound states * strange baryonic matter * kaon condensation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.053, year: 2011

  17. Quark-gluon plasma, and strangeness

    International Nuclear Information System (INIS)

    Rafelski, Johann; Letessier, Jean

    2002-01-01

    In order to recognize the new form of matter created at RHIC and SPS as the deconfined quark-gluon plasma state (QGP), we need to understand the expected properties of this phase near to the conditions of its formation and disintegration. Thus, we first develop a model of QGP considering the constrains arising from QCD properties and lattice results, and explore its properties. In the second part, we describe the kinetic theory of strangeness production in the QGP phase. We show that gluon fusion dominate and evaluate the degree of equilibration expected at RHIC

  18. Excitation of graphene plasmons as an analogy with the two-level system

    International Nuclear Information System (INIS)

    Fu, Jiahui; Lv, Bo; Li, Rujiang; Ma, Ruyu; Chen, Wan; Meng, Fanyi

    2016-01-01

    The excitation of graphene plasmons (GPs) is presented as an interaction between the GPs and the incident electromagnetic field. In this Letter, the excitation of GPs in a plasmonic system is interpreted as an analogy with the two-level system by taking the two-coupled graphene-covered gratings as an example. Based on the equivalent circuit theory, the excitation of GPs in the graphene-covered grating is equivalent to the resonance of an oscillator. Thus, according to the governing equation, the electric currents at the resonant frequencies for two-coupled graphene-covered gratings correspond to the energy states in a two-level system. In addition, the excitation of GPs in different two-coupled graphene-covered gratings is numerically studied to validate our theoretical model. Our work provides an intuitive understanding of the excitation of GPs using an analogy with the two-level system. - Highlights: • The excitation of graphene plasmons (GPs) in graphene-covered grating is equivalent to the resonance of an oscillator. • We establish the equivalent circuit of two-level system to analyze the resonant character. • The excitation of GPs in different two-coupled graphene-covered gratings are numerically studied to validate our theoretical model.

  19. Excitation of graphene plasmons as an analogy with the two-level system

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiahui [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China); Lv, Bo, E-mail: lb19840313@126.com [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China); Li, Rujiang [College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027 (China); Ma, Ruyu; Chen, Wan; Meng, Fanyi [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China)

    2016-02-15

    The excitation of graphene plasmons (GPs) is presented as an interaction between the GPs and the incident electromagnetic field. In this Letter, the excitation of GPs in a plasmonic system is interpreted as an analogy with the two-level system by taking the two-coupled graphene-covered gratings as an example. Based on the equivalent circuit theory, the excitation of GPs in the graphene-covered grating is equivalent to the resonance of an oscillator. Thus, according to the governing equation, the electric currents at the resonant frequencies for two-coupled graphene-covered gratings correspond to the energy states in a two-level system. In addition, the excitation of GPs in different two-coupled graphene-covered gratings is numerically studied to validate our theoretical model. Our work provides an intuitive understanding of the excitation of GPs using an analogy with the two-level system. - Highlights: • The excitation of graphene plasmons (GPs) in graphene-covered grating is equivalent to the resonance of an oscillator. • We establish the equivalent circuit of two-level system to analyze the resonant character. • The excitation of GPs in different two-coupled graphene-covered gratings are numerically studied to validate our theoretical model.

  20. High resolution study of proton resonances in 65Ga and 67Ga

    International Nuclear Information System (INIS)

    Sales, K.B.

    1980-01-01

    Differential cross sections were measured for 64 Zn(p,p) from 2.50 to 3.24 MeV and for 66 Zn(p,p) from 2.60 to 3.26 MeV at laboratory angles of 90 0 , 105 0 , 135 0 , and 160 0 . These experiments were performed with the Triangle Universities Nuclear Laboratory 3 MV Van de Graaff accelerator and associated electrostatic analyzer-homogenizer system. The total overall energy resolution was 420 to 525 eV for 64 Zn(p,p) and 360 to 405 eV for 66 Zn(p,p). Resonances observed in the excitation functions were analyzed with a multilevel R-Matrix formalism. Resonance energies, spins, parities, and elastic widths were extracted for 39 resonances in 65 Ga and 148 resonances in 67 Ga. The l = 0 proton strength functions were calculated for 64 Zn and 66 Zn. The s-wave strength function shows an increase for A=66, which is consistent with earlier results from (p,n) cross section studies. Statistical properties of the 1/2 + resonances in 65 Ga and 67 Ga were examined. The spacing and reduced width distributions were compared with the Wigner and Porter-Thomas distributions, respectively. This comparison indicates that 50% of the 1/2 + resonances were missed in 65 Ga and that 70% of the 1/2 + resonances were missed in 67 Ga. The observed s-wave level densities in 65 Ga and 67 Ga are compared with predictions from conventional level density models. The analogs of the 0.867 MeV, the 0.910 MeV, and the 1.370 MeV states of 65 Zn are observed in 65 Ga; the analogs of the 0.093 MeV and the 0.394 MeV states of 67 Zn are observed in 67 Ga. The analog states in 65 Ga were fragmented into only two or three resonances, while the two analog states in 67 Ga were highly fragmented. Fits to the fine structure distributions of these two analogs were obtained and the resulting parameters compared with the Robson model. Coulomb energies were extracted for these five analogs

  1. Resonance – Journal of Science Education | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 22; Issue 12. The Inveterate Tinkerer 10. Analog ComputingWith Soap Films. Chirag Kalelkar. Classroom Volume 22 Issue 12 December 2017 pp 1213-1218 ... Keywords. Plateau border, catenoid, motorway problem, analog computer.

  2. Quark-flavor mixing and the nucleon strangeness form factors

    International Nuclear Information System (INIS)

    Ito, H.

    1995-01-01

    We have calculated the strangeness form factors of the nucleon G E s (Q), G M s (Q) and G A s (Q) and the electromagnetic form factors G E N (Q) as well, by using a relativistic constituent quark model of the nucleon wave function on the light-cone. Octet of Goldstone bosons (π, K, η) are assumed to induce the SU flavor mixing among the light constituent quarks; d-→K+s →d for example, and this mechanism induces the strangeness content in the nucleon. To calculate the meson-loop corrections to the electroweak couplings of constituent quarks, we have employed two models of the quark-meson vertex; (1) composite model of the Goldstone bosons (2) and (3) chiral quark Lagrangian. The loop momenta are regulated in a gauge-invariant way for both models

  3. Strangeness production in heavy ion collisions: What have we learned with the energy increase from SPS to RHIC

    International Nuclear Information System (INIS)

    Odyniec, Grazyna

    2002-01-01

    A review of strange particle production in heavy ion collisions at ultrarelativistic energies is presented. The particle yields and ratios from SPS and RHIC are discussed in view of the newest developments in understanding collision dynamics, and in view of their role in the search for a quark gluon plasma. A strangeness enhancement, most notably observed in CERN Pb-beam results, shows a remarkable two fold global enhancement with a much larger effect seen in the case of multistrange baryons. Hadronic models did fail to explain this pattern. At RHIC energy strangeness assumes a different role, since temperatures are higher and the central rapidity region almost baryon-free. An intriguing question: ''Did RHIC change the way we understand strangeness production in heavy ion collisions ?'' is discussed

  4. Dark matter admixed strange quark stars in the Starobinsky model

    Science.gov (United States)

    Lopes, Ilídio; Panotopoulos, Grigoris

    2018-01-01

    We compute the mass-to-radius profiles for dark matter admixed strange quark stars in the Starobinsky model of modified gravity. For quark matter, we assume the MIT bag model, while self-interacting dark matter inside the star is modeled as a Bose-Einstein condensate with a polytropic equation of state. We numerically integrate the structure equations in the Einstein frame, adopting the two-fluid formalism, and we treat the curvature correction term nonperturbatively. The effects on the properties of the stars of the amount of dark matter as well as the higher curvature term are investigated. We find that strange quark stars (in agreement with current observational constraints) with the highest masses are equally affected by dark matter and modified gravity.

  5. Strangeness production in proton–proton and proton–nucleus ...

    Indian Academy of Sciences (India)

    journal of. April 2006 physics pp. 765–780. Strangeness production in ... computing power necessary for the numerical treatment, lattice QCD has only ... tering reactions, it is necessary to use effective methods for the description of the ..... nucleus, it provides an appropriate tool to learn about the behaviour of the nuclear.

  6. Notes on properties of holographic strange metals

    International Nuclear Information System (INIS)

    Lee, Bum-Hoon; Pang, Da-Wei

    2010-01-01

    We investigate properties of holographic strange metals in p+2 dimensions, generalizing the analysis performed in [S. A. Hartnoll et al. J. High Energy Phys. 04 (2010) 120]. The bulk spacetime is a p+2-dimensional Lifshitz black hole, while the role of charge carriers is played by probe D-branes. We mainly focus on massless charge carriers, where most of the results can be obtained analytically. We obtain exact results for the free energy and calculate the entropy density and the heat capacity, as well as the speed of sound at low temperature. We obtain the DC conductivity and DC Hall conductivity and find that the DC conductivity takes a universal form in the large density limit, while the Hall conductivity is also universal in all dimensions. We also study the resistivity in different limits and clarify the condition for the linear dependence on the temperature, which is a key feature of strange metals. We show that our results for the DC conductivity are consistent with those obtained via the Kubo formula and we obtain the charge diffusion constant analytically. The corresponding properties of massive charge carriers are also discussed in brief.

  7. Today's View on Strangeness

    CERN Document Server

    Ellis, Jonathan Richard

    2005-01-01

    There are several different experimental indications, such as the pion-nucleon sigma term and polarized deep-inelastic scattering, which suggest that the nucleon wave function contains a hidden s bar s component. This is expected in chiral soliton models, which also predicted the existence of new exotic baryons that may recently have been observed. Another hint of hidden strangeness in the nucleon is provided by copious phi production in various N bar N annihilation channels, which may be due to evasions of the Okubo-Zweig-Iizuka rule. One way to probe the possible polarization of hidden s bar s pairs in the nucleon may be via Lambda polarization in deep-inelastic scattering.

  8. Production of strange neutral particles and measurement of the polarization of {lambda} in the NOMAD experiment at CERN; Etude de la production des particules neutres etranges et mesure de la polarisation du {lambda} dans l'experience NOMAD au CERN

    Energy Technology Data Exchange (ETDEWEB)

    Lachaud, C

    2000-05-01

    The experiment NOMAD (CERN) is dedicated to the study of the neutrino-nucleon interaction. In these interactions many strange particles are produced: particularly K{sub s}{sup 0}, {lambda} and {lambda}-bar that are more easily detectable and this work is dedicated to them. The study of the polarization of {lambda} allows to go back to the measurements of spin transfer that are not well known. The identification of strange particles is difficult, 2 methods have been used in this work: likelihood ratios and {alpha}-asymmetry method. Once neutral strange particles were identified, their production rate (global and differential) have been made out, K{sup *{+-}}, and {sigma}{sup *{+-}} resonances and the decay of {xi} have been revealed. The second part of this work deals with the measurement of {lambda} polarization. The quality of the reconstruction of events and the cumulated statistics data allowed to give an accurate value of {lambda} polarization. A thorough study of the transverse polarization has been made and we see a dependence of the transverse impulse of {lambda} on the hadronic jet similar to that observed in hadronic collisions.

  9. An effective equation of state for dense matter with strangeness

    International Nuclear Information System (INIS)

    Balberg, S.; Gal, A.

    1997-01-01

    An effective equation of state which generalizes the Lattimer-Swesty equation for nuclear matter is presented for matter at supernuclear densities including strange baryons. It contains an adjustable baryon potential energy density, based on models of local potentials for the baryon-baryon interactions. The features of the equation rely on the properties of nuclei for the nucleon-nucleon interactions, and mainly on experimental data from hypernuclei for the hyperon-nucleon and hyperon-hyperon interactions. The equation is used to calculate equilibrium compositions and thermodynamic properties of high density matter with strangeness in two astrophysical contexts: neutron star matter (transparent to neutrinos) and proto-neutron star matter (opaque to neutrinos). The effective equation of state reproduces typical properties of high density matter found in theoretical microscopic models. Of these, the main result is that hyperons appear in both types of matter at about twice the nuclear saturation density, and that their appearance significantly softens the equation of state. The range of maximal masses of neutron stars found in a comprehensive parameter survey is 1.4-1.7 M s un. Another typical result is that the maximal mass of a proto-neutron star with strange baryons is higher than that of an evolved neutron star (opposite to the case of nuclear matter), setting the stage for a ''delayed collapse'' scenario. (orig.)

  10. Strange quark matter in the Universe and accelerator nuclear beams

    International Nuclear Information System (INIS)

    Okonov, Eh.

    1995-01-01

    An almost symmetric mixture of u, d and s-quarks - Strange Quark Matter (SQM) is strongly argued to be the ground and absolutely stable of the matter. Astrophysical objects, supposed to be the SQM states, could be formed as the result of the Big Bang (in the early Universe) and the conversion of neutron stars into strange ones. Such objects are considered to be favourable candidates as black holes. The unique possibility to produce the SQM under terrestrial conditions (at accelerator laboratories) are violent relativistic nucleus-nucleus collisions so called 'little big bang'. The expected singulares of SQM are reviewed which could be revealed from astrophysical observations of peculiarities of large SQM objects as well as from accelerator experiments with searching smaller SQM states including the simplest one - metastable six-quark H dihyperon. The first results of the Dubna search experiments, with considerable heating of matter and formation a dense strangeness abundant fireball (mixed phase?) in central nuclear collisions, is presented. Under these favourable conditions a candidate for H dihyperon is observed and an upper limit of production cross sections of this SQM state is estimated. Some prospects and advantages of further searches for light SQM states, using the JINR new superconducting accelerator - Nuclotron with energy 5-6 GeV per nucleon, are briefly outlined. 19 refs., 7 figs

  11. Study of Strange Quark Mass in CFL Phase

    Institute of Scientific and Technical Information of China (English)

    LI Xin; L(U) Xiao-Fu

    2006-01-01

    In this paper we introduce bilocal fields in the global color symmetry model and consider color and electrical neutrality conditions simultaneously to study the effect of strange quark mass Ms for the momentum-dependent condensate of color-flavor locked phase. Consequently we find that there will be a quantum phase transition occurring.

  12. Strangeness production in p-Pb and Pb-Pb collisions with ALICE at LHC

    CERN Document Server

    Colella, Domenico

    2017-01-01

    The main goal of the ALICE experiment is to study the properties of the hot and dense medium created in ultra-relativistic heavy-ion collisions. The measurement of the (multi-)strange particles is an important tool to understand particle production mechanisms and the dynamics of the quark-gluon plasma (QGP). We report on the production of K$^{0}_{S}$, $\\Lambda$($\\overline{\\Lambda}$), $\\Xi^{-}$($\\overline{\\Xi}^{+}$) and $\\Omega^{-}$($\\overline{\\Omega}^{+}$) in proton-lead (p-Pb) collisions at $\\sqrt{s_{\\rm NN}}$ = 5.02 TeV and lead-lead (Pb-Pb) collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV measured by ALICE at the LHC. The comparison of the hyperon-to-pion ratios in the two colliding systems may provide insight into strangeness production mechanisms, while the comparison of the nuclear modification factors helps to determine the contribution of initial state effects and the suppression from strange quark energy loss in nuclear matter.

  13. The Elliptic Flow of Multi-Strange Hadrons in √SNN=200GeV Au + Au Collisions at STAR%The Elliptic Flow of Multi-Strange Hadrons in √SNN=200GeV Au + Au Collisions at STAR

    Institute of Scientific and Technical Information of China (English)

    张小平

    2012-01-01

    Azimuthal anisotropy, especially for the multi-strange hadrons, is expected to be sensitive to the dynamical evolution in the early stage of high energy nuclear collisions. In this paper we present the latest results of multi-strange hadron elliptic flow in Au + Au collisions at √SNN=200GeV from the STAR experiment at RHIC. The number-of-quark scaling is evidenced with φ(ss) and Ω(sss) with highly statistical data, which shows strange quark collectivity at RHIC. The u2 of φ meson is found to be consistent with that of proton within statistical error bars at pw 〈 1 GeV/c.

  14. Dynamically generated resonances from the vector octet-baryon octet interaction

    Energy Technology Data Exchange (ETDEWEB)

    Oset, E. [Institutos de Investigacion de Paterna, Departamento de Fisica Teorica e IFIC, Centro Mixto Universidad de Valencia-CSIC, Valencia (Spain); Ramos, A. [Universitat de Barcelona, Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Barcelona (Spain)

    2010-06-15

    We study the interaction of vector mesons with the octet of stable baryons in the framework of the local hidden gauge formalism using a coupled-channels unitary approach. We examine the scattering amplitudes and their poles, which can be associated to known J{sup P}=1/2{sup -}, 3/2{sup -} baryon resonances, in some cases, or give predictions in other ones. The formalism employed produces doublets of degenerate J{sup P}= 1/2{sup -}, 3/2{sup -} states, a pattern which is observed experimentally in several cases. The findings of this work should also be useful to guide present experimental programs searching for new resonances, in particular in the strange sector where the current information is very poor. (orig.)

  15. Strange particles: production by Cosmotron beams as observed in diffusion cloud chambers

    International Nuclear Information System (INIS)

    Fowler, W.B.

    1989-01-01

    Proton beams, from the 1GeV Cosmotron accelerator at Brookhaven, were used in the 1950s to produce strange particles. One big leap forward technologically was the development of the diffusion cloud chamber which made detecting particle tracks more accurate and sensitive. A large co-operative team worked on its development. By the mid 1950s enough tracks had been observed to show the associated production of strange particles. It was the same Brookhaven workers who developed the eighty-inch hydrogen bubble chamber which took the first photograph of the long predicted omega minus particle at the end of the decade. (UK)

  16. Strangeness and charm production in nucleus-nucleus collisions at beam energies near the thresholds

    International Nuclear Information System (INIS)

    Senger, P.

    2001-01-01

    The creation of strangeness and charm in nucleus-nucleus collisions at threshold beam energies is discussed as a probe for compressed baryonic matter. Experimental data on strangeness production at SIS energies indicate that the properties of kaons and antikaons are modified in the dense nuclear medium. An experiment is proposed to explore the QCD phase diagram in the region of highest baryon densities. An important observable will be charm production close to threshold. (orig.)

  17. Measurement of the strange quark contribution to the proton spin using neutral kaons at HERMES

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Shaojun

    2007-03-15

    This thesis reports a new ''isoscalar'' measurement of {delta}s + {delta} anti s. Because strange quarks carry no isospin, the strange seas in the proton and neutron are identical. In the deuteron, an isoscalar target, the fragmentation process in DIS can be described without any assumptions regarding isospin dependent fragmentation. In the isoscalar extraction of {delta}s + {delta} anti s only the spin asymmetry for K{sup 0}{sub s} A{sup K{sup 0}{sub s1,d}} (x,Q{sup 2}, z) and the inclusive asymmetry A{sub 1,d}(x,Q{sup 2}) are used. An accurate measurement of the total non-strange quark polarisation {delta}Q = {delta}u + {delta} anti u + {delta}d + {delta} anti d comes directly from A{sub 1,d}(x,Q{sup 2}). The fragmentation functions needed for a leading order (LO) extraction of {delta}S = {delta}s + {delta} anti s are measured directly at HERMES kinematics using the same data. As a result of this analysis, the helicity densities for the strange quarks are consistent with zero with the experimental uncertainty over the measured x kinematic range. (orig.)

  18. Production of strange neutral particles and measurement of the polarization of {lambda} in the NOMAD experiment at CERN; Etude de la production des particules neutres etranges et mesure de la polarisation du {lambda} dans l'experience NOMAD au CERN

    Energy Technology Data Exchange (ETDEWEB)

    Lachaud, C

    2000-05-01

    The experiment NOMAD (CERN) is dedicated to the study of the neutrino-nucleon interaction. In these interactions many strange particles are produced: particularly K{sub s}{sup 0}, {lambda} and {lambda}-bar that are more easily detectable and this work is dedicated to them. The study of the polarization of {lambda} allows to go back to the measurements of spin transfer that are not well known. The identification of strange particles is difficult, 2 methods have been used in this work: likelihood ratios and {alpha}-asymmetry method. Once neutral strange particles were identified, their production rate (global and differential) have been made out, K{sup *{+-}}, and {sigma}{sup *{+-}} resonances and the decay of {xi} have been revealed. The second part of this work deals with the measurement of {lambda} polarization. The quality of the reconstruction of events and the cumulated statistics data allowed to give an accurate value of {lambda} polarization. A thorough study of the transverse polarization has been made and we see a dependence of the transverse impulse of {lambda} on the hadronic jet similar to that observed in hadronic collisions.

  19. Feedback control of acoustic musical instruments: collocated control using physical analogs.

    Science.gov (United States)

    Berdahl, Edgar; Smith, Julius O; Niemeyer, Günter

    2012-01-01

    Traditionally, the average professional musician has owned numerous acoustic musical instruments, many of them having distinctive acoustic qualities. However, a modern musician could prefer to have a single musical instrument whose acoustics are programmable by feedback control, where acoustic variables are estimated from sensor measurements in real time and then fed back in order to influence the controlled variables. In this paper, theory is presented that describes stable feedback control of an acoustic musical instrument. The presentation should be accessible to members of the musical acoustics community who may have limited or no experience with feedback control. First, the only control strategy guaranteed to be stable subject to any musical instrument mobility is described: the sensors and actuators must be collocated, and the controller must emulate a physical analog system. Next, the most fundamental feedback controllers and the corresponding physical analog systems are presented. The effects that these controllers have on acoustic musical instruments are described. Finally, practical design challenges are discussed. A proof explains why changing the resonance frequency of a musical resonance requires much more control power than changing the decay time of the resonance. © 2012 Acoustical Society of America.

  20. Thermal structure of accreting neutron stars and strange stars

    International Nuclear Information System (INIS)

    Miralda-Escude, J.; Paczynski, B.; Haensel, P.

    1990-01-01

    Steady-state models of accreting neutron stars and strange stars are presented, and their properties as a function of accretion rate are analyzed. The models have steady-state envelopes, with stationary hydrogen burning taken into account, the helium shell flashes artificially suppressed, and the crust with a large number of secondary heat sources. The deep interiors are almost isothermal and are close to thermal equilibrium. A large number of models were calculated for many values of the accretion rates, with ordinary, pion-condensed, and strange cores, with and without secondary heat sources in the crust, and with the heavy element content of the accreting matter in the range Z = 0.0002-0.02. All models show a similar pattern of changes as the accretion rate is varied. For low accretion rates, the hydrogen burning shell is unstable; for intermediate rates, the hydrogen burning shell is stable, but helium burning is not; for high rates, the two shell sources burn together and are unstable. 60 refs

  1. Neural underpinnings of divergent production of rules in numerical analogical reasoning.

    Science.gov (United States)

    Wu, Xiaofei; Jung, Rex E; Zhang, Hao

    2016-05-01

    Creativity plays an important role in numerical problem solving. Although the neural underpinnings of creativity have been studied over decades, very little is known about neural mechanisms of the creative process that relates to numerical problem solving. In the present study, we employed a numerical analogical reasoning task with functional Magnetic Resonance Imaging (fMRI) to investigate the neural correlates of divergent production of rules in numerical analogical reasoning. Participants performed two tasks: a multiple solution analogical reasoning task and a single solution analogical reasoning task. Results revealed that divergent production of rules involves significant activations at Brodmann area (BA) 10 in the right middle frontal cortex, BA 40 in the left inferior parietal lobule, and BA 8 in the superior frontal cortex. The results suggest that right BA 10 and left BA 40 are involved in the generation of novel rules, and BA 8 is associated with the inhibition of initial rules in numerical analogical reasoning. The findings shed light on the neural mechanisms of creativity in numerical processing. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Fast storage of nuclear quadrupole resonance signals

    International Nuclear Information System (INIS)

    Anferov, V.P.; Molchanov, S.V.; Levchun, O.D.

    1988-01-01

    Fast multichannel storage of nuclear quadrupole resonance (NQR) signals is described. Analog-to-digital converter, arithmetic-logical unit, internal memory device (IMD) selection-storage unit and control unit are the storage main units. The storage is based on 43 microcircuits and provides for record and storage of NQR-signals at the contributed operation with Mera-60 microcomputer. Time of analog-to-digital conversion and signal recording into IMD is ∼ 1 mks. Capacity of analog-to-digital converter constitutes 8-10 bits. IMD capacity is 4 K bitsx16. Number of storage channels is 4

  3. Synthesis and anticancer structure activity relationship investigation of cationic anthraquinone analogs.

    Science.gov (United States)

    Shrestha, Jaya P; Fosso, Marina Y; Bearss, Jeremiah; Chang, Cheng-Wei Tom

    2014-04-22

    We have synthesized a series of novel 4,9-dioxo-4,9-dihydro-1H-naphtho[2,3-d][1,2,3]triazol-3-ium salts, which can be viewed as analogs of cationic anthraquinones. Unlike the similar analogs that we have reported previously, these compounds show relatively weak antibacterial activities but exert strong anticancer activities (low μM to nM GI50), in particular, against melanoma, colon cancer, non-small cell lung cancer and central nervous system (CNS) cancer. These compounds are structurally different from their predecessors by having the aromatic group, instead of alkyl chains, directly attached to the cationic anthraquinone scaffold. Further investigation in the structure-activity relationship (SAR) reveals the significant role of electron donating substituents on the aromatic ring in enhancing the anticancer activities via resonance effect. Steric hindrance of these groups is disadvantageous but is less influential than the resonance effect. The difference in the attached groups at N-1 position of the cationic anthraquinone analog is the main structural factor for the switching of biological activity from antibacterial to anticancer. The discovery of these compounds may lead to the development of novel cancer chemotherapeutics. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  4. Strange mesonic transition form factor in the chiral constituent quark model

    International Nuclear Information System (INIS)

    Ito, H.; Ramsey-Musolf, M.J.

    1998-01-01

    The form factor g ρπ (S) (Q 2 ) of the strange vector current transition matrix element left-angle ρ|bar sγ μ s|π right-angle is calculated within the chiral quark model. A strange vector current of the constituent U and D quarks is induced by kaon radiative corrections and this mechanism yields the nonvanishing values of g ρπ (S) (0). The numerical result at the photon point is consistent with the one given by the φ-meson dominance model, but the falloff in the Q 2 dependence is faster than the monopole form factor. Mesonic radiative corrections are also examined for the electromagnetic ρ-to-π and K * -to-K transition amplitudes. copyright 1998 The American Physical Society

  5. Connecting long distance: semantic distance in analogical reasoning modulates frontopolar cortex activity.

    Science.gov (United States)

    Green, Adam E; Kraemer, David J M; Fugelsang, Jonathan A; Gray, Jeremy R; Dunbar, Kevin N

    2010-01-01

    Solving problems often requires seeing new connections between concepts or events that seemed unrelated at first. Innovative solutions of this kind depend on analogical reasoning, a relational reasoning process that involves mapping similarities between concepts. Brain-based evidence has implicated the frontal pole of the brain as important for analogical mapping. Separately, cognitive research has identified semantic distance as a key characteristic of the kind of analogical mapping that can support innovation (i.e., identifying similarities across greater semantic distance reveals connections that support more innovative solutions and models). However, the neural substrates of semantically distant analogical mapping are not well understood. Here, we used functional magnetic resonance imaging (fMRI) to measure brain activity during an analogical reasoning task, in which we parametrically varied the semantic distance between the items in the analogies. Semantic distance was derived quantitatively from latent semantic analysis. Across 23 participants, activity in an a priori region of interest (ROI) in left frontopolar cortex covaried parametrically with increasing semantic distance, even after removing effects of task difficulty. This ROI was centered on a functional peak that we previously associated with analogical mapping. To our knowledge, these data represent a first empirical characterization of how the brain mediates semantically distant analogical mapping.

  6. Light hadrons from lattice QCD with light (u,d), strange and charm dynamical quarks

    International Nuclear Information System (INIS)

    Baron, R.

    2010-04-01

    We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (N f =2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark masses is performed at two values of the lattice spacing a ∼ 0:078 fm and a ∼0.086 fm with lattice sizes ranging from L∼1.9 fm to L∼2.8 fm. We measure with high statistical precision the light pseudoscalar mass m PS and decay constant f PS in a range 270 PS 0 and anti l 3,4 of SU(2) chiral perturbation theory. We use the two values of the lattice spacing, several lattice sizes as well as different values of the light, strange and charm quark masses to explore the systematic effects. A first study of discretisation effects in light-quark observables and a comparison to N f =2 results are performed. (orig.)

  7. Strange Quark Matter Status and Prospects

    Science.gov (United States)

    Sandweiss, J.

    2004-01-01

    The existence of quark states with more than three quarks is allowed in QCD. The stability of such quark matter states has been studied with lattice QCD and phenomenological bag models, but is not well constrained by theory. The addition of strange quarks to the system allows the quarks to be in lower energy states despite the additional mass penalty. There is additional stability from reduced Coulomb repulsion. SQM is expected to have a low Z/A. Stable or metastable massive multiquark states contain u, d, and s quarks.

  8. Finite Volume Effect of Baryons in Strange Hadronic Matter

    Institute of Scientific and Technical Information of China (English)

    SUN Bao-Xi; LI Lei; NING Ping-Zhi; ZHAO En-Guang

    2001-01-01

    The finite volume effect of baryons in strange hadronic matter (SHM) is studied within the framework of relativistic mean-field theory. As this effect is concerned, the saturation density of SHM turns lower, and the binding energy per baryon decreases. Its influence to the compression modulus of SHM is also discussed.

  9. Detecting analogical resemblance without retrieving the source analogy.

    Science.gov (United States)

    Kostic, Bogdan; Cleary, Anne M; Severin, Kaye; Miller, Samuel W

    2010-06-01

    We examined whether people can detect analogical resemblance to an earlier experimental episode without being able to recall the experimental source of the analogical resemblance. We used four-word analogies (e.g., robin-nest/beaver-dam), in a variation of the recognition-without-cued-recall method (Cleary, 2004). Participants studied word pairs (e.g., robin-nest) and were shown new word pairs at test, half of which analogically related to studied word pairs (e.g., beaver-dam) and half of which did not. For each test pair, participants first attempted to recall an analogically similar pair from the study list. Then, regardless of whether successful recall occurred, participants were prompted to rate the familiarity of the test pair, which was said to indicate the likelihood that a pair that was analogically similar to the test pair had been studied. Across three experiments, participants demonstrated an ability to detect analogical resemblance without recalling the source analogy. Findings are discussed in terms of their potential relevance to the study of analogical reasoning and insight, as well as to the study of familiarity and recognition memory.

  10. Strangeness production in proton and heavy ion collisions at 200 A GeV

    International Nuclear Information System (INIS)

    Amelin, N.S.; Bravina, L.V.; Csernai, L.P.; Toneev, V.D.; Gudima, K.K.; Sivoklokov, S.Y.

    1992-11-01

    Strangeness production at SPS-CERN energies is studied within the Quark Gluon String Model. The observed shape of rapidity and transverse mass distributions are reproduced fairly well for both peripheral and central heavy ion collisions. However, for central collisions the model underpredicts strange particle abundances by a factor of about 2:2:4 for K S 0 , Λ and antiΛ, respectively. This discrepancy can be considered as a possible manifestation of collective string-string interactions similar to the formation of a color rope. Model predictions for coming experiments with the Pb beam at CERN are given. 30 refs. 11 figs., 3 tabs

  11. Three-body hadronic structure of low-lying 1/2+ Σ and Λ resonances

    International Nuclear Information System (INIS)

    Martinez Torres, A.; Khemchandani, K.P.; Oset, E.

    2008-01-01

    We discuss the dynamical generation of some low-lying 1/2 + Σ's and Λ's in two-meson one-baryon systems. These systems have been constructed by adding a pion in the S-wave to the anti KN pair and its coupled channels, where the 1/2 - Λ(1405)-resonance gets dynamically generated. We solve Faddeev equations in the coupled-channel approach to calculate the T-matrix for these systems as a function of the total energy and the invariant mass of one of the meson-baryon pairs. This squared T-matrix shows peaks at the energies very close to the masses of the strangeness -1,1/2 + resonances listed in the particle data book. (orig.)

  12. Despina Hatzifotiadou: ALICE Master Class 3 - Theory: strangeness enhancement; centrality of lead-lead collisions; efficiency, yield, background etc

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    This is the 3rd of 4 short online videos. It explains what is: strangeness enhancement; centrality of lead-lead collisions; efficiency, yield, background etc. More details and related links on this indico event page. In more detail: What is Physics Master Classes Students after morning lectures, run programmes in the afternoon to do measurements. These tutorials are about how to use the software required to do these measurements. Background info and examples  Looking for strange particles with ALICE http://aliceinfo.cern.ch/Public/MasterCL/MasterClassWebpage.html Introduction to first part of the exercise : what are strange particles, V0 decays, invariant mass. Demonstration of the software for the 1st part of the exercise - visual identification of V0s Introduction to second part of the exercise : strangeness enhancement; centrality of lead-lead collisions; explanation of efficiency, yield, background etc Demonstration of the software for the 2nd part of the exercise - invariant mass spectr...

  13. Multiple photon resonances

    International Nuclear Information System (INIS)

    Elliott, C.J.; Feldman, B.J.

    1979-02-01

    A detailed theoretical analysis is presented of the interaction of intense near-resonant monochromatic radiation with an N-level anharmonic oscillator. In particular, the phenomenon of multiple photon resonance, the process by which an N-level system resonantly absorbs two or more photons simultaneously, is investigated. Starting from the Schroedinger equation, diagrammatic techniques are developed that allow the resonant process to be analyzed quantitatively, in analogy with well-known two-level coherent phenomena. In addition, multiple photon Stark shifts of the resonances, shifts absent in two-level theory, are obtained from the diagrams. Insights into the nature of multiple photon resonances are gained by comparing the quantum mechanical system with classical coupled pendulums whose equations of motion possess identical eigenvalues and eigenvectors. In certain limiting cases, including that of the resonantly excited N-level harmonic oscillator and that of the equally spaced N-level system with equal matrix elements, analytic results are derived. The influence of population relaxation and phase-disrupting collisions on the multiple photon process are also analyzed, the latter by extension of the diagrammatic technique to the density matrix equations of motion. 11 figures

  14. High-precision calculation of the strange nucleon electromagnetic form factors

    Energy Technology Data Exchange (ETDEWEB)

    Green, Jeremy [Johannes Gutenberg Univ., Mainz (Germany); Meinel, Stefan [Univ. of Arizona, Tucson, AZ (United States); Brookhaven National Lab. (BNL), Upton, NY (United States); Engelhardt, Michael G. [New Mexico State Univ., Las Cruces, NM (United States); Krieg, Stefan [Bergische Univ., Wuppertal (Germany); Julich Supercomputing Centre, Julich (Germany); Laeuchli, Jesse [College of William and Mary, Williamsburg, VA (United States); Negele, John W. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Orginos, Kostas [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Pochinsky, Andrew [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Syritsyn, Sergey [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-08-26

    We report a direct lattice QCD calculation of the strange nucleon electromagnetic form factors GsE and GsM in the kinematic range 0 ≤ Q2 ≤ 1.2GeV2. For the first time, both GsE and GsM are shown to be nonzero with high significance. This work uses closer-to-physical lattice parameters than previous calculations, and achieves an unprecented statistical precision by implementing a recently proposed variance reduction technique called hierarchical probing. We perform model-independent fits of the form factor shapes using the z-expansion and determine the strange electric and magnetic radii and magnetic moment. As a result, we compare our results to parity-violating electron-proton scattering data and to other theoretical studies.

  15. [Search for strange quark matter and antimatter produced in high energy heavy ion collisions

    International Nuclear Information System (INIS)

    1992-01-01

    This document describes the development and progress of our group's research program in high energy heavy ion physics. We are a subset of the Yale experimental high energy physics effort (YAUG group) who became interested in the physics of high energy heavy ions in 1988. Our interest began with the possibility of performing significant searches for strange quark matter. As we learned more about the subject and as we gained experimental experience through our participation in AGS experiment 814, our interests have broadened. Our program has focused on the study of new particles, including (but not exclusively) strange quark matter, and the high sensitivity measurement of other composite nuclear systems such as antinuclei and various light nuclei. The importance of measurements of the known, but rare, nuclear systems lies in the study of production mechanisms. A good understanding of the physics and phenomenology of rare composite particle production in essential for the interpretation of limits to strange quark matter searches. We believe that such studies will also be useful in probing the mechanisms involved in the collision process itself. We have been involved in the running and data analysis for AGS E814. We have also worked on the R ampersand D for AGS E864, which is an approved experiment designed to reach sensitivities where there will be a good chance of discovering strangelets or of setting significant limits on the parameters of strange quark matter

  16. Elastic properties of gamma-Pu by resonant ultrasound spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Migliori, Albert [Los Alamos National Laboratory; Betts, J [Los Alamos National Laboratory; Trugman, A [Los Alamos National Laboratory; Mielke, C H [Los Alamos National Laboratory; Mitchell, J N [Los Alamos National Laboratory; Ramos, M [Los Alamos National Laboratory; Stroe, I [WORXESTER, MA

    2009-01-01

    Despite intense experimental and theoretical work on Pu, there is still little understanding of the strange properties of this metal. We used resonant ultrasound spectroscopy method to investigate the elastic properties of pure polycrystalline Pu at high temperatures. Shear and longitudinal elastic moduli of the {gamma}-phase of Pu were determined simultaneously and the bulk modulus was computed from them. A smooth linear and large decrease of all elastic moduli with increasing temperature was observed. We calculated the Poisson ratio and found that it increases from 0.242 at 519K to 0.252 at 571K.

  17. LHCb: Prospect for rare strange decays at LHCb

    CERN Multimedia

    Marin Benito, C

    2014-01-01

    Prospects on rare strange decays at LHCb are presented. The latest results from the K_s \\to \\mu \\mu search are reported, together with the future prospects for this decay. A search for K_s \\to \\pi^0 \\mu \\mu, a K^+ mass measurement, a search for K_s \\to 4 \\el and a search for \\Sigma^+ \\to p\\mu\\mu are also presented.

  18. Anomalies, symmetries and strangeness content of the proton

    Indian Academy of Sciences (India)

    The matrix elements of the operators of strange quark fields s ¯ s where is 1 or 5 between a proton state is calculated. The sigma term is found to be ≈ 41 MeV and the (3) singlet axial matrix element is found to be ≈ 0.22, both in agreement with experiment. The sigma term is found using the trace anomaly, ...

  19. Strangeness-changing vector currents in τ-lepton decays

    International Nuclear Information System (INIS)

    Bednyakov, V.A.; Osipov, A.A.

    1992-01-01

    The Cabibbo suppressed τ-lepton decays into a kaon and a non-strange pseudoscalar meson have been investigated in the U(3)-version of the superconducting quark model with allowance for ΦA-mixing. The total and differential widths of four τ-lepton decays were obtained. The number of these decays per year at the c-τ-factory was calculated. 6 refs.; 4 figs.; 2 tabs

  20. Exotic states in the S=1 N-pi-K system and low-lying 1/2+ S=-1 resonances

    Directory of Open Access Journals (Sweden)

    Oset E.

    2010-04-01

    Full Text Available In this manuscript we discuss about our study of the $N pi ar{K}$ and the NπK systems made by solving the Faddeev equations with the two-body t-matrices obtained by solving the Bethe-Salpeter equations with the potentials obtained from chiral dynamics. In the strangeness = -1 case, we found that all the Λ and Σ resonances listed by the particle data group, with spin-parity 1/2+ , in the 1550-1800 MeV region get generated due to the involved three-body dynamics. This motivated us to study the strangeness =1 three-body system, i.e., NπK , where we did not find any evidence for the Θ+ (1542 but found a broad bump around 1700 MeV which has a κ(800N structure.

  1. Parity Violation in Elastic Electron-Proton Scattering and the Proton's Strange Magnetic Form Factor

    International Nuclear Information System (INIS)

    Spayde, D. T.; Averett, T.; Barkhuff, D.; Beck, D. H.; Beise, E. J.; Benson, C.; Breuer, H.; Carr, R.; Covrig, S.; DelCorso, J.

    2000-01-01

    We report a new measurement of the parity-violating asymmetry in elastic electron scattering from the proton at backward scattering angles. This asymmetry is sensitive to the strange magnetic form factor of the proton as well as electroweak axial radiative corrections. The new measurement of A=-4.92±0.61±0.73 ppm provides a significant constraint on these quantities. The implications for the strange magnetic form factor are discussed in the context of theoretical estimates for the axial corrections. (c) 2000 The American Physical Society

  2. Ted Madden's Network Methods: Applications to the Earth's Schumann Resonances

    Science.gov (United States)

    Williams, E. R.; Yu, H.

    2014-12-01

    Ted Madden made clever use of electrical circuit concepts throughout his long career in geophysical research: induced polarization, DC resistivity, magnetotellurics, Schumann resonances, the transport properties of rocks and even elasticity and the brittle failure of stressed rocks. The general methods on network analogies were presented in a terse monograph (Madden, 1972) which came to be called "The Grey Peril" by his students, named more for the challenge of deciphering the material as for the color of its cover. This talk will focus on Ted's first major use of the transmission line analogy in treating the Earth's Schumann resonances. This approach in Madden and Thompson (1965) provided a greatly simplified two-dimensional treatment of an electromagnetic problem with a notable three-dimensional structure. This skillful treatment that included the role of the Earth's magnetic field also led to predictions that the Schumann resonance energy would leak into space, predictions that have been verified nearly 50 years later in satellite observations. An extension of the network analogy by Nelson (1967) using Green's function methods provides a means to treat the inverse problem for the background Schumann resonances for the global lightning activity. The development of Madden's methods will be discussed along with concrete results based on them for the monitoring of global lightning.

  3. Strange stars in f(R,Script T) gravity

    Science.gov (United States)

    Deb, Debabrata; Rahaman, Farook; Ray, Saibal; Guha, B. K.

    2018-03-01

    In this article we try to present spherically symmetric isotropic strange star model under the framework of f(R,Script T) theory of gravity. To this end, we consider that the Lagrangian density is a linear function of the Ricci scalar R and the trace of the energy momentum tensor Script T given as f(R,Script T)=R+2χ Script T. We also assume that the quark matter distribution is governed by the simplest form of the MIT bag model equation of state (EOS) as p=1/3(ρ‑4B), where B is the bag constant. We have obtained an exact solution of the modified form of the Tolman-Oppenheimer-Volkoff (TOV) equation in the framework of f(R,Script T) gravity theory and have studied the dependence of different physical properties, viz., the total mass, radius, energy density and pressure for the chosen values of χ. Further, to examine physical acceptability of the proposed stellar model, we have conducted different tests in detail, viz., the energy conditions, modified TOV equation, mass-radius relation, causality condition etc. We have precisely explained the effects arising due to the coupling of the matter and geometry on the compact stellar system. For a chosen value of the bag constant, we have predicted numerical values of the different physical parameters in tabular form for the different strange star candidates. It is found that as the factor χ decreases the strange star candidates become gradually massive and larger in size with less dense stellar configuration. However, when χ increases the stars shrink gradually and become less massive to turn into a more compact stellar system. Hence for χ>0 our proposed model is suitable to explain the ultra-dense compact stars well within the observational limits and for χ<0 case allows to represent the recent massive pulsars and super-Chandrasekhar stars. For χ=0 we retrieve as usual the standard results of the general relativity (GR).

  4. Analogical reasoning and prefrontal cortex: evidence for separable retrieval and integration mechanisms.

    Science.gov (United States)

    Bunge, Silvia A; Wendelken, Carter; Badre, David; Wagner, Anthony D

    2005-03-01

    The present study examined the contributions of prefrontal cortex (PFC) subregions to two component processes underlying verbal analogical reasoning: semantic retrieval and integration. Event-related functional magnetic resonance imaging data were acquired while subjects performed propositional analogy and semantic decision tasks. On each trial, subjects viewed a pair of words (pair 1), followed by an instructional cue and a second word pair (pair 2). On analogy trials, subjects evaluated whether pair 2 was semantically analogous to pair 1. On semantic trials, subjects indicated whether the pair 2 words were semantically related to each other. Thus, analogy--but not semantic--trials required integration across multiple retrieved relations. To identify regions involved in semantic retrieval, we manipulated the associative strength of pair 1 words in both tasks. Anterior left inferior PFC (aLIPC) was modulated by associative strength, consistent with a role in controlled semantic retrieval. Left frontopolar cortex was insensitive to associative strength, but was more sensitive to integration demands than was aLIPC, consistent with a role in integrating the products of semantic retrieval to evaluate whether distinct representations are analogous. Right dorsolateral PFC exhibited a profile consistent with a role in response selection rather than retrieval or integration. These findings indicate that verbal analogical reasoning depends on multiple, PFC-mediated computations.

  5. Halo structure of strange particles in nuclei

    International Nuclear Information System (INIS)

    Akaishi, Yoshinori; Yamazaki, Toshimitsu.

    1997-01-01

    Some characteristic behaviors of hyperons in nuclei which have recently been revealed experimentally and theoretically are discussed with the emphasis on the repulsive part of the hyperon-nucleus interaction. The observed Σ 4 He nucleus is a bound state with J π = 0 + and T ≅ 1/2. Its nucleus-Σ potential derived from a realistic ΣN interaction is characterized by inner repulsion and a strong Lane term, which play important roles in forming the Σ-hypernuclear bound state. In 208 Pb a typical Coulomb-assisted bound state is expected, where Σ is trapped in the surface region by the nucleus-Σ potential with the aid of Coulomb and centrifugal interactions. In the double-strangeness (S=-2) sector, there is a possibility that the lightest double-Λ hypernucleus ΛΛ 4 H is abundantly populated by stopping Ξ - on 4 He. Its formation branching amounts to about 15%. A stopped Ξ - on 9 Be will also produce efficiently a variety of double-Λ hyperfragments. Discrete spectra of weak-decay pions from the fragments will provide a means of mass spectroscopy of double-Λ hypernuclei. In the S=-2 five-body system an excited state Ξ 5 H is predicted to appear with 'strangeness halo' and the ground state ΛΛ 5 H with almost pure ΛΛ component. (author)

  6. Organization of fluorescent cholesterol analogs in lipid bilayers - lessons from cyclodextrin extraction.

    Science.gov (United States)

    Milles, Sigrid; Meyer, Thomas; Scheidt, Holger A; Schwarzer, Roland; Thomas, Lars; Marek, Magdalena; Szente, Lajos; Bittman, Robert; Herrmann, Andreas; Günther Pomorski, Thomas; Huster, Daniel; Müller, Peter

    2013-08-01

    To characterize the structure and dynamics of cholesterol in membranes, fluorescent analogs of the native molecule have widely been employed. The cholesterol content in membranes is in general manipulated by using water-soluble cyclodextrins. Since the interactions between cyclodextrins and fluorescent-labeled cholesterol have not been investigated in detail so far, we have compared the cyclodextrin-mediated membrane extraction of three different fluorescent cholesterol analogs (one bearing a NBD and two bearing BODIPY moieties). Extraction of these analogs was followed by measuring the Förster resonance energy transfer between a rhodamine moiety linked to phosphatidylethanolamine and the labeled cholesterol. The extraction kinetics revealed that the analogs are differently extracted from membranes. We examined the orientation of the analogs within the membrane and their influence on lipid condensation using NMR and EPR spectroscopies. Our data indicate that the extraction of fluorescent sterols from membranes is determined by several parameters, including their impact on lipid order, their hydrophobicity, their intermolecular interactions with surrounding lipids, their orientation within the bilayer, and their affinity with the exogenous acceptor. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Neutral strangeness production with the ZEUS detector at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Liu Chuanlei

    2007-12-15

    The inclusive production of the neutral strange particles, {lambda}, anti {lambda} and K{sup 0}{sub S} has been studied with the ZEUS detector at HERA. The measurement provides a way to understand the fragmentation process in ep collisions and to check the universality of this process. The strangeness cross sections have been measured and compared with Monte Carlo (MC) predictions. Over the kinematic regions of interest, no {lambda} to anti {lambda} asymmetry was observed. The relative yield of {lambda} and K{sup 0}{sub S} was determined and the result was compared with MC calculations and results from other experiments. A good agreement was found except for the enhancement in the photoproduction process. Clear rapidity correlation was observed for particle pairs where either quark flavor or baryon number compensation occurs. The K{sup 0}{sub S}K{sup 0}{sub S} Bose-Einstein correlation measurement gives a result consistent with those from LEP measurements. The {lambda} polarizations were measured to be consistent with zero for HERA I data. (orig.)

  8. Measurement of the strange quark contribution to the vector structure of the proton

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Sarah

    2007-11-30

    The goal of the G0 experiment is to determine the contribution of the strange quarks in the quark-antiquark sea to the structure of the nucleon. To this end, the experiment measured parityviolating asymmetries from elastic electron-proton scattering from 0.12 ≤ Q2 ≤ 1.0 (GeV/c)2 at Thomas Jefferson National Accelerator Facility. These asymmetries come from the interference of the electromagnetic and neutral weak interactions, and are sensitive to the strange quark contributions in the proton. The results from the forward-angle measurement, the linear combination of the strange electric and magnetic form factors GsE +ηGsM, suggest possible non-zero, Q2 dependent, strange quark contributions and provide new information to understand the magnitude of the contributions. This dissertation presents the analysis and results of the forward-angle measurement. In addition, the G0 experiment measured the beam-normal single-spin asymmetry in the elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q2 = 0.15, 0.25 (GeV/c)2 as part of the forward-angle measurement. The transverse asymmetry provides a direct probe of the imaginary component of the two-photon exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments. The results of the measurement indicate that calculations using solely the elastic nucleon intermediate state are insufficient and generally agree with calculations that include significant inelastic hadronic intermediate state contributions. This dissertation presents the analysis and results of this measurement.

  9. Measuring the strangeness content of the nucleon by observing the ϕ-meson mass shift in nuclear matter

    International Nuclear Information System (INIS)

    Gubler, Philipp; Ohtani, Keisuke

    2015-01-01

    The modification of the ϕ-meson at finite density is studied by using QCD sum rules in combination with the maximum entropy method. As a result, it is found that the mass shift of the ϕ-meson is strongly correlated to the strangeness content of the nucleon, , which governs the depletion of the strange quark condensate in nuclear matter. (author)

  10. Cosmic-ray cloud-chamber contributions to the discovery of the strange particles in the decade 1947-1957

    International Nuclear Information System (INIS)

    Rochester, G.D.

    1989-01-01

    This paper looks at the discovery and investigation of strange particles in the 1950s and points to the importance of two factors in achieving this, namely, penetrating-shower selection and counter control in cloud chambers. Experiments at Pic-du-Mide are detailed as is the Bagneres de Bigorre conference and concludes with some of the work done on charged strange particles. (UK)

  11. Specialization of the Rostral Prefrontal Cortex for Distinct Analogy Processes

    Science.gov (United States)

    Gilbert, Sam J.; Benoit, Roland G.; Burgess, Paul W.

    2010-01-01

    Analogical reasoning is central to learning and abstract thinking. It involves using a more familiar situation (source) to make inferences about a less familiar situation (target). According to the predominant cognitive models, analogical reasoning includes 1) generation of structured mental representations and 2) mapping based on structural similarities between them. This study used functional magnetic resonance imaging to specify the role of rostral prefrontal cortex (PFC) in these distinct processes. An experimental paradigm was designed that enabled differentiation between these processes, by temporal separation of the presentation of the source and the target. Within rostral PFC, a lateral subregion was activated by analogy task both during study of the source (before the source could be compared with a target) and when the target appeared. This may suggest that this subregion supports fundamental analogy processes such as generating structured representations of stimuli but is not specific to one particular processing stage. By contrast, a dorsomedial subregion of rostral PFC showed an interaction between task (analogy vs. control) and period (more activated when the target appeared). We propose that this region is involved in comparison or mapping processes. These results add to the growing evidence for functional differentiation between rostral PFC subregions. PMID:20156841

  12. Multi-strange baryon production in pp, p-Pb and Pb-Pb collisions at LHC measured with ALICE

    CERN Document Server

    Colella, Domenico

    2015-01-01

    Transverse momentum spectra and yields of charged $\\Xi$ and $\\Omega$ at mid-rapidity in pp, p-Pb and Pb-Pb collisions at the LHC have been measured by the ALICE Collaboration. These baryons are identified by reconstruction of their weak decay topology, in modes with only charged decay products, using the excellent tracking and particle identification capabilities of the detector. The recent measurements of the multi-strange baryon production relative to non-strange particles in p-Pb collisions are presented: this would help to understand the change in relative strangeness production from pp collisions to Pb-Pb collisions. Results on the nuclear modification factors for the charged $\\Xi$ and $\\Omega$ particles, compared with those for other light particles, are also reported.

  13. The PANDA physics program: Strangeness and more

    Energy Technology Data Exchange (ETDEWEB)

    Iazzi, Felice, E-mail: felice.iazzi@polito.it [INFN-Sezione di Torino, Turin (Italy); Politecnico di Torino, Turin (Italy); Collaboration: PANDA Collaboration

    2016-06-21

    The physics program of the PANDA experiment at FAIR is illustrated, with a particular attention to the planned activity in the field of the doubly strange systems. The investigation of these systems can help, among others, to shed light on the role of the hyperons in the composition of the neutron stars. The great advantages that can be reached in the field of the charmed systems and nucleon structure by using high quality and intense antiproton beams are also recalled.

  14. The PANDA physics program: Strangeness and more

    International Nuclear Information System (INIS)

    Iazzi, Felice

    2016-01-01

    The physics program of the PANDA experiment at FAIR is illustrated, with a particular attention to the planned activity in the field of the doubly strange systems. The investigation of these systems can help, among others, to shed light on the role of the hyperons in the composition of the neutron stars. The great advantages that can be reached in the field of the charmed systems and nucleon structure by using high quality and intense antiproton beams are also recalled.

  15. Rank One Strange Attractors in Periodically Kicked Predator-Prey System with Time-Delay

    Science.gov (United States)

    Yang, Wenjie; Lin, Yiping; Dai, Yunxian; Zhao, Huitao

    2016-06-01

    This paper is devoted to the study of the problem of rank one strange attractor in a periodically kicked predator-prey system with time-delay. Our discussion is based on the theory of rank one maps formulated by Wang and Young. Firstly, we develop the rank one chaotic theory to delayed systems. It is shown that strange attractors occur when the delayed system undergoes a Hopf bifurcation and encounters an external periodic force. Then we use the theory to the periodically kicked predator-prey system with delay, deriving the conditions for Hopf bifurcation and rank one chaos along with the results of numerical simulations.

  16. Interactive NMR: A Simulation Based Teaching Tool for Fundamentals to Applications with Tangible Analogies

    Science.gov (United States)

    Griesse-Nascimento, Sarah; Bridger, Joshua; Brown, Keith; Westervelt, Robert

    2011-03-01

    Interactive computer simulations increase students' understanding of difficult concepts and their ability to explain complex ideas. We created a module of eight interactive programs and accompanying lesson plans for teaching the fundamental concepts of Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) that we call interactive NMR (iNMR). We begin with an analogy between nuclear spins and metronomes to start to build intuition about the dynamics of spins in a magnetic field. We continue to explain T1, T2, and pulse sequences with the metronome analogy. The final three programs are used to introduce and explain the Magnetic Resonance Switch, a recent diagnostic technique based on NMR. A modern relevant application is useful to generate interest in the topic and confidence in the students' ability to apply their knowledge. The iNMR module was incorporated into a high school AP physics class. In a preliminary evaluation of implementation, students expressed enthusiasm and demonstrated enhanced understanding of the material relative to the previous year. Funded by NSF PHY-0646094 grant.

  17. Strange Animals and Creatures in Islamic Miniatures: Focusing on Miniatures of the Conference of the Birds

    Directory of Open Access Journals (Sweden)

    Neda Rohani

    2017-09-01

    Full Text Available Strange animals and creatures have always existed in every mythological culture. In Iran's pre-Islamic and post-Islamic miniatures and reliefs, there are many strange animals and creatures such as dragons and phoenix which were associated with the Iranian culture and civilization. Because of presence of these strange creatures, particularly human life, these creatures are first used in mythological life and then symbolically to express human ideas. However, these animals were present in both mythology and epics and, later in the Islamic era, in the mystical stories, educational stories and admonishing anecdotes like Sanai, Attar, and Rumi. This study tends to investigate genealogy of strange animals and creatures in ancient Iranian reliefs and their continued presence in miniatures of Islamic era as well as presence of these creatures in miniatures which are based on Attar’s Conference of the Birds. In fact, this study reviews elements and symbolic concepts of animals, allowing a deeper understanding of function of elements and symbolism in works of Iranian miniaturists. Contemplation of miniatures, icons and the relationship between literature and miniatures will lead to many results in recognition of mystical intellectual foundations. Therefore, this study tends to investigate mysterious and unknown aspects of Iranian miniatures and find their relationship with culture and stories.

  18. ALICE Masterclass on strangeness

    Directory of Open Access Journals (Sweden)

    Foka Panagiota

    2014-04-01

    Full Text Available An educational activity, the International Particle Physics Masterclasses, was developed by the International Particle Physics Outreach Group with the aim to bring the excitement of cutting-edge particle-physics research into the classroom. Thousands of pupils, every year since 2005, in many countries all over the world, are hosted in research centers or universities close to their schools and become “scientists for a day” as they are introduced to the mysteries of particle physics. The program of a typical day includes lectures that give insight to topics and methods of fundamental research followed by a “hands-on” session where the high-school students perform themselves measurements on real data from particle-physics experiments. The last three years data from the ALICE experiment at LHC were used. The performed measurement “strangeness enhancement” and the employed methodology are presented.

  19. Role of repulsive interactions in the interplay with missing strange resonances

    Directory of Open Access Journals (Sweden)

    Alba Paolo

    2018-01-01

    Full Text Available The standard implementation of the HRG model has been shown to be unable to describe all the available data on QCD matter. Here we show the balance of repulsive and attractive hadronic interactions on QCD thermodynamics through observables both calculated by lattice simulations and measured in experiment. Attractive interactions are mediated by resonance formation, which are here implemented through extra states predicted by the Quark Model, while repulsive interactions are modelled by means of Excluded Volume (EV effects. Informations on flavour dependent effective sizes are extracted. It is found that EV effects are present in lattice QCD thermodynamics, and are essential for a comprehensive description of higher order fluctuations of conserved charges.

  20. Hawking-Unruh Hadronization and Strangeness Production in High Energy Collisions

    CERN Document Server

    Castorina, P

    2014-01-01

    The thermal multihadron production observed in different high energy collisions poses many basic problems: why do even elementary, $e^+e^-$ and hadron-hadron, collisions show thermal behaviour? Why is there in such interactions a suppression of strange particle production? Why does the strangeness suppression almost disappear in relativistic heavy ion collisions? Why in these collisions is the thermalization time less than $\\simeq 0.5$ fm/c? We show that the recently proposed mechanism of thermal hadron production through Hawking-Unruh radiation can naturally answer the previous questions. Indeed, the interpretation of quark- antiquark pairs production, by the sequential string breaking, as tunneling through the event horizon of colour confinement leads to thermal behavior with a universal temperature, $T \\simeq 170$ Mev,related to the quark acceleration, a, by $T=a/2\\pi$. The resulting temperature depends on the quark mass and then on the content of the produced hadrons, causing a deviation from full equilib...

  1. Strange metals and quantum phase transitions from gauge/gravity duality

    Science.gov (United States)

    Liu, Hong

    2011-03-01

    Metallic materials whose thermodynamic and transport properties differ significantly from those predicted by Fermi liquid theory, so-called non-Fermi liquids, include the strange metal phase of cuprate superconductors, and heavy fermion systems near a quantum phase transition. We use gauge/gravity duality to identify a class of non-Fermi liquids. Their low-energy behavior is governed by a nontrivial infrared fixed point which exhibits non-analytic scaling behavior only in the temporal direction. Some representatives of this class have single-particle spectral functions and transport behavior similar to those of the strange metals, with conductivity inversely proportional to the temperature. Such holographic systems may also exhibit novel ``magnetic instabilities'', where the quantum critical behavior near the transition involves a nontrivial interplay between local and bulk physics, with the local physics again described by a similar infrared fixed point. The resulting quantum phase transitions do not obey the standard Landau-Ginsburg-Wilson paradigm and resemble those of the heavy fermion quantum critical points.

  2. White dwarf stars as strange quark matter detectors

    Energy Technology Data Exchange (ETDEWEB)

    Benvenuto, O G [Departamento de AstronomIa y AstroFisica, Pontificia Universidad Catolica, Vicuna Mackenna 4860, Casilla 306, Santiago (Chile); Facultad de Ciencias Astronomicas y GeoFisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, B1900FWA, La Plata (Argentina)

    2005-11-01

    We show that the presence of a strange matter core inside a white dwarf (WD) star produces a drastic change in the spectrum of non-radial oscillations in the range of periods corresponding to gravity modes. The distinctive, observable signal for such a core is a very short period spacing between consecutive modes, far shorter than in the case of pulsating WDs without any compact core. (letter to the editor)

  3. Strange meson spectroscopy in Kω and KΦ at 11 GeV/c and Cherenkov ring imaging at SLD

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Youngjoon [Stanford Univ., CA (United States)

    1993-01-01

    This thesis consists of two independent parts; development of Cherenkov Ring Imaging Detector (CRID) system and analysis of high-statistics data of strange meson reactions from the LASS spectrometer. Part 1: The CRID system is devoted to charged particle identification in the SLAC Large Detector (SLD) to study e+e- collisions at √s = mZ0. By measuring the angles of emission of the Cherenkov photons inside liquid and gaseous radiators, {pi}/K/p separation will be achieved up to ~30 GeV/c. The signals from CRID are read in three coordinates, one of which is measured by charge-division technique. To obtain a ~1% spatial resolution in the charge-division, low-noise CRID preamplifier prototypes were developed and tested resulting in <1000 electrons noise for an average photoelectron signal with 2 x 105 gain. To help ensure the long-term stability of CRID operation at high efficiency, a comprehensive monitoring and control system was developed. Part 2: Results from the partial wave analysis of strange meson final states in the reactions K-p → K-ωp and K-p → $\\bar{K}$0Φn are presented. The analyses are based on data from a 4.1 event/nb exposure of the LASS spectrometer in K-p interactions at 11 GeV/c. The data sample of K-ωp final state contains {approximately}105 events. From the partial wave analysis, resonance structures of JP= 2-, 3- and 2+ amplitudes are observed in the Kω system. The analysis of 2- amplitudes provides an evidence for two strange meson states in the mass region around 1.75 GeV/c2. The appropriate branching fractions are calculated and compared with the SU(3) predictions. The partial wave analysis of $\\bar{K}$0Φ system favors JP = 1- and 2+ states in the 1.9--2.0 GeV/c2 region.

  4. Strange hadronic physics in electroproduction experiments at the Mainz Microtron

    Czech Academy of Sciences Publication Activity Database

    Achenbach, P.; Esser, A.; Gayoso, C. A.; Böhm, R.; Borodina, O.; Bosnar, D.; Bozkurt, V.; Bydžovský, Petr; Debenjak, L.; Distler, M. O.; Friscic, I.; Fujii, Y.; Gogami, T.; Gomez, M.R.; Hashimoto, O.; Hirose, S.; Kim, E.; Margaryan, A.; Merkel, H.; Müller, U.; Nagao, S.; Nakamura, S. N.; Pochodzalla, J.; Rappold, C.; Reinhold, J.; Saito, T.; Lorente, A.S.; Majos, S. S.; Schlimme, B. S.; Schoth, M.; Schulz, F.; Sfienti, C.; Sirca, S.; Tang, L.; Thiel, M.; Tsukada, K.

    2012-01-01

    Roč. 881, 5/6 (2012), s. 187-198 ISSN 0375-9474 R&D Projects: GA MŠk(CZ) LG11005 Institutional support: RVO:61389005 Keywords : strangeness reactions * Kaon electroproduction * missing mass spectroscopy * hypernuclei * decay-pion spectroscopy Subject RIV: BE - Theoretical Physics Impact factor: 1.525, year: 2012

  5. Isobaric analog impurities from neutron capture and transmission by magnesium

    International Nuclear Information System (INIS)

    Weigmann, H.; Macklin, R.L.; Harvey, J.A.

    1976-01-01

    Resonance neutron interactions with the stable isotopes of magnesium were measured at the Oak Ridge Electron Linear Accelerator time-of-flight facility. The transmission of a natural metal sample (78.7% 24 Mg) was measured at 200 m, and capture by natural metal and by enriched isotope samples was measured at 40 m. Twenty-six resonances in 24 Mg + n up to 1.8 MeV were fitted with Breit--Wigner multilevel parameters. The data were sufficient to assign spin and parity to 19 of these. The capture data were analyzed for resonances up to 850 keV for 24 Mg + n, 265 keV for 25 Mg + n (17 + resonances), and 440 keV for 26 Mg + n (4 resonances). Average capture at stellar interior temperatures was calculated. The 24 Mg + n data serve to assess the isospin impurities in three isobaric analog states. Three other states exhibit reduced neutron widths, each several percent of the Wigner limit, which may be understood in terms of simple shell model configurations

  6. Synthesis and antimicrobial properties of 1,3,4-oxadiazole analogs containing dibenzosuberone moiety

    Energy Technology Data Exchange (ETDEWEB)

    Moger, Manjunath [Mangalore University, Karnataka (India). Department of Chemistry; Satam, Vijay; Paniraj, A.S.; Gopinath, Vadiraj S.; Hindupur, Rama Mohan; Pati, Hari N., E-mail: hari.pati@advinus.com [Advinus Therapeutics Ltd., 21 and 22, Phase II, Peenya Industrial Area, Karnataka (India); Govindaraju, Darshan Raj C. [Department of Bio-Medicinal Research, Vidya Herbs Pvt. Ltd., Karnataka (India)

    2014-01-15

    A series of ten novel 1,3,4-oxadiazole analogs containing dibenzosuberone moiety were synthesized using linear as well as convergent synthesis approach. All the compounds were characterized by mass spectrometry, infrared (IR), {sup 1}H and {sup 13}C nuclear magnetic resonance ({sup 1}H NMR and {sup 13}C NMR) spectroscopies and elemental analysis. These compounds were evaluated for antibacterial and antifungal activities. Among ten analogs, four compounds, namely, 8a, 8d, 8e and 8j were found to be highly active antibacterial and antifungal agents (author)

  7. Evidence for strange kinetics in Hasegawa-Mima turbulent transport

    International Nuclear Information System (INIS)

    Annibaldi, S.V.; Drury, L.O'C.; Manfredi, G.; Dendy, R.O.

    2000-01-01

    We have studied the transport of test particle ensembles moving in turbulent electrostatic fields governed by the Hasegawa-Mima (HM) equation. As a result of the interplay of the linear dispersive term and the nonlinear term in the HM equation, 'strange kinetics' emerge: the poloidal particle transport undergoes a qualitative transition from diffusive, through supradiffusive, to ballistic. (author). Letter-to-the-editor

  8. Analogical scaffolding: Making meaning in physics through representation and analogy

    Science.gov (United States)

    Podolefsky, Noah Solomon

    This work reviews the literature on analogy, introduces a new model of analogy, and presents a series of experiments that test and confirm the utility of this model to describe and predict student learning in physics with analogy. Pilot studies demonstrate that representations (e.g., diagrams) can play a key role in students' use of analogy. A new model of analogy, Analogical Scaffolding, is developed to explain these initial empirical results. This model will be described in detail, and then applied to describe and predict the outcomes of further experiments. Two large-scale (N>100) studies will demonstrate that: (1) students taught with analogies, according to the Analogical Scaffolding model, outperform students taught without analogies on pre-post assessments focused on electromagnetic waves; (2) the representational forms used to teach with analogy can play a significant role in student learning, with students in one treatment group outperforming students in other treatment groups by factors of two or three. It will be demonstrated that Analogical Scaffolding can be used to predict these results, as well as finer-grained results such as the types of distracters students choose in different treatment groups, and to describe and analyze student reasoning in interviews. Abstraction in physics is reconsidered using Analogical Scaffolding. An operational definition of abstraction is developed within the Analogical Scaffolding framework and employed to explain (a) why physicists consider some ideas more abstract than others in physics, and (b) how students conceptions of these ideas can be modeled. This new approach to abstraction suggests novel approaches to curriculum design in physics using Analogical Scaffolding.

  9. Coherence Phenomena in Coupled Optical Resonators

    Science.gov (United States)

    Smith, D. D.; Chang, H.

    2004-01-01

    We predict a variety of photonic coherence phenomena in passive and active coupled ring resonators. Specifically, the effective dispersive and absorptive steady-state response of coupled resonators is derived, and used to determine the conditions for coupled-resonator-induced transparency and absorption, lasing without gain, and cooperative cavity emission. These effects rely on coherent photon trapping, in direct analogy with coherent population trapping phenomena in atomic systems. We also demonstrate that the coupled-mode equations are formally identical to the two-level atom Schrodinger equation in the rotating-wave approximation, and use this result for the analysis of coupled-resonator photon dynamics. Notably, because these effects are predicted directly from coupled-mode theory, they are not unique to atoms, but rather are fundamental to systems of coherently coupled resonators.

  10. Analog measurement of delayed antiproton annihilation time spectra in a high intensity pulsed antiproton beam

    International Nuclear Information System (INIS)

    Niestroj, A.; Hayano, R.S.; Ishikawa, T.; Tamura, H.; Torii, H.A.; Morita, N.; Yamazaki, T.; Sugai, I.; Nakayoshi, K.; Horvath, D.; Eades, J.; Widmann, E.

    1996-01-01

    An analog detection system has been developed to measure delayed antiproton annihilation time spectra for laser resonance spectroscopy of metastable antiprotonic helium atoms using the high-intensity pulsed beam of antiprotons from LEAR at CERN. (orig.)

  11. Strange hadron decays involving e{sup +}e{sup -} pairs

    Energy Technology Data Exchange (ETDEWEB)

    Soyeur, M

    1997-12-31

    A high resolution, large acceptance e{sup +}e{sup -} detector like HADES coupled to intense secondary kaon beams could offer a remarkable opportunity to study at GSI both the electromagnetic and electroweak decays of strange hadrons. Such data can be very consistently interpreted using effective chiral Lagrangians based on the SU(3) x SU(3) symmetry. Of particular interest are a complete set of data on the electromagnetic form factors for the {rho},{omega}, {phi} and K* Dalitz decays, which would put very strong constraints on departures from ideal SU(3) mixings, and measurements of Dalitz decays of hyperons, whose electromagnetic structure is very much unknown. Better data on the nonleptonic radiative (e{sup +}e{sup -}) decays of kaons would be most useful to study the strangeness changing weak currents and effects related to CP violation. A major progress in the understanding of these decays came recently from their description in chiral perturbation theory, where the chiral dynamics of Goldstone bosons is coupled to the weak and electromagnetic gauge fields. Those studies could be extended to the electroweak decays of hyperons. (author). 42 refs.

  12. Parton recombination model including resonance production. RL-78-040

    International Nuclear Information System (INIS)

    Roberts, R.G.; Hwa, R.C.; Matsuda, S.

    1978-05-01

    Possible effects of resonance production on the meson inclusive distribution in the fragmentation region are investigated in the framework of the parton recombination model. From a detailed study of the data on vector-meson production, a reliable ratio of the vector-to-pseudoscalar rates is determined. Then the influence of the decay of the vector mesons on the pseudoscalar spectrum is examined, and the effect found to be no more than 25% for x > 0.5. The normalization of the non-strange antiquark distributions are still higher than those in a quiescent proton. The agreement between the calculated results and data remain very good. 36 references

  13. Parton recombination model including resonance production. RL-78-040

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R. G.; Hwa, R. C.; Matsuda, S.

    1978-05-01

    Possible effects of resonance production on the meson inclusive distribution in the fragmentation region are investigated in the framework of the parton recombination model. From a detailed study of the data on vector-meson production, a reliable ratio of the vector-to-pseudoscalar rates is determined. Then the influence of the decay of the vector mesons on the pseudoscalar spectrum is examined, and the effect found to be no more than 25% for x > 0.5. The normalization of the non-strange antiquark distributions are still higher than those in a quiescent proton. The agreement between the calculated results and data remain very good. 36 references.

  14. Preface to the Special Issue: Proceedings of the International Symposium on Strangeness in Nuclear and Hadronic Systems

    International Nuclear Information System (INIS)

    2010-01-01

    The International Symposium on "Strangeness in Nuclear and Hadronic Systems (SENDAI08)" was held at the Tohoku University Centennial Hall from Monday, 15th December, through Thursday, 18th December 2008; while a pre-symposium was also organized on 14th December. About 126 scientists participated in SENDAI08, including more than 46 from abroad. The symposium was organized as the third in the SENDAI symposium series on strangeness nuclear physics, which was initiated by the Tohoku University's experimental nuclear physics group in 1998. This time, it is motivated by recent progress of the research on nuclear and hadronic systems involving strangeness degree of freedom, particularly, by beams of electrons and photons at JLab, FINUDA, SPring8, LNS Tohoku, etc. and also at new facilities that will be completed in the near future such as J-PARC, etc.

  15. Light hadrons from lattice QCD with light (u,d), strange and charm dynamical quarks

    Energy Technology Data Exchange (ETDEWEB)

    Baron, R. [CEA, Centre de Saclay, 91 - Gif-sur-Yvette (France). IRFU/Service de Physique Nucleaire; Boucaud, P. [CNRS et Paris-Sud 11 Univ., 91 - Orsay (France). Lab. de Physique Theorique; Carbonell, J. [Lab. de Physique Subatomique et Cosmologie, 38 - Grenoble (FR)] (and others)

    2010-04-15

    We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (N{sub f}=2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark masses is performed at two values of the lattice spacing a {approx} 0:078 fm and a {approx}0.086 fm with lattice sizes ranging from L{approx}1.9 fm to L{approx}2.8 fm. We measure with high statistical precision the light pseudoscalar mass m{sub PS} and decay constant f{sub PS} in a range 270strange and charm quark masses to explore the systematic effects. A first study of discretisation effects in light-quark observables and a comparison to N{sub f}=2 results are performed. (orig.)

  16. Strangeness S = -2 baryon-baryon interactions using chiral effective field theory

    NARCIS (Netherlands)

    Polinder, H.; Haidenbauer, J.; Meissner, U.G.

    2007-01-01

    We derive the leading order strangeness S =−2 baryon–baryon interactions in chiral effective field theory. The potential consists of contact terms without derivatives and of one-pseudoscalar-meson exchanges. The contact terms and the couplings of the pseudoscalar mesons to the baryons are related

  17. Nuclear physics with strange particles

    International Nuclear Information System (INIS)

    Dover, C.B.

    1988-01-01

    Recent progress in the understanding of strange particle interactions with nuclear systems is reviewed. We discuss the relative merits of various reactions such as (K - , π/sup +-/), (π + , K + ), or (γ, K + ) for hypernuclear production. The structure of /sub Λ/ 13 C is analyzed in some detail, in order to illustrate the role of the ΛN residual interaction and approximate dynamical symmetries in hypernuclear structure. Recent results on the single particle states of a Λ in heavy systems, as revealed by (π + , K + ) reaction studies, are used to extract information on the density dependence and effective mass which characterize the Λ-nucleus mean field. Finally, we develop the idea the K + -nucleus scattering at low energies is sensitive to the subtle ''swelling'' effects for nucleons bound in nuclei. 64 refs., 13 figs

  18. The two dynamical states in sinusoidal potentials: An analog simulation experiment

    Science.gov (United States)

    Sawkmie, Ivan Skhem; Mahato, Mangal C.

    2018-04-01

    The phenomenon of stochastic resonance (SR) is usually found to occur theoretically as well as experimentally in bi-stable systems [1]. Recently, it was numerically shown that SR is found to occur in underdamped (friction coefficient γ) sinusoidal potentials also. The occurrence of SR is explained in terms of two competing dynamical states of trajectories as a response to the external periodic drive. We setup an analog simulation experiment similar to the analog simulation work done earlier to study stochastic nonlinear dynamics [2], to verify the existence of the two dynamical states and to investigate the occurrence of SR in sinusoidal potentials obtained earlier [3]. We discuss our experimental setup and the results obtained in detail.

  19. Strange mass corrections to hyperonic semi-leptonic decays in statistical model

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, A.; Batra, M. [Thapar University, School of Physics and Material Science, Patiala (India)

    2013-12-15

    We study the spin distribution, weak decay coupling constant ratios for strange baryon octets with SU(3) breaking effects. Baryon is taken as an ensemble of quark-gluon Fock states in the sea with three valence quarks with definite spin, color and flavor quantum numbers. We apply the statistical model to calculate the probabilities of each Fock states, to analyze the impact of SU(3) breaking in the weak decays. The symmetry breaking effects are studied in terms of a parameter ''r '' whose best-fit value is obtained from the experimental data of semi-leptonic weak decay coupling constant ratios. We suggest the dominant contribution from H{sub 1}G{sub 8} (sea with spin one and color octet) where symmetry breaking corrections lead to the deviations in the value of the axial-vector matrix elements ratio F/D from experimental values by 17%. We conclude that symmetry breaking also significantly affects the polarization of quark in strange baryons. (orig.)

  20. Multi-strange baryon production in Au+Au collisions at √sNN = 130 GeV

    International Nuclear Information System (INIS)

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Badyal, S.K.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bezverkhny, B.I.; Bhardwaj, S.; Bhaskar, P.; Bhati, A.K.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Dong, X.; Draper, J.E.; Du, F.; Dubey, A.K.; Dunin, V.B.; Dunlop, J.C.; Dutta Majumdar, M.R.; Eckardt, V.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Ganti, M.S.; Gutierrez, T.D.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Grachov, O.; Grigoriev, V.; Gronstal, S.; Grosnick, D.; Guedon, M.; Guertin, S.M.; Gupta, A.; Gushin, E.; Hallman, T.J.; Hardtke, D.; Harris, J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Huang, S.L.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Koetke, D.D.; Kollegger, T.; Konstantinov, A.S.; Kopytine, M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kumar, A.

    2003-01-01

    The transverse mass spectra and mid-rapidity yields for Ξs and (Omega)s plus their anti-particles are presented. The 10% most central collision yields suggest that the amount of multi-strange particles produced per produced charged hadron increases from SPS to RHIC energies. A hydrodynamically inspired model fit to the spectra, which assumes a thermalized source, seems to indicate that these multi-strange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to π, K, p and λs

  1. Multi-strange baryon production in Au-Au collisions at √(sNN) = 130 GeV

    International Nuclear Information System (INIS)

    Adams, J.; Adler, C.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson, B.D.; Anderson, M; Arkhipkin, D.; Averichev, G.S.; Badyal, S.K.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bezverkhny, B.I.; Bhardwaj, S.; Bhaskar, P.; Bhati, A.K.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Dong, X.; Draper, J.E.; Du, F.; Dubey, A.K.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Filip, P.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Ganti, M.S.; Gutierrez, T.D.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.E.; Grachov, O.; Grigoriev, V.; Cronstal, S.; Grosnick, D.; Guedon, M.; Guertin, S.M.; Gupta, A.; Gushin, E.; Hallman, T.J.; Hardtke, D.; Harris, J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Huang, S.L.; Hughes, E.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Jiang, H.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Koetke, D.D.; Kollegger, T.; Konstantinov, A.S.; Kopytine, S.M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.

    2003-01-01

    The transverse mass spectra and mid-rapidity yields for Ξs and (Omega)s plus their anti-particles are presented. The 10% most central collision yields suggest that the amount of multi-strange particles produced per produced charged hadron increases from SPS to RHIC energies. A hydrodynamically inspired model fit to the spectra, which assumes a thermalized source, seems to indicate that these multi-strange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to π, K, p and Λs

  2. Nuclear corrections in neutrino deep inelastic scattering and the extraction of the strange quark distribution

    International Nuclear Information System (INIS)

    Boros, C.

    1999-01-01

    Recent measurement of the structure function F 2 υ in neutrino deep inelastic scattering allows us to compare structure functions measured in neutrino and charged lepton scattering for the first time with reasonable precision. The comparison between neutrino and muon structure functions made by the CCFR Collaboration indicates that there is a discrepancy between these structure functions at small Bjorken x values. In this talk I examine two effects which might account for this experimental discrepancy: nuclear shadowing corrections for neutrinos and contributions from strange and anti-strange quarks. Copyright (1999) World Scientific Publishing Co. Pte. Ltd

  3. Strangeness production in hadronic and nuclear collisions in the dual parton model

    International Nuclear Information System (INIS)

    Capella, A.; Tran Thanh Van, J.; Ranft, J.

    1993-01-01

    Λ, antiΛ and K s 0 production is studied in a Monte Carlo Dual Parton model for hadron-hadron, hadron-nucleus and nucleus-nucleus collisions with a SU(3) symmetric sea for chain formation (chain ends) but strangeness suppression in the chain fragmentation. Additionally, (qq)-(antiqantiq) production from the sea was introduced into the chain formation process with the same probability as for the q → qq branching within the chain decay process. This together with the popcorn mechanism of diquark fragmentation result in a new central component of hyperon production, which was not present in previous versions of the model. With these assumptions rapidity distributions and multiplicity ratios for strange particles in hadron-hadron, hadron-nucleus and nucleus-nucleus collisions are compared to a comprehensive collection of experimental data. 5 figs., 2 tabs., 15 refs

  4. Overview of the electromagnetic production of strange mesons at MAMI

    Czech Academy of Sciences Publication Activity Database

    Achenbach, P.; Rodriguez, M. G.; Tsukada, K.; Gayoso, C. A.; Böhm, R.; Borodina, O.; Bosnar, D.; Bozkurt, V.; Bydžovský, Petr; Debenjak, L.; Distler, M. O.; Esser, A.; Friscic, I.; Fujii, Y.; Gogami, T.; Hashimoto, O.; Hirose, S.; Kanda, H.; Kaneta, M.; Kim, E.; Margaryan, A.; Merkel, H.; Müller, U.; Nagao, S.; Nakamura, S. N.; Pochodzalla, J.; Rappold, C.; Reinhold, J.; Saito, T. R.; Lorente, A.S.; Majos, S. S.; Schlimme, B. S.; Schoth, M.; Schultz, F.; Sfienti, C.; Sirca, S.; Tang, L.; Thiel, M.

    2013-01-01

    Roč. 914, SEP (2013), s. 41-50 ISSN 0375-9474 R&D Projects: GA ČR(CZ) GAP203/12/2126 Institutional support: RVO:61389005 Keywords : strangeness reactions * Kaon electro-production * missing mass spectroscopy * structure functions Subject RIV: BE - Theoretical Physics Impact factor: 2.499, year: 2013 http://www.sciencedirect.com/science/article/pii/S0375947413000304

  5. A strange familiarity? Place perceptions among the globally mobile

    DEFF Research Database (Denmark)

    Pristed Nielsen, Helene; Faber, Stine Thidemann

    2014-01-01

    How do globally mobile people perceive and make sense of a new place in which they have to create an everyday life for themselves? And how may their place perception be communicated through photographs? These are the questions around which this article revolves. The visual material discussed...... of strangeness and familiarity occur along unexpected lines of difference and similarity depending on the embodied positionality of the involved participants....

  6. On Mature Reflection: "Strange Objects" and the Cultivation of Reflective Reading.

    Science.gov (United States)

    Heyde, Emma

    2000-01-01

    Examines Gary Crew's novel written for a young adult audience, called "Strange Objects," a story containing verifiable historical fact interwoven with elements of fiction and the supernatural. Shows how the numerous genres and viewpoints in the book challenge and contradict one another, forcing young readers to perform resistant readings…

  7. Generalizations of an integral for Legendre polynomials by Persson and Strang

    NARCIS (Netherlands)

    Diekema, E.; Koornwinder, T.H.

    2012-01-01

    Persson and Strang (2003) evaluated the integral over [−1,1] of a squared odd degree Legendre polynomial divided by x2 as being equal to 2. We consider a similar integral for orthogonal polynomials with respect to a general even orthogonality measure, with Gegenbauer and Hermite polynomials as

  8. Automatic activation of categorical and abstract analogical relations in analogical reasoning.

    Science.gov (United States)

    Green, Adam E; Fugelsang, Jonathan A; Dunbar, Kevin N

    2006-10-01

    We examined activation of concepts during analogical reasoning. Subjects made either analogical judgments or categorical judgments about four-word sets. After each four-word set, they named the ink color of a single word in a modified Stroop task. Words that referred to category relations were primed (as indicated by longer response times on Stroop color naming) subsequent to analogical judgments and categorical judgments. This finding suggests that activation of category concepts plays a fundamental role in analogical thinking. When colored words referred to analogical relations, priming occurred subsequent to analogical judgments, but not to categorical judgments, even though identical four-word stimuli were used for both types of judgments. This finding lends empirical support to the hypothesis that, when people comprehend the analogy between two items, they activate an abstract analogical relation that is distinct from the specific content items that compose the analogy.

  9. Strange Quark Contributions to Parity-Violating Asymmetries in the Forward G0 Electron-Proton Scattering Experiment

    Energy Technology Data Exchange (ETDEWEB)

    David Armstrong; Francois Arvieux; Razmik Asaturyan; Todd Averett; Stephanie Bailey; Guillaume Batigne; Douglas Beck; Elizabeth Beise; Jay Benesch; Louis Bimbot; James Birchall; Angela Biselli; Peter Bosted; Elodie Boukobza; Herbert Breuer; Roger Carlini; R. Carr; Nicholas Chant; Yu-Chiu Chao; Swapan Chattopadhyay; Russell Clark; Silviu Covrig; Anthony Cowley; Daniel Dale; C. Davis; Willie Falk; John Finn; Tony Forest; Gregg Franklin; Christophe Furget; David Gaskell; Joseph Grames; Keith Griffioen; Klaus Grimm; Benoit Guillon; Hayko Guler; Lars Hannelius; R. Hasty; A. Hawthorne Allen; Tanja Horn; Kathleen Johnston; Mark Jones; Peter Kammel; Reza Kazimi; Paul King; Ameya Kolarkar; Elie Korkmaz; Wolfgang Korsch; Serge Kox; Joachim Kuhn; Jeff Lachniet; Lawrence Lee; Jason Lenoble; Eric Liatard; J. Liu; Berenice Loupias; A. Lung; Glen MacLachlan; Dominique Marchand; J.W. Martin; Kenneth McFarlane; Daniella Mckee; Robert McKeown; Fernand Merchez; Hamlet Mkrtchyan; Bryan Moffit; M. Morlet; Itaru Nakagawa; Kazutaka Nakahara; Melissa Nakos; Retief Neveling; Silvia Niccolai; S. Ong; Shelley Page; Vassilios Papavassiliou; Stephen Pate; Sarah Phillips; Mark Pitt; Benard Poelker; Tracy Porcelli; Gilles Quemener; Brian Quinn; William Ramsay; Aamer Rauf; Jean-Sebastien Real; Julie Roche; Philip Roos; Gary Rutledge; Jeffery Secrest; Neven Simicevic; G.R. Smith; Damon Spayde; Samuel Stepanyan; Marcy Stutzman; Vincent Sulkosky; Vardan Tadevosyan; Raphael Tieulent; Jacques Van de Wiele; Willem van Oers; Eric Voutier; William Vulcan; G. Warren; S.P. Wells; Steven Williamson; S.A. Wood; Chen Yan; Junho Yun; Valdis Zeps

    2005-06-01

    We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < Q{sup 2} < 1.0 GeV{sup 2}. These asymmetries, arising from interference of the electromagnetic and neutral weak interactions, are sensitive to strange quark contributions to the currents of the proton. The measurements were made at JLab using a toroidal spectrometer to detect the recoiling protons from a liquid hydrogen target. The results indicate non-zero, Q{sup 2} dependent, strange quark contributions and provide new information beyond that obtained in previous experiments.

  10. Application of minicomputer Mera-400 to analog data acquisition from pulsed nuclear magnetic resonance experiment

    International Nuclear Information System (INIS)

    Gazdzinski, R.; Jasinski, A.; Stachurowa, M.

    1979-01-01

    Minicomputer Mera-400 based analog signal data acquisition system is described. The peripherical controlers of the computer and the operating system SOM-3 are used. The analog signal is first digitized and stored in 1024 words of 8 bit buffer memory of the transient recorder and then transferred into the minicomputer memory for averaging. 1 k words of the computer memory can be shown on a CRT of a simple graphic display or registered on a X-Y recorder. A detail description of the hardware and of the software written in the assembler is also presented. (author)

  11. Strangeness condensation and ''clearing'' of the vacuum

    International Nuclear Information System (INIS)

    Brown, G.E.; Kubodera, Kuniharu; Rho, M.; State Univ. of New York, Stony Brook

    1987-01-01

    We show that a substantial amount of strange quark-antiquark pair condensates in the nucleon required by the πN sigma term implies that kaons could condense in nuclear matter at a density about three times that of normal nuclear matter. This phenomenon can be understood as the ''cleansing'' of qanti q condensates from the QCD vacuum by a dense nuclear matter, resulting in a (partial) restoration of the chiral symmetry explicitly broken in the vacuum. It is suggested that the condensation signals a new phase distinct from that of quark plasma and that of ordinary dense hadronic matter. (orig.)

  12. Strange bedfellows: Cervantes and Mary Wollstonecraft Shelley

    Directory of Open Access Journals (Sweden)

    Alfredo Moro

    2017-11-01

    Full Text Available Miguel de Cervantes and Mary Shelley do seem, at first sight, two strange bedfellows. Notwithstanding the evident differences between the narrative of both authors, the English novelist showed a notable interest for the life and works of Miguel de Cervantes throughout her literary career. This article intends to offer a precise portrait of the Cervantean interests of the author of Frankenstein, tracing these through her personal correspondence, her narrative production, and finally, through her contribution to the realm of Cervantean studies: Shelley’s Life of Cervantes (1837, published in Dyonisius Lardner’s Cabinet Cyclopaedia.

  13. Strange Curves, Counting Rabbits, & Other Mathematical Explorations

    CERN Document Server

    Ball, Keith

    2011-01-01

    How does mathematics enable us to send pictures from space back to Earth? Where does the bell-shaped curve come from? Why do you need only 23 people in a room for a 50/50 chance of two of them sharing the same birthday? In Strange Curves, Counting Rabbits, and Other Mathematical Explorations, Keith Ball highlights how ideas, mostly from pure math, can answer these questions and many more. Drawing on areas of mathematics from probability theory, number theory, and geometry, he explores a wide range of concepts, some more light-hearted, others central to the development of the field and used dai

  14. Analog computing

    CERN Document Server

    Ulmann, Bernd

    2013-01-01

    This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

  15. Common and dissociable prefrontal loci associated with component mechanisms of analogical reasoning.

    Science.gov (United States)

    Cho, Soohyun; Moody, Teena D; Fernandino, Leonardo; Mumford, Jeanette A; Poldrack, Russell A; Cannon, Tyrone D; Knowlton, Barbara J; Holyoak, Keith J

    2010-03-01

    The ability to draw analogies requires 2 key cognitive processes, relational integration and resolution of interference. The present study aimed to identify the neural correlates of both component processes of analogical reasoning within a single, nonverbal analogy task using event-related functional magnetic resonance imaging. Participants verified whether a visual analogy was true by considering either 1 or 3 relational dimensions. On half of the trials, there was an additional need to resolve interference in order to make a correct judgment. Increase in the number of dimensions to integrate was associated with increased activation in the lateral prefrontal cortex as well as lateral frontal pole in both hemispheres. When there was a need to resolve interference during reasoning, activation increased in the lateral prefrontal cortex but not in the frontal pole. We identified regions in the middle and inferior frontal gyri which were exclusively sensitive to demands on each component process, in addition to a partial overlap between these neural correlates of each component process. These results indicate that analogical reasoning is mediated by the coordination of multiple regions of the prefrontal cortex, of which some are sensitive to demands on only one of these 2 component processes, whereas others are sensitive to both.

  16. The investigation of strangeness photoproduction in the threshold region at ELPH-Tohoku

    Czech Academy of Sciences Publication Activity Database

    Kaneta, M.; Beckford, B.; Bydžovský, Petr; Fujibayashi, T.; Fujii, T.; Fujii, Y.; Futatsukawa, K.; Gogami, T.; Han, Y. C.; Hashimoto, O.; Hirose, K.; Hosomi, K.; Honda, R.; Iguchi, A.; Ishikawa, T.; Kanda, H.; Kaneko, Y.; Kasai, Y.; Kawasaki, T.; Kimura, C.; Kiyokawa, S.; Koike, T.; Maeda, K.; Maruyama, N.; Matsubara, M.; Miwa, K.; Miyagi, Y.; Nagao, S.; Nakamura, S. N.; Okuyama, A.; Sotona, Miloslav; Tamae, T.; Tamura, H.; Tsukada, K.; Terada, N.; Wang, T. S.; Yamamoto, F.; Yamamoto, T.; Yamazaki, H.

    2013-01-01

    Roč. 914, SEP (2013), s. 69-73 ISSN 0375-9474 Institutional support: RVO:61389005 Keywords : strangeness * photoproduction * tagged photon beam * lambda detection Subject RIV: BE - Theoretical Physics Impact factor: 2.499, year: 2013 http://www.sciencedirect.com/science/article/pii/S0375947413005344

  17. Studying Strangeness Production with HADES

    Science.gov (United States)

    Schuldes, Heidi

    2018-02-01

    The High-Acceptance DiElectron Spectrometer (HADES) operates in the 1 - 2A GeV energy regime in fixed target experiments to explore baryon-rich strongly interacting matter in heavy-ion collisions at moderate temperatures with rare and penetrating probes. We present results on the production of strange hadrons below their respective NN threshold energy in Au+Au collisions at 1.23A GeV ( = 2.4 GeV). Special emphasis is put on the enhanced feed-down contribution of ϕ mesons to the inclusive yield of K- and its implication on the measured spectral shape of K-. Furthermore, we investigate global properties of the system, confronting the measured hadron yields and transverse mass spectra with a Statistical Hadronization Model (SHM) and a blastwave parameterization, respectively. These supplement the world data of the chemical and kinetic freeze-out temperatures.

  18. Connected, disconnected and strange quark contributions to HVP

    Energy Technology Data Exchange (ETDEWEB)

    Bijnens, Johan; Relefors, Johan [Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14A, SE 223-62 Lund (Sweden)

    2016-11-14

    We calculate all neutral vector two-point functions in Chiral Perturbation Theory (ChPT) to two-loop order and use these to estimate the ratio of disconnected to connected contributions as well as contributions involving the strange quark. We extend the ratio of −1/10 derived earlier in two flavour ChPT at one-loop order to a large part of the higher order contributions and discuss corrections to it. Our final estimate of the ratio disconnected to connected is negative and a few % in magnitude.

  19. Connected, disconnected and strange quark contributions to HVP

    Science.gov (United States)

    Bijnens, Johan; Relefors, Johan

    2016-11-01

    We calculate all neutral vector two-point functions in Chiral Perturbation Theory (ChPT) to two-loop order and use these to estimate the ratio of disconnected to connected contributions as well as contributions involving the strange quark. We extend the ratio of -1/10 derived earlier in two flavour ChPT at one-loop order to a large part of the higher order contributions and discuss corrections to it. Our final estimate of the ratio disconnected to connected is negative and a few % in magnitude.

  20. Connected, disconnected and strange quark contributions to HVP

    International Nuclear Information System (INIS)

    Bijnens, Johan; Relefors, Johan

    2016-01-01

    We calculate all neutral vector two-point functions in Chiral Perturbation Theory (ChPT) to two-loop order and use these to estimate the ratio of disconnected to connected contributions as well as contributions involving the strange quark. We extend the ratio of −1/10 derived earlier in two flavour ChPT at one-loop order to a large part of the higher order contributions and discuss corrections to it. Our final estimate of the ratio disconnected to connected is negative and a few % in magnitude.

  1. The (ν,ν'Nγ) reaction on 16O and the strangeness content of the nucleon

    International Nuclear Information System (INIS)

    Kolbe, E.

    1998-01-01

    Recently we have pointed out that photons with energies between 5 and 10 MeV, generated by the (ν,ν''pγ) and (ν,ν''nγ) reactions on 16 O, constitute a signal which allows a unique identification of supernova ν μ and ν τ neutrinos in water Cerenkov detectors. It was also shown that the cross sections for neutrino-induced knockout of a nucleon via a neutral current reaction on nuclei are affected by the strange quark content of the nucleon. Hence strangeness in the nucleon could have an influence on the energy spectrum of the photons emitted in these processes, which is investigated in the following. (orig.)

  2. Making the Familiar Strange: Creative Cultural Storytelling within the Communication Classroom

    Science.gov (United States)

    Blinne, Kristen C.

    2012-01-01

    In this activity, students employ mock campfire storytelling to "make the familiar strange" in the same spirit as Horace Miner's (1956) classic tale of the "Nacirema." Students work individually, in pairs, or as small groups (around three) to create a whimsical story that deconstructs a mundane, everyday ritual (event, activity, practice) into a…

  3. Strange metal from Gutzwiller correlations in infinite dimensions

    Science.gov (United States)

    Ding, Wenxin; Žitko, Rok; Mai, Peizhi; Perepelitsky, Edward; Shastry, B. Sriram

    2017-08-01

    Recent progress in extremely correlated Fermi liquid theory (ECFL) and the dynamical mean field theory (DMFT) enables us to accurately compute in the d →∞ limit the resistivity of the t -J model after setting J →0 . This is also the U =∞ Hubbard model. Since J is set to zero, our study isolates the dynamical effects of the single occupation constraint enforced by the projection operator originally introduced by Gutzwiller. We study three densities n =.75 ,.8 ,.85 that correspond to a range between the overdoped and optimally doped Mott insulating state. We delineate four distinct regimes separated by three crossovers, which are characterized by different behaviors of the resistivity ρ . We find at the lowest temperature T a Gutzwiller correlated Fermi liquid regime with ρ ∝T2 extending up to an effective Fermi temperature that is dramatically suppressed from the noninteracting value by the proximity to half filling, n ˜1 . This is followed by a Gutzwiller correlated strange metal regime with ρ ∝(T -T0) , i.e., a linear resistivity extrapolating back to ρ =0 at a positive T0. At a higher temperature scale this crosses over into the bad metal regime with ρ ∝(T +T1) , i.e., a linear resistivity extrapolating back to a finite resistivity at T =0 and passing through the Ioffe-Regel-Mott value where the mean free path is a few lattice constants. This regime finally gives way to the high T metal regime, where we find ρ ∝T , i.e., a linear resistivity extrapolating back to zero at T =0 . The present work emphasizes the first two, i.e., the two lowest temperature regimes, where the availability of an analytical ECFL theory is of help in identifying the changes in related variables entering the resistivity formula that accompanies the onset of linear resistivity, and the numerically exact DMFT helps to validate the results. We also examine thermodynamical variables such as the magnetic susceptibility, compressibility, heat capacity, and entropy and

  4. Strangeness Vector and Axial-Vector Form Factors of the Nucleon

    Directory of Open Access Journals (Sweden)

    Pate Stephen

    2014-03-01

    Full Text Available A revised global fit of electroweak ep and vp elastic scattering data has been performed, with the goal of determining the strange quark contribution to the vector and axial-vector form factors of the nucleon in the momentum-transfer range 0 < Q2 < 1 GeV2. The two vector (electric and magnetic form factors GsE(Q2 and GsM(Q2 are strongly constrained by ep elastic scattering data, while the major source of information on the axial-vector form factor GsA(Q2 is vp scattering data. Combining the two kinds of data into a single global fit makes possible additional precision in the determination of these form factors, and provides a unique way to determine the strange quark contribution to the nucleon spin, ΔS , independently of leptonic deep-inelastic scattering. The fit makes use of data from the BNL-E734, SAMPLE, HAPPEx, G0, and PVA4 experiments; we will also compare the result of the fit with recent data from MiniBooNE, and anticipate how this fit can be improved when new data from MicroBooNE become available.

  5. Strangeness production in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions in the dual parton model

    International Nuclear Information System (INIS)

    Moehring, H.; Ranft, J.; Capella, A.; Tran Thanh Van, J.

    1993-01-01

    Λ, bar Λ, and K S 0 production is studied in a Monte Carlo dual parton model for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions with an SU(3) symmetric sea for chain formation (chain ends) but strangeness suppression in the chain fragmentation process. Additionally, (qq)-(bar q bar q) production from the sea was introduced into the chain formation process with the same probability as for the q→qq branching within the chain decay process. With these assumptions, multiplicity ratios and Feynman-x distributions for strange particles in h-h and multiplicity ratios in heavy ion collisions are reasonably well reproduced

  6. Science Teachers' Analogical Reasoning

    Science.gov (United States)

    Mozzer, Nilmara Braga; Justi, Rosária

    2013-08-01

    Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.

  7. Study of the interaction between bovine hemoglobin and analogs of biphenyldicarboxylate by spectrofluorimetry

    International Nuclear Information System (INIS)

    Wang, Ruiyong; Yin, Yujing; Wang, Ruiqiang; Xie, Yuanzhe; Ge, Baoyu; Li, Zhigang; Li, Zhen; Shi, Jie; Chang, Junbiao

    2013-01-01

    The interaction between bovine hemoglobin and analogs of Biphenyldicarboxylate was investigated by fluorescence, synchronous fluorescence, ultraviolet–vis absorbance, resonance light-scattering spectra and three-dimensional fluorescence spectra at pH 7.40. The quenching mechanism and binding constants were determined by the quenching of bovine hemoglobin fluorescence in presence of analogs. Results showed that the nature of the quenching was of static type. Both the van der Waals and hydrogen bonding played a major role in stabilizing the complex. The distance between donor and acceptors was obtained to be 2.11–2.25 nm according to Förster's theory. The influence of analogs on the conformation of bovine hemoglobin was investigated. -- Highlights: • The interactions between bovine hemoglobin and analogs of DDB have been investigated. • Results reveal that DDB has the strongest affinity for hemoglobin among four compounds. • The van der Waals and hydrogen bonding play major role in the binding process. • The influence of molecular structure on the binding aspects has been investigated

  8. A Stylistic Analysis of the Dialogues in Pirates of the Caribbean: On Strange Tides%A Stylistic Analysis of the Dialogues in Pirates of the Caribbean:On Strange Tides

    Institute of Scientific and Technical Information of China (English)

    李冯茹

    2017-01-01

    Dialogues in classical films are always the concentrated scripts studied by scholars. This thesis performs a stylistic analysis of dialogues from Pirates of the Caribbean: On Strange Tides at the levels of phonology, lexicon, syntax, semantics and pragmatics to make a good attempt in the application of stylistic analysis.

  9. Determination of strange form factors of nucleon by parity violation asymmetry by polarized electron-proton elastic scattering

    International Nuclear Information System (INIS)

    Jardillier, Johann

    1999-01-01

    In the quark model, the proton is described as a system of three quarks UUD. However, recent experiments (CERN, SLAC) have shown that the strange quarks may contribute in a significant way to the mass and the spin of the proton. The HAPPEX experiment gives one further knowledge about the question of the role the strange quarks play inside the proton. It measures parity violating asymmetry in the scattering of polarized electrons from a proton because the latter is sensitive to the contribution of the strange quarks to the electromagnetic form factors of the nucleon. The observed asymmetry is in the order of a few ppm (part per million). The main difficulty of the experiment is to identify, to estimate and to minimize, as much as possible, all the systematic effects which could give rise to false asymmetries. This thesis discusses the principle of the HAPPEX experiment, its implementation at the Jefferson Lab (JLab), the processing and the analysis of the data, the systematic errors, and finally presents the result of the first data taking (1999) and its present interpretation. The HAPPEX experiment has measured, at Q 2 = 0.5 (GeV/c) 2 , a strange quarks contribution of (1.0 ± 2.3)% to the electromagnetic form factors of the nucleon. The statistics and the systematic effects (measure of the electron beam polarization and knowledge of the neutron electric form factor) contribute equally to the error. (author)

  10. Radial stability of anisotropic strange quark stars

    Energy Technology Data Exchange (ETDEWEB)

    Arbañil, José D.V.; Malheiro, M., E-mail: jose.arbanil@upn.pe, E-mail: malheiro@ita.br [ITA—Instituto Tecnológico de Aeronáutica—Departamento de Física, 12228-900, São José dos Campos, São Paulo (Brazil)

    2016-11-01

    The influence of the anisotropy in the equilibrium and stability of strange stars is investigated through the numerical solution of the hydrostatic equilibrium equation and the radial oscillation equation, both modified from their original version to include this effect. The strange matter inside the quark stars is described by the MIT bag model equation of state. For the anisotropy two different kinds of local anisotropic σ = p {sub t} − p {sub r} are considered, where p {sub t} and p {sub r} are respectively the tangential and the radial pressure: one that is null at the star's surface defined by p {sub r} ( R ) = 0, and one that is nonnull at the surface, namely, σ {sub s} = 0 and σ {sub s} {sub ≠} {sub 0}. In the case σ {sub s} = 0, the maximum mass value and the zero frequency of oscillation are found at the same central energy density, indicating that the maximum mass marks the onset of the instability. For the case σ {sub s} {sub ≠} {sub 0}, we show that the maximum mass point and the zero frequency of oscillation coincide in the same central energy density value only in a sequence of equilibrium configurations with the same value of σ {sub s} . Thus, the stability star regions are determined always by the condition dM / d ρ {sub c} {sub >} {sub 0} only when the tangential pressure is maintained fixed at the star surface's p {sub t} ( R ). These results are also quite important to analyze the stability of other anisotropic compact objects such as neutron stars, boson stars and gravastars.

  11. The Universe is a Strange Place

    Science.gov (United States)

    Wilczek, Frank

    2006-01-01

    Our understanding of ordinary matter is remarkably accurate and complete, but it is based on principles that are very strange and unfamiliar. As I'll explain, we've come to understand matter to be a Music of the Void, in a remarkably literal sense. Just as we physicists finalized that wonderful understanding, towards the end of the twentieth century, astronomers gave us back our humility, by informing us that ordinary matter - what we, and chemists and biologists, and astronomers themselves, have been studying all these centuries constitutes only about 5% of the mass of the universe as a whole. I'll describe some of our promising attempts to rise to this challenge by improving, rather than merely complicating, our description of the world.

  12. Extraordinary acoustic transmission mediated by Helmholtz resonators

    Directory of Open Access Journals (Sweden)

    Vijay Koju

    2014-07-01

    Full Text Available We demonstrate perfect transmission of sound through a rigid barrier embedded with Helmholtz resonators. The resonators are confined within a waveguide and they are oriented such that one neck protrudes onto each side of the barrier. Perfect sound transmission occurs even though the open area of the necks is less than 3% of the barrier area. Maximum transmission occurs at the resonant frequency of the Helmholtz resonator. Because the dimensions of the Helmholtz resonators are much smaller than the resonant wavelength, the transmission is independent of the direction of sound on the barrier and of the relative placement of the necks. Further, we show that the transmitted sound experiences a continuous phase transition of π radians as a function of frequency through resonance. In simulations of adjacent resonators with slightly offset resonance frequencies, the phase difference leads to destructive interference. By expanding the simulation to a linear array of tuned Helmholtz resonators we show that it is possible to create an acoustic lens. The ability of Helmholtz resonator arrays to manipulate the phase of a plane acoustic wave enables a new class of sonic beam-forming devices analogous to diffractive optics.

  13. Analog synthetic biology.

    Science.gov (United States)

    Sarpeshkar, R

    2014-03-28

    We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations.

  14. Strange-face-in-the-mirror illusion and schizotypy during adolescence.

    Science.gov (United States)

    Fonseca-Pedrero, Eduardo; Badoud, Deborah; Antico, Lia; Caputo, Giovanni B; Eliez, Stephan; Schwartz, Sophie; Debbané, Martin

    2015-03-01

    Patients with schizophrenia can sometimes report strange face illusions when staring at themselves in the mirror; such experiences have been conceptualized as anomalous self-experiences that can be experienced with a varying degree of depersonalization. During adolescence, anomalous self-experiences can also be indicative of increased risk to develop schizophrenia-spectrum disorders. To date however, the Mirror-Gazing test (MGT), an experimentally validated experiment to evaluate the propensity of strange face illusions in nonclinical and clinical adults, has yet to be investigated in an adolescent sample. The first goal of the present study was to examine experimentally induced self-face illusions in a nonclinical sample of adolescents, using the MGT. The second goal was to investigate whether dimensions of adolescent trait schizotypy were differentially related to phenomena arising during the MGT. One hundred and ten community adolescents (59 male) aged from 12 to 19 years (mean age = 16.31, SD age = 1.77) completed the MGT and Schizotypal Personality Questionnaire. The results yielded 4 types of strange face illusions; 2 types of illusions (slight change of light/color [20%] and own face deformation [45.5%]) lacked depersonalization-like phenomena (no identity change), while 2 other types (vision of other identity [27.3%], and vision of non-human identity [7.3%]) contained clear depersonalization-like phenomena. Furthermore, the disorganization dimension of schizotypy associated negatively with time of first illusion (first press), and positively with frequency of illusions during the MGT. Statistically significant differences on positive and disorganized schizotypy were found when comparing groups on the basis of degree of depersonalization-like phenomena (from slight color changes to non-human visions). Similarly to experimentally induced self-face illusions in patients with schizophrenia, such illusions in a group of nonclinical adolescents present

  15. Strange-particle production via the weak interaction

    International Nuclear Information System (INIS)

    Adera, G. B.; Van Der Ventel, B. I. S.; Niekerk, D. D. van; Mart, T.

    2010-01-01

    The differential cross sections for the neutrino-induced weak charged current production of strange particles in the threshold energy region are presented. The general representation of the weak hadronic current is newly developed in terms of eighteen unknown invariant amplitudes to parametrize the hadron vertex. The Born-term approximation is used for the numerical calculations in the framework of the Cabibbo theory and SU(3) symmetry. For unpolarized octet baryons four processes are investigated, whereas in the case of polarized baryons only one process is chosen to study the sensitivity of the differential cross section to the various polarizations of the initial-state nucleon and the final-state hyperon.

  16. Study of multi-strange baryon production with ALICE at the LHC energies

    CERN Document Server

    Colella, Domenico

    This thesis reports on the measurement of the multi-strange baryon production in lead-lead (Pb-Pb) and proton-proton (pp) collisions at the centre-of-mass energy of 2.76 TeV per nucleon pair using the ALICE detector. The cascade identification technique, based on the topological reconstruction of weak decays into charged particles only is very effective thanks to the excellent particle identification and tracking capability of the ALICE central barrel detectors. The comparison of the transverse momentum (p$_T$) spectra for the $\\Xi^{-}$ and $\\Omega^{-}$ (and corresponding anti-particle) in Pb-Pb collisions with expectations from recent hydro models confirms the importance of an hydrodynamical approach in the description of the created system evolution. In addition, recent PYTHIA tunes results to underestimate the yields for the cascades in pp collisions. The measurements of the strangeness enhancement, one of the predicted signatures of the QGP formation, for the $\\Xi$ and $\\Omega$ at the LHC energy have been...

  17. CLS 2+1 flavor simulations at physical light- and strange-quark masses

    International Nuclear Information System (INIS)

    Mohler, Daniel; Schaefer, Stefan; Simeth, Jakob

    2017-12-01

    We report recent efforts by CLS to generate an ensemble with physical light- and strange-quark masses in a lattice volume of 192 x 96 3 at β=3.55 corresponding to a lattice spacing of 0.064 fm. This ensemble is being generated as part of the CLS 2+1 flavor effort with improved Wilson fermions. Our simulations currently cover 5 lattice spacings ranging from 0.039 fm to 0.086 fm at various pion masses along chiral trajectories with either the sum of the quark masses kept fixed, or with the strange-quark mass at the physical value. The current status of simulations is briefly reviewed, including a short discussion of measured autocorrelation times and of the main features of the simulations. We then proceed to discuss the thermalization strategy employed for the generation of the physical quark-mass ensemble and present first results for some simple observables. Challenges encountered in the simulation are highlighted.

  18. CLS 2+1 flavor simulations at physical light- and strange-quark masses

    Energy Technology Data Exchange (ETDEWEB)

    Mohler, Daniel [Helmholtz-Institut Mainz (Germany); Mainz Univ. (Germany); Schaefer, Stefan [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Simeth, Jakob [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik

    2017-12-15

    We report recent efforts by CLS to generate an ensemble with physical light- and strange-quark masses in a lattice volume of 192 x 96{sup 3} at β=3.55 corresponding to a lattice spacing of 0.064 fm. This ensemble is being generated as part of the CLS 2+1 flavor effort with improved Wilson fermions. Our simulations currently cover 5 lattice spacings ranging from 0.039 fm to 0.086 fm at various pion masses along chiral trajectories with either the sum of the quark masses kept fixed, or with the strange-quark mass at the physical value. The current status of simulations is briefly reviewed, including a short discussion of measured autocorrelation times and of the main features of the simulations. We then proceed to discuss the thermalization strategy employed for the generation of the physical quark-mass ensemble and present first results for some simple observables. Challenges encountered in the simulation are highlighted.

  19. A New EM CKM Matrix: Implications of the Nucleon Strange Quark Content, Anomalous Magnetic Moments of Nucleons and Electric and Magnetic Nucleon Form Factors

    Science.gov (United States)

    Ward, Thomas

    2013-10-01

    A new electromagnetic neutral-current quark mixing matrix, analog to the well-known Cabibbo-Kobayashi-Maskawa (CKM) weak charge-current matrix, is proposed to account for the strange quark content of the neutron and proton and part of the anomalous axial vector magnetic moments. The EM-CKM matrix is shown to be equivalent to the weak-CKM matrix following an EM to weak gauge symmetry transformation, demonstrating the universality of the Standard Model (SM) CKM quark mixing matrix. The electric and magnetic form factors are reformulated using a new QCD three quark nucleon gyromagnetic factor, Dirac and Pauli form factors and anomalous kappa factors. The old 1943 Jauch form factors which have been systematically used and developed for many years is shown to be in stark disagreement with the new global set of experimental polarized electron-proton scattering data whereas the reformulated SM parameter set of this study is shown to agree very well, lending strong support for this new EM SM approach.

  20. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-02-01

    A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS

  1. The investigation of strangeness photoproduction in the threshold region at ELPH-Tohoku

    Energy Technology Data Exchange (ETDEWEB)

    Kaneta, M., E-mail: kaneta@lambda.phys.tohoku.ac.jp [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Beckford, B. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Bydžovský, P. [Nuclear Institute, 25068 Řež (Czech Republic); Fujibayashi, T.; Fujii, T.; Fujii, Y.; Futatsukawa, K.; Gogami, T. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Han, Y.C. [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Hashimoto, O. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Hirose, K. [Research Center of Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Hosomi, K.; Honda, R.; Iguchi, A. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Ishikawa, T. [Research Center of Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Kanda, H.; Kaneko, Y.; Kasai, Y.; Kawasaki, T.; Kimura, C. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); and others

    2013-09-20

    The strangeness photoproduction processes near the threshold have been intensively studied by measuring K{sup +} in reactions such as γ+p→K{sup +}+Λ(Σ{sup 0}). There has been no reliable data on the neutron and as a consequence theoretical investigation suffered seriously from the lack of the data. We have an effort to measure the γ+d→K{sup 0}(Λ)+X reaction in the π{sup +}π{sup −} (pπ{sup −}) decay channel of K{sub S}{sup 0} (Λ) using a liquid D{sub 2} target and internally-tagged photon beams (E{sub γ}=0.80–1.08 GeV) at Research Center for Electron Photon Science (ELPH), Tohoku University. We have renewed the spectrometer (NKS2) and took data with a liquid D{sub 2} target in 2005–2007. More recently, we took data in 2010 after a detector upgrade in the vertex region to substantially increase the acceptance. The results of Λ single measurements on a deuterium target were obtained for differential cross-section as a function of momentum, as a function of angle, and integrated cross-section as a function of beam energy. The results are compared with recent theoretical studies: Isobar models (Kaon-MAID and Saclay-Lyon A) and a Regge-plus-Resonance model.

  2. Search for a Narrow Baryonic Resonance Decaying to $K^0_s p$ or $K^0_s \\bar{p}$ in Deep Inelastic Scattering at HERA

    OpenAIRE

    Aktas, A.; Andreev, V.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.

    2006-01-01

    A search for a narrow baryonic resonance decaying to $K^0_s p$ or $K^0_s \\bar p$ is carried out in deep inelastic ep scattering with the H1 detector at HERA. Such a resonance could be a strange pentaquark \\thplns, evidence for which has been reported by several experiments. The $K^0_s p$ and $K^0_s \\bar p$ invariant mass distributions presented here do not show any significant peak in the mass range from threshold up to 1.7 GeV. Mass dependent upper limits on $\\sigma(ep \\to e \\thplf X)\\times ...

  3. Cross-Cultural Patterns of Attachment: A Meta-Analysis of t?Y Strange Situation.

    Science.gov (United States)

    van IJzendoorn, Marinus H.; Kroonenberg, Pieter M.

    1988-01-01

    Examines 2,000 Strange Situation classifications obtained in eight different countries. Differences and similarities between distributions in classifications of samples are investigated using correspondence analysis. Substantial intracultural differences are established; data also suggest a pattern of cross-cultural differences. (Author/RWB)

  4. Multi-strange baryon production in pp, p-Pb and Pb-Pb collisions measured with ALICE at the LHC

    CERN Document Server

    INSPIRE-00381902

    2014-01-01

    Multi-strange baryons are of particular interest in the understanding of particle production mechanisms, as their high strangeness content makes them susceptible to changes in the hadrochemistry of the colliding systems. In ALICE, these hyperons are reconstructed via the detection of their weak decay products, which are identified through their measured ionisation losses and momenta in the Time Projection Chamber. The production rates of charged $\\Xi$ and $\\Omega$ baryons in proton-proton (pp), proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions are reported as a function of $p_{\\mathrm{T}}$. A direct comparison in the hyperon-to-pion ratios between the three collision systems is made as a function of event charged-particle multiplicity. The recently measured production rates in p-Pb interactions reveal an enhancement with increasing event multiplicity, consistent with a hierarchy dependent on the strangeness content of the hyperons. These results are discussed in the context of chemical equilibrium predictio...

  5. Strange and charm HVP contributions to the muon ( g - 2) including QED corrections with twisted-mass fermions

    Science.gov (United States)

    Giusti, D.; Lubicz, V.; Martinelli, G.; Sanfilippo, F.; Simula, S.

    2017-10-01

    We present a lattice calculation of the Hadronic Vacuum Polarization (HVP) contribution of the strange and charm quarks to the anomalous magnetic moment of the muon including leading-order electromagnetic corrections. We employ the gauge configurations generated by the European Twisted Mass Collaboration (ETMC) with N f = 2 + 1 + 1 dynamical quarks at three values of the lattice spacing ( a ≃ 0 .062 , 0 .082 , 0 .089 fm) with pion masses in the range M π ≃ 210-450 MeV. The strange and charm quark masses are tuned at their physical values. Neglecting disconnected diagrams and after the extrapolations to the physical pion mass and to the continuum limit we obtain: a μ s ( α em 2 ) = (53.1 ± 2.5) · 10- 10, a μ s ( α em 3 ) = (-0.018 ± 0.011) · 10- 10 and a μ c ( α em 2 ) = (14.75 ± 0.56) · 10- 10, a μ c ( α em 3 ) = (-0.030 ± 0.013) · 10- 10 for the strange and charm contributions, respectively.

  6. High resolution study of the two-bayons-system with strangeness - 1 by means of the reaction pp→K+X

    International Nuclear Information System (INIS)

    Siebert, R.

    1989-01-01

    The inclusive reaction pp→K + X was studied in the missing mass range 2050-2160 MeV/c 2 . The bombarding energy was 2300 MeV. Kaons were detected at four forward angles between 6 0 and 12 0 using the magnetic spectrometer SPES 4 at the Laboratoire National Saturne. Kaon identification was performed with four total reflection Cerenkov detectors and the time-of-flight between intermediate and final focal plane of the spectrometer. All spectra show a strong final-state enhancement of the double differential cross section near the Λp-threshold and a sharp peak anomaly at 2131 ± 1.5 MeV/c 2 close to the ΣN thresholds with a width of 9 ± 1 MeV/c 2 and a production cross section of 0.5 μb/sr. The anomaly is discussed with respect to the strange (S = -1) analog state of the deuteron, the H 1 + state. Quark model predictions of narrow dibaryon states D s and D t have not been observed. Upper limits for the production cross section between 15 and 30 nb/sr are deduced

  7. Anisotropic strange stars under simplest minimal matter-geometry coupling in the f (R ,T ) gravity

    Science.gov (United States)

    Deb, Debabrata; Guha, B. K.; Rahaman, Farook; Ray, Saibal

    2018-04-01

    We study strange stars in the framework of f (R ,T ) theory of gravity. To provide exact solutions of the field equations it is considered that the gravitational Lagrangian can be expressed as the linear function of the Ricci scalar R and the trace of the stress-energy tensor T , i.e. f (R ,T )=R +2 χ T , where χ is a constant. We also consider that the strange quark matter (SQM) distribution inside the stellar system is governed by the phenomenological MIT bag model equation of state (EOS), given as pr=1/3 (ρ -4 B ) , where B is the bag constant. Further, for a specific value of B and observed values of mass of the strange star candidates we obtain the exact solution of the modified Tolman-Oppenheimer-Volkoff (TOV) equation in the framework of f (R ,T ) gravity and have studied in detail the dependence of the different physical parameters, like the metric potentials, energy density, radial and tangential pressures and anisotropy etc., due to the chosen different values of χ . Likewise in GR, as have been shown in our previous work [Deb et al., Ann. Phys. (Amsterdam) 387, 239 (2017), 10.1016/j.aop.2017.10.010] in the present work also we find maximum anisotropy at the surface which seems an inherent property of the strange stars in modified f (R ,T ) theory of gravity. To check the physical acceptability and stability of the stellar system based on the obtained solutions we have performed different physical tests, viz., the energy conditions, Herrera cracking concept, adiabatic index etc. In this work, we also have explained the effects, those are arising due to the interaction between the matter and the curvature terms in f (R ,T ) gravity, on the anisotropic compact stellar system. It is interesting to note that as the values of χ increase the strange stars become more massive and their radius increase gradually so that eventually they gradually turn into less dense compact objects. The present study reveals that the modified f (R ,T ) gravity is a suitable

  8. Neutral strange particle production in π+/K+p interactions at 250 GeV/c

    International Nuclear Information System (INIS)

    Scholten, A.J.

    1988-01-01

    This thesis in which a detailed study of K n inclusive production in K + p and π + p interactions at 250 GeV/c is presented, concentrates on neutral strange interaction products and draws some conclusions about the fate of the strange quark. In ch. 2 the experimental setup is described and in ch. 3 the series of computer programs that perform data reduction. Ch. 4 deals with the selectionn of events and neutral kaons. Also the calculations needed to correct for losses and background are described there. In ch. 5 inclusive and semi-inclusive distributions are presented and compared to data obtained in experiments at lower beam energy. In ch. 6 the data are compared with model predictions. In ch. 7 the main conclusions are summarized. (H.W.). 64 refs.; 39 refs.; 19 tabs

  9. Production of strange and multistrange hadrons in nucleus-nucleus collisions at the SPS

    Czech Academy of Sciences Publication Activity Database

    Antinori, F.; Bakke, H.; Beusch, W.; Staroba, Pavel; Závada, Petr

    1999-01-01

    Roč. 661, - (1999), 130c-139c ISSN 0375-9474 Institutional research plan: CEZ:AV0Z1010920 Keywords : production * nucleus-nucleus collisions * hadrons * strangeness * model predictions Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 2.088, year: 1999

  10. Search for a narrow baryonic resonance decaying to Ks0p or Ks0p¯ in deep inelastic scattering at HERA

    Science.gov (United States)

    H1 Collaboration; Aktas, A.; Andreev, V.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J. G.; Coughlan, J. A.; Cox, B. E.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Dau, W. D.; Daum, K.; de Boer, Y.; Delcourt, B.; Del Degan, M.; de Roeck, A.; de Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Flucke, G.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerlich, C.; Ghazaryan, S.; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B. R.; Grindhammer, G.; Gwilliam, C.; Haidt, D.; Hajduk, L.; Hansson, M.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laštovička-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Lüke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Marti, L.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Papadopoulou, T.; Pascaud, C.; Patel, G. D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Plačakytė, R.; Portheault, B.; Povh, B.; Prideaux, P.; Rahmat, A. J.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D. P. C.; Sauvan, E.; Schätzel, S.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Steder, M.; Stella, B.; Stiewe, J.; Stoilov, A.; Straumann, U.; Sunar, D.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Toll, T.; Tomasz, F.; Traynor, D.; Truöl, P.; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Urban, M.; Usik, A.; Utkin, D.; Valkárová, A.; Vallée, C.; van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wessling, B.; Wissing, Ch.; Wolf, R.; Wünsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2006-08-01

    A search for a narrow baryonic resonance decaying to Ks0p or Ks0p¯ is carried out in deep inelastic ep scattering with the H1 detector at HERA. Such a resonance could be a strange pentaquark Θ, evidence for which has been reported by several experiments. The Ks0p and Ks0p¯ invariant mass distributions presented here do not show any significant peak in the mass range from threshold up to 1.7 GeV. Mass dependent upper limits on σ(ep→eΘX)×BR(Θ→Kp) are obtained at the 95% confidence level.

  11. Giant 4p-quadrupole resonances in the Rare Earths

    International Nuclear Information System (INIS)

    Matthew, J.A.D.; Netzer, F.P.; Clark, C.W.; Morar, J.F.

    1987-01-01

    X-ray absorption of Ce obtained by partial secondary yield, is compared with previously obtained electron-energy loss measurements in reflection mode. The absence of a strong feature below 4p 3/2 threshold in photon absorption provides confirmation that the peak in EELS is nondipole in character. Theoretical analysis supports interpretation in terms of a p-f giant quadrupole resonance, a result which broadens the analogy between giant resonances in atomic and nuclear physics

  12. Top quark asymmetry and dijet resonances

    CERN Document Server

    Jung, Sunghoon; Wells, James D.

    2011-01-01

    CDF recently reported an anomaly in the $m_{jj}$ distribution of dijet events produced in association with a $W$ boson. If this anomaly is associated with a new flavor conserving vector resonance, $V$, one might have expected to observe effects in the analogous $m_{jj}$ distribution produced in association with a $\\gamma$. No such excess is observed. A single $u-t-V$ flavor changing coupling, however, can contribute to the $m_{jj}$ anomaly while being consistent with other resonance searches. Furthermore, it gives a potential explanation of the observed forward-backward asymmetry in top quark production.

  13. Strange pathways for black hole formation

    International Nuclear Information System (INIS)

    Prakash, M.

    2000-01-01

    Immediately after they are born, neutron stars are characterized by an entropy per baryon of order unity and by the presence of trapped neutrinos. If the only hadrons in the star are nucleons, these effects slightly reduce the maximum mass relative to cold, catalyzed matter. However, if strangeness-bearing hyperons, a kaon condensate, or quarks are also present, these effects result in an increase in the maximum mass of up to ∼ 0.3M [odot] compared to that of a cold, neutrino-free star. This makes a sufficiently massive proto-neutron star metastable, so that after a delay of 10-100 seconds, the PNS collapses into a black hole. Such an event might be straightforward to observe as an abrupt cessation of neutrinos when the instability is triggered

  14. Strangeness in hot and dense nuclear matter

    International Nuclear Information System (INIS)

    Nappi, E.

    2009-01-01

    Ultra-relativistic heavy-ion collisions are believed to provide the extreme conditions of energy densities able to lead to a transition to a short-lived state, called Quark-Gluon Plasma (QGP), where the quarks are no longer bound inside hadrons. The studies performed so far, formerly at SPS (CERN) and later at RHIC (BNL) allowed to achieve a multitude of crucial results consistent with the hypothesis that a new phase of the QCD matter has been indeed created. However, the emerging picture is that of the formation of a strongly interacting medium with negligibly small viscosity, a perfect liquid, rather than the ideal perturbative QCD parton-gas predicted by most theorists. The head-on collision between lead nuclei at the unprecedented energies of the forthcoming Large Hadron Collider (LHC) at CERN, due to start in 2008, will allow to measure the properties of compressed and excited nuclear matter at even higher initial densities and temperatures, far above the predicted QCD phase transition point. The longer duration of the quark-gluon plasma phase and the much more abundant production of hard probes, which depend much less on details of the later hadronic phase, will likely provide a consistent and uncontroversial experimental evidence of the QGP formation. Among the signals what witness the charge in the nature of the state of nuclear matter, the chemical equilibrium value of the strangeness plays a key role since it is directly sensitive to the matter properties and provides information on the link between the partonic and the hadronic phases. The aim of this course is to overview the underlying goals, the current status and the prospect of the physics of the nucleus-nucleus collisions at ultrarelativistic energies. Among the experimental methods adopted to investigate the challenging signatures of the QGP formation, emphasis on those related to the strangeness flavour will be given.

  15. V0 Reconstruction of Strange Hadrons in Au+Au Collisions at 1.23 AGeV with HADES

    International Nuclear Information System (INIS)

    Scheib, T

    2015-01-01

    Preliminary results on the production of weakly decaying strange hadrons are reported for collisions of Au+Au at 1.23 AGeV beam energy studied with the HADES detector at GSI in Darmstadt. At this collision energy all strange particles are created below their elementary threshold. The reconstruction of the investigated particles (i.e. Λ and K 0 s ) via the topology of their charged decay products (V 0 reconstruction) is presented in detail. From the corrected yields of Λ and K 0 s the ratio K 0 S /Λ can be calculated and included into a statistical model fit. (paper)

  16. Neutral strange particle production in neutrino interactions at Tevatron energies

    International Nuclear Information System (INIS)

    De, K.

    1988-05-01

    This thesis reports on a study of neutral strange particle production by high energy muon-neutrinos. The neutrinos were obtained from a 800 GeV proton beam-dump at Fermilab. Neutrino events were observed using a hybrid bubble chamber detector system. The data contained deep inelastic neutrino-nucleon interactions with an average momentum transfer 2 > = 23 (GeV/c) 2 . Rates for K 0 and Λ production in neutrino and anti-neutrino charged current events are presented. The distributions of these particles in Feynman x and rapidity are also studied. Significant differences were observed in the production mechanism for the K 0 meson and the Λ baryon. The production rates of K 0 's were observed to increase with energy, whereas the rates for Λ production remained essentially constant. In Feynman x, the K 0 's were produced in the central region and the Λ's were produced backwards. The data are compared with the LUND monte carlo for string fragmentation. In the monte carlo, K 0 's are mostly produced from s/bar s/ pair production during fragmentation. The Λ's are generally produced through recombination with the diquark from the target nucleon. The data agree with this model for strange particle production. 39 refs., 24 figs., 10 tabs

  17. Rhetoric and analogies

    OpenAIRE

    Aragonès, Enriqueta; Gilboa, Itzhak; Postlewaite, Andrew; Schmeidler, David; Universitat Autònoma de Barcelona. Unitat de Fonaments de l'Anàlisi Econòmica; Universitat Autònoma de Barcelona. Institut d'Anàlisi Econòmica

    2013-01-01

    The art of rhetoric may be defined as changing other people's minds (opinions, beliefs) without providing them new information. One tech- nique heavily used by rhetoric employs analogies. Using analogies, one may draw the listener's attention to similarities between cases and to re-organize existing information in a way that highlights certain reg- ularities. In this paper we offer two models of analogies, discuss their theoretical equivalence, and show that finding good analogies is a com- p...

  18. Ultrarelativistic cascades and strangeness production

    Energy Technology Data Exchange (ETDEWEB)

    Kahana, D.E. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Physics; Kahana, S.H. [Brookhaven National Lab., Upton, NY (United States). Physics Dept.

    1998-08-24

    A two-phase cascade code, LUCIFER II, developed for the treatment of ultra high energy-ion-ion collisions is applied to the production of strangeness at SPS energies {radical}(s)=17-20. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy-ion experiments at the CERN SPS. (orig.) 26 refs.

  19. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-01-01

    A two-phase cascade code, LUCIFER II, developed for the treatment of ultra high energy-ion-ion collisions is applied to the production of strangeness at SPS energies √(s)=17-20. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy-ion experiments at the CERN SPS. (orig.)

  20. Nucleic Acid Base Analog FRET-Pair Facilitating Detailed Structural Measurements in Nucleic Acid Containing Systems

    DEFF Research Database (Denmark)

    Börjesson, Karl; Preus, Søren; El-Sagheer, Afaf

    2009-01-01

    We present the first nucleobase analog fluorescence resonance energy transfer (FRET)-pair. The pair consists of tCO, 1,3-diaza-2-oxophenoxazine, as an energy donor and the newly developed tC(nitro), 7-nitro-1,3-diaza-2-oxophenothiazine, as an energy acceptor. The FRET-pair successfully monitors d...

  1. Some statistical properties of strange attractors: engineering view

    International Nuclear Information System (INIS)

    Mijangos, M; Kontorovich, V; Aguilar-Torrentera, J

    2008-01-01

    In this paper, the statistical characterization of strange attractors is investigated via the so-called 'model distribution' approach. It is shown that in order to calculate the first four cumulants, which are necessary to create a model distribution of kurtosis approximation, a systematic method for the calculus of the variance needs to be considered. Correspondently, an analytical method based on the Kolmogorov-Sinai (K-S) entropy for variance approximation is herein proposed. The methodology is of interest for its application in the statistical analysis of chaotic systems that model physical phenomena found in some areas of electrical (communication) engineering

  2. Search for heavy pentaquark exotic baryons with hidden strangeness in the reactions p + N → (pφ) + N and p + N → [Λ(1520)K+] + N at Ep = 70 GeV

    International Nuclear Information System (INIS)

    Balatz, M.Ya.; Belyaev, I.M.; Dorofeev, V.A.

    1993-01-01

    In the experiments at the SPHINX facility on the 70 GeV proton beam of the IHEP accelerator a wide program of studying of the baryon diffractive production and search for exotic baryons in these processes is being carried out. The first data for the reactions p + N → (K + K - p) + N, p + N → (pφ) + N and p + N → [Λ(1520)K + ] + N are presented. The very sensitive upper limits for the cross sections for diffractive production of heavy narrow cryptoexotic baryon resonances with hidden strangeness in the mass region up to 4.5 GeV are obtained. 14 refs., 12 figs., 2 tabs

  3. Diffractive production of charmed strange mesons by neutrinos and antineutrinos

    Science.gov (United States)

    Asratyan, A. E.; Aderholz, M.; Ammosov, V. V.; Burkot, W.; Clayton, E. F.; Coghen, T.; Erriquez, O.; Gapienko, G. S.; Gapienko, V. A.; Guy, J.; Hantke, D.; Jones, G. T.; Kaftanov, V. S.; Katz, U. F.; Kern, J.; Korotkov, V. A.; Krutchinin, S. P.; Kubantsev, M. A.; Marage, P.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; Sacton, J.; Schmitz, N.; Varvell, K.; Venus, W.; Wittek, W.; Zaetz, V. G.

    1993-03-01

    The diffractive production of charmed strange D {s/*} and possibly D s mesons by neutrinos and antineutrinos on nucleons in hydrogen, deuterium and neon targets is observed. The slope parameter of the t distribution is 3.3±0.8 (GeV)-2. The production rate per charged current neutrino interaction with an isoscalar target times the D{s/+}→φτ+ branching fraction is (1.03±0.27)×10-4.

  4. Diffractive production of charmed strange mesons by neutrinos and antineutrinos

    International Nuclear Information System (INIS)

    Asratyan, A.E.; Kaftanov, V.S.; Krutchinin, S.P.; Kubantsev, M.A.; Aderholz, M.; Hantke, D.; Katz, U.F.; Kern, J.; Schmitz, N.; Wittek, W.; Ammosov, V.V.; Gapienko, G.S.; Gapienko, V.A.; Korotkov, V.A.; Zaetz, V.G.; Burkot, W.; Coghen, T.; Clayton, E.F.; Miller, D.B.; Mobayyen, M.M.; Erriquez, O.; Guy, J.; Venus, W.; Jones, G.T.; Varvell, K.; Marage, P.; Sacton, J.; Morrison, D.R.O.; Neveu, M.

    1993-01-01

    The diffractive production of charmed strange D s * and possibly D s mesons by neutrinos and antineutrinos on nucleons in hydrogen, deuterium and neon targets is observed. The slope parameter of the t distribution is 3.3±0.8 (GeV) -2 . The production rate per charged current neutrino interaction with an isoscalar target times the D s + →φπ + branching fraction is (1.03±0.27)x10 -4 . (orig.)

  5. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  6. 1-4 Strangeness Production in Antiproton Induced Nuclear Reactions.

    Institute of Scientific and Technical Information of China (English)

    Feng; Zhaoqing[1

    2014-01-01

    More localized energy deposition is able to be produced in antiproton-nucleus collisions in comparison withheavy-ion collisions due to annihilation reactions. Searching for the cold quark-gluon plasma (QGP) with antiprotonbeamshas been considered as a hot topic both in experiments and in theretical calculations over the past severaldecades. Strangeness production and hypernucleus formation in antiproton-induced nuclear reactions are importancein exploring the hyperon (antihyperon)-nucleon (HN) potential and the antinucleon-nucleon interaction, whichhave been hot topics in the forthcoming experiments at PANDA in Germany.

  7. Influence of rescattering on the spectra of strange particles

    International Nuclear Information System (INIS)

    David, C.; Hartnack, C.; Kerveno, M.; Le Pallec, J.Ch.; Aichelin, J.

    1996-11-01

    Applying a new method of rescattering based on neural network technique the influence of rescattering on the spectra of strange particles produced in heavy ion reactions is studied. A comparison of our calculations for the system Ni(1.93 A GeV)+Ni with recent data of the FOPI collaboration is presented. It is found that even for this small system rescattering changes the observables considerably but does not invalidate the role of the kaons as a messenger from the high density zone. (K.A.)

  8. Strangeness suppression of qq creation observed in exclusive reactions.

    Science.gov (United States)

    Mestayer, M D; Park, K; Adhikari, K P; Aghasyan, M; Pereira, S Anefalos; Ball, J; Battaglieri, M; Batourine, V; Bedlinskiy, I; Biselli, A S; Boiarinov, S; Briscoe, W J; Brooks, W K; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L; Contalbrigo, M; Cortes, O; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; Deur, A; Djalali, C; Doughty, D; Dupre, R; El Alaoui, A; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fleming, J A; Forest, T A; Garillon, B; Garçon, M; Ghandilyan, Y; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Golovatch, E; Gothe, R W; Griffioen, K A; Guegan, B; Guidal, M; Hakobyan, H; Hanretty, C; Hattawy, M; Holtrop, M; Hughes, S M; Hyde, C E; Ilieva, Y; Ireland, D G; Jiang, H; Jo, H S; Joo, K; Keller, D; Khandaker, M; Kim, A; Kim, W; Koirala, S; Kubarovsky, V; Kuleshov, S V; Lenisa, P; Levine, W I; Livingston, K; Lu, H Y; MacGregor, I J D; Mayer, M; McKinnon, B; Meyer, C A; Mirazita, M; Mokeev, V; Montgomery, R A; Moody, C I; Moutarde, H; Movsisyan, A; Camacho, C Munoz; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Pappalardo, L L; Paremuzyan, R; Peng, P; Phelps, W; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Protopopescu, D; Puckett, A J R; Raue, B A; Rimal, D; Ripani, M; Rizzo, A; Rosner, G; Roy, P; Sabatié, F; Saini, M S; Schott, D; Schumacher, R A; Simonyan, A; Sokhan, D; Strauch, S; Sytnik, V; Tang, W; Tian, Ye; Ungaro, M; Vernarsky, B; Vlassov, A V; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Wei, X; Weinstein, L B; Wood, M H; Zachariou, N; Zhang, J; Zhao, Z W; Zonta, I

    2014-10-10

    We measured the ratios of electroproduction cross sections from a proton target for three exclusive meson-baryon final states: ΛK(+), pπ(0), and nπ(+), with the CLAS detector at Jefferson Lab. Using a simple model of quark hadronization, we extract qq creation probabilities for the first time in exclusive two-body production, in which only a single qq pair is created. We observe a sizable suppression of strange quark-antiquark pairs compared to nonstrange pairs, similar to that seen in high-energy production.

  9. Radial oscillations of strange quark stars admixed with condensed dark matter

    Science.gov (United States)

    Panotopoulos, G.; Lopes, Ilídio

    2017-10-01

    We compute the 20 lowest frequency radial oscillation modes of strange stars admixed with condensed dark matter. We assume a self-interacting bosonic dark matter, and we model dark matter inside the star as a Bose-Einstein condensate. In this case the equation of state is a polytropic one with index 1 +1 /n =2 and a constant K that is computed in terms of the mass of the dark matter particle and the scattering length. Assuming a mass and a scattering length compatible with current observational bounds for self-interacting dark matter, we have integrated numerically first the Tolman-Oppenheimer-Volkoff equations for the hydrostatic equilibrium, and then the equations for the perturbations ξ =Δ r /r and η =Δ P /P . For a compact object with certain mass and radius we have considered here three cases, namely no dark matter at all and two different dark matter scenarios. Our results show that (i) the separation between consecutive modes increases with the amount of dark matter, and (ii) the effect is more pronounced for higher order modes. These effects are relevant even for a strange star made of 5% dark matter.

  10. Flavour symmetry breaking and tuning the strange quark mass for 2+1 quark flavours

    Energy Technology Data Exchange (ETDEWEB)

    Bietenholz, W. [Universidad Autonoma de Mexico (Mexico). Inst. de Ciencias Nucleares; Bornyakov, V. [Institute for High Energy Physics, Protovino (Russian Federation); Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Goeckeler, M. [Regensburg Univ. (DE). Inst. fuer Theoretische Physik] (and others)

    2010-12-15

    QCD lattice simulations with 2+1 flavours typically start at rather large up-down and strange quark masses and extrapolate first the strange quark mass to its physical value and then the updown quark mass. An alternative method of tuning the quark masses is discussed here in which the singlet quark mass is kept fixed, which ensures that the kaon always has mass less than the physical kaon mass. Using group theory the possible quark mass polynomials for a Taylor expansion about the flavour symmetric line are found, which enables highly constrained fits to be used in the extrapolation of hadrons to the physical pion mass. Numerical results confirm the usefulness of this expansion and an extrapolation to the physical pion mass gives hadron mass values to within a few percent of their experimental values. (orig.)

  11. Production of multi-strange baryons in 7 TeV proton-proton collisions with ALICE

    CERN Document Server

    Maire, Antonin

    2012-01-01

    In the perspective of comparisons between proton-proton and heavy-ion physics, understanding the production mechanisms (soft and hard) in pp that lead to strange particles is of importance. Measurements of charged multi-strange (anti-)baryons (Omega and Xi) are presented for pp collisions at sqrt(s) = 7 TeV. This report is based on results obtained by ALICE (A Large Ion Collider Experiment) from the 2010 data-taking. Taking advantage of the characteristic cascade-decay topology, the identification of Xi-, anti-Xi+, Omega- and anti-Omega+ can be performed, over a wide range of momenta (e.g. from 0.6 to 8.5 GeV/c for Xi-, with the present statistics analysed). The production at central rapidity (|y| < 0.5) as a function of transverse momentum, dN/dptdy, is presented. These results are compared to PYTHIA Perugia 2011 predictions.

  12. Strange hadrons and antiprotons as probes of hot and dense nuclear matter in relativistic heavy-ion collisions; Seltsame Hadronen und Antiprotonen als Proben heisser und dichter Kernmaterie in relativistischen Schwerionenkollisionen

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Henry

    2010-09-15

    Strange particles play an important role as probes of relativistic heavy-ion collisions where hot and dense matter is studied. The focus of this thesis is on the production of strange particles within a transport model of Boltzmann-Uehling-Uhlenbeck (BUU) type. Current data of the HADES Collaboration concerning K{sup {+-}} and {phi} spectra provide the appropriate experimental framework. Moreover, the double-strange hyperon {xi}{sup -} is analyzed below the free NN production threshold. Hadron multiplicities, transversemomentum and rapidity spectra are compared with recent experimental data. Further important issues are in-medium mass shifts, the nuclear equation of state as well as the mean field of nucleons. Besides the study of AA collisions a comparison with recent ANKE data regarding the {phi} yield in pA collisions is done. Transparency ratios are determined and primarily investigated for absorption of {phi} mesons by means of the BUU transport code. Thereby, secondary {phi} production channels, isospin asymmetry and detector acceptance are important issues. A systematic analysis is presented for different system sizes. The momentum integrated Boltzmann equations describe dense nuclear matter on a hadronic level appearing in the Big Bang as well as in little bangs, in the context of kinetic off-equilibrium dynamics. This theory is applied to antiprotons and numerically calculated under consideration of various expansion models. Here, the evolution of proton- and antiproton densities till freeze-out is analyzed for ultra-relativistic heavy-ion collisions within a hadrochemic resonance gas model acting as a possible ansatz for solving the ''antiproton puzzle''. Furthermore, baryonic matter and antimatter is investigated in the early universe and the adiabatic path of cosmic matter is sketched in the QCD phase diagram. (orig.)

  13. The strange and light quark contributions to the nucleon mass from lattice QCD

    International Nuclear Information System (INIS)

    Bali, Gunnar S.; Collins, Sara; Goeckeler, Meinulf

    2011-12-01

    We determine the strangeness and light quark fractions of the nucleon mass by computing the quark line connected and disconnected contributions to the matrix elements m q left angle N vertical stroke anti qq vertical stroke N right angle in lattice QCD, using the non-perturbatively improved Sheikholeslami-Wohlert Wilson Fermionic action. We simulate n F =2 mass degenerate sea quarks with a pion mass of about 285 MeV and a lattice spacing ∼0.073 fm. The renormalization of the matrix elements involves mixing between contributions from different quark flavours. The pion-nucleon σ-term is extrapolated to physical quark masses exploiting the sea quark mass dependence of the nucleon mass. We obtain the renormalized values σ πN =(38±12) MeV at the physical point and f T s =σ s /m N =0.012(14) +10 -3 for the strangeness contribution at our larger than physical sea quark mass. (orig.)

  14. The strange and light quark contributions to the nucleon mass from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Bali, Gunnar S.; Collins, Sara; Goeckeler, Meinulf [Regensburg Univ. (DE). Inst. fuer Theoretische Physik] (and others)

    2011-12-15

    We determine the strangeness and light quark fractions of the nucleon mass by computing the quark line connected and disconnected contributions to the matrix elements m{sub q} left angle N vertical stroke anti qq vertical stroke N right angle in lattice QCD, using the non-perturbatively improved Sheikholeslami-Wohlert Wilson Fermionic action. We simulate n{sub F}=2 mass degenerate sea quarks with a pion mass of about 285 MeV and a lattice spacing {approx}0.073 fm. The renormalization of the matrix elements involves mixing between contributions from different quark flavours. The pion-nucleon {sigma}-term is extrapolated to physical quark masses exploiting the sea quark mass dependence of the nucleon mass. We obtain the renormalized values {sigma}{sub {pi}}{sub N}=(38{+-}12) MeV at the physical point and f{sub T{sub s}}={sigma}{sub s}/m{sub N}=0.012(14){sup +10}{sub -3} for the strangeness contribution at our larger than physical sea quark mass. (orig.)

  15. A birational mapping with a strange attractor: post-critical set and covariant curves

    International Nuclear Information System (INIS)

    Bouamra, M; Hassani, S; Maillard, J-M

    2009-01-01

    We consider some two-dimensional birational transformations. One of them is a birational deformation of the Henon map. For some of these birational mappings, the post-critical set (i.e. the iterates of the critical set) is infinite and we show that this gives straightforwardly the algebraic covariant curves of the transformation when they exist. These covariant curves are used to build the preserved meromorphic 2-form. One may also have an infinite post-critical set yielding a covariant curve which is not algebraic (transcendental). For two of the birational mappings considered, the post-critical set is finite and we claim that there is no algebraic covariant curve and no preserved meromorphic 2-form. For these two mappings with finite post-critical sets, attracting sets occur and we show that they pass the usual tests (Lyapunov exponents and the fractal dimension) for being strange attractors. The strange attractor of one of these two mappings is unbounded.

  16. Strangeness production in p+Pb reactions at 200 GeV/c

    International Nuclear Information System (INIS)

    Greiner, D.E.; Andersen, E.; Blaes, R.; Cherney, M.; Cruz, B. de la; Fernandez, C.; Garabatos, C.; Garzon, J.A.; Geist, W.M.; Gruhn, C.R.; Hafidouni, M.; Hrubec, J.; Jones, P.G.; Judd, E.G.; Kuipers, J.P.M.; Ladrem, M.; Ladron de Guevara, P.; Loevhoeiden, G.; MacNaughton, J.; Mosquera, J.; Natkaniec, Z.; Nelson, J.M.; Neuhofer, G.; Perez de los Heros, C.; Plo, M.; Porth, P.; Powell, B.; Ramil, A.; Rohringer, H.; Sakrejda, I.; Thorsteinsen, T.F.; Traxler, J.; Voltolini, C.; Wozniak, K.; Yanez, A.; Zybert, R.

    1994-01-01

    The production of the strange particles Λ, anti Λ and K S 0 in p+Pb collisions at 200 GeV/c has been measured using the NA36 TPC. Rapidity distributions and multiplicity dependences are presented and compared to model calculations. Reinteractions in the target are important to describe the observed spectra. Inverse slopes T∼200 MeV are extracted from the transverse mass distributions. (orig.)

  17. Strangeness production in Ni+Ni collisions at 1.93 AGeV

    International Nuclear Information System (INIS)

    Lopez, X.

    2004-12-01

    This work deals with the production of strange particles in Ni + Ni collisions at 1.93 A GeV detected with the Fopi (four pi) detector at the heavy ion synchrotron SIS (GSI - Germany). We have limited our investigation to the study of Λ and Ξ hyperons. The first chapter presents the models used to describe ultra-relativistic heavy ions collisions. In the second chapter we present the main experimental results concerning the production and transport of strange particles in an energy domain ranging from SIS to RHIC (relativistic heavy ion collider) energies. The third chapter is dedicated to the specificities of the Fopi detector. The fourth chapter deals with the production of Λ particles in Ni + Ni collisions. An analysis method based on neuron network has been used in parallel with a more classical method. The production rate and temperature of Λ have been deduced from both methods. The neuron network method gives a statistical gain and allows a better identification of particles with low transverse impulses. The fifth chapter is dedicated to the detection of the doubly strange Ξ - particle. A detailed study about the stability of the signal is presented. In the last chapter all our experimental results are confronted with theoretical predictions. The UrQMD model that uses a hard equation of state, can simulate satisfactorily the production rates of Λ and K + as well as their dependency on collision centrality despite the fact that this model does not use a potential linked to the medium density. The comparison between experimental results and predictions given by the IQMD model (that is based on a soft equation of state) is better when the version of the model that does not take into account the effects of the media is used. We see that the choices for the nuclear matter compressibility, for the particles involved in Kaon and Λ creation process, or for the interaction potential with dense medium, appear to be degrees of freedom that are difficult to adjust

  18. High-speed and high-resolution analog-to-digital and digital-to-analog converters

    NARCIS (Netherlands)

    van de Plassche, R.J.

    1989-01-01

    Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog

  19. Search for a Narrow Baryonic Resonance Decaying to $K^0_s p$ or $K^0_s \\bar{p}$ in Deep Inelastic Scattering at HERA

    CERN Document Server

    Aktas, A.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J.G.; Coughlan, J.A.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; de Boer, Y.; Delcourt, B.; Del Degan, M.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkewicz, A.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Flucke, G.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerlich, C.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B.R.; Grindhammer, G.; Gwilliam, C.; Haidt, D.; Hajduk, L.; Hansson, M.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, Andreas Werner; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Luke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Marti, L.; Martisikova, M.; Martyn, H.-U.; Maxfield, S.J.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Papadopoulou, T.; Pascaud, C.; Patel, G.D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Placakyte, R.; Portheault, B.; Povh, B.; Prideaux, P.; Rahmat, A.J.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D.P.C.; Sauvan, E.; Schatzel, S.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R.N.; Sheviakov, I.; Shtarkov, L.N.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Steder, M.; Stella, B.; Stiewe, J.; Stoilov, A.; Straumann, U.; Sunar, D.; Tchoulakov, V.; Thompson, Graham; Thompson, P.D.; Toll, T.; Tomasz, F.; Traynor, D.; Truol, P.; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Urban, Marcel; Usik, A.; Utkin, D.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wessling, B.; Wissing, Ch.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y.C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2006-01-01

    A search for a narrow baryonic resonance decaying to $K^0_s p$ or $K^0_s \\bar p$ is carried out in deep inelastic ep scattering with the H1 detector at HERA. Such a resonance could be a strange pentaquark \\thplns, evidence for which has been reported by several experiments. The $K^0_s p$ and $K^0_s \\bar p$ invariant mass distributions presented here do not show any significant peak in the mass range from threshold up to 1.7 GeV. Mass dependent upper limits on $\\sigma(ep \\to e \\thplf X)\\times BR(\\thplf \\to K^0 p)$ are obtained at the 95% confidence level.

  20. Study of the K Kπ meson resonances produced in antiproton proton annihilations at 750 MeV/c

    International Nuclear Information System (INIS)

    Gil Lopez, E.

    1977-01-01

    In this work we present an analysis of the antiproton proton annihilations into strange particles at 700 and 750 MeV/c, restricted to the four and five body final states. We study in detail the resonances decaying into the K Kπ; system, in particular the D and E mesons. For the D meson we present a determination of i ts mass, width, isospin, G-parity, C-parity and spin. For the E meson we present parametrizations of the complete final state which decrease its statistical significance in this type of production. (Author)

  1. STRANGE ATTRACTORS ON PSEUDOSPECTRAL SOLUTIONS FOR DISSIPATIVE ZAKHAROV EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    马书清; 常谦顺

    2004-01-01

    In this paper, the pseudospcctral method to solve the dissipative Zakharov equations is used. Its convergence is proved by priori estinates. The existence of the global attractors and the estimates of dimension are presented. A class of steady state solutions is also disscussed. The numerical results show that if the steady state solutions satisfy some special conditions, they become unstable and limit cycles and strange attractors will occur for very small perturbations.The largest Lyapunov exponent and analysis of the lincarized system are applied to explain these phenomena.

  2. Morphology, magnetic and resonance properties of Fe/MgO multilayers

    International Nuclear Information System (INIS)

    Garcia-Garcia, A; Algarabel, P A; Ibarra, M R; Vovk, A; Strichovanec, P; Pardo, J A; Magen, C; Golub, V; Salyuk, O

    2011-01-01

    Magnetic, resonance and transport properties of Fe(t nm)/MgO(3.0 nm) multilayers prepared by pulsed laser deposition were investigated. Comparison of the data allows conclusions on Fe layers morphology. For t 1.25 nm a continuous coverage of MgO by Fe takes place. However, the morphology of Fe layers is rough. This causes the appearance of magnetostatic resonance modes analogous to those observed for continuous films deposited on embossed surfaces.

  3. Production and decay of baryonic resonances in pion induced reactions

    Directory of Open Access Journals (Sweden)

    Przygoda Witold

    2016-01-01

    Full Text Available Pion induced reactions give unique opportunities for an unambiguous description of baryonic resonances and their coupling channels. A systematic energy scan and high precision data, in conjunction with a partial wave analysis, allow for the study of the excitation function of the various contributions. A review of available world data unravels strong need for modern facilities delivering measurements with a pion beam. Recently, HADES collaboration collected data in pion-induced reactions on light (12C and heavy (74W nuclei at a beam momentum of 1.7 GeV/c dedicated to strangeness production. It was followed by a systematic scan at four different pion beam momenta (0.656, 0.69, 0.748 and 0.8 GeV/c in π− − p reaction in order to tackle the role of N(1520 resonance in conjunction with the intermediate ρ production. First results on exclusive channels with one pion (π− p and two pions (nπ+π−, pπ−π0 in the final state are discussed.

  4. Interacting hadron resonance gas model in the K -matrix formalism

    Science.gov (United States)

    Dash, Ashutosh; Samanta, Subhasis; Mohanty, Bedangadas

    2018-05-01

    An extension of hadron resonance gas (HRG) model is constructed to include interactions using relativistic virial expansion of partition function. The noninteracting part of the expansion contains all the stable baryons and mesons and the interacting part contains all the higher mass resonances which decay into two stable hadrons. The virial coefficients are related to the phase shifts which are calculated using K -matrix formalism in the present work. We have calculated various thermodynamics quantities like pressure, energy density, and entropy density of the system. A comparison of thermodynamic quantities with noninteracting HRG model, calculated using the same number of hadrons, shows that the results of the above formalism are larger. A good agreement between equation of state calculated in K -matrix formalism and lattice QCD simulations is observed. Specifically, the lattice QCD calculated interaction measure is well described in our formalism. We have also calculated second-order fluctuations and correlations of conserved charges in K -matrix formalism. We observe a good agreement of second-order fluctuations and baryon-strangeness correlation with lattice data below the crossover temperature.

  5. Resonances in micro- and macro-physics

    International Nuclear Information System (INIS)

    Gareev, F.A.; Kazacha, G.S.; Ratis, Yu.L.

    1996-01-01

    The Balmer-like mass formula and quantization conditions derived from the first principles have been applied to systematic analysis of the gross structure of all known hadronic resonances. These equations are very useful at least for prediction and estimation of the invariant masses of unknown resonances. The correspondence principle between old classical and new quantum theories plays an outstanding role in the interpretation of the results and allows us to go even into fine details. We have demonstrated that the dimensional analysis, the principles of similitude and automodelity and the methods of analogy can put some bridge between the various branches of physics. 18 refs., 2 tabs

  6. Sigma terms and strangeness content of the nucleon with N{sub f}=2+1+1 twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Dinter, Simon; Drach, Vincent [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Frezzotti, Roberto; Rossi, Giancarlo [Roma Tor Vergata Univ. (Italy). Dipt. di Fisica; INFN Sezione di Roma Tor Vergata, Roma (Italy); Herdoiza, Gregorio [Univ. Autonoma de Madrid (Spain). Dept. de Fisica Teorica y Inst. de Fisica Teorica UAM/CSIC; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Roma Tor Vergata Univ. (Italy). Dipt. di Fisica; INFN Sezione di Roma Tor Vergata, Roma (Italy)

    2012-02-15

    We study the nucleon matrix elements of the quark scalar-density operator using maximally twisted mass fermions with dynamical light (u,d), strange and charm degrees of freedom. We demonstrate that in this setup the nucleon matrix elements of the light and strange quark densities can be obtained with good statistical accuracy, while for the charm quark counterpart only a bound can be provided. The present calculation which is performed at only one value of the lattice spacing and pion mass serves as a benchmark for a future more systematic computation of the scalar quark content of the nucleon. (orig.)

  7. Comparing phenomenological recipes with a microscopic model for the electric amplitude in strangeness photoproduction

    NARCIS (Netherlands)

    Korchin, AY; Scholten, O

    2003-01-01

    Corrections to the Born approximation in photoinduced strangeness production off a proton are calculated in a semirealistic microscopic model. The vertex corrections and internal contributions to the amplitude of the gammap-->K+Lambda reaction are included on the one-loop level. Different

  8. Strangeness of the nucleon from lattice quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrou, Constantia [The Cyprus Institute, Nicosia (Cyprus). Computation-based Science and Technology Research Center (CaSToRC); Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Constantinou, Martha; Hadjiyiannakou, Kyriakos [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Dinter, Simon; Drach, Vincent [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Jansen, Karl [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Koutsou, Giannis; Vaquero, Alejandro [The Cyprus Institute, Nicosia (Cyprus). Computation-based Science and Technology Research Center (CaSToRC); Collaboration: ETM Collaboration

    2013-10-15

    We present a non-perturbative calculation of the strangeness of the nucleon y{sub N} within the framework of lattice QCD. This observable is known to be an important cornerstone to interpret results from direct dark matter detection experiments. We perform a lattice computation for y{sub N} with an analysis of systematic effects originating from discretization, finite size, chiral extrapolation and excited state effects leading to a value of y{sub N}=0.135(46) which turns out to be rather small. As a main result of our work, we demonstrate that the error for y{sub N} is dominated by systematic uncertainties.

  9. Numerical simulations of resonant tunneling with the presence of inelastic processes

    International Nuclear Information System (INIS)

    Jauho, A.P.

    1990-01-01

    We describe simulations of resonant tunneling through a time-modulated double barrier potential. The harmonic modulation frequency ω leads to emission and/or absorption of modulation quanta of energy ℎω in close analogy with emission and/or absorption of dispersionless bosons (optical phonons, photons, plasmons etc.). The transmission coefficient shows satellite peaks in addition to the main resonance. Momentum space snap-shots can be used to extract detailed information of the dynamics of the inelastic tunneling processes, such as opening and closing boson mediated resonant channels, their relative importance, and related time-scales. (orig.)

  10. Interaction of plasma vortices with resonant particles

    DEFF Research Database (Denmark)

    Jovanovic, D.; Pécseli, Hans; Juul Rasmussen, J.

    1990-01-01

    Kinetic effects associated with the electron motion along magnetic field lines in low‐beta plasmas are studied. Using the gyrokinetic description of electrons, a kinetic analog of the reduced magnetohydrodynamic equations is derived, and it is shown that in the strongly nonlinear regime...... particles. The evolution equations indicate the possibility of excitation of plasma vortices by electron beams....... they possess localized solutions in the form of dipolar vortices, which can efficiently interact with resonant electrons. In the adiabatic limit, evolution equations are derived for the vortex parameters, describing exchange of the energy, enstrophy, and of the Poynting vector between the vortex and resonant...

  11. "Making strange": a role for the humanities in medical education.

    Science.gov (United States)

    Kumagai, Arno K; Wear, Delese

    2014-07-01

    Stories, film, drama, and art have been used in medical education to enhance empathy, perspective-taking, and openness to "otherness," and to stimulate reflection on self, others, and the world. Yet another, equally important function of the humanities and arts in the education of physicians is that of "making strange"-that is, portraying daily events, habits, practices, and people through literature and the arts in a way that disturbs and disrupts one's assumptions, perspectives, and ways of acting so that one sees the self, others, and the world anew. Tracing the development of this concept from Viktor Shklovsky's "enstrangement" (ostranenie) through Bertolt Brecht's "alienation effect," this essay describes the use of this technique to disrupt the "automaticity of thinking" in order to discover new ways of perceiving and being in the world.Enstrangement may be used in medical education in order to stimulate critical reflection and dialogue on assumptions, biases, and taken-for-granted societal conditions that may hinder the realization of a truly humanistic clinical practice. In addition to its ability to enhance one's critical understanding of medicine, the technique of "making strange" does something else: By disrupting fixed beliefs, this approach may allow a reexamination of patient-physician relationships in terms of human interactions and provide health care professionals an opportunity-an "open space"-to bear witness and engage with other individuals during challenging times.

  12. Are We Losing the Next Generation? A Strange Experience on a Poetry Course.

    Science.gov (United States)

    Holbrook, David

    1981-01-01

    Examining the attitudes and behaviors of his adolescent students in rural Yorkshire, the author finds in them a strange lack of respect for adults, which he attributes to disruptions of consciousness caused by the constant bombardment of pop music and television. Two other authors comment on pp128-30. (SJL)

  13. Possibility of narrow resonances of the omega anti omega-system

    International Nuclear Information System (INIS)

    Duerr, H.P.

    1975-01-01

    The possibility of resonances of the Ω anti Ω-system is discussed on the basis of the medium and long range meson exchange forces. The total and partial widths of these resonances are estimated by using well known formulas of nuclear physics. It is demonstrated that analogously the phi- and rho-mesons may be interpreted as p-states of the K anti K- and π π-system, respectively. There appears, however, only a slim chance to interpret the new narrow resonances psi (3100) and psi (3700) as 7 d 1 - and 7 g 1 -Ω anti Ω configurations

  14. Charm-conserving strangeness-changing two body hadronic decays of charmed baryons

    International Nuclear Information System (INIS)

    Khanna, M.P.

    1993-10-01

    The charm-conserving strangeness-changing two body hadronic decays of charmed baryons are examined in the SU(4) symmetry scheme. In addition to the 20''-Hamiltonian, we consider a 15-piece of the weak Hamiltonian which may arise due to SU(4) breaking or due to some non-conventional dynamics. The numerical estimates for decay widths of some of the modes are presented. (author). 15 refs, 3 tabs

  15. The strange quark mass and Lambda parameter of two flavor QCD

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsch, Patrick; Marinkovic, Marina [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Knechtli, Francesco; Leder, Bjoern [Wuppertal Univ. (Germany). Fachbereich C - Mathematik und Naturwissenschaften; Schaefer, Stefan [CERN, Geneva (Switzerland). Physics Dept.; Sommer, Rainer; Virotta, Francesco [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2012-06-15

    We complete the non-perturbative calculations of the strange quark mass and the {lambda} parameter in two flavor QCD by the ALPHA collaboration. The missing lattice scale is determined via the kaon decay constant, for whose chiral extrapolation complementary strategies are compared. We also give a value for the scale r{sub 0} in physical units as well as an improved determination of the renormalization constant Z{sub A}.

  16. Structured Analog CMOS Design

    CERN Document Server

    Stefanovic, Danica

    2008-01-01

    Structured Analog CMOS Design describes a structured analog design approach that makes it possible to simplify complex analog design problems and develop a design strategy that can be used for the design of large number of analog cells. It intentionally avoids treating the analog design as a mathematical problem, developing a design procedure based on the understanding of device physics and approximations that give insight into parameter interdependences. The proposed transistor-level design procedure is based on the EKV modeling approach and relies on the device inversion level as a fundament

  17. Analog and hybrid computing

    CERN Document Server

    Hyndman, D E

    2013-01-01

    Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

  18. Energy and multiplicity dependence of strange and non-strange particle production in proton-proton collisions at the LHC with ALICE

    Directory of Open Access Journals (Sweden)

    Celeste Fionda Fiorella Maria

    2018-01-01

    Full Text Available The study of energy and multiplicity dependence of hadron production in proton-proton collisions provides a powerful tool to understand similarities and differences between small and large colliding systems. In this work we present mid-rapidity measurements of the pT spectra and yields of identified hadrons, namely pions, kaons, protons, K0S, Ξ, Ω and in pp collisions at √s = 7 and 13 TeV. The comparison of results at √s = 13 TeV to earlier results at 7 TeV provides insights about the energy dependence of the strangeness enhancement. Comparisons between data and expectations from commonly-used Monte Carlo event generators will be presented.

  19. Precise Determination of the Strangeness Magnetic Moment of the Nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Leinweber, D B; Boinepalli, S; Cloet, I C; Thomas, A W; Williams, A G; Young, R D; Zanotti, J M; Zhang, J B

    2005-06-01

    By combining the constraints of charge symmetry with new chiral extrapolation techniques and recent low mass lattice QCD simulations of the individual quark contributions to the magnetic moments of the nucleon octet, we obtain a precise determination of the strange magnetic moment of the proton. The result, namely G{sub M}{sup s} = -0.051 +/- 0.021 mu{sub N}, is consistent with the latest experimental measurements but an order of magnitude more precise. This poses a tremendous challenge for future experiments.

  20. Effective Hamiltonians in quantum physics: resonances and geometric phase

    International Nuclear Information System (INIS)

    Rau, A R P; Uskov, D

    2006-01-01

    Effective Hamiltonians are often used in quantum physics, both in time-dependent and time-independent contexts. Analogies are drawn between the two usages, the discussion framed particularly for the geometric phase of a time-dependent Hamiltonian and for resonances as stationary states of a time-independent Hamiltonian