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Nuclear Theory·nucl-th

Monday·September 19, 2016

10 papers—5 primary·5 cross-listed

All10Primary5Cross-lists5
  1. 01

    [Submitted on 15 Sept 2016]

    Updates to the p+p and A+A chemical freeze-out lines from the new experimental data

    V. V. Begun🇵🇱 · V. Vovchenko🇩🇪 · M. I. Gorenstein🇩🇪

    We show that the new data on mean multiplicities measured in p+p and A+A collisions together with the updated list of resonances lead to the significant changes of the obtained freeze-out lines. The new A+A line gives much smaller temperatures at high collision energies and agrees with the values obtained at the LHC. The newly obtained p+p line is much closer to the A+A line than previously expected, and even touches it in the region where the horn appears in the data. It indicates that the temperatures that will be obtained in the beam energy and system size scan by the NA61/SHINE Collaboration might be very close. However, our analysis shows that the chemical potentials could be very different for the same energies in A+A and p+p. It adds more puzzles to the set of surprising coincidences at the energies close to the possible onset of deconfinement.

    Comments:
    Contribution to the conference Strangeness in Quark Matter 2016 (SQM2016)
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    1609.04827 [pdf]
    J.Phys.Conf.Ser.(2017)·12 citations
  2. 02

    [Submitted on 15 Sept 2016]

    Vortex structure in superfluid color-flavor locked quark matter

    Mark G. Alford🇺🇸 · S. Kumar Mallavarapu🇺🇸 · Tanmay Vachaspati🇺🇸 · Andreas Windisch🇺🇸

    The core region of a neutron star may feature quark matter in the color-flavor- locked (CFL) phase. The CFL condensate breaks the baryon number symmetry, such that the phenomenon of superfluidity arises. If the core of the star is rotating, vortices will form in the superfluid, carrying the quanta of angular momentum. In a previous study we have solved the question of stability of these vortices, where we found numerical proof of a conjectured instability, according to which superfluid vortices will decay into an arrangement of so-called semi-superfluid fluxtubes. Here we report first results of an extension of our framework that allows us to study multi-vortex dynamics. This will in turn enable us to investigate the structure of semi-superfluid string lattices, which could be relevant to study pinning phenomena at the boundary of the core.

    Comments:
    Conference proceedings 'QCD@Work 2016'
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
    arXiv:
    1609.04863 [pdf]
    EPJ Web Conf.(2016)·1 citation
  3. 03

    [Submitted on 16 Sept 2016]

    The quark mean field model with pion and gluon corrections

    Xueyong Xing🇨🇳 · Jinniu Hu🇨🇳 · Hong Shen🇨🇳

    The properties of nuclear matter and finite nuclei are studied within the quark mean field (QMF) model by taking the effects of pion and gluon into account at the quark level. The nucleon is described as the combination of three constituent quarks confined by a harmonic oscillator potential. To satisfy the spirit of QCD theory, the contributions of pion and gluon on the nucleon structure are treated in second-order perturbation theory. For the nuclear many-body system, nucleons interact with each other by exchanging mesons between quarks. With different constituent quark mass, , we determine three parameter sets about the coupling constants between mesons and quarks, named as QMF-NK1, QMF-NK2, and QMF-NK3 by fitting the ground-state properties of several closed-shell nuclei. It is found that all of the three parameter sets can give satisfactory description on properties of nuclear matter and finite nuclei, meanwhile they can also predict the larger neutron star mass around without the hyperon degrees of freedom.

    Comments:
    19 pages, 6 figures, 4 tables, accepted to Phys. Rev. C
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1609.04911 [pdf]
    PRC(2016)·13 citations
  4. 04

    [Submitted on 16 Sept 2016]

    Linearly increasing radius of the light fragment during the spontaneous fission of Cn

    D. N. Poenaru · R. A. Gherghescu

    In a previous article published in Phys. Rev. C 94 (2016) 014309 we have shown for the first time that the best dynamical trajectory during the deformation toward fission of the superheavy nucleus Fl is a linearly increasing radius of the light fragment, . This macroscopic-microscopic result reminds us about the or cluster preformation at the nuclear surface, assumed already in 1928, and proved microscopically many times. This time we give more detailed arguments for the neighboring nucleus Cn. Also similar figures are presented for heavy nuclei Pu and Cf. The deep minimum of total deformation energy near the surface is shown for the first time as a strong argument for cluster preformation.

    Comments:
    18 pages, 11 figures and 2 tables. arXiv admin note: substantial text overlap with arXiv:1609.00847
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1609.04942 [pdf]
    EPJA(2016)·11 citations
  5. 05

    [Submitted on 16 Sept 2016]

    Cumulants and nonlinear response of high harmonic flow at TeV

    Jacquelyn Noronha-Hostler🇩🇪 · Barbara Betz🇺🇸 · Miklos Gyulassy🇧🇷 · Matthew Luzum🇧🇷 · Jorge Noronha🇺🇸 · Israel Portillo🇺🇸 · Claudia Ratti🇺🇸

    Event-by-event fluctuations caused by quantum mechanical fluctuations in the wave function of colliding nuclei in ultrarelativistic heavy ion collisions were recently shown to be necessary for the simultaneous description of as well as the elliptic and triangular flow harmonics at high in PbPb collisions at the Large Hadron Collider. In fact, the presence of a finite triangular flow as well as cumulants of the flow harmonic distribution that differ from the mean are only possible when these event-by-event fluctuations are considered. In this paper we combine event-by-event viscous hydrodynamics and jet quenching to make predictions for high , , , and in PbPb collisions at TeV. With an order of magnitude larger statistics we find that high elliptic flow does not scale linearly with the soft elliptical flow, as originally thought, but has deviations from perfectly linear scaling. A new experimental observable, which involves the difference between the ratio of harmonic flow cumulants at high and low , is proposed to investigate the fluctuations of high flow harmonics and measure this nonlinear response. By varying the path length dependence of the energy loss and the viscosity of the evolving medium we find that and strongly depend on the choice for the path length dependence of the energy loss, which can be constrained using the new LHC run 2 data.

    Comments:
    23 pages, 17 figures; v2 updated text
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    1609.05171 [pdf]
    PRC(2017)·86 citations

Affiliations

first authorsco-authorsvia INSPIRE