PaperPanorama
FAQ

Nuclear Theory·nucl-th

Monday·July 18, 2016

13 papers—9 primary·4 cross-listed

All13Primary9Cross-lists4
  1. 10

    [Submitted on 14 Jul 2016] (cross-list from hep-th)

    Radial vibrations of BPS skyrmions

    C. Adam🇪🇸 · M. Haberichter🇯🇵 · T. Romanczukiewicz🇵🇱 · A. Wereszczynski🇵🇱

    We study radial vibrations of spherically symmetric skyrmions in the BPS Skyrme model. Concretely, we numerically solve the linearised field equations for small fluctuations in a skyrmion background, both for linearly stable oscillations and for (unstable) resonances. This is complemented by numerical solutions of the full nonlinear system, which confirm all the results of the linear analysis. In all cases, the resulting fundamental excitation provides a rather accurate value for the Roper resonance, supporting the hypothesis that the BPS Skyrme model already gives a reasonable approximate description of this resonance. Further, for many potentials additional higher resonances appear, again in agreement with known experimental results.

    Comments:
    Latex, 41 pages, 22 pdf figures; v2: minor changes
    Subjects:
    High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    1607.04286 [pdf]
    PRD(2016)·9 citations
  2. 11

    [Submitted on 14 Jul 2016] (cross-list from hep-ph)

    Synchrotron contribution to photon emission from quark-gluon plasma

    B.G. Zakharov🇷🇺

    We study the influence of the magnetic field on the photon emission from the quark-gluon plasma created in collisions. We find that even for very optimistic assumption on the magnitude of the magnetic field for noncentral collisions the effect of magnetic field is very small.

    Comments:
    5 pages, 2 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1607.04314 [pdf]
    JETP Lett.(2016)·10 citations
  3. 12

    [Submitted on 15 Jul 2016] (cross-list from hep-ph)

    High Gluon Densities in Heavy Ions Collisions

    Jean-Paul Blaizot🇫🇷

    The early stages of heavy ion collisions are dominated by high density systems of gluons that carry each a small fraction of the momenta of the colliding nucleons. A distinguishing feature of such systems is the phenomenon of "saturation" which tames the expected growth of the gluon density as the energy of the collision increases. The onset of saturation occurs at a particular transverse momentum scale, the "saturation momentum", that emerges dynamically and that marks the onset of non-linear gluon interactions. At high energy, and for large nuclei, the saturation momentum is large compared to the typical hadronic scale, making high density gluons amenable to a description with weak coupling techniques. This paper reviews some of the challenges faced in the study of such dense systems of small gluons, and of the progress made in addressing them. The focus is on conceptual issues, and the presentation is both pedagogical, and critical. Examples where high gluon density could play a visible role in heavy ion collisions are briefly discussed at the end, for illustration purpose.

    Comments:
    Submitted to Reports on Progress in Physics
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1607.04448 [pdf]
    Rept.Prog.Phys.(2017)·98 citations
  4. 13

    [Submitted on 15 Jul 2016] (cross-list from astro-ph.HE)

    Electrical conductivity tensor of dense plasma in magnetic fields

    Arus Harutyunyan · Armen Sedrakian

    Electrical conductivity of finite-temperature plasma in neutron star crusts is studied for applications in magneto-hydrodynamical description of compact stars. We solve the Boltzmann kinetic equation in relaxation time approximation taking into account the anisotropy of transport due to the magnetic field, the effects of dynamical screening in the scattering matrix element and corre- lations among the nuclei. We show that conductivity has a minimum at a non-zero temperature, a low-temperature decrease and a power-law increase with increasing temperature. Selected numerical results are shown for matter composed of carbon, iron, and heavier nuclei present in the outer crusts of neutron star.

    Comments:
    12 pages, 5 figures, supplemental material contains 21 tables. Proceedings of "The Modern Physics of Compact Stars and Relativistic Gravity 2015", 30 September 2015 - 3 October 2015 Yerevan, Armenia
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    1607.04541 [pdf]
    PoS(2016)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE