PaperPanorama

Nuclear Theory·nucl-th

Friday·March 24, 2017

6 papers3 primary·3 cross-listed

  1. 04

    [Submitted on 22 Mar 2017] (cross-list from nucl-ex)

    Experimentally Study the Deep Dirac Levels with High-Intensity Lasers

    Xiaopeng Zhang · Changbo Fu · Dechang Dai

    Various theories have predicted the deep Dirac levels (DDLs) in atoms for many years. However, the existence of the DDL is still under debating, and need to be confirmed experimentally. With the development of high intensive lasers, nowadays, electrons can been accelerated to relativistic energy by high intensive lasers, electron-positron pairs can be created, and nuclear reactions can been ignited, which provide a new tool to explore the DDL related fields. In this paper, we propose a new experimental method to study the DDL levels by monitoring nuclei's orbital electron capture life time in plasma induced by high intensive lasers. If a DDL exists, a nuclear electron capture rate could be enhanced by factor of over , which makes it practically detectable in nowadays high intensive laser environments.

    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1703.07837 [pdf]
    0 citations
  2. 05

    [Submitted on 23 Mar 2017] (cross-list from hep-ph)

    Charmonium spectrum with a Dirac potential model in the momentum space

    D. Molina🇨🇴 · M. De Sanctis🇨🇴 · C. Fernandez-Ramirez🇲🇽

    We study the charmonium spectrum using a complete one gluon exchange approach based on a phenomenological relativistic potential model with Dirac spinors in momentum space. We use phenomenological screening factors to include vacuum quantum effects. Our formulation does not rely on nonrelativistic approximations. We fit the lowest-lying charmonia (below the threshold) and predict the higher-lying resonances of the spectrum. In general, we reproduce the overall structure of the charmonium spectrum and, in particular, we can reasonably describe the resonance mass as (mostly) a state. The numerical values of the free parameters of the model are determined taking into account also the experimental uncertainties of the resonance energies. In this way, we are able to obtain the uncertainties of the theoretical resonance masses and the correlation among the free parameters of the model.

    Comments:
    16 pages, 3 figures, 6 tables, to be published in Physical Review D
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1703.08097 [pdf]
    PRD(2017)·17 citations
  3. 06

    [Submitted on 23 Mar 2017] (cross-list from hep-ph)

    Effects of magnetic field on the plasma evolution in relativistic heavy-ion collisions

    Arpan Das🇮🇳 · Shreyansh S. Dave🇮🇳 · P. S. Saumia🇷🇺 · Ajit M. Srivastava🇮🇳

    Very strong magnetic fields can arise in non-central heavy-ion collisions at ultrarelativistic energies, which may not decay quickly in a conducting plasma. We carry out relativistic magnetohydrodynamics (RMHD) simulations to study the effects of this magnetic field on the evolution of the plasma and on resulting flow fluctuations in the ideal RMHD limit. Our results show that magnetic field leads to enhancement in elliptic flow for small impact parameters while it suppresses it for large impact parameters (which may provide a signal for initial stage magnetic field). Interestingly, we find that magnetic field in localized regions can temporarily increase in time as evolving plasma energy density fluctuations lead to reorganization of magnetic flux. This can have important effects on chiral magnetic effect. Magnetic field has non-trivial effects on the power spectrum of flow fluctuations. For very strong magnetic field case one sees a pattern of even-odd difference in the power spectrum of flow coefficients arising from reflection symmetry about the magnetic field direction if initial state fluctuations are not dominant. We discuss the situation of nontrivial magnetic field configurations arising from collision of deformed nuclei and show that it can lead to anomalous elliptic flow. Special (crossed body-body) configurations of deformed nuclei collision can lead to presence of quadrupolar magnetic field which can have very important effects on the rapidity dependence of transverse expansion (similar to {\it beam focusing} from quadrupole fields in accelerators).

    Comments:
    15 pages, 16 figures, New figure included showing effect of magnetic field on momentum eccentricity
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Plasma Physics (physics.plasm-ph)
    arXiv:
    1703.08162 [pdf]
    PRC(2017)·77 citations

Affiliations

first authorsco-authorsvia INSPIRE