PaperPanorama

Nuclear Theory·nucl-th

Monday·December 10, 2018

8 papers6 primary·2 cross-listed

  1. 07

    [Submitted on 6 Dec 2018] (cross-list from hep-ph)

    Analysing direct photon spectra and elliptic flow from heavy ion collision measurements at the top RHIC energy within the integrated hydrokinetic model

    V. Yu. Naboka🇺🇦 · Yu. M. Sinyukov🇺🇦 · G. M. Zinovjev🇺🇦

    The integrated HydroKinetic Model (iHKM) is applied to analyse the results of direct photon spectra and elliptic flow measurements in 200A GeV Au+Au collisions at RHIC for the three centrality bins. We detect the strong centrality dependence of photon elliptic flow as -coefficient increases towards peripheral collisions. The photon production in the model is accumulated from the different sources along with the process of relativistic heavy ion collision developing. Those include the primary hard photons from the parton collisions at very early stage of the process, the photons generated at the pre-thermal phase of matter evolution, then thermal photons at equilibrated quark-gluon stage together with radiation displaying a confinement and, finally, from the hadron gas phase. Along the way a hadronic medium evolution is treated in two distinct, in a sense opposite, approaches: chemically equilibrated and chemically frozen system expansion. We find that similar as it was found in iHKM for the LHC energies, a description of the direct photon spectra and elliptic flows is significantly improved if an additional portion of the photon radiation, that is associated with hadronization processes, is included into consideration.

    Comments:
    16 pages, 4 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1812.02763 [pdf]
    0 citations
  2. 08

    [Submitted on 12 Nov 2018] (cross-list from physics.gen-ph)

    The criticality of multiplicative processes

    Bernard Gaveau🇫🇷 · Marc-Thierry Jaekel🇫🇷 · Jacques Maillard · Jorge Silva🇫🇷

    Keeping in view applications to numerical simulations of the evolution of a nuclear reactor core around criticality, we use a general mathematical framework for describing the evolutions of multiplicative processes (processes involving particle creation) both in particle generations and in time. This framework allows us to obtain, within a same formalism, two corresponding estimates of the multiplication factor which describes the growth of particle numbers at large times. We obtain the relative positions of both estimates with respect to each other and to criticality. These relations may show particularly useful when simulating in a realistic way the monitoring of nuclear cores in subcritical states, such as is the case for Accelerator Driven Systems (ADS). More generally, this study applies to various multiplicative processes which can be found in nature.

    Comments:
    21 pages
    Subjects:
    physics.gen-ph (physics.gen-ph); Nuclear Theory (nucl-th)
    arXiv:
    1812.03171 [pdf]
    0 citations

Affiliations

first authorsco-authorsvia INSPIRE