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Nuclear Theory·nucl-th

Thursday·January 23, 2020

6 papers—4 primary·2 cross-listed

All6Primary4Cross-lists2
  1. 01

    Collective inertial masses in nuclear reactions

    Kai Wen · Takashi Nakatsukasa

    Towards the microscopic theoretical description for large amplitude collective dynamics, we calculate the coefficients of inertial masses for low-energy nuclear reactions. Under the scheme of energy density functional, we apply the adiabatic self-consistent collective coordinate (ASCC) method, as well as the Inglis' cranking formula to calculate the inertias for the translational and the relative motions, in addition to those for the rotational motion. Taking the scattering between two particles as an example, we investigate the impact of the time-odd components of the mean-field potential on the collective inertial masses. The ASCC method asymptotically reproduces the exact masses for both the relative and translational motions. On the other hand, the cranking formula fails to do so when the time-odd components exist.

    nucl-thFront.in Phys.(2020)·2 citations
  2. 02

    Traces of non-equilibrium effects, initial condition, bulk dynamics and elementary collisions in the charm observables

    Taesoo Song🇩🇪 · Pierre Moreau🇺🇸 · Yingru Xu🇺🇸 · Vitalii Ozvenchuk🇵🇱 · Elena Bratkovskaya🇩🇪 · Jorg Aichelin🇫🇷 · Steffen A. Bass🇺🇸 · Pol Bernard Gossiaux🇫🇷 · Marlene Nahrgang🇫🇷

    We study how heavy quark dynamics is affected by the nature of the bulk evolution of the QCD matter, the initial condition of the system, and the treatment of elementary interactions between heavy quarks and the surrounding medium. For the same initial condition and the same QGP expansion scenario we discuss the consequences of the assumption of a local equilibrium by comparing the consequences for the nuclear modification factor and the elliptic flows of charm quarks. For this purpose we employ the parton-hadron-string dynamics (PHSD), which is an off-shell microscopic transport approach, as well as the linearized-Boltzmann (LB) scheme obtained by coarse graining the PHSD bulk and assuming local equilibrium for the interactions of the charm quarks with the bulk. The of charm quarks stemming from the later LB approach is also compared to a genuine fluid dynamics evolution initiated by the coarse grained PHSD, which allows to further assess the consequences of reducing the full n-body dynamics. We then proceed to a systematic comparison of PHSD with MC@HQ, another transport model for heavy flavors which also relies on LB approach. In particular, we investigate the consequences for the nuclear modification factor of charm quarks if we vary separately the initial heavy quark distribution function in matter, the expansion dynamics of the QGP and the elementary interactions of heavy quarks of these models. We find that the results for both models vary significantly depending on the details of the calculation. However, both models achieve very similar predictions for key heavy quark observables for certain combinations of initial condition, bulk evolution and interactions. We conclude that this ambiguity limits our ability to determine the different properties of the system based on the current set of observables.

    nucl-thPRC(2020)·16 citations
  3. 03

    Equivalence between first-order causal and stable hydrodynamics and Israel-Stewart theory for boost-invariant systems with a constant relaxation time

    Arpan Das🇵🇱 · Wojciech Florkowski🇵🇱 · Jorge Noronha🇺🇸 · Radoslaw Ryblewski🇵🇱

    We show that the recently formulated causal and stable first-order hydrodynamics has the same dynamics as Israel-Stewart theory for boost-invariant, Bjorken expanding systems with a conformal equation of state and a regulating sector determined by a constant relaxation time. In this case, the general solution of the new first-order formulation can be determined analytically.

    nucl-thhep-phPLB(2020)·27 citations
  4. 04

    Lee-Yang-inspired energy-density functional including contributions from -wave scattering

    Jeremy Bonnard🇬🇧 · Marcella Grasso🇫🇷 · Denis Lacroix🇫🇷

    The ELYO functional proposed in [M. Grasso, D. Lacroix, and C. J. Yang, Phys. Rev. C \textbf{95}, 054327 (2017)] belongs to the family of energy-density functionals (EDFs) inspired by effective-field theories (EFTs) and constrained by \textit{ab--initio} pseudo-data. We present here an extension of this EDF which also accounts for the first -wave term appearing in the low-density expansion from which it derives. It is shown that this enrichment of the ansatz on which the functional is based leads to a significant improvement of the description of neutronic systems, especially in regimes besides the pseudo--data set employed to adjust the parameters. As an illustrative application, the mass-radius relation of neutron stars is considered. In contrast to its initial version, the new functional predicts values which are qualitatively consistent with recent observations.

    nucl-thPRC(2020)·12 citations

Affiliations

first authorsco-authorsvia INSPIRE