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Nuclear Theory·nucl-th

Tuesday·June 11, 2019

9 papers—4 primary·5 cross-listed

All9Primary4Cross-lists5
  1. 01

    Sensitivity of the excitation functions of collective flow to relativistic scalar and vector meson interactions in the relativistic quantum molecular dynamics model RQMD.RMF

    Yasushi Nara🇯🇵 · Horst Stoecker🇩🇪

    Relativistic quantum molecular dynamics with scalar and vector interactions based on the relativistic mean meson field theory, RQMD.RMF, is developed.It is implemented into the microscopic transport code JAM.The sensitivity of the directed and of the elliptic proton flow in high energy heavy-ion collisions on the stiffness of the RMF equation of state (EoS) is examined. These new calculations are compared to experimental data at mid-central Au + Au collisions in the beam energy range GeV. This new RQMD model with the relativistic mean field scalar and vector meson interactions does describe consistently, with one RMF parameter set,the beam energy dependence of both the directed flow and the elliptic flow,from SIS18 to AGS and RHIC BES-II energies, GeV.There are different sensitivities of these different kinds of flow to the EoS: elliptic flow is most sensitive to the nuclear incompressibility constant,at the moderate beam energies GeV,whereas the directed flow is most sensitive to the effective baryon mass at saturation density at GeV. Matters abruptly change in the next higher energy range, GeV:the directed flow data show a double change of sign of the slope of , inverting twice in this energy range,in sudden contradiction to the RQMD.RMF calculation for a monotonous, stiff EoS. This surprising oscillating behavior,a double change of sign of the slope, points to the appearance of a hitherto unknown first-order phase transition in excited QCD matter at high baryon densities in mid-central Au + Au collisions.

    nucl-thhep-phnucl-exPRC(2019)·42 citations
  2. 02

    Ab initio calculations of p-shell nuclei up to N2LO in chiral Effective Field Theory

    Pieter Maris🇺🇸

    Nuclear structure and reaction theory are undergoing a major renaissance with advances in many-body methods, realistic interactions with greatly improved links to Quantum Chromodynamics, the advent of high performance computing, and improved computational algorithms. State-of-the-art two- and three-nucleon interactions obtained from chiral Effective Field Theory provide a theoretical foundation for nuclear theory with controlled approximations. With highly efficient numerical codes, tuned to the current generation of supercomputers, we can perform ab-initio nuclear structure calculations for a range of nuclei to a remarkable level of numerical accuracy, with quantifiable numerical uncertainties. Here we present an overview of recent results for No-Core Configuration Interaction calculations of p-shell nuclei using these chiral interactions up to next-to-next-to-leading order, including three-body forces. We show the dependence of the ground state energies on the chiral order; we also present excitation spectra for selected nuclei and compare the results with experimental data.

    nucl-thJ.Phys.Conf.Ser.(2019)·4 citations
  3. 03

    Correlations in ultra-relativistic nuclear collisions with strings

    Martin Rohrmoser🇵🇱 · Wojciech Broniowski🇵🇱

    While string models describe initial state radiation in ultra-relativistic nuclear collisions well, they mainly differ in their end-point positions of the strings in spatial rapidity. We present a generic model where wounded constituents are amended with strings whose both end-point positions fluctuate and analyze semi-analytically various scenarios of string-end-point fluctuations. In particular we constrain the different cases to experimental data on rapidity spectra from collisions at ~GeV, and explore their respective two-body correlations, which allows to partially discriminate the possible solutions.

    nucl-thActa Phys.Polon.Supp.(2020)·0 citations
  4. 04

    Bayesian analysis of capture reactions and

    Pradeepa Premarathna · Gautam Rupak

    Bayesian analysis of the radiative capture reactions and are performed to draw inferences about the cross sections at threshold. We do a model comparison of two competing effective field theory power countings for the capture reactions. The two power countings differ in the contribution of two-body electromagnetic currents. In one power counting, two-body currents contribute at leading order, and in the other they contribute at higher orders. The former is favored for if elastic scattering data in the incoming channel is considered in the analysis. Without constraints from elastic scattering data, both the power countings are equally favored. For , the first power counting with two-body current contributions at leading order is favored with or without constraints from elastic scattering data.

    nucl-thastro-ph.SREPJA(2020)·25 citations

Affiliations

first authorsco-authorsvia INSPIRE