Nuclear Theory·nucl-th

Tuesday·May 1, 2018

13 papers—7 primary·6 cross-listed

01
Optimized Perturbation Theory Applied to a Model with Flavour Symmetry $S U_{f} (3)$
Juan C. Macías🇧🇷 · Marcus Benghi Pinto🇧🇷
The \textit{optimized perturbation theory} (OPT) is implemented in the $S U_{f} (3)$ flavor symmetric Nambu--Jona-Lasinio (NJL) model to generate non-pertubative corrections to the quark pressure beyond the large- $N$ approximation. The correctness of this implementation is verified by the recovery of the already known non-perturbative results in the Hartree-Fock approximation, and by having the large- $N$ approximation as a limiting case. This formalism is then used to revisit a discussion on the discordance between the lattice data and the two flavor model prediction of the dynamical vector repulsive interactions, beyond the pseudocritical temperature. It is shown that these contradictory predictions can be corrected by considering a three quark flavor system.
nucl-thhep-lathep-ph0 citations
02
Signatures of thermalized charm quarks in all charged flow observables
Jacquelyn Noronha-Hostler🇺🇸 · Claudia Ratti🇺🇸
A long standing question in the field of heavy-ion collisions is whether charm quarks are thermalized within the Quark Gluon Plasma. In recent years, progress in lattice QCD simulations has led to reliable results for the equation of state of a system of 2+1 flavors (up, down, and strange) and 2+1+1 flavors (up, down, strange, and charm). We find that the equation of state strongly affects differential flow harmonics and a preference is seen for thermalized charm quarks at the LHC. Predictions are also made for the event-plane correlations at RHIC AuAu $s_{N N} = 200$ GeV collisions, and the scaling of differential flow observables and factorization breaking for all charged particles at LHC PbPb $s_{N N} = 5.02$ TeV collisions compared to LHC XeXe $s_{N N} = 5.44$ TeV collisions, which could be useful in answering the question: are charm quarks thermalized?
nucl-thhep-phnucl-ex4 citations
03
Studies of the structure of massive hybrid stars within a modified NJL model
Cheng-Ming Li🇨🇳 · Jin-Li Zhang🇨🇳 · Yan Yan🇨🇳 · Yong-Feng Huang🇨🇳 · Hong-Shi Zong🇨🇳
In this paper, we use the equation of state based on a modification of 2+1 flavors Nambu-Jona- Lasinio (NJL) model to study the quark matter of hybrid stars. For comparison, we utilize five EOSs of the relativistic mean-field (RMF) model to describe the hadronic phase. With the 3- window crossover interpolation approach, we try to construct relatively soft hybrid EOSs but find the maximum masses of hybrid stars do not differ too much. The results are quite close to two solar mass, which is consistent with the mass constraint of PSR J0348+0432. Furthermore it is noteworthy that the heaviest stable stars have central densities higher than that of the deconfinement transition thus suggesting a pure quark core in the hybrid star.
nucl-thastro-ph.HEPRD(2018)·41 citations
04
Distinct ground state features and the decay chains of Z = 121 Superheavy Nuclei
G. Saxena · U. K. Singh · M. Kumawat · M. Kaushik · S. K. Jain · Mamta Aggarwal
A fully systematic study of even and odd isotopes (281 $\leq$ A $\leq$ 380) of Z = 121 superheavy nuclei is presented in theoretical frameworks of Relativistic mean-field plus state dependent BCS approach and Macroscopic-Microscopic approach with triaxially deformed Nilson Strutinsky prescription. The ground state properties namely shell correction, binding energy, two- and one- proton and neutron separation energy, shape, deformation, density profile and the radius are estimated that show strong evidence for magicity in N = 164, 228. Central depletion in the charge density due to large repulsive Coulomb field indicating bubble-like structure is reported. A comprehensive analysis of the possible decay modes specifically $α$ -decay and spontaneous fission (SF) is presented and the probable $α$ -decay chains are evaluated. Results are compared with FRDM calculations and the available experimental data which show excellent agreement.
nucl-thIJMPE(2018)·8 citations
05
Description of Nuclei with Magic Number Z(N) = 6
M. Kumawat · G. Saxena · M. Kaushik · R. Sharma · S. K. Jain
Encouraged with the evidence for Z = 6 magic number in neutron-rich carbon isotopes, we have performed relativistic mean-field plus BCS calculations to investigate ground state properties of entire chains of isotopes(isotones) with Z(N) = 6 including even and odd mass nuclei. Our calculations include deformation, binding energy, separation energy, single particle energy, rms radii along with charge and neutron density profile etc., and are found in an excellent match with latest experimental results demonstrating Z = 6 as a strong magic number. N = 6 is also found to own similar kind of strong magic character.
nucl-thCan.J.Phys.(2018)·4 citations
06
Perspectives on Nuclear Structure and Scattering with the Ab Initio No-Core Shell Model
James P. Vary🇺🇸 · Pieter Maris🇺🇸 · Patrick J. Fasano🇺🇸 · Mark A. Caprio🇺🇸
Nuclear structure and reaction theory are undergoing a major renaissance with advances in many-body methods, strong interactions with greatly improved links to Quantum Chromodynamics (QCD), the advent of high performance computing, and improved computational algorithms. Predictive power, with well-quantified uncertainty, is emerging from non-perturbative approaches along with the potential for new discoveries such as predicting nuclear phenomena before they are measured. We present an overview of some recent developments and discuss challenges that lie ahead. Our focus is on explorations of alternative truncation schemes in the harmonic oscillator basis, of which our Japanese--United States collaborative work on the No-Core Monte-Carlo Shell Model is an example. Collaborations with Professor Takaharu Otsuka and his group have been instrumental in these developments.
nucl-thJPS Conf.Proc.(2018)·3 citations
07
Z+jet correlation with NLO-matched parton-shower and jet-medium interaction in high-energy nuclear collisions
Shan-Liang Zhang🇨🇳 · Tan Luo🇨🇳 · Xin-Nian Wang🇨🇳 · Ben-Wei Zhang🇨🇳
The impact of jet quenching on $Z^{0}$ -tagged jets in relativistic heavy-ion collisions at the Large Hadron Collider (LHC) is investigated. We employ Sharpa Monte Carlo program that combines next-to-leading order matrix elements with matched resummation of parton shower to compute the initial $Z^{0}$ +jet production. The Linear Boltzmann Transport (LBT) model is then used to simulate the propagation, energy attenuation of and medium response induced by jet partons in the quark-gluon plasma. With both higher-order corrections and matched soft/collinear radiation as well as a sophisticated treatment of parton energy loss and medium response in LBT, our numerical calculations can provide the best description so far of all available observables of $Z^{0}$ +jet simultaneously in both p+p and Pb+Pb collisions, in particular, the shift of the distribution in transverse momentum asymmetry $x_{jZ} = p_{T}^{jet} / p_{T}^{Z}$ , the modification of azimuthal angle correlation in $Δ ϕ_{j Z} = ∣ ϕ_{jet} - ϕ_{Z} ∣$ and the overall suppression of average number of $Z^{0}$ -tagged jets per boson $R_{jZ}$ at $s = 5.02$ TeV as measured by the CMS experiment. We also show that higher-order corrections to $Z^{0}$ +jet production play an indispensable role in understanding $Z^{0}$ +jet azimuthal angle correlation at small and intermediate $Δ ϕ_{jZ}$ , and momentum imbalance at small $x_{jZ}$ . Jet quenching of the sub-leading jets is shown to lead to suppression of $Z^{0}$ +jet correlation at small azimuthal angle difference $Δ ϕ_{jZ}$ and at small $x_{jZ}$ .
nucl-thhep-phnucl-exPRC(2018)·60 citations

Affiliations

first authorsco-authorsvia INSPIRE

Optimized Perturbation Theory Applied to a Model with Flavour Symmetry SUf​(3)

Signatures of thermalized charm quarks in all charged flow observables

Studies of the structure of massive hybrid stars within a modified NJL model

Distinct ground state features and the decay chains of Z = 121 Superheavy Nuclei

Description of Nuclei with Magic Number Z(N) = 6

Perspectives on Nuclear Structure and Scattering with the Ab Initio No-Core Shell Model

Z+jet correlation with NLO-matched parton-shower and jet-medium interaction in high-energy nuclear collisions

Affiliations

Optimized Perturbation Theory Applied to a Model with Flavour Symmetry $S U_{f} (3)$