Nuclear Theory·nucl-th

Wednesday·May 9, 2018

9 papers—5 primary·4 cross-listed

01
[Submitted on 7 May 2018]
Calculating charged particle observables using modified Wood Saxon model in HIJING for U+U collisions at $s_{N N}$ = 193 GeV
S. K. Tripathy🇮🇳 · M. Younus🇮🇳 · Z. Naik🇮🇳 · P. K. Sahu🇮🇳
We have implemented spherical harmonics in default Wood Saxon distribution of the HIJING model and calculated various physical observables such as transverse momentum, charged particle multiplicity, nuclear modification factor and particle ratios for charged particles at top RHIC energy with collisions of Uranium (U) nuclei. Results have been compared with available experimental data. We observe that, a particular type of collision configuration can produce significant magnitude change in observables. We have noticed that the tip-tip configuration shows higher magnitude of particle yield in central collisions, while the body-body configuration shows higher value in the cases of peripheral collisions, with the flip in the trend occurring for the mid-central U+U collisions. We observe that particle ratios are independent of configuration type.
Comments:
10 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1805.02713 [pdf]
NPA(2018)·5 citations
02
[Submitted on 7 May 2018]
Consistent relativistic mean-field models: critical parameters values
M. Dutra · O. Lourenço · D. P. Menezes
We revisit the study published in [1], related to the behavior of 34 relativistic mean-field models, previously selected because they satisfy bulk nuclear matter properties, here used to compute the critical parameters of the symmetric nuclear matter. We evaluate their critical temperature, pressure, and density and compare with some values encountered in the literature. We also show that these parameters are correlated with the incompressibility calculated at the zero temperature regime.
Comments:
4 pages, 3 figures, 3 table. Invited talk presented at the XIV International Workshop on Hadron Physics, Florianópolis, Brazil, March 2018
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1805.02735 [pdf]
1 citation
03
[Submitted on 7 May 2018]
Multinucleon Short-Range Correlation Model for Nuclear Spectral Functions
Oswaldo Artiles🇺🇸
The main goal of the research presented in this dissertation was to develop a theoretical model for relativistic nuclear spectral functions at high missing momenta and removal energies based on the multi-nucleon short-range correlation (SRC) model. The nuclear spectral functions are necessary for the description of high energy nuclear processes currently being studied at different labs such as JLAB, LHC and FNAL. The model followed the effective Feynman diagrammatic approach in order to account for the relativistic effects important in the SRC domain. In addition to the two-nucleon (2N) SRC with center of mass motion contribution, the contribution of the three-nucleon SRCs to the spectral functions was also derived. The latter was modeled based on the assumption that the 3N SRCs are a product of two sequential short range nucleon-nucleon (NN) interactions. The nuclear spectral functions models were derived from two theoretical frameworks for evaluating covariant Feynman diagrams: In the first, referred to as the virtual nucleon approximation, the Feynman diagrams were reduced to the time ordered non-covariant diagrams by evaluating the nucleon spectators in the SRC at their positive energy poles, neglecting explicitly the contribution from vacuum diagrams. In the second approach, referred to as the light-front approximation, the boost invariant nuclear spectral function was formulated in the light-front reference frame in which case the vacuum diagrams are kinematically suppressed and the bound nucleon is described by its light-front variables such as momentum fraction, transverse momentum and invariant mass. On the basis of the derived nuclear spectral functions, the corresponding computational models were developed from which the numerical estimates of the SRC spectral functions, the SRC momentum distributions, and the SRC density matrices were obtained.
Comments:
150 pages, 29 figures, PhD Dissertation (Department of Physics, Florida International University, Miami, Florida)
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1805.02778 [pdf]
1 citation
04
[Submitted on 8 May 2018]
Description of neutron-rich odd-mass krypton isotopes within the interacting boson-fermion model based on the Gogny energy density functional
K. Nomura · R. Rodríguez-Guzmán · L. M. Robledo
The low-lying structure of neutron-rich odd-mass Kr isotopes is studied within the interacting boson-fermion model (IBFM) based on the Gogny-D1M energy density functional (EDF). The $(β, γ)$ -deformation energy surfaces, spherical single-particle energies and occupation probabilities of the odd-mass systems are obtained using the constrained Hartree-Fock-Bogoliubov (HFB) approximation. Those quantities are used as a microscopic input to determine most of the parameters of the IBFM Hamiltonian. The remaining parameters are specifically tailored to the experimental spectrum for each of the studied odd-mass nuclei. A gradual structural evolution is predicted for the odd-mass isotopes $^{87 - 95}$ Kr as a function of the nucleon number which, agrees well with the gradual growth of collectivity observed experimentally in the neighboring even-even isotopes.
Comments:
9 pages, 11 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1805.02865 [pdf]
PRC(2018)·11 citations
05
[Submitted on 8 May 2018]
Towards QCD-assisted hydrodynamics for heavy-ion collision phenomenology
A. Dubla🇩🇪 · S. Masciocchi🇩🇪 · J. M. Pawlowski🇩🇪 · B. Schenke🇺🇸 · C. Shen🇺🇸 · J. Stachel🇩🇪
Heavy-ion collisions are well described by a dynamical evolution with a long hydrodynamical phase. In this phase the properties of the strongly coupled quark-gluon plasma are reflected in the equation of state (EoS) and the transport coefficients, most prominently by the shear and bulk viscosity over entropy density ratios $η$ /s(T) and $ζ$ /s(T), respectively. While the EoS is by now known to a high accuracy, the transport coefficients and in particular their temperature and density dependence are not well known from first-principle computations yet, as well as the possible influence they can have once used in hydrodynamical simulations. In this work, the most recent QCD-based parameters are provided as input to the MUSIC framework. A ratio $η$ /s(T) computed with a QCD based approach is used for the first time \cite{Haas:2013hpa,Christiansen:2014ypa}. The IP-Glasma model is used to describe the initial energy density distribution, and UrQMD for the dilute hadronic phase. Simulations are performed for Pb--Pb collisions at $s_{NN}$ = 2.76 TeV, for different centrality intervals. The resulting kinematic distributions of the particles produced in the collisions are compared to data from the LHC, for several experimental observables. The high precision of the experimental results and the broad variety of observables considered allow to critically verify the quality of the description based on first-principle input to the hydrodynamic evolution.
Comments:
10 pages, 8 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1805.02985 [pdf]
NPA(2018)·40 citations
06
[Submitted on 7 May 2018] (cross-list from hep-ph)
Second-order Hydrodynamics in Next-to-Leading-Order QCD
Jacopo Ghiglieri🇨🇭 · Guy D. Moore🇩🇪 · Derek Teaney🇺🇸
We compute the hydrodynamic relaxation times $τ_{π}$ and $τ_{j}$ for hot QCD at next-to-leading order in the coupling with kinetic theory. We show that certain dimensionless ratios of second-order to first-order transport coefficients obey bounds which apply whenever a kinetic theory description is possible; the computed values lie somewhat above these bounds. Strongly coupled theories with holographic duals strongly violate these bounds, highlighting their distance from a quasiparticle description.
Comments:
5 pages, 3 figures. v2: note and reference added, version accepted for publication on Phys. Rev. Lett
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1805.02663 [pdf]
PRL(2018)·35 citations
07
[Submitted on 7 May 2018] (cross-list from hep-ph)
Particle multiplicities in the central region of high-energy collisions from $k_{T}$ -factorization with running coupling corrections
Adrian Dumitru🇺🇸 · Andre V. Giannini🇧🇷 · Matthew Luzum🇧🇷 · Yasushi Nara🇯🇵
Horowitz and Kovchegov have derived a $k_{T}$ -factorization formula for particle production at small $x$ which includes running coupling corrections. We perform a first numerical analysis to confront the theory with data on the energy and centrality dependence of particle multiplicities at midrapidity in high-energy p+A (and A+A) collisions. Moreover, we point out a strikingly different dependence of the multiplicity per participant on $N_{part}$ in p+Pb vs.\ Pb+Pb collisions at LHC energies, and argue that the observed behavior follows rather naturally from the convolution of the gluon distributions of an asymmetric vs. symmetric projectile and target.
Comments:
8 pages, 8 figures; v3: 2 new figures, matches the version accepted by Physics Letters B
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1805.02702 [pdf]
PLB(2018)·13 citations
08
[Submitted on 8 May 2018] (cross-list from nucl-ex)
Search for the Chiral Magnetic Effect in Relativistic Heavy-Ion Collisions
Jie Zhao🇺🇸
Relativistic heavy-ion collisions provide an ideal environment to study the emergent phenomena in quantum chromodynamics (QCD). The chiral magnetic effect (CME) is one of the most interesting, arising from the topological charge fluctuations of QCD vacua, immersed in a strong magnetic field. Since the first measurement nearly a decade ago of the possibly CME-induced charge correlation, extensive studies have been devoted to background contributions to those measurements. Many new ideas and techniques have been developed to reduce or eliminate the backgrounds. This article reviews these developments and the overall progress in the search for the CME.
Comments:
37 pages, 25 figures, invited review by International Journal of Modern Physics A
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1805.02814 [pdf]
Int.J.Mod.Phys.A(2018)·29 citations
09
[Submitted on 8 May 2018] (cross-list from hep-ph)
The gluon and charm content of the deuteron
Stanley J. Brodsky🇺🇸 · Kelly Yu-Ju Chiu🇺🇸 · Jean-Philippe Lansberg🇫🇷 · Nodoka Yamanaka🇫🇷
We evaluate the frame-independent gluon and charm parton-distribution functions (PDFs) of the deuteron utilizing light-front quantization and the impulse approximation. We use a nuclear wave function obtained from solving the nonrelativistic Schroedinger equation with the realistic Argonne v18 nuclear force, which we fold with the proton PDF. The predicted gluon distribution in the deuteron (per nucleon) is a few percent smaller than that of the proton in the domain x_{bj} = Q^2 / (2 p_N \cdot q) \sim 0.4, whereas it is strongly enhanced for x_{bj} larger than 0.6. We discuss the applicability of our analysis and comment on how to extend it to the kinematic limit x_{bj} \to 2. We also analyze the charm distribution of the deuteron within the same approach by considering both the perturbatively and non-perturbatively generated (intrinsic) charm contributions. In particular, we note that the intrinsic-charm content in the deuteron will be enhanced due to 6-quark "hidden-color" QCD configurations.
Comments:
9 pages, 10 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1805.03173 [pdf]
PLB(2018)·23 citations

Affiliations

first authorsco-authorsvia INSPIRE