Nuclear Theory·nucl-th

Wednesday·August 16, 2017

8 papers—5 primary·3 cross-listed

01
The symmetry energy in nucleon and quark matter
Lie-Wen Chen🇨🇳
The symmetry energy characterizes the isospin dependent part of the equation of state of isospin asymmetric strong interaction matter and it plays a critical role in many issues of nuclear physics and astrophysics. In this talk, we briefly review the current status on the determination of the symmetry energy in nucleon (nuclear) and quark matter. For nuclear matter, while the subsaturation density behaviors of the symmetry energy are relatively well-determined and significant progress has been made on the symmetry energy around saturation density, the determination of the suprasaturation density behaviors of the symmetry energy remains a big challenge. For quark matter, which is expected to appear in dense matter at high baryon densities, we briefly review the recent work about the effects of quark matter symmetry energy on the properties of quark stars and the implication of possible existence of heavy quark stars on quark matter symmetry energy. The results indicate that the $u$ and $d$ quarks could feel very different interactions in isospin asymmetric quark matter, which may have important implications on the isospin effects of partonic dynamics in relativistic heavy-ion collisions.
nucl-thastro-ph.HEhep-phnucl-exNucl.Phys.Rev.(2017)·32 citations
02
From quark and nucleon correlations to discrete symmetry and clustering in nuclei
Genis Musulmanbekov🇷🇺
Starting with a quark model of nucleon structure in which the valence quarks are strongly correlated within a nucleon, the light nuclei are constructed by assuming similar correlations of the quarks of neighboring nucleons. Applying the model to larger collections of nucleons reveals the emergence of the face-centered cubic (FCC) symmetry at the nuclear level. Nuclei with closed shells possess octahedral symmetry. Binding of nucleons are provided by quark loops formed by three and four nucleon correlations. Quark loops are responsible for formation of exotic (borromean) nuclei, as well. The model unifies independent particle (shell) model, liquid-drop and cluster models.
nucl-thExotic Nuclei (World Scientific, 2016), p…·0 citations
03
Open charm production in central Pb+Pb collisions at the CERN SPS: statistical model estimates
R. V. Poberezhnyuk🇺🇦 · M. Gazdzicki🇵🇱 · M. I. Gorenstein🇺🇦
Charm particle production in nucleus-nucleus collisions at the CERN SPS energies is considered within a statistical approach. Namely, the Statistical Model of the Early Stage is used to calculate mean multiplicity of charm particles in central Pb+Pb collisions. A small number of produced charm particles necessitates the use of the exact charm conservation law. The model predicts a rapid increase of mean charm multiplicity as a function of collision energy. The mean multiplicity calculated for central Pb+Pb collisions at the center of mass energy per nucleon pair $s_{N N} = 17.3$ GeV exceeds significantly the experimental upper limit. Thus, in order to describe open charm production model parameters and/or assumptions should be revised.
nucl-thhep-phActa Phys.Polon.B(2017)·12 citations
04
Addendum: Muon-neutrino-induced charged current pion production
U. Mosel🇩🇪 · K. Gallmeister🇩🇪
This short paper is an addendum to a recent publication on charged current neutrino-induced pion production (Phys.\ Rev.\ C96 (2017) no.1, 015503). It presents comparisons of pion production cross sections measured at the T2K near detector for a CH target.
nucl-thhep-exnucl-exPRC(2017)·31 citations
05
Existence of inelastic supernumerary nuclear rainbow in $^{16}$ O+ $^{12}$ C scattering
S. Ohkubo · Y. Hirabayashi · A. A. Ogloblin
The existence of a supernumerary nuclear rainbow in inelastic scattering is reported. This is done by studying inelastic $^{16}$ O scattering from $^{12}$ C, exciting the $2^{+}$ (4.44 MeV) state of $^{12}$ C and elastic scattering at the incident energies in the range 124 to 200 MeV, using the coupled channels method. An extended double folding potential is used. This is derived from realistic wave functions for $^{12}$ C and $^{16}$ O calculated with a microscopic $α$ cluster model and a finite-range density-dependent nucleon-nucleon force. Excitations to the $2^{+}$ (4.44 MeV), 3 $^{-}$ (9.64 MeV) and $4^{+}$ (14.08 MeV) states of $^{12}$ C, and the $3^{-}$ (6.13 MeV) and $2^{+}$ (6.92 MeV) states of $^{16}$ O are included in the coupled channels calculations. The emergence of the supernumerary bow is understood by the properties of both the Luneburg-lens-like potential in the internal region and diffuse attraction in the outer region. The existence of a supernumerary rainbow for inelastic scattering in addition to the existence of a dynamically created secondary rainbow and a dynamically refracted primary rainbow for elastic scattering, which are not observed in meteorological rainbows, further deepens the understanding of nuclear rainbows.
nucl-thnucl-exPRC(2017)·3 citations
06
Anomalous thermoelectric phenomena in lattice models of multi-Weyl semimetals
E. V. Gorbar · V. A. Miransky · I. A. Shovkovy · P. O. Sukhachov
The thermoelectric transport coefficients are calculated in a generic lattice model of multi-Weyl semimetals with a broken time-reversal symmetry by using the Kubo's linear response theory. The contributions connected with the Berry curvature-induced electromagnetic orbital and heat magnetizations are systematically taken into account. It is shown that the thermoelectric transport is profoundly affected by the nontrivial topology of multi-Weyl semimetals. In particular, the calculation reveals a number of thermal coefficients of the topological origin which describe the anomalous Nernst and thermal Hall effects in the absence of background magnetic fields. Similarly to the anomalous Hall effect, all anomalous thermoelectric coefficients are proportional to the integer topological charge of the Weyl nodes. The dependence of the thermoelectric coefficients on the chemical potential and temperature is also studied.
↳ cond-mat.mes-hallnucl-thPRB(2017)·34 citations
07
The Role of QCD Monopoles in Jet Quenching
Adith Ramamurti🇺🇸 · Edward Shuryak🇺🇸
QCD monopoles are magnetically charged quasiparticles whose Bose-Einstein condensation (BEC) at $T < T_{c}$ creates electric confinement and flux tubes. The "magnetic scenario" of QCD proposes that scattering on the non-condensed component of the monopole ensemble at $T > T_{c}$ is responsible for the unusual kinetic properties of QGP. In this paper, we study the contribution of the monopoles to jet quenching phenomenon, using the BDMPS framework and hydrodynamic backgrounds. In the lowest order for cross sections, we calculate the nuclear modification factor, $R_{AA},$ and azimuthal anisotropy, $v_{2}$ , of jets, as well as the dijet asymmetry, $A_{j}$ , and compare those to the available data. We find relatively good agreement with experiment when using realistic hydrodynamic backgrounds. In addition, we find that event-by-event fluctuations are not necessary to reproduce $R_{AA}$ and $v_{2}$ data, but play a role in $A_{j}$ . Since the monopole-induced effects are maximal at $T \approx T_{c}$ , we predict that their role should be significantly larger, relative to quarks and gluons, at lower RHIC energies.
↳ hep-phnucl-thPRD(2018)·14 citations
08
Mass spectra and radiative transitions of doubly heavy baryons in a relativized quark model
Qi-Fang Lü🇨🇳 · Kai-Lei Wang🇨🇳 · Li-Ye Xiao🇨🇳 · Xian-Hui Zhong🇨🇳
We study the mass spectra and radiative decays of doubly heavy baryons within the diquark picture in a relativized quark model. The mass of the $J^{P} = 1/ 2^{+}$ $Ξ_{cc}$ ground state is predicted to be 3606 MeV, which is consistent with the mass of $Ξ_{cc}^{++} (3621)$ newly observed by the LHCb collaboration. The predicted mass gap between two $S$ wave states, $Ξ_{cc}^{*}$ ( $J^{P} = 3/ 2^{+}$ ) and $Ξ_{cc}$ ( $J^{P} = 1/ 2^{+}$ ), is 69 MeV. Furthermore, the radiative transitions of doubly heavy baryons are also estimated by using the realistic wave functions obtained from relativized quark model. The radiative decay widths of $Ξ_{cc}^{*++} \to Ξ_{cc}^{++} γ$ and $Ξ_{cc}^{*+} \to Ξ_{cc}^{+} γ$ are predicted to be about 7 and 4 keV, respectively. These predictions of doubly heavy baryons can provide helpful information for future experimental searches.
↳ hep-phhep-exnucl-thPRD(2017)·119 citations

Affiliations

first authorsco-authorsvia INSPIRE