Nuclear Theory·nucl-th

Thursday·September 29, 2016

8 papers—4 primary·4 cross-listed

01
Comprehending particle production at RHIC and LHC energies using global measurements
Sadhana Dash🇮🇳 · Basanta K. Nandi🇮🇳 · Ranjit Nayak🇮🇳 · Ashutosh Kumar Pandey🇮🇳 · Priyanka Sett🇮🇳
The centrality dependence of the charged-particle multiplicity densities ( $d N_{c h} / d η$ ) and transverse energy densities ( $d E_{T} / d η$ ) are investigated using the two-component Glauber approach for broad range of energies in heavy ion collisions at RHIC and LHC. A comprehensive study shows that the data is well described within the framework of two component model which includes the contribution of "soft processes" and "hard processes" for different centrality classes and energies. The data at two different energies are compared by means of the ratio of $d N_{c h} / d η$ (and $d E_{T} / d η$ ) to see the interplay of energy and $x$ -scaling.
nucl-thhep-phMod.Phys.Lett.A(2017)·1 citation
02
Dependence of fusion on isospin dynamics
K. Godbey · A.S. Umar · C. Simenel
We introduce a new microscopic approach to calculate the dependence of fusion barriers and cross-sections on isospin dynamics. The method is based on the time-dependent Hartree-Fock theory and the isoscalar and isovector properties of the energy density functional (EDF). The contribution to the fusion barriers originating from the isoscalar and isovector parts of the EDF is calculated. It is shown that for non-symmetric systems the isovector dynamics influence the sub-barrier fusion cross-sections. For most systems this results in an enhancement of the sub-barrier cross-sections, while for others we observe differing degrees of hindrance. We use this approach to provide an explanation of recently measured fusion cross sections which show a surprising enhancement at low $E_{c.m.}$ energies for the system $^{40}$ Ca+ $^{132}$ Sn as compared to the more neutron-rich system $^{48}$ Ca+ $^{132}$ Sn, and discuss the dependence of sub-barrier fusion cross-sections on transfer.
nucl-thPRC(2017)·47 citations
03
Tidal deformability of neutron and hyperon star with relativistic mean field equations of state
Bharat Kumar🇮🇳 · S. K. Biswal🇮🇳 · S. K. Patra🇮🇳
We systematically study the tidal deformability for neutron and hyperon stars using relativistic mean field (RMF) equations of state (EOSs). The tidal effect plays an important role during the early part of the evolution of compact binaries. Although, the deformability associated with the EOSs has a small correction, it gives a clean gravitational wave signature in binary inspiral. These are characterized by various love numbers kl (l=2, 3, 4), that depend on the EOS of a star for a given mass and radius. The tidal effect of star could be efficiently measured through advanced LIGO detector from the final stages of inspiraling binary neutron star (BNS) merger.
nucl-thPRC(2017)·71 citations
04
Three-body system of $π π Σ_{c}$
Bingwei Long🇨🇳
The existence of near-threshold charmed baryon $Λ_{c} (2595)^{+}$ implies that the pion and the lightest, isospin- $1$ charmed baryon $Σ_{c}$ interact very strongly at extremely low energies. Using the two-flavor version of heavy hadron chiral perturbation theory, I explore the direct consequences of this strong force by investigating whether the $Σ_{c}$ can trap two very soft pions to form any visible hadronic states. The answer is positive. It is found without tuning any free parameters or ultraviolet cutoff that the state in question, with quantum numbers $I (J^{P}) = 1 (\frac{1}{2}^{+})$ , presents itself as a resonance pole only a few MeVs away from the $π π Σ_{c}$ threshold. Subleading corrections are estimated with power-counting arguments, and the smallness of pion momenta is found to facilitate the reliability of the analysis. Because of its proximity in mass, this excited $Σ_{c}$ resonance is speculated to be related to the broad resonance labeled as $Λ_{c}^{+} (2765)$ .
nucl-thhep-exhep-ph3 citations
05
Study of hot and dense nuclear matter in effective QCD model
Chowdhury Aminul Islam🇮🇳
In this thesis we use various effective QCD models to investigate hot and dense nuclear matter created in heavy ion collisions. To characterize such matter, we mainly exploit correlation functions and some of the associated spectral properties. We explore the vector meson current-current correlation function with and without the influence of vector interaction in Nambu\textendash Jona-Lasinio (NJL) model and also in its Polyakov loop extended version (PNJL). As a spectral property we have computed the dilepton rate which is found to be enhanced in strongly interacting QGP (sQGP) as compared to the Born rate in a weakly coupled QGP. We further consider the idea of entanglement between the chiral and confinement dynamics through the entangled PNJL (EPNJL) model and re-explore the vector spectral function and the spectral property such as the dilepton production rate studied in our earlier effort. Because of the strong entanglement, the coupling strengths run with the temperature and chemical potential. The implications of such running on the dilepton rate have been discussed in details. The Euclidean vector correlator and the response of the conserved density fluctuations related with the temporal vector correlator have also been investigated. We have considered both the scenarios, i.e. presence and absence of the vector interaction. The inclusion of the vector interaction also brings forth some intriguing issues in the fluctuation of conserved density, namely the QNS. It has been discussed in details and we try to address it using EPNJL model. We also assume the QGP to be made of a non-interacting quarks, antiquarks and gluons and construct a partition function which is restricted by the assumption of a color singlet projection to conform with the $S U (3)_{c}$ symmetry. This type of simple quantum statistical description exhibits very interesting features, which we have discussed in details.
↳ hep-phnucl-th0 citations
06
A review of the open charm and open bottom systems
Hua-Xing Chen🇨🇳 · Wei Chen🇨🇦 · Xiang Liu🇨🇳 · Yan-Rui Liu🇨🇳 · Shi-Lin Zhu🇨🇳
Since the discovery of the first charmed meson in 1976, many open-charm and open-bottom hadrons were observed. In 2003 two narrow charm-strange states $D_{s 0}^{*} (2317)$ and $D_{s 1} (2460)$ were discovered by the BaBar and CLEO Collaborations, respectively. After that, more excited heavy hadrons were reported. In this work, we review the experimental and theoretical progress in this field.
↳ hep-phhep-exhep-latnucl-ex+1Rept.Prog.Phys.(2017)·480 citations
07
Anomalous transport from holography: Part II
Yanyan Bu🇮🇱 · Michael Lublinsky🇮🇱 · Amir Sharon🇮🇱
This is a second study of chiral anomaly induced transport within a holographic model consisting of anomalous $U (1)_{V} \times U (1)_{A}$ Maxwell theory in Schwarzschild- $A d S_{5}$ spacetime. In the first part, chiral magnetic/separation effects (CME/CSE) are considered in presence of a static spatially-inhomogeneous external magnetic field. Gradient corrections to CME/CSE are analytically evaluated up to third order in the derivative expansion. Some of the third order gradient corrections lead to an anomaly-induced negative $B^{2}$ -correction to the diffusion constant. We also find non-linear in $B$ modifications to the chiral magnetic wave (CMW). In the second part, we focus on the experimentally interesting case of the axial chemical potential being induced dynamically by a constant magnetic and time-dependent electric fields. Constitutive relations for the vector/axial currents are computed employing two different approximations: (a) derivative expansion (up to third order) but fully nonlinear in the external fields, and (b) weak electric field limit but resuming all orders in the derivative expansion. A non-vanishing non-linear axial current (CSE) is found in the first case. Dependence on magnetic field and frequency of linear transport coefficient functions (TCFs) is explored in the second.
↳ hep-thcond-mat.mes-hallhep-phnucl-thEPJC(2017)·15 citations
08
Skyrme model study of proton and neutron properties in a strong magnetic field
Bing-Ran He🇨🇳
The proton and neutron properties in a uniform magnetic field are investigated. The Gell-Mann-Nishijima formula is shown to be satisfied for baryon states. It is found that with increasing magnetic field strength, the proton mass first decreases and then increases, while the neutron mass always increases. The ratio between magnetic moment of proton and neutron increases with the increase of the magnetic field strength. With increasing magnetic field strength, the size of proton first increases and then decreases, while the size of neutron always decreases. The present analyse implies that in the core part of the magnetar, the equation of state depend on the magnetic field, which modifies the mass limit of the magnetar.
↳ hep-phnucl-thPLB(2017)·17 citations

Affiliations

first authorsco-authorsvia INSPIRE