Nuclear Theory·nucl-th

Friday·May 3, 2019

11 papers—4 primary·7 cross-listed

05
Conformal perturbation theory confronts lattice results in the vicinity of a critical point
Michele Caselle🇮🇹 · Nicodemo Magnoli🇮🇹 · Alessandro Nada🇩🇪 · Marco Panero🇮🇹 · Marcello Scanavino🇮🇹
We study the accuracy and predictive power of conformal perturbation theory by a comparison with lattice results in the neighborhood of the finite-temperature deconfinement transition of SU(2) Yang-Mills theory, assuming that the infrared properties of this non-Abelian gauge theory near criticality can be described by the Ising model. The results of this comparison show that conformal perturbation theory yields quantitatively accurate predictions in a broad temperature range. We discuss the implications of these findings for the description of the critical point (belonging to the same universality class) of another strongly coupled, non-supersymmetric non-Abelian gauge theory: the critical end-point in the phase diagram of QCD at finite temperature and finite quark chemical potential.
↳ hep-lathep-phhep-thnucl-thPRD(2019)·7 citations
06
Investigate the pentaquark resonance in the $N K$ system
Xuejie Liu🇨🇳 · Hongxia Huang🇨🇳 · Jialun Ping🇨🇳
A dynamical calculation of pentaquark systems with quark contents $uu dd s ˉ$ is performed in the framework of quark delocalization color screening model with the help of resonating group method. The effective potentials between baryon and meson clusters are given, and the possible bound states or resonances are investigated. The single calculations show that the $N K^{*}$ with $I = 0, J^{P} = \frac{1}{2}^{-}$ , $Δ K^{*}$ with $I = 1, J^{P} = \frac{1}{2}^{-}$ , and $Δ K^{*}$ with $I = 2, J^{P} = \frac{3}{2}^{-}$ are all bound, but they all turns into scattering states by coupling with the corresponding open channels. A possible resonance state $Δ K^{*}$ with $I = 1, J^{P} = \frac{5}{2}^{-}$ is proposed. The mass is around $2110.5$ MeV, and the decay modes are $N K$ in $D$ -wave or $N K π π$ in $P$ -waves.
↳ hep-phnucl-thPRC(2019)·6 citations
07
$Ξ (1690)^{-}$ resonance production via $K^{-} p \to K^{+} K^{-} Λ$
Seung-il Nam🇰🇷 · Jung Keun Ahn🇰🇷
In this talk, we investigate $Ξ (1690)^{-}$ production from the $K^{-} p \to K^{+} K^{-} Λ$ reaction wit the effective Lagrangian method and consider the $s$ - and $u$ -channel $Σ/Λ$ ground states and resonances for the $Ξ$ -pole contributions, in addition to the $s$ -channel $Λ$ , $u$ -channel nucleon pole, and $t$ -channel $K^{-}$ -exchange for the $ϕ$ -pole contributions. The $Ξ$ -pole includes $Ξ (1320)$ , $Ξ (1535)$ , $Ξ (1690) (J^{p} = 1/ 2^{-})$ , and $Ξ (1820) (J^{p} = 3/ 2^{-})$ . We compute the Dalitz plot density of $(d^{2} σ / d M_{K^{+} K^{-}} d M_{K^{-} Λ}$ at 4.2 GeV $/ c$ ) and the total cross sections for the $K^{-} p \to K^{+} K^{-} Λ$ . Employing the parameters from the fit, we present the cross sections for the two-body $K^{-} p \to K^{+} Ξ (1690)^{-}$ reaction near the threshold. We also demonstrate that the Dalitz plot analysis for $p_{K^{-}} = 1.915 \sim 2.065$ GeV/c makes us to explore direct information for $Ξ (1690)^{-}$ production, which can be done by future $K^{-}$ beam experiments.
↳ hep-phhep-exnucl-thJPS Conf.Proc.(2019)·2 citations
08
Role of crustal physics in the tidal deformation of a neutron star
Bhaskar Biswas · Rana Nandi · Prasanta Char · Sukanta Bose
In the late inspiral phase, gravitational waves from binary neutron star mergers carry the imprint of the equation of state due to the tidally deformed structure of the components. If the stars contain solid crusts, then their shear modulus can affect the deformability of the star and, thereby, modify the emitted signal. Here, we investigate the effect of realistic equations of state (EOSs) of the crustal matter, with a realistic model for the shear modulus of the stellar crust in a fully general relativistic framework. This allows us to systematically study the deviations that are expected from fluid models. In particular, we use unified EOSs, both relativistic and non-relativistic, in our calculations. We find that realistic EOSs of crusts cause a small correction, of $\sim 1%$ , in the second Love number. This correction will likely be subdominant to the statistical error expected in LIGO-Virgo observations at their respective advanced design sensitivities, but rival that error in third generation detectors. For completeness, we also study the effect of crustal shear on the magnetic-type Love number and find it to be much smaller.
↳ gr-qcastro-ph.HEnucl-thPRD(2019)·29 citations
09
Diffractive excitation in $pp$ and $p A$ collisions at high energies
V. P. Goncalves🇧🇷 · R. Palota da Silva🇧🇷 · P. V. R. G. Silva🇧🇷
In this paper we consider the Good - Walker approach for the diffractive excitation and updated the Miettinen -- Pumplin (MP) model for $pp / p ˉ p$ collisions considering the recent LHC data for the total and elastic $pp$ cross sections. The behavior of the total, elastic and diffractive cross sections is analyzed and predictions for the energies of Run 3 of the LHC and those of the Cosmic Rays experiments are derived. Our results demonstrate that the MP model is able to describe the current data and that it implies that the cross section for the diffraction excitation in $pp$ collisions is almost constant in the energy range probed by the LHC and slowly decreases at higher energies. Our results indicate that the Pumplin bound is not reached at the LHC and Cosmic Ray energies. Moreover, the implications of the diffractive excitation in $p A$ collisions is discussed. In particular, the MP model, constrained by the $pp$ data, is used to derive the main quantities present in the treatment of the diffractive excitation in $p A$ collisions. Predictions for the total, elastic and diffractive $p A$ cross sections are presented considering different nuclei. We demonstrate that the effect of fluctuations decreases at larger energies and heavier nuclei. The energy dependence of the diffractive excitation cross section in $p A$ collisions is estimated for different nuclei and compared with the predictions for the proton dissociation induced by photon interactions.
↳ hep-phhep-exnucl-thPRD(2019)·10 citations
10
Equation of state for hot QCD and compact stars from a mean field approach
Anton Motornenko🇩🇪 · Jan Steinheimer🇩🇪 · Volodymyr Vovchenko🇩🇪 · Stefan Schramm🇩🇪 · Horst Stoecker🇩🇪
The thermodynamic properties of high temperature and high density QCD-matter are explored within the Chiral SU(3)-flavor parity-doublet Polyakov-loop quark-hadron mean-field model, CMF. The quark sector of the CMF model is tuned to describe the $μ_{B} = 0$ thermodynamics data of lattice QCD. The resulting lines of constant physical variables as well as the baryon number susceptibilities are studied in some detail in the temperature/chemical potential plane. The CMF model predicts three consecutive transitions, the nuclear first-order liquid-vapor phase transition, chiral symmetry restoration, and the cross-over transition to a quark-dominated phase. All three phenomena are cross-over, for most of the $T - μ_{B}$ -plane. The deviations from the free ideal hadron gas baseline at $μ_{B} = 0$ and $T \approx 100 - 200$ MeV can be attributed to remnants of the liquid-vapor first order phase transition in nuclear matter. The chiral crossing transition determines the baryon fluctuations at much higher $μ_{B} \approx 1.5$ GeV, and at even higher baryon densities $μ_{B} \approx 2.4$ GeV, the behavior of fluctuations is controlled by the deconfinement cross-over. The CMF model also describe well the static properties of high $μ_{B}$ neutron stars as well as the new neutron star merger observations. The effective EoS presented here describes simultaneously lattice QCD results at $μ_{B} = 0$ , as well as observed physical phenomena (nuclear matter and neutron star matter) at $T ≅ 0$ and high densities, $μ_{B} > 1$ GeV.
↳ hep-phastro-ph.HEnucl-thPRC(2020)·118 citations
11
Dark matter and bubble nucleation in old neutron stars
A. Herrero🇪🇸 · M. A. Pérez-García🇪🇸 · J. Silk🇫🇷 · C. Albertus🇪🇸
We study the probability for nucleation of quark matter droplets in the dense cold cores of old neutron stars induced by the presence of a self-annihilating dark matter component, $χ$ . Using a parameterized form of the equation of state for hadronic and quark phases of ordinary matter, we explore the thermodynamic conditions under which droplet formation is facilitated by the energy injection from $χ$ self-annihilations. We obtain the droplet nucleation time as a function of the dark matter candidate mass, $m_{χ}$ . We discuss further observational consequences.
↳ hep-phastro-ph.HEnucl-thPRD(2019)·24 citations

Affiliations

first authorsco-authorsvia INSPIRE

Conformal perturbation theory confronts lattice results in the vicinity of a critical point

Investigate the pentaquark resonance in the NK system

Ξ(1690)− resonance production via K−p→K+K−Λ

Role of crustal physics in the tidal deformation of a neutron star

Diffractive excitation in pp and pA collisions at high energies

Equation of state for hot QCD and compact stars from a mean field approach

Dark matter and bubble nucleation in old neutron stars

Affiliations

Investigate the pentaquark resonance in the $N K$ system

$Ξ (1690)^{-}$ resonance production via $K^{-} p \to K^{+} K^{-} Λ$

Diffractive excitation in $pp$ and $p A$ collisions at high energies