Nuclear Theory·nucl-th

Thursday·August 9, 2018

6 papers—2 primary·4 cross-listed

01
Constraints on the hybrid equation of state with a crossover hadron-quark phase transition in the light of GW170817
Cheng-Ming Li🇨🇳 · Yan Yan🇨🇳 · Jin-Jun Geng🇨🇳 · Yong-Feng Huang🇨🇳 · Hong-Shi Zong🇨🇳
In this paper, we use the recent updated source properties of GW170817 to constrain the hybrid equation of state (EOS) constructed by a three-window modeling between the hadronic EOS and quark EOS. Specifically, the hadronic EOS is described by NL3 $ω ρ$ model whose corresponding pure neutron star (NS) is already excluded by the constraint of tidal deformability (TD) from GW170817, and the quark EOS is calculated with 2+1 flavors Nambu-Jona-Lasinio (NJL) model. We also consider other four constraints on the hybrid EOS. As a result, we find the parameter set ( $B^{\frac{1}{4}}, μ ~, Γ$ ) can be well constrained, indicating the possible existence of the hybrid star (HS) with a crossover inside. The type of the two stars in the binary system for nine representative hybrid EOSs is shown in this paper too. Furthermore, the HSs restricted by five constraints do not suggest a pure quark core but a mixed-phase in center.
nucl-thPRD(2018)·52 citations
02
Extraction of $γ n \to π N$ observables from deuteron-target data
Satoshi X. Nakamura (Universidade Cruzeiro do Sul)🇧🇷
An examination is conducted on a commonly used procedure for extracting (un)polarized $γ n \to π^{-} p$ and $γ n \to π^{0} n$ observables from $d (γ, π^{-}) pp$ and $d (γ, π^{0}) p n$ data, using a model that consists of the impulse term and the final-state interaction (FSI) terms due to nucleon- and pion-exchange. Recent experimental and theoretical analyses used an extraction method that does not impose a cut on the final $π N$ invariant mass $W$ . I demonstrate that the use of this method can result in the $γ n \to π N$ observables that are seriously distorted by the nucleon Fermi motion, and that one can efficiently avoid this problem by imposing a cut on $W$ . It is also shown that the use of kinematical cuts of recent experimental analyses can still leave in the selected samples substantial FSI effects that must be corrected in extracting the $γ n \to π N$ cross sections. In terms of the nucleon- and pion-exchange mechanisms, I give the first qualitative explanation of the FSI corrections, obtained in a recent MAMI experiment, for extracting $γ n \to π^{0} n$ cross sections.
nucl-thhep-phnucl-exPRC(2018)·14 citations

Affiliations

first authorsco-authorsvia INSPIRE

Constraints on the hybrid equation of state with a crossover hadron-quark phase transition in the light of GW170817

Extraction of γn→πN observables from deuteron-target data

Affiliations

Extraction of $γ n \to π N$ observables from deuteron-target data