Chiral crossover characterized by Mott transition at finite temperature

Net quark number probability distribution near the chiral crossover transition

We investigate properties of the probability distribution of the net quark number near the chiral crossover transition in the quark-meson model. The calculations are performed within the functional renormalization group approach, as well as in the mean-field approximation. We find, that there is a substantial influence of the underlying chiral phase transition on the properties of the probability distribution. In particular, for a physical pion mass, the distribution which includes the effect of mesonic fluctuations, differs considerably from both, the mean-field and Skellam distributions. The…

Chiral condensate and Mott-Anderson freeze-out

We present the idea of a Mott-Anderson freeze-out that suggests a key role of the localization of the hadron wave functions when traversing the hadronization transition. The extension of hadron wave functions in dense matter is governed by the behavior of the chiral quark condensate such that its melting at finite temperatures and chemical potentials entails an increase of the size of hadrons and thus their geometrical strong interaction cross sections. It is demonstrated within a schematic resonance gas model, that a kinetic freeze-out condition reveals a correlation with the reduction of the…

来自Lee-Yang边缘奇点的QCD手征交叉线

QCD Chiral Crossover Line from Lee-Yang Edge Singularities

本研究提出基于普适性的方法，利用Lee-Yang边缘奇点重建QCD手征交叉线，应用于Wuppertal-Budapest合作组数据得到的结果与现有格点QCD结果一致，为QCD交叉线提供了定量约束并建立可系统改进的框架。

Chiral condensates for neutron stars in hadron-quark crossover; from a parity doublet nucleon model to an NJL quark model

In this contribution, we summarize our recent studies on the chiral invariant mass and the chiral condensates in neutron star matter. We construct a unified equations of state assuming the crossover phase transition from hadronic matter described by a parity doublet model to quark matter by an Nambu--Jona-Lasinio type quark model. We first show that the chiral invariant mass is constrained to be 600 MeV $\lesssim m_0 \lesssim$ 900 MeV from recent observations of neutron stars. We then determine the density dependence of the chiral condensate in the crossover description, and show that the chir…

Nonperturbative Flavor Breaking in Topological Susceptibility at Chiral Crossover

We demonstrate that the QCD topological susceptibility nonperturbatively gets a significant contribution signaled by flavor-nonuniversal quark condensates at around the pseudo-critical temperature of the chiral crossover. It implies a remarkable flavor breaking in the axial anomaly as well as the QCD theta vacuum in high temperature QCD, which are almost flavor universal in the vacuum. A nontrivial flavor breaking is triggered by nonperturbative thermal loop corrections at around the chiral crossover, which is different from the trivial flavor violation just scaled by the quark mass ratio, obs…

手征交叉相变与稠密核物质中的手征密度波

Chiral crossover vs chiral density wave in dense nuclear matter

基于核子-介子模型，研究冷稠密核物质中各向同性手征交叉与各向异性手征密度波的竞争，发现手征密度波仅在约6倍核饱和密度以上出现。

QCD物质中手征交叉转变的旋转效应

Rotational effects on the chiral crossover transition in QCD matter

本文在强子共振气体模型中研究旋转对QCD手征交叉转变的影响，发现角速度增大和重子化学势增强均抑制赝临界温度，且远离旋转轴时转变温度降低。

Quark-hadron crossover equations of state for neutron stars: constraining the chiral invariant mass in a parity doublet model

We construct an equation of state (EOS) for neutron stars by interpolating hadronic EOS at low density and quark EOS at high density. A hadronic model based on the parity doublet structure is used for hadronic matter and a quark model of Nambu--Jona-Lasinio type is for quark matter. We assume crossover between hadronic matter and quark matter in the the color-flavor locked phase. The nucleon mass of the parity doublet model has a mass associated with the chiral symmetry breaking, and a chiral invariant mass $m_0$ which is insensitive to the chiral condensate. The value of $m_0$ affects the nuc…

Momentum scale dependence of the net quark number fluctuations near chiral crossover

We investigate properties of the net baryon number fluctuations near chiral crossover in a hot and dense medium of strongly interacting quarks. The chirally invariant quark-antiquark interactions are modeled by an effective quark-meson Lagrangian. To preserve remnants of criticality in the O(4) universality class, we apply the functional renormalization group method to describe thermodynamics near chiral crossover. Our studies are focused on the influence of the momentum cuts on the critical behavior of different cumulants of the net quark number fluctuations. We use the momentum scale depende…

手征交叉处QCD物质的声速

Speed of sound of QCD matter at chiral crossover

本研究基于广义Beth-Uhlenbeck方法提出热强相互作用物质统一状态方程，分析手征交叉处声速特性，发现强子气体声速因手征对称恢复变负与格点QCD数据矛盾，引入部分子激发可解决该问题。

Mott Effect and J/Psi Dissociation at the Quark-Hadron Phase Transition

We investigate the in-medium modification of pseudoscalar and vector mesons in a QCD motivated chiral quark model by solving the Dyson-Schwinger equations for quarks and mesons at finite temperature for a wide mass range of meson masses, from light (pi, rho) to open-charm (D, D*) states. At the chiral / deconfinement phase transition, the quark-antiquark bound states enter the continuum of unbound states and become broad resonances (the hadronic Mott effect). We calculate the in-medium cross sections for charmonium dissociation due to collisions with light hadrons in a chiral Lagrangian approa…

Light mesons around critical end points in $T-μ_B-μ_I-eB$ space

Light mesons $(σ, π^0, π^\pm)$ are investigated in $T-μ_B-μ_I-eB$ space by using a two-flavor NJL model, which are related to the chiral symmetry restoration and pion superfluid phase transition. In $T-μ_B-eB$ space, during the chiral restoration process, the mass of pseudo-Goldstone mode $π^0$ keeps increasing, together with the sudden mass jump. At the critical end point region, $π^0$ meson has a very sharp but continuous mass increase, together with a sudden mass jump at the Mott transition, and in the first order chiral phase transition region nearby, we observe twice $π^0$ mass jumps, ind…

Towards quantitative precision in the chiral crossover: masses and fluctuation scales

We investigate the relation between the physical pion pole and screening masses and the mesonic fluctuation scale in low-energy QCD, which relates to the curvature of the mesonic effective potential. This relation is important for the correct relative weight of quantum, thermal and density fluctuations. Hence, it governs the location of phase boundaries as well as the phase structure of QCD. The identification of the correct physics scales is also primarily important for the correct adjustment of the parameters of effective models for low-energy QCD. It is shown that subject to an appropriate …