Related papers: Implication of neutron star observations to the or…
We investigate the constraints on the strength of first-order phase transitions in neutron star matter and its relation to the origin of nucleon mass. By combining the parity doublet model for the hadronic phase, the Nambu-Jona-Lasinio…
The recent NICER observation of PSR J0614-3329, revealing the smallest reliably measured neutron star radius of $R = 10.29^{+1.01}_{-0.86}$ km at mass $M = 1.44^{+0.06}_{-0.07} M_\odot$, provides an unprecedented constraint on the equation…
Clarifying the origin of hadron mass is one of the fundamental problems in particle physics, relevant from hadronic scales to astrophysical observations. At low energies, this issue is reflected in the decomposition of the hadron mass into…
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…
Recent neutron star observations set new constraints for the equation of state of baryonic matter. A chiral effective field theory approach is used for the description of neutron-dominated nuclear matter present in the outer core of neutron…
We review the equation of state of matter in neutron stars from the solid crust through the liquid nuclear matter interior to the quark regime at higher densities. We focus in detail on the question of how quark matter appears in neutron…
We review the chiral variant and invariant components of nucleon masses and its consequence on the chiral restoration in extreme conditions, neutron star matter in particular. We consider a model of linear realization of chiral symmetry…
Radio observations of neutron star binary pulsar systems have constrained strongly the masses of eight neutron stars. Assuming neutron star masses are uniformly distributed between lower and upper bounds $m_l$ and $m_u$, the observations…
Neutron star matter is investigated in a hadronic chiral model approach using the lowest flavor-SU(3) multiplets for baryons and mesons. The parameters are determined to yield consistent results for saturated nuclear matter as well as for…
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…
I describe a possible scenario for the origin of proton mass in terms of Cheshire Cat, half-skyrmions, topology change and interplay between hidden chiral-scale symmetry and induced local symmetry. This differs from the standard…
One of the key ingredients to understand the properties of neutrons stars is the equation of state at finite densities far beyond nuclear saturation. Investigating the phase structure of quark matter that might be realized in the core of NS…
We consider the possibility that Dirac neutrino masses may be a manifestation of chiral symmetry breaking via non-perturbative QCD dynamics. The key role played by light quarks in this mechanism can naturally lead to signals that are…
The properties of neutron stars are studied in a composite model of the strong interaction. In the regime of low to medium baryonic densities a covariant hadronic model is adopted which includes an exclusive channel for the hyperon-hyperon…
Recent observations of neutron star masses close to the maximum predicted by nucleonic equations of state begin to challenge our understanding of dense matter in neutron stars, and constrain the possible presence of quark matter in their…
We investigate the possibility and impacts of a first-order phase transition from hadronic matter to quark matter in neutron stars (NSs) using two specific models: the parity doublet model (PDM) for the hadronic phase and the…
We analyze hyperon and nucleon mass shifts in nuclear matter using chiral perturbation theory. Expressions for the mass shifts that include strong interaction effects at leading order in the density are derived. Corrections to our results…
After decades-long attempts to measure the mass shift and understand the origin of hadron mass, it became clear that one has to analyze hadrons with small vacuum width. Also, to identify the effect of chiral symmetry breaking, one has to…
We present in this article an overview of the problem of neutron star masses. After a brief appraisal of the methods employed to determine the masses of neutron stars in binary systems, the existing sample of measured masses is presented,…
We investigate binary neutron star (BNS) mergers using general-relativistic numerical simulations with hadronic and hybrid equations of state (EOSs), incorporating the latest observations and theoretical constraints. We address two viable…