Related papers: Parity Doublet Model applied to Neutron Stars
Quartic gravity theory is considered with the Einstein-Hilbert Lagrangean $R+aR^{2}+bR_{\mu \nu}R^{\mu \nu},$ $R_{\mu \nu}$ being Ricci\'s tensor and R the curvature scalar. The parameters $a$ and $b$ are taken of order 1 km$^{2}.$…
We introduce in this work a class of relativistic models for nuclear matter and neutron stars which exhibits a parameterization, through mathematical constants, of the non-linear meson-baryon couplings. For appropriate choices of the…
A new type of neutrino mixing named bi-pair neutrino mixing is proposed to describe the current neutrino mixing pattern with a vanishing reactor mixing angle and is determined by a mixing matrix with two pairs of identical magnitudes of…
Based on a thorough comparison of the nucleon and $\Delta$ excitation spectrum with models we show that parity doublets observed in the mass spectra do not entail the consequence that highly excited $N$ or $\Delta$ resonances are…
We investigate the fluctuations of the net-baryon number density in dense hadronic matter. Chiral dynamics is modeled via the parity doublet Lagrangian, and the mean-field approximation is employed to account for chiral criticality. We…
We improve so called ``naive'' and ``mirror'' models for the positive and negative parity nucleons, $N$ and $N^{*}$, by introducing nonlinear terms allowed by chiral symmetry. Both models in this improvement reproduce the observed nucleon…
We propose an extension of the standard model introducing large $SU(2)_L$ multiplet fields which are quartet and septet scalars and quintet Majorana fermions. These multiplets can induce the neutrino masses via interactions with the $SU(2)$…
Due to sphaleron processes in the high-temperature symmetric phase of the standard model the cosmological baryon asymmetry is related to neutrino properties. For hierarchical neutrino masses, with $B-L$ broken at the unification scale…
We report neutron star predictions based on our most recent equations of state. These are derived from chiral effective field theory, which allows for a systematic development of nuclear forces, order by order. We utilize high-quality…
Baryon resonances with even and odd parity are collectively investigated from the viewpoint of chiral symmetry(ChS). We propose a quartet scheme where Delta's and N^*'s with even and odd parity form a chiral multiplet. This scheme gives…
We perform a study of infinite hadronic matter, finite nuclei and hypernuclei with an improved method of calculating the effective baryon mass. A detailed study of the predictions of the model is made in comparison with the available data…
General relativistic calculations are made of neutrino-antineutrino annihilation into electron-positron pairs near the surface of a neutron star. It is found that the efficiency of this process is enhanced over the Newtonian values up to a…
The sensitivity of nuclear symmetry energy elements at the saturation density to the binding energies of ultra neutron-rich nuclei (neutron to proton ratio $\sim$ 2) and the maximum mass of neutron star is explored within a relativistic…
We propose a model that simultaneously addresses the existence of a dark matter candidate, baryon asymmetry and tiny neutrino masses and mixing by introducing two SU(2) triplet scalars and an inert SU(2) doublet scalar on top of the…
We study inhomogeneous chiral phases in nuclear matter using a hadronic model with the parity doublet structure. With an extended ansatz for the dual chiral density wave off the chiral limit, we numerically determine the phase structure. A…
We show a phase diagram of a two-flavored parity doublet model on top of the nuclear matter ground state within the mean field approximation. An exotic phase with unbroken center symmetry of chiral group is also discussed. When crossing…
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 derive an equation of state for magnetized charge neutral nuclear matter relevant for neutron star structure. The calculations are performed within an effective chiral model based on generalization of sigma model with nonlinear self…
Parity doubling is observed in hadron states around 1.5 GeV - and the estimated energy density is found to be high. When a large excitation energy is available and the pions decouple from the quarks, the QCD interaction is still not…
Motivated by a recent astrophysical measurement of the pressure of cold matter above nuclear-matter saturation density, we compute the equation of state of neutron star matter using accurately calibrated relativistic models. The uniform…