In this work, we have studied the effect of three-nucleon interaction on the neutron stars structure. In our calculations, we have considered the neutron star matter as a beta-stable nuclear matter. We have put the results concerning the TBF effect in perspective against two-body results and other calculations of three-nucleon interactions, using the Urbana v14 potential and the parabolic approximation of the nuclear-matter energy for approximating the problem of asymmetric nuclear matter. As such, solving the Tolman-Oppenheimer-Volkoff equation, we have estimated bulk properties of neutron stars and investigated how the present calculations would agree with the expected dynamical-stability condition.
We report benchmark calculations of the energy per particle of pure neutron matter as a function of the baryon density using three independent many-body methods: Brueckner-Bethe-Goldstone, Fermi hypernetted chain/single-operator chain, and auxiliary-field diffusion Monte Carlo. Significant technical improvements are implemented in the latter two methods. The calculations are made for two distinct families of realistic coordinate-space nucleon-nucleon potentials fit to scattering data, including the standard Argonne $v_{18}$ interaction and two of its simplified versions, and four of the new No…
We study the effects of free space nucleon radius on nuclear matter and neutron stars within the framework of quark mean field model. The nucleon radius is treated self-consistently with this model, where quark confinement is adjusted to fit different values of nucleon radius. Corrections due to center-of-mass motion, quark-pion coupling, and one gluon exchange are included to obtain the nucleon mass in vacuum. The meson coupling constants that describe the behavior of many-body nucleonic system are newly-constructed by reproducing the empirical saturation properties of nuclear matter, includi…
Recent observations of neutron-star properties, in particular the recent detection of gravitational waves emitted from binary neutron stars, GW 170817, open the way to put strong constraints on nuclear interactions. In this paper, we review the state of the art in calculating the equation of state of strongly interacting matter from first principle calculations starting from microscopic interactions among nucleons. We then review selected properties of neutron stars that can be directly compared with present and future observations.
Thermal conductivity and shear viscosity of npe$μ$ matter in non-superfluid neutron star cores are considered in the framework of Brueckner-Hartree-Fock many-body theory. We extend our previous work (Shternin, Baldo and Haensel, 2013) by analysing different nucleon-nucleon potentials and different three-body forces. We find that the use of different potentials leads up to one order of magnitude variations in the values of the nucleon contribution to transport coefficients. The nucleon contribution dominates the thermal conductivity, but for all considered models the shear viscosity is dominate…
The strongly isospin-dependent tensor force leads to short-range correlations (SRC) between neutron-proton (deuteron-like) pairs much stronger than those between proton-proton and neutron-neutron pairs. As a result of the short-range correlations, the single-nucleon momentum distribution develops a high-momentum tail above the Fermi surface. Because of the strongly isospin-dependent short-range correlations, in neutron-rich matter a higher fraction of protons will be depleted from its Fermi sea and populate above the Fermi surface compared to neutrons. This isospin-dependent nucleon momentum d…
Nucleon-Nucleon Phase Shifts and Pairing in Neutron Matter and Nuclear Matter
我们考虑了无限中子物质和核物质中的1 S 0配对，并指出在最低阶近似下，当配对相互作用取为1 S 0通道中的裸核子-核子（NN）相互作用时，配对相互作用和能隙可以直接由1 S 0相移确定.这是由于在这个分波中NN相互作用的几乎可分离的特征。由于最近的NN相互作用是电荷相关的，我们必须解决耦合的间隙方程质子，中子，中子和中子质子配对的核物质。结果，然而，被发现是接近与电荷无关的电位所获得的。
We consider the thermal conductivity, shear viscosity, and momentum relaxation rates in the nucleon cores of the neutron stars. We study how the choice of the nuclear interaction and the model for three-body forces may affect these transport coefficients calculated within the Brueckner-Hartree-Fock many-body nuclear theory. We find that at relatively large densities the model dependence of the results is substantial. In addition we provide the analytical approximations which allow to incorporate our results in practical simulations.
We delineate the properties of dense QCD matter through equations of state constrained by the neutron star observations. The two solar mass constraint, the radius constraint of 11-13 km, and the causality constraint on the speed of sound, are used to develop the picture of hadron-quark continuity in which hadronic matter continuously transforms into quark matter. A unified equation of state at zero temperature and beta-equilibrium is constructed by a phenomenological interpolation between nuclear and quark matter equations of state. For applications to supernovae and neutron star mergers, the …
We perform simulations of the Kelvin-Helmholtz cooling phase of proto-neutron stars with a new numerical code in spherical symmetry and using the quasi-static approximation. We use for the first time the full set of charged-current neutrino-nucleon reactions, including neutron decay and modified Urca processes, together with the energy-dependent numerical representation for the inclusion of nuclear correlations with random-phase approximation. Moreover, convective motions are taken into account within the mixing-length theory. As we vary the assumptions for computing neutrino-nucleon reaction …
Three-nucleon force effects in polarization transfers from the doubly spin-polarized initial neutron-deuteron state to the outgoing neutron in neutron-deuteron scattering
The scale-dependence of the nucleon-nucleon interaction, which in recent years has been extensively analysed within the context of chiral effective field theory, is, in fact, inherent in any potential models constrained by a fit to scattering data. A comparison between a purely phenomenological potential and local interactions derived from chiral effective field theory suggests that--thanks to the ability to describe nucleon-nucleon scattering at higher energies, as well as the deuteron momentum distribution extracted from electro-disintegration data--phenomenological potentials are best suite…
The properties of neutron star are studied in the framework of relativistic Hartree-Fock (RHF) model with realistic nucleon-nucleon ($NN$) interactions, i.e. Bonn potentials. The strong repulsion of $NN$ interaction at short range is properly removed by the unitary correlation operator method (UCOM). Meanwhile, the tensor correlation is neglected due to the very rich neutron environment in neutron star, where the total isospin of two nucleons can be approximately regarded as $T=1$. The equations of state of neutron star matter are calculated in $β$ equilibrium and charge neutrality conditions.…
Nucleon-nucleon short-range correlations (SRCs) induce a high momentum tail (HMT) in the single-nucleon momentum distribution function $n_{ǩ}^J(ρ,δ)$ in cold neutron-rich matter. While there are clear experimental evidences that the SRC/HMT effects are different for neutrons and protons and their strengths depend strongly on the isospin asymmetry of finite nuclei mostly based on electron-nucleus scattering experiments, much less is known experimentally about the SRC/HMT effects in the dense neutron-rich matter. To facilitate further explorations of SRC/HMT effects in dense neutron-rich matter …
Phenomenological implications of the nucleon's meson cloud
相互作用核子的长距离结构从其与轻强子自由度的耦合中得到重要贡献-轻介子云-而类似的非微扰机制预计将产生质子波函数的固有魅力（IC）分量。我们调查这两种可能性，保持为前者一个特殊的眼睛，以提高理论理解的π介子核子顶点的光建议的测量。关于IC的后一种可能性，我们强调了Hobbs等人（Phys Rev D 89：074008，2014）提出的光阵面模型的全球QCD分析所获得的最新结果。
The nuclear matter equation of state is relatively well constrained at sub-saturation densities thanks to the knowledge from nuclear physics. However, studying its behavior at supra-saturation densities is a challenging task. Fortunately, the extraordinary progress recently made in observations of neutron stars and neutron star mergers has provided us with unique opportunities to unfold the properties of dense matter. Under the assumption that nucleons are the only constituents of neutron star cores, we perform a Bayesian inference using the so-called meta-modeling technique with a nuclear-phy…
We employ two models of the nucleon-nucleon force: the OPE-Gaussian as well as the chiral N4LO and N4LO+ interactions with semilocal regularization in momentum space to study correlations among two-nucleon and three-nucleon elastic scattering observables. These models contain a number of free parameters whose values and covariance matrices are evaluated from a fit to the two-nucleon data. Such detailed knowledge of parameters allows us to create, using various sets of statistically generated parameters, numerous versions of these potentials and next apply them to two- and three-nucleon scatter…
Enhanced Neutrino Cooling from Parity-Doubled Nucleons in Neutron Star Cooling Simulations
Catholic Institute of Technology（天主教理工学院）；Universidade Federal Fluminense（弗鲁米嫩塞联邦大学）；ICRANet（国际相对论天体物理中心网络）；Washington University in St. Louis（圣路易斯华盛顿大学）；Frankfurt Institute for Advanced Studies (FIAS)（法兰克福高等研究所）；GSI Helmholtzzentrum für Schwerionenforschung GmbH（德国重离子研究中心）；Kent State University（肯特州立大学）；Brookhaven National Laboratory（布鲁克海文国家实验室）
We consider transport properties of the hypernuclear matter in neutron star cores. In particular, we calculate the thermal conductivity, the shear viscosity, and the momentum transfer rates for np$Σ^{-}Λeμ$ composition of dense matter in $β$--equilibrium for baryon number densities in the range $0.1-1$~fm$^{-3}$. The calculations are based on baryon interactions treated within the framework of the non-relativistic Brueckner-Hartree-Fock theory. Bare nucleon-nucleon (NN) interactions are described by the Argonne v18 phenomenological potential supplemented with the Urbana IX three-nucleon force.…
We outline two important effects that are missing from most evaluations of the dark matter capture rate in neutron stars. As dark matter scattering with nucleons in the star involves large momentum transfer, nucleon structure must be taken into account via a momentum dependence of the hadronic form factors. In addition, due to the high density of neutron star matter, we should account for nucleon interactions rather than modeling the nucleons as an ideal Fermi gas. Properly incorporating these effects is found to suppress the dark matter capture rate by up to four orders of magnitude for the h…
In order to reveal the difference between the latest neutron star observation experiment GW170817 and the existing theory, we mainly consider the effect of the nucleon radius on the neutron star from the existing theory. We believe that the effect of nucleon radius in neutron star is not negligible, and the mass radius of nucleon should be used instead of the charge radius. The nucleon mass radius is set as $r_m = 0.55\pm0.09$ fm from the new measurements. It is considered as an input to the "Excluded Volume Effects" model in the equation of state of nuclear matter. We propose a novel neutron …
A renewed version of the computer code GAMOW ~\cite{[Ve82]} is given in which the difficulties in calculating broad neutron resonances are amended. New types of phenomenological neutron potentials with strict finite range are built in. Landscape of the S-matrix can be generated on a given domain of the complex wave number plane and S-matrix poles in the domain are localized. Normalized Gamow wave functions and trajectories of given poles can be calculated optionally.
We calculate the differential scattering rate for thermal neutrinos in a hot and dilute gas of interacting neutrons using linear response theory. The dynamical structure factors for density and spin fluctuations of the strongly interacting neutron matter, expected in the neutrino decoupling regions of supernovae and neutron star mergers, are calculated in the virial expansion for the first time. Correlations due to nucleon-nucleon interactions are taken into account using a pseudo-potential that reproduces measured nucleon-nucleon phase shifts, and we find that attractive s-wave interactions e…
We present the equation of state of infinite neutron matter as obtained from highly-realistic Hamiltonians that include nucleon-nucleon and three-nucleon coordinate-space potentials. We benchmark three independent many-body methods: Brueckner-Bethe-Goldstone (BBG), Fermi hypernetted chain/single-operator chain (FHNC/SOC), and auxiliary-field diffusion Monte Carlo (AFDMC). We find them to provide similar equations of state when the Argonne $v_{18}$ and the Argonne $v_{6}^\prime$ nucleon-nucleon potentials are used in combination with the Urbana IX three-body force. Only at densities larger than…
Mean free paths and in-medium scattering cross sections of energetic nucleons in neutron-rich nucleonic matter within the relativistic impulse approximation
