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Related papers: Short-Range Correlations and Urca Process in Neutr…

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We argue that significant probability of protons with momenta above their Fermi surface leads for proton concentrations p/n > 1/8 to the enhancement of termally excited direct and modified URCA processes within a cold neutron star, and to a…

High Energy Physics - Phenomenology · Physics 2008-11-26 Leonid Frankfurt , Mark Strikman

Charged current neutrino-nucleon reactions, generally called Urca processes, are crucial actors of a neutron star's thermal evolution. The so-called direct processes show a pronounced threshold under which the reaction is kinematically…

Nuclear Theory · Physics 2026-01-12 Lami Suleiman , Micaela Oertel , Marco Mancini

We study the heat capacity and neutrino emission reactions (direct and modified Urca processes, nucleon-nucleon bremsstrahlung, Cooper pairing of nucleons) in matter of supranuclear density of the neutron star cores with superfluid neutrons…

Astrophysics · Physics 2011-02-16 D. G. Yakovlev , K. P. Levenfish , Yu. A. Shibanov

Dense matter in compact stars cools efficiently by neutrino emission via the direct Urca processes n -> p + e + nu and p + e -> n + nu. Below the pairing phase transition temperature Tc these processes are suppressed - at asymptotically low…

Nuclear Theory · Physics 2009-11-10 Armen Sedrakian

The bulk viscosity of the neutron star matter due to the direct Urca processes involving nucleons, electrons and muons is studied taking into account possible superfluidity of nucleons in the neutron star cores. The cases of singlet-state…

Astrophysics · Physics 2009-05-13 P. Haensel , K. P. Levenfish , D. G. Yakovlev

It is proposed that a rearrangement of single-particle degrees of freedom may occur in a portion of the quantum fluid interior of a neutron star. Such a rearrangement is associated with the pronounced softening of the spin-isospin…

Astrophysics · Physics 2009-10-31 D. N. Voskresensky , V. A. Khodel , M. V. Zverev , J. W. Clark

Flavor-changing charged current ("Urca") processes are of central importance in the astrophysics of neutron stars. Standard calculations approximate the Urca rate as the sum of two contributions, direct Urca and modified Urca. Attempts to…

Nuclear Theory · Physics 2024-06-21 Mark G. Alford , Alexander Haber , Ziyuan Zhang

We calculate and provide analytic fits of the factors which describe the reduction of the neutrino emissivity of modified Urca and nucleon-nucleon bremsstrahlung processes by superfluidity of neutrons and protons in neutron-star cores. We…

Astrophysics · Physics 2011-07-19 M. E. Gusakov

Using a model for the equation of state and composition of dense matter and the magnitude of singlet proton superconductivity and triplet neutron superfluidity, we perform the first simultaneous fit of neutron star masses and radii…

Nuclear Theory · Physics 2019-11-13 Spencer Beloin , Sophia Han , Andrew W. Steiner , Khorgolkhuu Odbadrakh

Short range correlations (SRC) have been known to be an important aspect of nuclear theory for some time. Recent works have re-ignited interest on this topic, particularly due to the fact that it has recently been demonstrated that SRC may…

Neutrino emission from the dense hadronic component in neutron stars is subject to strong modifications due to collective effects in the nuclear medium. We implement new estimates of the neutrino emissivities of two processes operating in…

Astrophysics · Physics 2011-05-23 Ch. Schaab , D. Voskresensky , A. D. Sedrakian , F. Weber , M. K. Weigel

Observation of cooling neutron stars can potentially provide information about the states of matter at supernuclear densities. We review physical properties important for cooling such as neutrino emission processes and superfluidity in the…

Astrophysics · Physics 2009-11-10 D. G. Yakovlev , C. J. Pethick

It is well known that strongly correlated neutron-proton pairs, the short-range correlations (SRC), can modify many of the nuclear properties. In this work we have introduced, for the first time, short range correlations in the calculation…

Nuclear Theory · Physics 2023-09-19 Mateus R. Pelicer , Débora P. Menezes , Mariana Dutra , Odilon Lourenço

Recent observations by the Chandra observatory suggest that some neutron stars may cool rapidly, perhaps by the direct URCA process which requires a high proton fraction. The proton fraction is determined by the nuclear symmetry energy…

Nuclear Theory · Physics 2009-11-07 C. J. Horowitz , J. Piekarewicz

Experiments with cold Fermi atoms can be tuned to probe strongly interacting fluids that are very similar to the low-density neutron matter found in the crusts of neutron stars. In contrast to traditional superfluids and superconductors,…

Nuclear Theory · Physics 2008-11-26 Alexandros Gezerlis , J. Carlson

We study thermal evolution of isolated neutron stars in scalar-tensor theories for the first time. Whether the rapid cooling due to the direct Urca process occurs or not is an interesting question in the viewpoint of the temperature…

General Relativity and Quantum Cosmology · Physics 2021-07-27 Akira Dohi , Ryotaro Kase , Rampei Kimura , Kazuhiro Yamamoto , Masa-aki Hashimoto

The thermal evolution of hypernuclear compact stars is studied for stellar models constructed on the basis of covariant density functional theory in Hartree and Hartree-Fock approximation. Parametrizations of both types are consistent with…

Nuclear Theory · Physics 2019-06-27 Adriana R. Raduta , Jia Jie Li , Armen Sedrakian , Fridolin Weber

We show that the direct Urca process of neutrino emission is allowed in two possible phases of nonspherical nuclei (inverse cylinders and inverse spheres) in the mantle of a neutron star near the crust-core interface. The process is open…

Astrophysics · Physics 2009-11-10 M. E. Gusakov , D. G. Yakovlev , P. Haensel , O. Y. Gnedin

The neutrino energy emission rate due to formation of Cooper pairs of neutrons and protons in the superfluid cores of neutron stars is studied. The cases of singlet-state pairing with isotropic superfluid gap and triplet-state pairing with…

Astrophysics · Physics 2011-05-23 D. G. Yakovlev , A. D. Kaminker , K. P. Levenfish

As pointed out by Kutschera and W{\'o}jcik, very low concentration of protons combined with a specific density dependence of effective neutron-proton interaction could lead to a localization of ``proton impurities'' in neutron medium at…

Astrophysics · Physics 2011-03-17 D. A. Baiko , P. Haensel
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