Low temperature kinetics of nuclear superfluids

Previously published and as yet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and non-perturbative aspects of strong interactions to be carried out using hadronic Z and tau decays. The studies presented include precise determinations of the strong coupling constant, tests of its avour independence, tests of the SU(3) gauge structure of QCD, study of coherence eects, and measurements of single-particle inclusive distributions and two-particle correlations for many identied baryons and mesons.

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“…Imperfections This value is comparable with those obtained at lower energy e + e colliders [183,184,185,186].…”

Section: Bose-einstein Correlationssupporting

confidence: 76%

Studies of Quantum Chromodynamics with the ALEPH detector

Barate¹,

Buskulic²,

Décamp³

et al. 1998

Physics Reports

320

301

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“…In the context of neutron stars, this was not studied in detail (see however Refs. [213,214]). A thorough investigation of the Bogoliubov quasiparticle contribution to transport coefficients remains an open problem, but the key features at low temperatures can be worked out, neglecting all the modifications to the quasiparticle collision integral except the spectrum modification by the gap (for the neutron thermal conductivity this was done by Baiko et al [186]).…”

Section: Effects Of Cooper Pairingmentioning

confidence: 99%

Reaction Rates and Transport in Neutron Stars

Schmitt

Shternin

2018

Astrophysics and Space Science Library

100

122

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Understanding signals from neutron stars requires knowledge about the transport inside the star. We review the transport properties and the underlying reaction rates of dense hadronic and quark matter in the crust and the core of neutron stars and point out open problems and future directions. arXiv:1711.06520v3 [astro-ph.HE] 29 Oct 2018 65 References 66 I. INTRODUCTION A. ContextTransport describes how conserved quantities such as energy, momentum, particle number, or electric charge are transferred from one region to another. Such a transfer occurs if the system is out of equilibrium, for instance through a temperature gradient or a non-uniform chemical composition. Different theoretical methods are used to understand transport, depending on how far the system is away from its equilibrium state. If the system is close to equilibrium locally and perturbations are on large scales in space and time, hydrodynamics is a powerful technique. Further away from equilibrium other techniques are required, for example kinetic theory, which can also be used to provide the transport coefficients needed in the hydrodynamic equations. In any case, transport is determined by interactions on a microscopic level, and it is the resulting transport properties that we are concerned with in this review.Signals from neutron stars are sensitive to equilibrium properties such as the equation of state but also, to a large extent, to transport properties -here, by neutron stars we mean all objects with a radius of about 10 km and a mass of about 1-2 solar masses, including the possibilities of hybrid stars, which have a quark matter core, and pure quark stars. Therefore, understanding transport is crucial to interpret astrophysical observations, and, turning the argument around, we can use astrophysical observations to improve our understanding of transport in dense matter and thus ultimately our understanding of the microscopic interactions.Transport properties are most commonly computed from particle collisions. (Although, in strongly coupled systems, the picture of well-defined particles scattering off each other has to be taken with care.) These can be scattering processes in which energy and momentum is exchanged without changing the chemical composition of the system, or these can be flavor-changing processes from the electroweak interaction. Understanding transport thus amounts to understanding the rates of these processes, as a function of temperature and density. Electroweak processes are well understood, but large uncertainties arise if the strong interaction is involved in a reaction that contributes to transport. Therefore, approximations such as weak-coupling techniques or one-pion exchange for nucleon-nucleon collisions are being used, and efforts in current research aim at improving these approximations.In a neutron star, most of the particles involved in these processes are fermions: electrons, muons, neutrinos, neutrons, protons, hyperons, and quarks. Since the Fermi momenta of these fermions are typically much larger tha...

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Low temperature kinetics of nuclear superfluids

Cited by 2 publications

References 11 publications

Studies of Quantum Chromodynamics with the ALEPH detector

Studies of Quantum Chromodynamics with the ALEPH detector

Reaction Rates and Transport in Neutron Stars

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