Nuclear matter

About: Nuclear matter is a research topic. Over the lifetime, 10180 publications have been published within this topic receiving 248261 citations.

Creation of quark–gluon plasma droplets with three distinct geometries

Abstract: Experimental studies of the collisions of heavy nuclei at relativistic energies have established the properties of the quark–gluon plasma (QGP), a state of hot, dense nuclear matter in which quarks and gluons are not bound into hadrons1–4. In this state, matter behaves as a nearly inviscid fluid5 that efficiently translates initial spatial anisotropies into correlated momentum anisotropies among the particles produced, creating a common velocity field pattern known as collective flow. In recent years, comparable momentum anisotropies have been measured in small-system proton–proton (p+p) and proton–nucleus (p+A) collisions, despite expectations that the volume and lifetime of the medium produced would be too small to form a QGP. Here we report on the observation of elliptic and triangular flow patterns of charged particles produced in proton–gold (p+Au), deuteron–gold (d+Au) and helium–gold (3He+Au) collisions at a nucleon–nucleon centre-of-mass energy $\sqrt {s_{{\mathrm{NN}}}} = 200$ GeV. The unique combination of three distinct initial geometries and two flow patterns provides unprecedented model discrimination. Hydrodynamical models, which include the formation of a short-lived QGP droplet, provide the best simultaneous description of these measurements.

Microscopic nuclear equation of state with three-body forces and neutron star structure

Abstract: We calculate static properties of non-rotating neu- tronstars(NS's)usingamicroscopicequationofstate(EOS)for asymmetric nuclear matter, derived from the Brueckner-Bethe- Goldstone many-body theory with explicit three-body forces WeusetheArgonneAV14andtheParistwo-bodynuclearforce, implemented by the Urbana model for the three-body force We obtain a maximum mass conguration with Mmax =1 : 8 M ( Mmax =1 :94M) when the AV14 (Paris) interaction is used They are both consistent with the observed range of NS masses The onset of direct Urca processes occurs at densities n 0:65 fm 3 for the AV14 potential and n 0:54 fm 3 for the Paris potential Therefore, NS's with masses above M Urca =1 : 4 Mfor the AV14 and M Urca =1 :24M for the Paris potential can undergo very rapid cooling, depending on the strength of superfluidity in the interior of the NS The comparison with other microscopic models for the EOS shows noticeable differences

Boltzmann equation for heavy ion collisions

Abstract: The sensitivity of inclusive observables in heavy ion collisions to the nuclear equation of state can be tested with the Boltzmann equation. We solve the Boltzmann equation, including mean field and Pauli blocking effects, by a method that follows closely the cascade model. We find that the inclusive pion production is insensitive to the nuclear equation of state, contrary to recent claims.

Dense Nuclear Matter in a Strong Magnetic Field

Abstract: We investigate in a relativistic Hartree theory the gross properties of cold symmetric nuclear matter and nuclear matter in beta equilibrium under the influence of strong magnetic fields. If the field strengths are above the critical values for electrons and protons, the respective phase spaces are strongly modified. This results in additional binding of the systems with distinctively softer equations of state compared to the field free cases. For magnetic field $\ensuremath{\sim}{10}^{20}$ G and beyond, the nuclear matter in beta equilibrium practically converts into a stable proton-rich matter.