Nuclear matter

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

Deuteron Formation in Expanding Nuclear Matter from a Strong Coupling BCS Approach

Abstract: Central heavy ion collisions at E/A in the 50 to 200 MeV range can roughly be described by the initial build up of compressed and hot nuclear matter and by a sequential decompression. Some of these reactions have recently been reported [1] to end up with final fragments not heavier than α-particles, at most. This is the kind of scenario we shall address in this work. Our main aim is to develop the first steps of a transport theory which goes beyond BUU in a systematic fashion to include light cluster formation in a consistent way. By the latter we mean that cluster formation is followed throughout the entire reaction process without any ad hoc switching on and off of clustering or coalescence processes. In such a way for example memory effects in the formation process and Pauli principle will be fully accounted for. We here shall be mainly concerned with deuteron formation. However, in the end we shall shortly touch upon α-particle production as well. Our theoretical tools will be based on BCS and quasi-particle RPA theory.

Neutron star radii, universal relations, and the role of prior distributions

Abstract: We investigate constraints on neutron star structure arising from the assumptions that neutron stars have crusts, that recent calculations of pure neutron matter limit the equation of state of neutron star matter near the nuclear saturation density, that the high-density equation of state is limited by causality and the largest high-accuracy neutron star mass measurement, and that general relativity is the correct theory of gravity. We explore the role of prior assumptions by considering two classes of equation of state models. In a first, the intermediate- and high-density behavior of the equation of state is parameterized by piecewise polytropes. In the second class, the high-density behavior of the equation of state is parameterized by piecewise continuous line segments. The smallest density at which high-density matter appears is varied in order to allow for strong phase transitions above the nuclear saturation density. We critically examine correlations among the pressure of matter, radii, maximum masses, the binding energy, the moment of inertia, and the tidal deformability, paying special attention to the sensitivity of these correlations to prior assumptions about the equation of state. It is possible to constrain the radii of $ 1.4 M_{\odot}$ neutron stars to be larger than 10km, even without consideration of additional astrophysical observations, for example, those from photospheric radius expansion bursts or quiescent low-mass X-ray binaries. We are able to improve the accuracy of known correlations between the moment of inertia and compactness as well as the binding energy and compactness. We also demonstrate the existence of a correlation between the neutron star binding energy and the moment of inertia.

Centrality and pT dependence of J/psi suppression in proton-nucleus collisions from parton energy loss

Abstract: The effects of parton energy loss and pT-broadening in cold nuclear matter on the pT and centrality dependence, at various rapidities, of J/psi suppression in p-A collisions are investigated. Calculations are systematically compared to E866 and PHENIX measurements. The very good agreement between the data and the theoretical expectations further supports pT-broadening and the associated medium-induced parton energy loss as dominant effects in J/psi suppression in high-energy p-A collisions. Predictions for J/psi (and Upsilon) suppression in p-Pb collisions at the LHC are given.