Search arXiv⌕ Search

arXiv · nucl-th/0602038

Constraints on the high-density nuclear equation of state from the phenomenology of compact stars and heavy-ion collisions

Abstract

A new scheme for testing nuclear matter equations of state (EsoS) at high densities using constraints from neutron star phenomenology and a flow data analysis of heavy-ion collisions is suggested. An acceptable EoS shall not allow the direct Urca process to occur in neutron stars with masses below $1.5~M_{\odot}$, and also shall not contradict flow and kaon production data of heavy-ion collisions. Compact star constraints include the mass measurements of 2.1 +/- 0.2 M_sun (1 sigma level) for PSR J0751+1807, of 2.0 +/- 0.1 M_sun from the innermost stable circular orbit for 4U 1636-536, the baryon mass - gravitational mass relationships from Pulsar B in J0737-3039 and the mass-radius relationships from quasiperiodic brightness oscillations in 4U 0614+09 and from the thermal emission of RX J1856-3754. This scheme is applied to a set of relativistic EsoS constrained otherwise from nuclear matter saturation properties with the result that no EoS can satisfy all constraints simultaneously, but those with density-dependent masses and coupling constants appear most promising.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

T. Klahn, D. Blaschke, S. Typel, E. N. E. van Dalen, A. Faessler, C. Fuchs, T. Gaitanos, H. Grigorian, A. Ho, E. E. Kolomeitsev, M. C. Miller, G. Ropke, J. Trumper, D. N. Voskresensky, F. Weber, H. H. Wolter. 2006-02-13. Constraints on the high-density nuclear equation of state from the phenomenology of compact stars and heavy-ion collisions. https://doi.org/10.1103/physrevc.74.035802

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Wigner distribution modeling of nuclear state in NuWro Monte Carlo event generator

We develop a method to use the Wigner distribution (WD) description of the nuclear initial state of $^{12}$C, $^{16}$O, $^{40}$Ar, and $^{56}$Fe for quasielastic scattering in the NuWro Monte Carlo event generator. We propose two different algorithms to deal with the problem of negative values of the WDs. In our treatment, finite-nucleus WDs provide a correlation between the position and the momentum of bound nucleons that is very different from what is assumed in the standard approaches based on the Fermi gas model and spectral functions. We show that the use of WDs leads to effects that can be measured experimentally and may be relevant for future neutrino oscillation experiments.

nucl-th↗

Effects of in-medium $NN$ inelastic cross sections and the high-momentum tail of nucleon momentum distributions on pion production in heavy-ion collisions

Pion production in intermediate-energy heavy-ion collisions (HICs) provides a sensitive probe of the nuclear equation of state and of the isospin dependence of reaction dynamics. In particular, pion production near threshold is strongly affected by the nucleon-nucleon ($NN$) inelastic cross sections and by the high-momentum components of the nucleon momentum distribution. To explore the influence of these two ingredients on pion production and charged-pion ratios, the in-medium $NN$ inelastic cross sections calculated within the relativistic Boltzmann-Uehling-Uhlenbeck transport theory and the short-range correlation induced high-momentum tail (HMT) are introduced into the Ultra-relativistic Quantum Molecular Dynamics model. By simulating Au+Au collisions at intermediate energies, we find that the in-medium modification of the $NN$ inelastic cross sections suppresses the pion multiplicity by reducing the probability of $NΔ$ production in dense matter. The HMT, on the other hand, enhances the high-momentum components of nucleons and modifies the available energy in individual $NN$ collisions, thereby affecting $NN\rightarrow NΔ$ reactions and the subsequent pion production. With the simultaneous inclusion of these two effects, the pion yields and the $π^-/π^+$ ratio data can be better reproduced. These results highlight the importance of both the in-medium reaction cross sections and short-range correlation induced high-momentum components in pion production in intermediate energy HICs.

nucl-th↗

Neutron star cooling with medium-modified Urca rates

We study the effects of in-medium modification of the elementary cooling processes on observable properties of isolated neutron stars. We deduce the neutron star mass distributions compatible with the cooling analysis and compare with current theoretical models. We conclude that current cooling data require fast direct Urca cooling, moderated by proton superfluidity, to be active in most neutron stars, and that the DU onset threshold must lie below canonical masses. In that case medium modifications of modified Urca rates are practically insignificant, but the nn Bremsstrahlung rate plays a dominant role.

nucl-th↗