Neutrino energy loss rates and positron capture rates on {sup 55}Co for presupernova and supernova physics

Journal Article · Thu May 15 04:00:00 EDT 2008 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.77.055802· OSTI ID:21190017

Nabi, Jameel-Un; Sajjad, Muhammad ^[1]

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1. Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, Topi 23640, Swabi, NWFP (Pakistan)

Proton-neutron quasiparticle random phase approximation (pn-QRPA) theory has recently been used for the calculation of stellar weak interaction rates of the fp-shell nuclide with success. Neutrino losses from protoneutron stars play a pivotal role in deciding if these stars would be crushed into black holes or explode as supernovas. The product of abundance and positron capture rates on {sup 55}Co is substantial and as such can play a role in the fine tuning of input parameters of simulation codes especially in the presupernova evolution. Recently we introduced our calculation of capture rates on {sup 55}Co, in a luxurious model space of 7({Dirac_h}/2{pi}) {omega}, employing the pn-QRPA theory with a separable interaction. Simulators, however, may require these rates on a fine scale. Here we present for the first time an expanded calculation of the neutrino energy loss rates and positron capture rates on {sup 55}Co on an extensive temperature-density scale. This type of scale is appropriate for interpolation purposes and of greater utility for simulation codes. The pn-QRPA calculated neutrino energy loss rates are enhanced roughly up to two orders of magnitude compared with the large-scale shell model calculations and favor a lower entropy for the core of massive stars.

• OSTI ID: 21190017
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 5 Vol. 77; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ABUNDANCE
BLACK HOLES
CAPTURE
COBALT 55
DENSITY
ENERGY LOSSES
ENTROPY
INTERPOLATION
NEUTRINOS
NEUTRONS
POSITRONS
PROTON-NEUTRON INTERACTIONS
PROTONS
RANDOM PHASE APPROXIMATION
SHELL MODELS
SIMULATION
SPACE
SUPERNOVAE
WEAK INTERACTIONS