Bulg. J. Phys. vol.35 no.2 (2008), pp. 095-106



Neutrino Pair Bremsstrahlung in Supernova Environments

S. Banerjee
Natural Sciences Department, West Bengal University of Technology, Calcutta 700064, India
Abstract. Core collapse Supernova is among the most energetic explosions in the Universe, releasing tremendous amounts of energy in the form of large number of neutrinos of all flavours. This is a result of a supernova shock wave formed when the iron core collapses gravitationally and rebounds at high density. There are strong indications that the neutron rich region between the resulting proto-neutron core and shock wave, referred to as the 'hot bubble' region is the site for rapid nucleosynthesis (r-process) of heavy nuclei, a key role played by supernovae. In this article we propose a possible reaction occurring between these neutrons and nuclei within the infalling matter from the region exterior to the stalled shock front.This reaction takes place when the collapse is well underway and leads to neutrino pair bremsstrahlung, in this 'hot bubble' region.The emissivity is calculated and the temperature dependence of this reaction is studied and compared with other dominant mechanisms of neutrino emission.It is found that this reaction compares favorably with other mechanisms, thereby suggesting that this reaction plays a significant role in the total neutrino luminosity, a critical factor for successful Supernova explosion. The emissivity of this process is comparable to electron-nucleus neutrino bremsstrahlung and nucleon-nucleon neutrino bremsstrahlung under certain conditions.

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