Talk detail

Participant	Xue, She-Sheng
Institution	ICRANet, Phys. Department, University of Rome, La Sapienza - ICRANet, P.zza della Repubblica 10 - Pescara - I--65122 Pescara - Italy

Session	SF3	Accepted		Order	Time
Talk	Oral abstract	Title	Electron and positron pair production in gravitational collapse
Co-authors
Abstract	Neutral stellar core at or over nuclear densities is described by positive charged baryon core and negative charged electron fluid since they possess different masses and interactions. Based on a simplified model of gravitationally collapsing or pulsating baryon core, we approximately integrate the Einstein-Maxwell equations and the equations for the number and energy-momentum conservation of complete degenerate electron fluid. We show possible electric processes that lead to the production of electron-positron pairs in the boundary of baryon core, and calculate electron-positron pair energy. This might be important for understanding the energy source of gamma-ray bursts.

Session	SN1	Accepted		Order	Time
Talk	Oral abstract	Title	Neutrinos decoupled from $\beta$-processes and supernova explosion
Co-authors
Abstract	Based on the gravitational collapse time-scale is larger than the weak interaction time-scale at core densities $\rho > 10^{11} {\rm gr}/ {\rm cm}^{3}$, we approximately use the $\beta$-equilibrium condition and particle number conservations to calculate the number and energy densities of neutrino sphere in the process of gravitational core collapse towards the formation of a proto-neutron star. We find that at core densities $\rho_{\rm dec} > 10^{12} {\rm gr}/ {\rm cm}^{3}$, the $\beta$-equilibrium condition cannot be satisfied consistently with charge, baryon and lepton number conservations, leading to the presence of excess neutrinos decoupling from the $\beta$-equilibrium. These excess neutrinos interact with nucleons and electrons via the neutral current channel only and their diffusion time is about $10^{-2}\,$ sec. The excess neutrino flux could play an important role in an Supernova explosion, provided the fraction of excess neutrinos over all neutrinos is at least one present.