q-deformed statistics and the role of a light fermionic dark matter in the supernova SN1987A cooling

Abstract

Light dark matter($\simeq 1-30~\rm{MeV}$) particles pair produced in electron-positron annihilation $ e^-e^+ \stackrel{\gamma}{\longrightarrow} \chi \bar{\chi}$ inside the supernova core can take away the energy released in the supernova SN1987A explosion. Working within the formalism of $q$-deformed statistics (with the average value of the supernovae core temperature(fluctuating) being $T_{SN} = 30~\rm{MeV}$) and using the Raffelt's criterion on the emissivity for any new channel $\dot{\varepsilon}(e^+ e^- \to \chi \overline{\chi}) \le 10^{19}~{erg~g^{-1}s^{-1}}$, we find that as the deformation parameter $q$ changes from $1.0$ (undeformed scenario) to $1.1$(deformed scenario), the lower bound on the scale $\Lambda$ of the dark matter effective theory varies from $3.3\times 10^6$ TeV to $3.2 \times 10^7$ TeV for a dark matter fermion of mass $m_\chi = 30~\rm{MeV}$. Using the optical depth criteria on the free streaming of the dark matter fermion, we find the lower bound on $\Lambda \sim 10^{8}~\rm{TeV}$ for $m_\chi = 30~\rm{MeV}$. In a scenerio,where the dark matter fermions are pair produced in the outermost sector of the supernova core (with radius $0.9 R_c \le r \le R_c$, $R_c (=10~\rm{km})$ being the supernova core radius or the radius of proto-neutron star), we find that the bound on $\Lambda$ ($\sim 3 \times 10^7$ TeV)obtained from SN cooling criteria (Raffelt's criteria) is comparable with the bound obtained from free streaming (optical depth criterion) for light fermion dark matter of mass $m_{\chi}=10 - 30$ MeV.