Model-independent Astrophysical Constraints on Leptophilic Dark Matter in the Framework of Tsallis Statistics

Abstract

We derive model-independent astrophysical constraints on leptophilic dark matter (DM), considering its thermal production in a supernova core and taking into account core temperature fluctuations within the framework of $q$-deformed Tsallis statistics. In an effective field theory approach, where the DM fermions interact with the Standard Model via dimension-six operators of either scalar-pseudoscalar, vector-axial vector, or tensor-axial tensor type, we obtain bounds on the effective cut-off scale $\Lambda$ from supernova cooling and free-streaming of DM from supernova core, and from thermal relic density considerations, depending on the DM mass and the $q$-deformation parameter. Using Raffelt's criterion on the energy loss rate from SN1987A, we obtain a lower bound on $\text{Lda}\gtrsim 3$ (12) TeV corresponding to $q=1.0(1.1)$ and an average supernova core temperature of $T_{\mathrm{SN}}=30$ MeV. From the optical depth criterion on the free-streaming of DM fermions from the outer 10\% of the SN1987A core, the cooling bound is restricted to $\text{Lda}\gtrsim 1$ TeV. Both cooling and free-streaming bounds are insensitive to the DM mass $m_{\chi }$ for $m_{\chi }\lesssim T_{\mathrm{SN}}$, whereas for $m_{\chi }\gg T_{\mathrm{SN}}$, the bounds weaken significantly due to the Boltzmann-suppression of the DM number density. We also calculate the thermal relic density of the DM particles in this setup and find that it imposes an upper bound on ${\Lambda }^4/m_{\chi }^2$, which together with the cooling/free-streaming bound significantly constrains light leptophilic DM.

Comments: 27 pages, 9 figures and 3 tables