Speaker
Description
JUNO sensitivity to the annihilation cross section of MeV dark matter (DM) into neutrinos in the galactic halo (A. Abusleme et al. [JUNO], JCAP 09, 001 (2023)) constrains the DM-extended $U(1)_{L_\mu - L_\tau}$ model, characterized by the $Z'$ boson with mass $m_{Z’}$, the coupling $g_{Z’}$ between $Z’$ and the second and third generations of leptons, and the coupling $g_{\chi}$ between DM and $Z’$. Focusing on light DM with masses below 100 MeV, we study the annihilation channel $\chi\chi \to Z' \to \nu_{\mu, \tau}\bar{\nu}_{\mu, \tau}$ in the galactic halo with $m_{Z’}\approx 2m_{\chi}$. We impose the condition that the DM relic density matches the observed value $\Omega_\chi h^2=0.12$, which fixes the value of $\langle \sigma v \rangle$ in the early universe. Under this condition, we predict the value of resonance-enhanced $\langle \sigma v \rangle$ in the present-day universe as a function of the coupling product $g_{Z’}\cdot g_{\chi}$. We discuss the possibility of testing this resonance-enhanced annihilation by JUNO detector.
| Please choose your topic | Dark Matter |
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