Speaker
Description
In this work, we study the (co-)annihilation dynamics and lepton flavor violation (LFV) in the context of fermionic dark matter within the Scotogenic model, assuming trimaximal mixing (TM$_2$) nature for neutrino mixing matrix. TM$_2$ mixing matrix is used to parameterize the complex Yukawa coupling matrix. Our objective is to identify the parameter space that simultaneously satisfies data from neutrino oscillations, the cold dark matter (CDM) relic density, and the upper bound on the branching ratio of the LFV process Br($\mu \rightarrow e \gamma$). To explore the (co-)annihilation dynamics, we consider three scenarios, finding that only two are viable. Furthermore, regardless of whether the neutrino mass hierarchy is normal (NH) or inverted (IH), a mass splitting of $\lesssim 15\%$ between the mass of CDM particle $N_1$ and the next heavier particle $N_2$, is necessary to satisfy the constraints. In the IH case, the predicted range for Br($\mu \rightarrow e \gamma$) falls within the sensitivity of the MEG II experiment. In both hierarchies, CP-violating and CP-conserving solutions are allowed. Furthermore, the cosmological upper bound on the sum of neutrino masses excludes a significant portion of the effective Majorana mass parameter space ($|m_{ee}|$). The predicted range of $|m_{ee}|$ lies within the detection precision of neutrinoless double beta decay ($0\nu \beta \beta$) experiments for the IH case.
| Field of contribution | Phenomenology |
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