Lepton-portal Dark Matter in Hidden Valley model and the DAMPE recent results

Abstract: We study the recent $e^\pm$ cosmic ray excess reported by DAMPE in a Hidden Valley Model with lepton-portal dark matter. We find the electron-portal can account for the excess well and satisfy the DM relic density and direct detection bounds, while electron+muon/electron+muon+tau-portal suffers from strong constraints from lepton flavor violating observables, such as $\mu \to 3 e$. We also discuss possible collider signatures of our model, both at the LHC and a future 100 TeV hadron collider.