Leptophilic dark matter in gauged $L_μ-L_τ$ extension of MSSM

Abstract

Positron excess upto energies $\sim$350 GeV has been observed by AMS-02 result and it is consistent with the positron excess observed by PAMELA upto 100 GeV. There is no observed excess of anti-protons over the expected CR background. We propose a leptophilic dark matter with an $U(1)_{L_μ-L_τ}$ gauge extension of MSSM. The dark matter is an admixture of the $L_μ-L_τ$ gaugino and fermionic partners of the extra $SU(2)$ singlet Higgs boson, which break the $L_μ-L_τ$ symmetry. We construct the SM$\otimes U(1)_{ L_μ-L_τ}$ SUSY model which provides the correct relic density of dark matter and is consistent with constrain on $Z'$ from LHC. The large dark matter annihilation cross-section into $μ^{+}μ^{-}$ and $τ^{+}τ^{-}$, needed to explain PAMELA and AMS-02 is achieved by Breit-Wigner resonance.

16 pages, 3 figures, ref. updated, version accepted for publication in PRD