Leptophilic dark matter in gauged Lμ-Lτ extension of MSSM.

A positron excess up to energies of ~350 GeV has been observed by AMS-02, and it is consistent with the positron excess observed by PAMELA up to 100 GeV. There is no observed excess of antiprotons over the expected cosmic ray background. We propose a leptophilic dark matter with an U(1)Lμ-Lτ gauge extension of the minimal supersymmetric standard model. The dark matter is an admixture of the Lμ-Lτ gaugino and fermionic partners of the extra SU(2) singlet Higgs boson, which break the Lμ-Lτ symmetry. We construct the SM⊗U(1)Lμ-Lτ supersymmetry model which provides the correct relic density of dark matter and is consistent with the constraint on Z' from LHC. The large dark matter annihilation cross section into μ+μ- and τ+τ-, needed to explain PAMELA and AMS-02 results, is achieved by Breit-Wigner resonance. [ABSTRACT FROM AUTHOR]