Muon anomalous magnetic moment and positron excess at AMS-02 in a gauged horizontal symmetric model

Abstract: We studied an extension of the standard model with a fourth generation of fermions to explain the discrepancy in the muon (g −2) and explain the positron excess seen in the AMS-02 experiment. We introduce a gauged SU(2)<inf>HV</inf> horizontal symmetry between the muon and the 4th generation lepton families. The 4th generation right-handed neutrino is identified as the dark matter with mass ~ 700GeV. The dark matter annihilates only to (μ⁺μ⁻) and (ν<inf>μ</inf>^Cν<inf>μ</inf>) states via SU(2)<inf>HV</inf> gauge boson. The SU(2)<inf>HV</inf> gauge boson with mass ~ 1.4 TeV gives an adequate contribution to the (g − 2) of muon and fulfill the experimental constraint from BNL measurement. The higgs production constraints from 4th generation fermions is evaded by extending the higgs sector.