Constraining U(1)(L mu)-(L tau) charged dark matter model for muon g-2 anomaly with AMS-02 electron and positron data

Very recently, the Fermi-Lab reported the new experimental combined results on the magnetic momentum of muon with a 4.2 sigma discrepancy compared with the expectation of the Standard Model [1]. A new light gauge boson X in the L-mu - L-tau model provides a good explanation for the g - 2 anomaly. A Dirac fermion dark matter with a large L-mu - L-tau charge can explain both the g - 2 anomaly and the dark matter relic density [2]. In this work, we focus on the case that the mass of the dark matter is larger than the mass of muon (i.e. m(Psi) > m(mu)) for which the channel Psi Psi -> mu(-)mu(+) opens. Although the cross section (sigma v)(mu-mu+ ) is smaller by a factor of 1/q(Psi)(2) (q(Psi) epresents the L-mu - L-tau charge of the dark matter) compared with the channel -> XX -> nu nu(nu) over bar(nu) over bar, the resulting secondary electrons and positrons could imprint on their spectra above GeV energies due to the reacceleration effect of cosmic ray propagation. We use the AMS-02 measurements of electrons and positrons to constrain the annihilation cross section of the channel Psi Psi -> mu(-)mu(+), which rules out part of the parameter space of the large L-mu - L-tau charged dark matter model to account for the muon g-2 anomaly.

Automated summary

The study focuses on the case where the mass of dark matter in the L-mu - L-tau model is greater than that of the muon to explain the muon's magnetic momentum anomaly. The observation of secondary electrons and positrons resulting from dark matter annihilation helps constrain the parameter space of the model in explaining the anomaly.