Minimal dark matter model for muon g-2 with scalar lepton partners up to the TeV scale

Time : 2022/09/22 (Thu.) 12:30
Title: Minimal dark matter model for muon g-2 with scalar lepton partners up to the TeV scale

The E989 experiment at the Fermi National Laboratory (FNAL) reported a 4.2-sigma tension
between the measured magnetic dipole moment of the muon, and the SM prediction.
Taking the hypothesis that BSM physics can account for this so-called muon g-2 anomaly,
we propose a minimal extension to the SM. The particle spectrum of this BSM framework consists of:
a SM singlet Majorana fermion, referred to as the Bino, playing the role of DM; and muonic scalars,
referred to as sleptons. The sleptons, SM muon, and the Bino interact in a manner similar
to gaugino interactions in the MSSM. The presence of left-right mixing among the scalar muonic partners,
at a level that breaks the assumption of minimal flavor violation, allows for a sufficient
contribution to close the tension. We demonstrate that the relic density constraint can also
be satisfied in cases with sizable smuon mixing and particle masses at the TeV scale,
if we consider coannihilations among the extra species in the spectrum.
Additional constraints from perturbative unitarity and metastability of the electroweak vacuum
can be imposed on the model. Meanwhile, we show that future generation liquid noble gas detectors
are marginally sensitive to the region of the parameter space that satisfies both the g-2
and relic density limits. This motivates the exploration of alternative methods of probing our model,
such as neutron star kinetic heating, which may provide better sensitivity than conventional dark matter searches.