Abstract
We argue that in order to account for the muon anomalous magnetic moment $g\ensuremath{-}2$, dark matter and LHC data, nonuniversal gaugino masses ${M}_{i}$ at the high scale are required in the framework of the minimal supersymmetric standard model. We also need a right-handed smuon ${\stackrel{\texttildelow{}}{\ensuremath{\mu}}}_{R}$ with a mass around 100 GeV, evading LHC searches due to the proximity of a neutralino ${\stackrel{\texttildelow{}}{\ensuremath{\chi}}}_{1}^{0}$ several GeV lighter which allows successful dark matter. We discuss such a scenario in the framework of an $SU(5)$ grand unified theory (GUT) combined with ${A}_{4}$ family symmetry, where the three $\overline{5}$ representations form a single triplet of ${A}_{4}$ with a unified soft mass ${m}_{F}$, while the three 10 representations are singlets of ${A}_{4}$ with independent soft masses ${m}_{T1},{m}_{T2},{m}_{T3}$. Although ${m}_{T2}$ (and hence ${\stackrel{\texttildelow{}}{\ensuremath{\mu}}}_{R}$) may be light, the muon $g\ensuremath{-}2$ and relic density also requires light ${M}_{1}\ensuremath{\simeq}250\text{ }\text{ }\mathrm{GeV}$, which is incompatible with universal gaugino masses due to LHC constraints on ${M}_{2}$ and ${M}_{3}$ arising from gaugino searches. After showing that universal gaugino masses ${M}_{1/2}$ at the GUT scale are excluded by gluino searches, we provide a series of benchmarks which show that while ${M}_{1}={M}_{2}\ensuremath{\ll}{M}_{3}$ is in tension with 8 and 13 TeV LHC data, ${M}_{1}<{M}_{2}\ensuremath{\ll}{M}_{3}$ is currently allowed. Even this scenario is almost excluded by the tension between the muon $g\ensuremath{-}2$, relic density, dark matter direct detection and LHC data. We focus on a region of parameter space that has not been studied in detail before being characterized by low Higgsino mass $\ensuremath{\mu}\ensuremath{\approx}\ensuremath{-}300\text{ }\text{ }\mathrm{GeV}$, as required by the muon $g\ensuremath{-}2$. The LHC will be able to fully test this scenario with the upgraded luminosity via muon-dominated tri- and dilepton signatures resulting from Higgsino-dominated ${\stackrel{\texttildelow{}}{\ensuremath{\chi}}}_{1}^{\ifmmode\pm\else\textpm\fi{}}{\stackrel{\texttildelow{}}{\ensuremath{\chi}}}_{2}^{0}$ and ${\stackrel{\texttildelow{}}{\ensuremath{\chi}}}_{1}^{+}{\stackrel{\texttildelow{}}{\ensuremath{\chi}}}_{1}^{\ensuremath{-}}$ production.
Highlights
The minimal supersymmetric standard model (MSSM) remains an attractive candidate for physics beyond the standard model (BSM) even in the absence of any signal at the Large Hadron Collider (LHC)
We argue that in order to account for the muon anomalous magnetic moment g − 2, dark matter and LHC
We argue that in order to account for the muon anomalous magnetic moment and dark matter in supersymmetry, in our studied region of parameter space for μ ≈ −300 GeV, nonuniversal gaugino masses are required
Summary
The minimal supersymmetric standard model (MSSM) remains an attractive candidate for physics beyond the standard model (BSM) even in the absence of any signal at the Large Hadron Collider (LHC). We argue that in order to account for the muon anomalous magnetic moment and dark matter in supersymmetry, in our studied region of parameter space for μ ≈ −300 GeV, nonuniversal gaugino masses are required. To achieve the desired pattern of nonuniversality, we consider an SUð5Þ GUT combined with an A4 family symmetry, where the three 5 ̄ representations form a single triplet of A4 with a unified soft mass mF, while the three 10 representations are singlets of A4 with independent soft masses mT1; mT2; mT3.1 Assuming that mT2 ≪ mT1; mT3, as discussed above, we show that it is not possible to account for the muon g − 2 with universal gaugino masses.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
