Muon g -2 and dark matter suggest nonuniversal gaugino masses: S U (5 )×A4 case study at the LHC
Abstract
We argue that in order to account for the muon anomalous magnetic moment g -2 , dark matter and LHC data, nonuniversal gaugino masses Mi at the high scale are required in the framework of the minimal supersymmetric standard model. We also need a right-handed smuon μ∼R with a mass around 100 GeV, evading LHC searches due to the proximity of a neutralino χ∼10 several GeV lighter which allows successful dark matter. We discuss such a scenario in the framework of an S U (5 ) grand unified theory (GUT) combined with 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 mT 1,mT 2,mT 3. Although mT 2 (and hence μ∼R) may be light, the muon g -2 and relic density also requires light M1≃250 GeV , which is incompatible with universal gaugino masses due to LHC constraints on M2 and M3 arising from gaugino searches. After showing that universal gaugino masses M1 /2 at the GUT scale are excluded by gluino searches, we provide a series of benchmarks which show that while M1=M2≪M3 is in tension with 8 and 13 TeV LHC data, M1<M2≪M3 is currently allowed. Even this scenario is almost excluded by the tension between the muon g -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 μ ≈-300 GeV , as required by the muon g -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 χ∼1±χ∼20 and χ∼1+χ∼1- production.
- Publication:
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Physical Review D
- Pub Date:
- June 2018
- DOI:
- 10.1103/PhysRevD.97.115002
- arXiv:
- arXiv:1801.00514
- Bibcode:
- 2018PhRvD..97k5002B
- Keywords:
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- High Energy Physics - Phenomenology
- E-Print:
- 23 pages, 10 figures