Improved $$(g-2)_\mu $$ measurements and supersymmetry

Abstract

The electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for variety of experimental data. The lighest supersymmetric particle (LSP), which we take as the lightest neutralino, $${\tilde{\chi }}_{1}^0$$ χ ~ 1 0 , can account for the observed Dark Matter (DM) content of the universe via coannihilation with the next-to-LSP (NLSP), while being in agreement with negative results from Direct Detection (DD) experiments. Owing to relatively small production cross-sections a comparably light EW sector of the MSSM is also in agreement with the unsuccessful searches at the LHC. Most importantly, the EW sector of the MSSM can account for the persistent $$3-4\,\sigma $$ 3 - 4 σ discrepancy between the experimental result for the anomalous magnetic moment of the muon, $$(g-2)_\mu $$ ( g - 2 ) μ , and its Standard Model (SM) prediction. Under the assumption that the $${\tilde{\chi }}_{1}^0$$ χ ~ 1 0 provides the full DM relic abundance we first analyze which mass ranges of neutralinos, charginos and scalar leptons are in agreement with all experimental data, including relevant LHC searches. We find an upper limit of $$\sim 600 \,\, \mathrm {GeV}$$ ∼ 600 GeV for the LSP and NLSP masses. In a second step we assume that the new result of the Run 1 of the “MUON G-2” collaboration at Fermilab yields a precision comparable to the existing experimental result with the same central value. We analyze the potential impact of the combination of the Run 1 data with the existing $$(g-2)_\mu $$ ( g - 2 ) μ data on the allowed MSSM parameter space. We find that in this case the upper limits on the LSP and NLSP masses are substantially reduced by roughly $$100 \,\, \mathrm {GeV}$$ 100 GeV . This would yield improved upper limits on these masses of $$\sim 500 \,\, \mathrm {GeV}$$ ∼ 500 GeV . In this way, a clear target could be set for future LHC EW searches, as well as for future high-energy $$e^+e^-$$ e + e - colliders, such as the ILC or CLIC.

Supersymmetric gauged U(1)Lμ−LτBanerjee1, Byakti2, Roy3 2018Phys. Rev. D303180View full textAdd to dashboardCite

“…Current projections for the High-Luminosity LHC [73] show that the W h channel with a l +bb+MET final state may be the strongest probe of the electroweakinos [74], however it still cannot probe many of the scenarios described in this work. Especially, the parameter choices involving mildly compressed spectra amongst the lightest electroweakinos and sleptons would remain unconstrained.…”

Supersymmetric gauged $$ \mathrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} $$ model for electron and muon (g − 2) anomaly

“…Current projections for the High-Luminosity LHC [89] show that the W h channel with a l + bb + MET final state may be the strongest probe of the electroweakinos [90], however it still cannot probe many of the scenarios described in this work. Especially, the parameter choices involving mildly compressed spectra amongst the lightest electroweakinos and sleptons would remain unconstrained.…”

GUT-constrained supersymmetry and dark matter in light of the new (g − 2)μ determination

“…ref. [15] for further discussion about relevant analyses. In addition, we test our scenarios against the search for compressed supersymmetric spectra [105] by applying the cuts in the (m χ , m χ ±…”

“…It is well known that current LHC limits still easily allow SUSY corrections to δa µ to be quite large but only in phenomenological frameworks of SUSY with all parameters defined at the electroweak (EW) scale, like the Minimal Supersymmetric Standard Model (MSSM) [5][6][7][8][9][10][11][12][13][14][15][16]. The situation is generally very different in unified, i.e., based on grand unification theories (GUTs), or -in other words -GUT-constrained, SUSY models,…”

“…ref. [15] for a recent discussion. If the lightest neutralino is wino-like with the mass m χ ∼ a few hundred GeV and a very small mass splitting, m χ ± 1 − m χ ∼ O(100 MeV) then further important bounds come from searches for disappearing tracks [106,107].…”