Sleptonic SUSY: From UV Framework to IR Phenomenology

Abstract

We study an attractive scenario, "Sleptonic SUSY", which reconciles the 125 GeV Higgs scalar and the non-observation of superpartners thus far with potentially pivotal roles for slepton phenomenology: providing viable ongoing targets for LHC discovery, incorporating a co-annihilation partner for detectable thermal relic dark matter, and capable of mediating the existing muon g −2 anomaly. This is accomplished by a modestly hierarchical spectrum, with sub-TeV sleptons and electroweakinos and with multi-TeV masses for the other new states. We study new elements in the UV MSSM realization of Sleptonic SUSY based on higher-dimensional sequestering and the synergy between the resulting gauginomediation, hypercharge D-term mediation and Higgs-mediation of SUSY-breaking, so as to more fully capture the range of possibilities. This framework stands out by harmoniously solving the flavor, CP and µ − Bµ problems of the supersymmetric paradigm. We discuss its extension to orbifold GUTs, including gauge-coupling and b-tau unification. We also develop a non-minimal model with extra Higgs fields, in which the electroweak vacuum is more readily cosmologically stable against decay to a charge-breaking vacuum, allowing a broader range of sleptonic spectra than in the MSSM alone. We survey the rich set of signals possible at the LHC and future colliders, covering both R-parity conservation and violation, as well as for dark matter detection. While the multi-TeV squarks imply a Little Hierarchy Problem, intriguingly, small changes in parameter space to improve naturalness result in dramatic phase transitions to either electroweak-preservation or charge-breaking. In a Multiverse setting, the modest unnaturalness may then be explained by the "principle of living dangerously".

Speculations on the W-Mass Measurement at CDF

“…Still, this provides valuable information to understand the situation with scalar doublets at the loop level. One can consider extending the considerations to multiple specifies, mainly through lepton partners, e.g., light staus [35,36]. These can be a promising direction to explore.…”

Complementary signals of lepton flavor violation at a high-energy muon collider

“…This spectrum bears some resemblance to those studied from a UV perspective in ref. [8] in the context of the hierarchy problem and the muon (g − 2). The LHC bounds were compared to the flavor constraints for a similar spectrum in ref.…”

Flavor- and CP-safe explanation of $g_μ-2$ anomaly

“…2 An important theoretical consideration, which we do not consider here, is can g µ −2 be explained in models consistent with grand unification. It was shown that, at least in some unification models, it can be rectified [14,[25][26][27][28].…”

“…The CP-problem is solved by assuming a shift symmetry where the imaginary part of the SUSY breaking field receives a constant shift[35]. See also[28] for another construction of a CP-safe gaugino mediation model 5. In Ref [42],.…”