The Supersymmetric Parameter Space in Light of B-physics Observables and Electroweak Precision Data

TL;DR

This paper analyzes the supersymmetric parameter space using B-physics and electroweak data, performing fits within CMSSM and NUHM models, and explores implications for dark matter and preferred parameter regions.

Contribution

It combines recent experimental measurements with theoretical calculations to constrain supersymmetric models and identifies preferred parameter regions consistent with dark matter data.

Findings

CMSSM favors a low SUSY-breaking scale.

Some NUHM scenarios have lower chi^2 than CMSSM.

Preferred regions in M_A-tan_beta planes are identified.

Abstract

Indirect information about the possible scale of supersymmetry (SUSY) breaking is provided by B-physics observables (BPO) as well as electroweak precision observables (EWPO). We combine the constraints imposed by recent measurements of the BPO BR(b -> s gamma), BR(B_s -> mu^+ mu^-), BR(B_u -> tau nu_tau) and Delta M_{B_s} with those obtained from the experimental measurements of the EWPO M_W, sin^2 theta_eff, Gamma_Z, (g-2)_mu and M_h, incorporating the latest theoretical calculations of these observables within the Standard Model and supersymmetric extensions. We perform a chi^2 fit to the parameters of the constrained minimal supersymmetric extension of the Standard Model (CMSSM), in which the SUSY-breaking parameters are universal at the GUT scale, and the non-universal Higgs model (NUHM), in which this constraint is relaxed for the soft SUSY-breaking contributions to the Higgs masses. Assuming that the lightest supersymmetric particle (LSP) provides the cold dark matter density preferred by WMAP and other cosmological data, we scan over the remaining parameter space. Within the CMSSM, we confirm the preference found previously for a relatively low SUSY-breaking scale, though there is some slight tension between the EWPO and the BPO. In studies of some specific NUHM scenarios compatible with the cold dark matter constraint we investigate M_A-tan_beta planes and find preferred regions that have values of chi^2 somewhat lower than in the CMSSM.