Should we still believe in constrained supersymmetry?

TL;DR

This paper uses Bayesian analysis to evaluate how recent experimental results from LEP and LHC have significantly decreased confidence in the constrained minimal supersymmetric standard model (CMSSM).

Contribution

It provides a quantitative Bayesian assessment of the impact of multiple collider and dark matter experiments on the credibility of the CMSSM.

Findings

LEP and LHC results reduce belief in CMSSM by about two orders of magnitude.

LEP and LHC Higgs searches induce strong Occam factors.

Experimental data significantly challenge the viability of CMSSM.

Abstract

We calculate Bayes factors to quantify how the feasibility of the constrained minimal supersymmetric standard model (CMSSM) has changed in the light of a series of observations. This is done in the Bayesian spirit where probability reflects a degree of belief in a proposition and Bayes' theorem tells us how to update it after acquiring new information. Our experimental baseline is the approximate knowledge that was available before LEP, and our comparison model is the Standard Model with a simple dark matter candidate. To quantify the amount by which experiments have altered our relative belief in the CMSSM since the baseline data we compute the Bayes factors that arise from learning in sequence the LEP Higgs constraints, the XENON100 dark matter constraints, the 2011 LHC supersymmetry search results, and the early 2012 LHC Higgs search results. We find that LEP and the LHC strongly shatter our trust in the CMSSM (with $M_0$ and $M_{1/2}$ below 2 TeV), reducing its posterior odds by a factor of approximately two orders of magnitude. This reduction is largely due to substantial Occam factors induced by the LEP and LHC Higgs searches.