Study of constrained minimal supersymmetry

Abstract

Taking seriously the phenomenological indications for supersymmetry, we have made a detailed study of unified minimal SUSY, including many effects at the few percent level in a consistent fashion. We report here a general analysis of what can be studied without choosing a particular gauge group at the unification scale. Firstly, we find that the encouraging SUSY unification results of recent years do survive the challenge of a more complete and accurate analysis. Taking into account effects at the 5-10% level leads to several improvements of previous results, and allows us to sharpen our predictions for SUSY in the light of unification. We perform a thorough study of the parameter space and look for patterns to indicate SUSY predictions, so that they do not depend on arbitrary choices of some parameters or untested assumptions. Our results can be viewed as a fully constrained Minimal SUSY Standard Model (CMSSM).The resulting model forms a well-defined basis for comparing the physics potential of different facilities. Very little of the acceptable parameter space has been excluded by LEP or FNAL so far, but a significant fraction can be covered when these accelerators are upgraded. A number of initial applications to the understanding of the values of m h and m t , the SUSY spectrum, detectability of SUSY at LEP II or FNAL, BR(b → sγ), Γ(Z → bb), dark matter, etc., are included in a separate section that might be of more interest to some readers than the technical aspects of model-building. We formulate an approach to extracting SUSY parameters from data when superpartners are detected. For small tan β or large m t both m 1/2 and m 0 are entirely bounded from above at O(1 TeV) without having to use a fine-tuning constraint.

The soft supersymmetry-breaking Lagrangian: theory and applications

“…A subset of the mSUGRA parameter space gives low energy models that satisfy the basic phenomenological requirements (e.g. electroweak symmetry breaking) incorporated into what is known as the constrained MSSM (CMSSM) [106]. The CMSSM is by far the most popular scenario for L sof t amongst phenomenologists and experimenters; more phenomenological analyses have been performed for mSUGRA/CMSSM than for all other scenarios combined.…”

“…There has been a great deal of activity in computing the relic density for various regions of MSSM parameter space [415,416,417,418,419,414,413,420,421,422,423,424,425,426,106,427,428,429,430,431,432,433,434,435,436,437,438,439,440,441,442,443,444,445,446,447,448,449]. The state of the art numerical programs take into account nearly 8000 Feynman diagrams.…”

Scenarios for gluino coannihilation

“…The possibility of gluino coannihilation does not arise in the minimal supersymmetric extension of the Standard Model (MSSM) with the soft supersymmetry-breaking parameters constrained to be universal at the input GUT scale (the CMSSM) [14,[32][33][34][35][36][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91][92], nor in related models with non-universal Higgs masses [83,84,[93][94][95][96][97][98][99][100][101][102][103][104][105][106]. However, as we discuss in this paper, gluino coannihilation can become important in variants of the MSSM with non-universal gaugino masses, and in variations of pure gravity mediation (PGM) with non-minimal matter content such as additional vector-like supermultiplets [67][68][69].…”

GUT-inspired supersymmetric model forh→γγand the muong−2

“…These bounds combined with the bound of 125 GeV on the lightest CP even Higgs boson mass place stringent constraints on the slepton and gaugino (bino or wino) mass spectrum in several well studied scenarios such as constrained MSSM (cMSSM) [7], NUHM1 [8] and NUHM2 [9]. In particular, as we shall show later, in the above mentioned models, the first two generation sleptons are predicted to be more than 1 TeV in order to accommodate the light CP even Higgs with 125 GeV mass.…”