arXiv subjects

M. J. Dolan

Publications and source records attributed to M. J. Dolan.

21 records · Page 2Linked to original sources

arXiv2011

Implications of Initial LHC Searches for Supersymmetry

The CMS and ATLAS Collaborations have recently published the results of initial direct LHC searches for supersymmetry analyzing ~ 35/pb of data taken at 7 TeV in the centre of mass. We incorporate these results into a frequentist analysis of the probable ranges of parameters of simple versions of the minimal supersymmetric extension of the Standard Model (MSSM), namely the constrained MSSM (CMSSM), a model with common non-universal Higgs masses (NUHM1), the very constrained MSSM (VCMSSM) and minimal supergravity (mSUGRA). We present updated predictions for the gluino mass, m_gl, the light Higgs boson mass, M_h, BR(B_s to mu mu) and the spin-independent dark matter scattering cross section, sigma_SI. The CMS and ATLAS data make inroads into the CMSSM, NUHM1 and VCMSSM (but not mSUGRA) parameter spaces, thereby strengthening previous lower limits on sparticle masses and upper limits on sigma_SI in the CMSSM and VCMSSM. The favoured ranges of BR(B_s to mu mu) in the CMSSM, VCMSSM and mSUGRA are close to the Standard Model, but considerably larger values of BR(B_s to mu mu) are possible in the NUHM1. Applying the CMS and ATLAS constraints improves the consistency of the model predictions for M_h with the LEP exclusion limits.

hep-ph↗

arXiv2010

Selecting a Model of Supersymmetry Breaking Mediation

We study the problem of selecting between different mechanisms of supersymmetry breaking in the Minimal Supersymmetric Standard Model using current data. We evaluate the Bayesian evidence of four supersymmetry breaking scenarios: mSUGRA, mGMSB, mAMSB and moduli mediation. The results show a strong dependence on the dark matter assumption. Using the inferred cosmological relic density as an upper bound, minimal anomaly mediation is at least moderately favoured over the CMSSM. Our fits also indicate that evidence for a positive sign of the mu parameter is moderate at best. We present constraints on the anomaly and gauge mediated parameter spaces and some previously unexplored aspects of the dark matter phenomenology of the moduli mediation scenario. We use sparticle searches, indirect observables and dark matter observables in the global fit and quantify robustness with respect to prior choice. We quantify how much information is contained within each constraint.

hep-ph↗

arXiv2008

Global Fits of the Large Volume String Scenario to WMAP5 and Other Indirect Constraints Using Markov Chain Monte Carlo

We present global fits to the Large Volume Scenario (LVS) of string models using current indirect data. We use WMAP5 constraints on dark matter relic density, b-physics and electroweak observables as well as direct search constraints. Such data can be adequately fit by LVS, with the best-fit point for mu>0 having chi^2=13.6 for 8 degrees of freedom. The resulting constraints on parameter space are robust in that they do not depend much upon the prior, or upon whether one uses Bayesian or frequentist interpretations of the data. Sparticle masses are constrained to be well below the 1 TeV level, predicting early SUSY discovery at the LHC. We devise a method of quantifying which are the most important constraints. We find that the LEP2 Higgs mass constraint, the relic density of dark matter and the anomalous magnetic moment of the muon affect the fits to the strongest degree.

hep-ph↗