The CMSSM parameter space at large tan β

We extend previous combinations of LEP and cosmological relic density constraints on the parameter space of the constrained MSSM, with universal input supersymmetry-breaking parameters, to large tan beta. We take account of the possibility that the lightest Higgs boson might weigh about 115 GeV, but also retain the possibility that it might be heavier. We include the most recent implementation of the b --> s gamma constraint at large tan beta. We reline previous relic density calculations at large tanB by combining a careful treatment of the direct-channel Higgs poles in annihilation of pairs of neutralinos chi with a complete treatment of chi-<(<tau>)over tilde> coannihilation, and discuss carefully uncertainties associated with the mass of the h quark. We find that coannihilation and pole annihilations allow the CMSSM to yield an acceptable relic density at large tan beta, but it is consistent with all the constraints only if m(chi) > 140 (180) GeV for mu > 0 (mu < 0) for our default choices m(b)(m(b))(SM)(MS) over bar = 4.25 GeV, m(t) = 175 GeV, and A(0) = 0. (C) 2001 Elsevier Science B.V. All rights reserved.