New Cosmological and Experimental Constraints on the CMSSM

Abstract

We analyze the implications of several recent cosmological and experimental measurements for the mass spectra of the Constrained MSSM (CMSSM). We compute the relic abundance of the neutralino and compare the new cosmologically expected and excluded mass ranges with those ruled out by the final LEP bounds on the lightest chargino and Higgs masses, with those excluded by current experimental values of $\text{br}(B\to X_s\gamma )$, and with those favored by the recent measurement of the anomalous magnetic moment of the muon. We find that for $tan\beta \text{lsim}45$ there remains relatively little room for the mass spectra to be consistent with the interplay of the several constraints. On the other hand, at larger values of $tan\beta \$thedecreasingmassofthepseudoscalarHiggsgivesrisetoawideresonanceintheneutralinoWIMPpair-annihilation,whosepositiondependsontheratiooftopandbottomquarkmasses.Asaconsequence,thecosmologicallyexpectedregionsconsistentwithotherconstraintsoftengrowsignificantlyandgenerallyshifttowardssuperpartnermassesinthe$\tev$ range.

Comments: LaTex, 21 pages, 4 PS figures. Version published in JHEP, for updates see hep-ph/0206178