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The b->sgamma decay rate in NLO, Higgs boson limits, and LSP masses in the CMSSM

W. de Boer·M. Huber·A. Gladyshev·D. I. Kazakov
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Abstract

New NLO b->sgamma calculations have become available. We observe that at large tanbeta the dominant NLO term of the chargino amplitude, which is proportional to mu.tanbeta^2, changes the sign of this amplitude in a large region of the CMSSM parameter space, so that the preferred sign of the Higgs mixing parameter mu now agrees with the preferred sign of b-tau unification. We find that the b->sgamma rate does not constrain the CMSSM anymore, if the higher order contributions and its uncertainties from the incomplete calculations are taken into account. The Higgs boson mass in the CMSSM is found to be between 110 and 120 GeV for a top mass of 175 GeV, if the Higgs mass limit of 107.9 GeV from LEP, which implies tanbeta>3.3, is taken into account The mean Higgs boson mass value and its dominant errors are: m_h=115\pm 3(stop mass) \pm 1.5(stop mixing) \pm 2(theory) \pm 5(top mass) GeV. This Higgs mass range is valid for all tanbeta values above 20 and decreases for lower tanbeta. If the presently claimed evidence for dark matter by the DAMA Collaboration is interpreted as the Lightest Supersymmetric Particle (LSP) of the CMSSM, then it is at the edge of the parameter space allowed by the present Higgs limit of 107.9 GeV from LEP.

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W. de Boer, M. Huber, A. Gladyshev, D. I. Kazakov. 2000-07-09. The b->sgamma decay rate in NLO, Higgs boson limits, and LSP masses in the CMSSM. https://arxiv.org/abs/hep-ph/0007078

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