Phenomenological indications of the scale of supersymmetry

Electroweak precision measurements can provide indirect information about thepossible scale of supersymmetry already at the present level of accuracy. Weupdate the present-day sensitivities of precision data using the newexperimental top-quark mass, m_t = 172.7 \pm 2.9 GeV, within the constrainedminimal supersymmetric extension of the Standard Model (CMSSM), in which thereare three independent soft supersymmetry-breaking parameters m_{1/2}, m_0 andA_0. In addition to M_W and sin^2 theta_eff, the analysis is based on(g-2)_\mu, BR(b -> s gamma) and the lightest MSSM Higgs boson mass, M_h.Assuming initially that the lightest supersymmetric particle (LSP) is aneutralino, we display the CMSSM results as functions of m_{1/2}, fixing m_0 soas to obtain the cold dark matter density allowed by WMAP and othercosmological data for specific values of A_0, tan_beta and mu > 0. For a samplevalue of tan_beta we analyze how the global chi^2 function would changefollowing a possible future evolution of the experimental central value of m_tand its error. In a second step, we extend the analysis to other constrainedversions of the MSSM: the NUHM in which the soft supersymmetry-breakingcontributions to the Higgs masses are independent and the Higgs mixingparameter mu and the pseudoscalar Higgs mass M_A become additional freeparameters compared to the CMSSM, a VCMSSM in which the bilinear softsupersymmetry breaking parameter B_0 = A_0 - m_0, and the GDM in which the LSPis the gravitino. In all scenarios we find indications for relatively lightsoft supersymmetry-breaking masses, offering good prospects for the LHC and theILC, and in some cases also for the Tevatron.Comment: 49 pages, 15 figures. Diskussion on focus point region extended, other minor changes. Version to appear in JHE