Resurrecting no-scale supergravity phenomenology
TH Division, PH Department, CERN, 1211, Geneva 23, Switzerland
2 William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, MN, 55455, USA
Revised: 15 June 2010
Published online: 3 August 2010
In the context of phenomenological models in which the soft supersymmetry-breaking parameters of the MSSM become universal at some unification scale, M in, above the GUT scale, M GUT, it is possible that all the scalar mass parameters m 0, the trilinear couplings A 0 and the bilinear Higgs coupling B 0 vanish simultaneously, as in no-scale supergravity. Using these no-scale inputs in a renormalisation-group analysis of the minimal supersymmetric SU(5) GUT model, we pay careful attention to the matching of parameters at the GUT scale. We delineate the region of M in, m 1/2 and tan β where the resurrection of no-scale supergravity is possible, taking due account of the relevant phenomenological constraints such as electroweak symmetry breaking, m h ,b→s γ, the neutralino cold dark matter density Ω χ h 2 and g μ −2. No-scale supergravity survives in an L-shaped strip of parameter space, with one side having m 1/2≳200 GeV, the second (orthogonal) side having M in≳5×1016 GeV. Depending on the relative signs and magnitudes of the GUT superpotential couplings, these may be connected to form a triangle whose third side is a hypotenuse at larger M in, m 1/2 and tan β, whose presence and location depend on the GUT superpotential parameters. We compare the prospects for detecting sparticles at the LHC in no-scale supergravity with those in the CMSSM and the NUHM.
© Springer-Verlag / Società Italiana di Fisica, 2010