Mark Hindmarsh, D. R. Timothy Jones
We consider an MSSM extension with anomaly mediation as the source of supersymmetry-breaking, and a U(1) symmetry which solves the tachyonic slepton problem, and introduces both the see-saw mechanism for neutrino masses, and the Higgs mu-term. We compare its spectra with those from so-called minimal anomaly mediated supersymmetry breaking. We find a Standard Model-like Higgs of mass 124 GeV with a gravitino mass of 120 TeV and tan(beta)=17, while a contribution to the muon anomalous magnetic moment within 2 sigma of the discrepancy between Standard Model theory and experiment favours a slightly lower gravitino mass of around 80 TeV. The model naturally produces a period of hybrid inflation, with exit to a false vacuum characterised by large Higgs vevs, the true ground state being achieved after a period of thermal inflation. The scalar spectral index is reduced to approximately 0.975, and the correct abundance of dark matter can be produced by decays of thermally-produced gravitinos, provided the gravitino mass is high. Naturally light cosmic strings are produced, satisfying bounds from the Cosmic Microwave Background. The complementary pulsar timing and cosmic ray bounds require that strings decay primarily via loops into gravitational waves. Unless the loops are extremely small, the next generation pulsar timing array will rule out or detect the string-derived gravitational radiation background in this model.
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http://arxiv.org/abs/1203.6838
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