Mainly axion cold dark matter in the minimal supergravity model

Abstract

We examine the minimal supergravity (mSUGRA) model under the assumption that the strong CP problem is solved by the Peccei-Quinn mechanism. In this case, the relic dark matter (DM) abundance consists of three components: {\it i}). cold axions, {\it ii}). warm axinos from neutralino decay, and {\it iii}). cold or warm thermally produced axinos. To sustain a high enough re-heat temperature (T_R\agt 10^6 GeV) for many baryogenesis mechanisms to function, we find that the bulk of DM should consist of cold axions, while the admixture of cold and warm axinos should be rather slight, with a very light axino of mass \sim 100 keV. For mSUGRA with mainly axion cold DM (CDM), the most DM-preferred parameter space regions are precisely those which are least preferred in the case of neutralino DM. Thus, rather different SUSY signatures are expected at the LHC in the case of mSUGRA with mainly axion CDM, as compared to mSUGRA with neutralino CDM.

17 pages with 10 .eps figures; this version contains low resolution figures; this version is slightly updated

References in corpus (10)

• The Baryogenesis Window in the MSSM
• Dark Matter Candidates - Axions, Neutralinos, Gravitinos, and Axinos
• Dark matter allowed scenarios for Yukawa-unified SO(10) SUSY GUTs
• Axinos as Dark Matter Particles
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• SO(10) SUSY GUTs, the gravitino problem, non-thermal leptogenesis and axino dark matter
• Prospects for Yukawa Unified SO(10) SUSY GUTs at the CERN LHC
• Upper Limits on the Peccei-Quinn Scale and on the Reheating Temperature in Axino Dark Matter Scenarios
• Determining Reheating Temperature at LHC with Axino or Gravitino Dark Matter