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Title: Reconciling thermal leptogenesis with the gravitino problem in SUSY models with mixed axion/axino dark matter

Journal Article · · Journal of Cosmology and Astroparticle Physics
;  [1];  [2];  [3]
  1. Dept. of Physics and Astronomy, University of Oklahoma, 440 West Brooks, Norman, OK 73019 (United States)
  2. Laboratoire de Physique Subatomique et de Cosmologie, UJF Grenoble 1, CNRS/IN2P3, INPG, 53 Avenue des Martyrs, F-38026 Grenoble (France)
  3. Dept. of Physics, Florida State University, 513 Keen Bldg., Tallahassee, FL 32306 (United States)

Successful implementation of thermal leptogenesis requires re-heat temperatures T{sub R}∼>2 × 10{sup 9} GeV, in apparent conflict with SUSY models with TeV-scale gravitinos, which require much lower T{sub R} in order to avoid Big Bang Nucleosynthesis (BBN) constraints. We show that mixed axion/axino dark matter can reconcile thermal leptogenesis with the gravitino problem in models with m{sub G-tilde}∼>30 TeV, a rather high Peccei-Quinn breaking scale and an initial mis-alignment angle θ{sub i} < 1. We calculate axion and axino dark matter production from four sources, and impose BBN constraints on long-lived gravitinos and neutralinos. Moreover, we discuss several SUSY models which naturally have gravitino masses of the order of tens of TeV. We find a reconciliation difficult in Yukawa-unified SUSY and in AMSB with a wino-like lightest neutralino. However, T{sub R} ∼ 10{sup 10}−10{sup 12} GeV can easily be achieved in effective SUSY and in models based on mixed moduli-anomaly mediation. Consequences of this scenario include: 1. an LHC SUSY discovery should be consistent with SUSY models with a large gravitino mass, 2. an apparent neutralino relic abundance Ω{sub Z-tilde} {sub 1}h{sup 2}∼<1, 3. no WIMP direct or indirect detection signals should be found, and 4. the axion mass should be less than ∼ 10{sup −6} eV, somewhat below the conventional range which is explored by microwave cavity axion detection experiments.

OSTI ID:
22275467
Journal Information:
Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 11; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
Country of Publication:
United States
Language:
English