Gravitino dark matter from Q-ball decays

Understand

Affleck-Dine baryogenesis, accompanied by the formation and subsequent decay of Q-balls, can generate both the baryon asymmetry of the universe and dark matter in the form of gravitinos.

• The gravitinos from Q-ball decay dominate over the thermally produced population if the reheat temperature is less than 10^7 GeV.
• We show that a gravitino with mass around 1 GeV is consistent with all observational bounds and can explain the baryon-to-dark-matter ratio in the gauge-mediated models of supersymmetry breaking for a wide range of cosmological and Q-ball parameters.
• Moreover, decaying Q-balls can be the dominant production mechanism for m_{3/2} < 1 GeV gravitinos if the Q-balls are formed from a (B-L) = 0 condensate, which produces no net baryon asymmetry.