B-ball Baryogenesis and D-term Inflation

TL;DR

This paper explores how B-balls formed from squark condensates during D-term inflation can generate the observed baryon asymmetry and dark matter density, linking early Universe physics with cosmological observations.

Contribution

It demonstrates that B-ball formation and decay in D-term inflation models can naturally produce baryon asymmetry and dark matter, with implications for low reheating temperatures.

Findings

B-balls can carry baryon number and survive to influence cosmology.

Decay of B-balls can produce baryons and neutralino dark matter in observed ratios.

Low reheating temperatures are compatible with D-term inflation and baryogenesis.

Abstract

The MSSM has flat directions in its scalar potential, along which it is natural for Bose condensates of squarks to form in the early Universe. A baryon asymmetry can be induced in these condensates via Affleck-Dine baryogenesis. The condensates are unstable with respect to fragmentation to "B-balls", solitons made of squarks and carrying baryon number, which, if they survive thermalization, fill the Universe down to low temperatures, much lower than that of the electroweak phase transition, with interesting cosmological consequences. In particular, their decay implies a similar number density of baryons and dark matter neutralinos, in accordance with observations. Evasion of thermalization and the ability to account for the observed baryon asymmetry requires a very low reheating temperature, which, it is argued, is a natural feature of presently favoured D-term inflation models.