Q-ball collisions in the MSSM: gravity-mediated supersymmetry breaking
  Collisions of non-topological solitons, Q-balls, are studied in a typical potential in the Minimal Supersymmetric Standard Model where supersymmetry has been broken by a gravitationally coupled hidden sector. Q-ball collisions are studied numerically on a two dimensional lattice for a range of Q-ball charges. Total cross-sections, as well as cross-sections for fusion and charge-exchange are calculated. The average percentage increase in charge carried by the largest Q-ball after a collision is found to be weakly dependent on the initial charge. 
Tuomas Multamaki, Iiro Vilja