Excited Q-Balls in the MSSM with gravity mediated supersymmetry breaking

Flat directions in the minimal supersymmetric standard model are known to deform into non-topological solitons, Q-balls, which generally possess both baryon and lepton asymmetries. We investigate how Q-balls evolve if some of the constituent fields of the flat direction decay into light species. It is found that the Q-balls takes a new configuration whose energy per charge slightly increases due to the decay. Specifically, we show that all the stable Q-balls eventually transf...

All supersymmetric generalizations of the Standard Model allow for stable non-topological solitons of the Q-ball type which may have non-zero baryon and lepton numbers, as well as the electric charge. These solitons can be produced in the early Universe, can affect the nucleosynthesis, and can lead to a variety of other cosmological consequences.

We investigate the Q-ball decay in the gauge-mediated SUSY breaking. Q balls decay mainly into nucleons, and partially into gravitinos, while they are kinematically forbidden to decay into sparticles which would be cosmologically harmful. This is achieved by the Q-ball charge small enough to be unstable for the decay, and large enough to be protected kinematically from unwanted decay channel. We can then have right amounts of the baryon asymmetry and the dark matter of the un...

We discuss the production of gravity waves from the fragmentation of a supersymmetric condensate in the early universe. Supersymmetry predicts the existence of flat directions in the potential. At the end of inflation, the scalar fields develop large time-dependent vacuum expectation values along these flat directions. Under some general conditions, the scalar condensates undergo a fragmentation into non-topological solitons, Q-balls. We study this process numerically and con...

It has been recently suggested that stable, supersymmetric B-balls formed in the early universe could not only be the dark matter at the present epoch, but also be responsible for baryogenesis by their partial evaporation at high temperatures. We reinvestigate the efficiency of B-ball baryogenesis and find it to be limited by the diffusion of baryon number away from the B-balls. Successful baryogenesis may only occur for B-balls with charges Q\simle 10^{20} - 5\times 10^{23},...

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 m...

MSSM predicts the existence of Q-balls, some of which can be entirely stable. Both stable and unstable Q-balls can play an important role in cosmology. In particular, Affleck-Dine baryogenesis can result in a copious production of stable baryonic Q-balls, which can presently exist as a form of dark matter.

In theories with low energy supersymmetry breaking, the effective potential for squarks and sleptons has generically nearly flat directions, V(phi) ~ M^4 (log(phi/M))^n. This guarantees the existence of stable non-topological solitons, Q-balls, that carry large baryon number, B >> (M/m_p)^4, where m_p is the proton mass. We study the behaviour of these objects in a high temperature plasma. We show that in an infinitely extended system with a finite density of the baryon charg...

We construct nontopological solitonic solutions in (3+1)-dimensional Minkowski spacetime carrying a conserved global U(1) charge and nonvanishing angular momentum in a supersymmetric extension of the standard model with low-energy, gauge-mediated symmetry breaking.

In this thesis we investigate the stationary properties and formation process of a class of nontopological solitons, namely Q-balls. We explore both the quantum-mechanical and classical stability of Q-balls that appear in polynomial, gravity-mediated and gauge-mediated potentials. By presenting our detailed analytic and numerical results, we show that absolutely stable non-thermal Q-balls may exist in any kinds of the above potentials. The latter two types of potentials are m...