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Abstract:

Caesium atoms in a magnetic trap have a higher loss rate from latin-trap collisions than rubidium under comparable conditions. We have found that this loss from inelastic collisions can be suppressed by periodic optical pumping of the atoms back into the most strongly trapped magnetic state (F = 4, MF = +4), although this reclamation of the strayed atoms gives rise to some heating of the sample. This observation shows that the dominant loss mechanism in the magnetic bias field regime investigated is from collisions which change the magnetic sublevel (quantum number MF) and not the hyperfine level (F quantum number).

Abstract:

The phenomenology of supersymmetric models of inflation, where the inflationary vacuum energy is dominated by D-terms of a U(1), is investigated. Particular attention is paid to the questions of how to arrange for sufficient e-folds of inflation to occur, what kind of thermal history is expected after the end of inflation, and how to implement successful baryogenesis. Such models are argued to require a more restrictive symmetry structure than previously thought. In particular, it is non-trivial that the decays of the fields driving D-inflation can reheat the universe in such a way as to avoid the strong gravitino production constraints. We also show how the initial conditions for Affleck-Dine baryogenesis can arise in these models and that the simplest flat directions along which baryon number is generated can often be ruled out by the constraints coming from decoherence of the condensate in a hot environment. At the end, we find that successful reheating and baryogenesis can take place in a large subset of D-inflationary models.