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Vus and neutron beta decay
We discuss the effect of the recent change of by three standard
deviations on the standard model predictions for neutron beta decay
observables. We also discuss the effect the experimental error bars of have on such predictions. Refined precision tests of the standard model
will be made by a combined effort to improve measurements in neutron beta decay
and in strangeness-changing decays. By itself the former will yield very
precise measurements of and make also very precise predictions for
Prethermalization Production of Dark Matter
At the end of inflation, the inflaton field decays into an initially
nonthermal population of relativistic particles which eventually thermalize. We
consider the production of dark matter from this relativistic plasma, focusing
on the prethermal phase. We find that for a production cross section
with , the present dark matter abundance is produced
during the prethermal phase of its progenitors. For , entropy
production during reheating makes the nonthermal contribution to the present
dark matter abundance subdominant compared to that produced thermally. As
specific examples, we verify that the nonthermal contribution is irrelevant for
gravitino production in low scale supersymmetric models () and is dominant
for gravitino production in high scale supersymmetry models ().Comment: 12 pages, 4 figure
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