Subir Sarkar — Page 8

arXiv1996

A Supersymmetric Resolution of the KARMEN Anomaly

We consider the hypothesis that the recently reported anomaly in the time structure of signals in the KARMEN experiment is due to the production of a light photino (or Zino) which decays radiatively due to violation of $R$-parity. Such a particle is shown to be consistent with all experimental data and with cosmological nucleosynthesis. There are difficulties with constraints from SN~1987A but these may be evaded if squarks are non-degenerate in mass.

hep-ph↗

arXiv1995

Successful Supersymmetric Inflation

The temperature fluctuations in the cosmic microwave background observed by COBE provide strong support for an inflationary phase in the early universe, below the GUT scale. We argue that a singlet field in a hidden sector of an effective supergravity theory yields the required inflationary potential without fine tuning. Reheating occurs to a temperature low enough to avoid the gravitino problem, but high enough to allow subsequent baryogenesis. Two observational consequences are that gravitational waves contribute negligibly to the microwave background anisotropy, and the spectrum of scalar density perturbations is `tilted', improving the fit to large-scale structure in an universe dominated by cold dark matter.

hep-ph↗