Speaker: Alex Friedland
SLAC

“Sterile Neutrino Portal to Hidden Physics”

ABSTRACT:

Neutrinos have emerged as a powerful tool for studying Nature. They are recognized as being one of the key players in astrophysics and cosmology, while the discovery of neutrino oscillations is heralded as a fundamental breakthrough in particle physics. Are there more surprises in the neutrino sector: additional states perhaps, or new interactions? These are not idle speculations, but well-defined questions that can be answered with the next-generation experiments. In connection with this, a number of anomalies at short-baseline oscillation experiments have attracted considerable attention. It has been suggested that these anomalies could be reconciled with cosmology by invoking new forces in the hidden sector. We reexamine this framework and find that it points to a very specific window of parameters. Most importantly, this window will be conclusively tested in the near future, by a combination of short-baseline, Cosmic Microwave Background and Ultra-High Energy neutrino experiments, whose sensitivities are complementary. This parameter window also happens to have the right properties for self-interacting and neutrino-coupled dark matter​.