Theory Group Seminar

Dr. Tim Cohen, University of Oregon

"Naturalness"

2:00pm, RLM 7.104

Abstract: We present a new mechanism to stabilize the electroweak hierarchy. We introduce N copies of the Standard Model with varying values of the Higgs mass parameter. This generically yields a sector whose weak scale is parametrically removed from the cutoff by a factor of 1/√N. Ensuring that reheating deposits a majority of the total energy density into this lightest sector requires a modification of the standard cosmological history, providing a powerful probe of the mechanism. Current and near-future experiments will explore much of the natural parameter space. Furthermore, supersymmetric completions which preserve grand unification predict superpartners with mass below mw × Mpl /MGUT ?10 TeV.