Theory Group Seminar

Dr. Jing Ren, University of Toronto

"Gravitational Interaction of the Higgs and Dark Matter"

2:00pm, RLM 7.104

Abstract: With the LHC Higgs discovery, we are strongly motivated to study gravitational interactions of the Higgs boson. In this talk, I present a study along this line through the unique dimension-4 operator of the Higgs with Ricci curvature, in context of the effective field theory. This dimensionless nonminimal coupling affects weak gauge boson scattering amplitudes and yields perturbative unitarity violation in high energy, which may be probed at the LHC and future collider. The same operator makes it possible to drive inflation by the Higgs in early universe. The analysis of unitarity constraints is extended to the Higgs inflation with large background field. In the second part of the talk, I present another study along the line for the dark matter, where DM talks to the SM only via gravity. We construct a simple model with a scalar dark matter coupled nonminimally to the Ricci curvature. Together with the Higgs nonminimal coupling, it induces effective interactions between the DM and SM particles, which can account for the observed thermal relic abundance. Such a scalar gravitational dark matter turns out to be highly predictive and testable in various searches.