Theory HEP Seminar

Gravitational Interaction of the Higgs and Dark Matter

Jing Ren

University of Toronto

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 of the SM and General Relativity. This dimensionless nonminimal coupling affects weak gauge boson scattering amplitude and yields perturbative unitarity violation in high energy. It can be probed at the LHC and future collider. The analysis of unitarity constraints is extended to the Higgs inflation with large background field as well. In the second part of the talk, I present another study by asking a similar question to the dark matter. So far, all evidences of DM come from astrophysical and cosmological observations due to the gravitational interactions. It is intriguing to explore the possibility that the DM particle only joins gravitational interactions but nothing else. We construct a simple model with a scalar dark matter particle that joins the unique dimension-4 interaction with Ricci curvature. Together with the Higgs-curvature 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 direct/indirect detections and the collider search.