EPT Seminar

Date
Mon, Nov 30, 2015 3:00 pm - 4:30 pm
Location
PSC 3150

Description

Speaker: Josh Berger

Speaker Institution: SLAC

Title: Cosmological Probes of Nearly Decoupled Dark Sectors

Abstract: Little is known about any other forces that may couple to dark matter. If dark matter couples to a new U(1) gauge boson or Higgs boson, this dark mediator could have very small coupling with the standard model. In this talk, I present constraints on such a nearly decoupled dark mediator. If the particle is sufficiently long lived, it can disrupt standard big bang nucleosynthesis or distort the spectrum of cosmic microwave background radiation. These effects offer an effective probe of mixing angles in the range 10^-17 to 10^-10 for dark photons and 10^-15 to 10^-6 for dark Higgs for masses above 1 MeV. Dramatic improvements can be obtained in future experiments such as PIXIE.