NEXT ELUSIVES WEBINAR: "Millicharged particles in neutrino detectors"

Millicharged particles (mCPs) represent one of the most minimal extensions of the Standard Model, and, until recently, were surprisingly poorly constrained for masses greater than roughly ~100 MeV. Recent proposals to discover mCPs have focussed on intense proton beams which result in meson cascades that can provide extremely large fluxes of mCPs; this "beam" of mCPs can, in turn, be detected at downstream detectors. 

In this talk I will discuss how cosmic rays can act as a proton beam in their own right with the upper atmosphere serving as a fixed (and very thick) target. I will explain how, by combining well understood meson production cross sections, one can calculate the flux of mCPs from primary pp collisions. We find competitive constraints with accelerator based experiments, and find that our results can limit a recently proposed strongly-interacting dark matter "window".