Welcome to a new BSM Pandemic seminar!
Speaker: Roni Harnik (Fermilab)
Tittle: New Particle Searches with Nonlinear Optics
Abstract: I will present a proposal for a new way to use optical tools from quantum imaging and quantum communication to search for physics beyond the standard model. Spontaneous parametric down conversion (SPDC) is a commonly used source of entangled photons in which pump photons convert to a signal-idler pair. We propose to search for "dark SPDC" (dSPDC) events in which a new dark sector particle replaces the idler. Though it does not interact, the presence of a dark particle can be inferred by the properties of the signal photon. Examples of dark states include axion-like-particles and dark photons. The presence of an optical medium opens the phase space of the down-conversion process, or decay, which would be forbidden in vacuum. The signal rates in our proposal scales with the second power of the feeble coupling to new physics, as opposed to light-shining-through-wall experiments whose signal scales with coupling to the fourth. Search schemes with dedicated optical media and setups are proposed which employ imaging and/or spectroscopy of the signal photons.