Conformal Collider Physics at Large Charge

Abstract: We study energy correlators and other event shapes in states created by operators with large global $U(1)$ charge $Q$ in Conformal Field Theories. Focusing on theories whose large charge sector is described by the superfluid Effective Field Theory (EFT), we develop a systematic framework to compute event shapes within the EFT. As formerly observed, event shapes at leading order in $1/Q$ factorize into a product of classical expectation values determined by symmetry. In contrast, the subleading contribution to energy-energy and charge-charge correlators is a nontrivial prediction of the EFT, which we compute explicitly. Our results reveal a sharp collinear enhancement of the correlation between detectors, induced by the propagation of sound. We also generalize our findings to a broad class of event shapes.