Probing the CP violating Hγγ coupling using interferometry *

Abstract

Abstract The diphoton invariant mass distribution from the interference between and is almost antisymmetric around the Higgs mass . We propose a new observable , the ratio of the sign-reversed integral around (e.g. ) and the cross-section of the Higgs signal, to quantify this effect. We study both in the Standard Model (SM) and new physics with various CP violating couplings. in SM could reach a value of 10%, while for CP violating coupling could range from 10% to −10%, which could probably be detected in the HL-LHC experiments. with both CP violating and couplings is also studied, and its range of values is found to be slightly larger.