Measuring Higgs CP and Couplings with Hadronic Event Shapes

Abstract

Experimental validation of the Standard Model of Particle Physics involves the measurement of the CP quantum number and couplings of the Higgs boson. Both ATLAS and CMS have reported an SM Higgs-like excess around m_h=125 GeV. In this mass range the properties of the Higgs boson can be extracted from an analysis of the azimuthal angle distribution of the two jets in pp→hjj events. Instead of exploiting the jet angular correlation, we show that hadronic event shapes exhibit substantial discriminative power to separate a CP even from a CP odd Higgs. Some event shapes even show an increased sensitivity to the Higgs CP compared to the azimuthal angle correlation.