A fast track towards the 'Higgs' spin and parity

Abstract

The LHC experiments ATLAS and CMS have discovered a new boson that resembles the long-sought Higgs boson: it cannot have spin one, and has couplings to other particles that increase with their masses, but the spin and parity remain to be determined. We show here that the 'Higgs' + gauge boson invariant-mass distribution in 'Higgs'-strahlung events at the Tevatron or the LHC would be very di erent under the JP = 0+,0- and 2+ hypotheses. Our analysis is based on simulations of the experimental event selections and cuts using PYTHIA and Delphes, and incorporates statistical samples of 'toy' experiments. The observation of 'Higgs'-strahlung at the Tevatron and the expected peaking of backgrounds at low invariant masses suggest that this process could provide a fast-track indicator of the 'Higgs' spin and parity.