Is the new resonance spin 0 or 2? Taking a step forward in the Higgs boson discovery

Abstract

The observation of a new boson of mass similar to 125 GeV at the CERN LHC may finally have revealed the existence of a Higgs boson. Now we have the opportunity to scrutinize its properties, determining its quantum numbers and couplings to the standard model particles, in order to confirm or not its discovery. We show that by the end of the 8 TeV run, combining the entire data sets of ATLAS and CMS, it will be possible to discriminate between the following discovery alternatives: a narrow scalar J(P) = 0(+) or a tensor J(P) = 2(+) particle with minimal couplings to photons, at a 5 sigma statistical confidence level at least, using only diphoton events. Our results are based on the calculation of a center-edge asymmetry measure of the reconstructed sPlot scattering polar angle of the diphotons. the results based on asymmetries are shown to be robust against systematic uncertainties on signal and backgrounds normalizations with comparable discrimination power to a log likelihood ratio statistic. DOI: 10.1103/PhysRevD.86.113010