Does the ‘Higgs’ have Spin Zero?

Abstract

Abstract The Higgs boson is predicted to have spin zero. The ATLAS and CMS experiments have recently reported of an excess of events with mass ~ 125 GeV that has some of the characteristics expected for a Higgs boson. We address the questions whether there is already any evidence that this excess has spin zero, and how this possibility could be confirmed in the near future. The excess observed in the γγ final state could not have spin one, leaving zero and two as open possibilities. We review the angular distribution of γγ pairs from the decays of a graviton-like spin-two boson produced in gluon-gluon collisions, which is well-defined and distinct from the spin-zero case. We also calculate the distributions for lepton pairs that would be produced in the W W * decays of a spin-two boson, which are very different from those in Higgs decays, and note that the kinematics of the event selection currently used in the analysis of the W W * final state have reduced efficiency for spin two.