Study of the Mass and Spin-Parity of the Higgs Boson Candidate via Its Decays to Z Boson Pairs

A study is presented of the mass and spin-parity of the new boson recently observed at the LHC at a mass near 125 GeV. An integrated luminosity of $17.3\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, collected by the CMS experiment in proton-proton collisions at center-of-mass energies of 7 and 8 TeV, is used. The measured mass in the $ZZ$ channel, where both $Z$ bosons decay to $e$ or $\ensuremath{\mu}$ pairs, is $126.2\ifmmode\pm\else\textpm\fi{}0.6(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.2(\mathrm{syst})\text{ }\text{ }\mathrm{GeV}$. The angular distributions of the lepton pairs in this channel are sensitive to the spin-parity of the boson. Under the assumption of spin 0, the present data are consistent with the pure scalar hypothesis, while disfavoring the pure pseudoscalar hypothesis.