Study of the mass and spin-parity of the Higgs boson candidate via its decays to Z boson pairs

TL;DR

This paper investigates the mass and spin-parity of the Higgs boson candidate at 125 GeV using decay data from the CMS experiment, confirming its scalar nature with high confidence.

Contribution

It provides the first detailed analysis of the Higgs boson's spin-parity using ZZ decay channels at the LHC, supporting its scalar hypothesis.

Findings

Measured Higgs mass as 126.2 GeV with uncertainties

Data favor a scalar (spin 0) over pseudoscalar hypothesis

Confirmed the Higgs boson’s scalar nature with high confidence

Abstract

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 inverse femtobarns, 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 mu pairs, is 126.2 +/- 0.6 (stat.) +/- 0.2 (syst.) 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.