Precise determination of the mass of the Higgs boson and tests of compatibility of its couplings with the standard model predictions using proton collisions at 7 and 8 $$\,\text {TeV}$$ TeV

TLDR

CMS measured Higgs boson properties at 7 and 8 TeV using up to 19.7 fb⁻¹ of data, combining production and decay channels (γγ, ZZ, WW, ττ, bb, μμ) and probing couplings for deviations, including invisible decays. The Higgs mass is determined to be 125.02 GeV with statistical and systematic uncertainties, and the observed yields and signal strength of 1.00 ± 0.09 (stat) ± 0.07 (syst) agree with Standard Model expectations, with no significant deviations.

Abstract

Properties of the Higgs boson with mass near 125 $$\,\text {GeV}$$ are measured in proton-proton collisions with the CMS experiment at the LHC. Comprehensive sets of production and decay measurements are combined. The decay channels include $$\gamma \gamma $$ , $$\mathrm{Z}\mathrm{Z}$$ , $$\mathrm{W}\mathrm{W}$$ , $$\tau \tau $$ , $$\mathrm{b} \mathrm{b} $$ , and $$\mu \mu $$ pairs. The data samples were collected in 2011 and 2012 and correspond to integrated luminosities of up to 5.1 $$\,\text {fb}^\text {-1}$$ at 7 $$\,\text {TeV}$$ and up to 19.7 $$\,\text {fb}^\text {-1}$$ at 8 $$\,\text {TeV}$$ . From the high-resolution $$\gamma \gamma $$ and $$\mathrm{Z}\mathrm{Z}$$ channels, the mass of the Higgs boson is determined to be $$125.02\,{+0.26}_{-0.27} \,\text {(stat)} \,^{+0.14}_{-0.15} \,\text {(syst)} \,\text {GeV} $$ . For this mass value, the event yields obtained in the different analyses tagging specific decay channels and production mechanisms are consistent with those expected for the standard model Higgs boson. The combined best-fit signal relative to the standard model expectation is $$1.00\,\pm 0.09\,\text {(stat)} \,^{+0.08}_{-0.07}\,\text {(theo)} \,\pm 0.07\,\text {(syst)} $$ at the measured mass. The couplings of the Higgs boson are probed for deviations in magnitude from the standard model predictions in multiple ways, including searches for invisible and undetected decays. No significant deviations are found.