Abstract
Production cross sections of the Higgs boson are measured in the {mathrm{H}} rightarrow {mathrm{Z}} {mathrm{Z}} rightarrow 4ell (ell ={mathrm{e}},{{{upmu }}_{mathrm{}}^{mathrm{}}} ) decay channel. A data sample of proton–proton collisions at a center-of-mass energy of 13,text {TeV}, collected by the CMS detector at the LHC and corresponding to an integrated luminosity of 137,text {fb}^{-1} is used. The signal strength modifier mu , defined as the ratio of the Higgs boson production rate in the 4ell channel to the standard model (SM) expectation, is measured to be mu =0.94 pm 0.07 ,text {(stat)} ^{+0.09}_{-0.08} ,text {(syst)} at a fixed value of m_{{mathrm{H}}} = 125.38,text {GeV} . The signal strength modifiers for the individual Higgs boson production modes are also reported. The inclusive fiducial cross section for the {mathrm{H}} rightarrow 4ell process is measured to be 2.84^{+0.23}_{-0.22} ,text {(stat)} ^{+0.26}_{-0.21} ,text {(syst)} ,text {fb} , which is compatible with the SM prediction of 2.84 pm 0.15 ,text {fb} for the same fiducial region. Differential cross sections as a function of the transverse momentum and rapidity of the Higgs boson, the number of associated jets, and the transverse momentum of the leading associated jet are measured. A new set of cross section measurements in mutually exclusive categories targeted to identify production mechanisms and kinematical features of the events is presented. The results are in agreement with the SM predictions.
Highlights
The discovery of the Higgs boson (H) in 2012 by the ATLAS and CMS collaborations [1,2,3] has been a major step towards the understanding of the electroweak symmetry breaking mechanism [4,5,6,7,8,9]
The ZZ background contribution from quark-antiquark annihilation is simulated at next-toleading order (NLO) perturbative QCD (pQCD) with powheg 2.0 [80], while the gg → ZZ process is generated at leading order (LO) with mcfm 7.0.1 [81]
To further suppress events with leptons originating from hadron decays in jet fragmentation or from the decay of low-mass resonances, all four opposite-charge lepton pairs that can be built with the four leptons are required to satisfy the condition m + − > 4 GeV, where selected final-state radiation (FSR) photons are disregarded in the invariant mass computation
Summary
The discovery of the Higgs boson (H) in 2012 by the ATLAS and CMS collaborations [1,2,3] has been a major step towards the understanding of the electroweak symmetry breaking mechanism [4,5,6,7,8,9]. This paper presents the measurement of production cross sections in granular kinematic regions of the H boson in the H → ZZ → 4 decay channel. The results presented within the STXS framework depend on the SM simulation used to model the experimental acceptance of the signal processes, which could be modified in beyond the SM (BSM) scenarios These kinematic regions, referred to as bins, are defined in different stages corresponding to increasing degrees of granularity. Previous measurements of cross sections in stage 0 production bins in the H → 4 decay channel were already presented by the CMS Collaboration [18]. This paper presents a first set of the cross section measurements in the STXS stage 1.2 bins in the H → 4 decay channel.
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