Inclusive Fiducial Cross-sections Research Articles

Observation of double J/ψ meson production in pPb collisions at sNN=8.16 TeV

The first observation of the concurrent production of two J/ψ mesons in proton-nucleus collisions is presented. The analysis is based on a proton-lead (pPb) data sample recorded at a nucleon-nucleon center-of-mass energy of 8.16 TeV by the CMS experiment at the CERN LHC and corresponding to an integrated luminosity of 174.6 nb−1. The two J/ψ mesons are reconstructed in their μ+μ− decay channels with transverse momenta pT>6.5 GeV and rapidity |y|<2.4. Events where one of the J/ψ mesons is reconstructed in the dielectron channel are also considered in the search. The pPb→J/ψJ/ψ+X process is observed with a significance of 5.3 standard deviations. The measured inclusive fiducial cross section, using the four-muon channel alone, is σ(pPb→J/ψJ/ψ+X)=22.0±8.9(stat)±1.5(syst) nb. A fit of the data to the expected rapidity separation for pairs of J/ψ mesons produced in single (SPS) and double (DPS) parton scatterings yields σSPSpPb→J/ψJ/ψ+X=16.5±10.8(stat)±0.1(syst) nb and σDPSpPb→J/ψJ/ψ+X=5.4±6.2(stat)±0.4(syst) nb, respectively. This latter result can be transformed into a lower bound on the effective DPS cross section, closely related to the squared average interparton transverse separation in the collision, of σeff>1.0 mb at 95% confidence level. © 2024 CERN, for the CMS Collaboration 2024 CERN

Measurements of inclusive and differential cross sections for the Higgs boson production and decay to four-leptons in proton-proton collisions at sqrt{s} = 13 TeV

Measurements of the inclusive and differential fiducial cross sections for the Higgs boson production in the H → ZZ → 4ℓ (ℓ = e, μ) decay channel are presented. The results are obtained from the analysis of proton-proton collision data recorded by the CMS experiment at the CERN LHC at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb−1. The measured inclusive fiducial cross section is 2.73 ± 0.26 fb, in agreement with the standard model expectation of 2.86 ± 0.1 fb. Differential cross sections are measured as a function of several kinematic observables sensitive to the Higgs boson production and decay to four leptons. A set of double-differential measurements is also performed, yielding a comprehensive characterization of the four leptons final state. Constraints on the Higgs boson trilinear coupling and on the bottom and charm quark coupling modifiers are derived from its transverse momentum distribution. All results are consistent with theoretical predictions from the standard model.

Measurement of the Higgs boson inclusive and differential fiducial production cross sections in the diphoton decay channel with pp collisions at sqrt{s} = 13 TeV

The measurements of the inclusive and differential fiducial cross sections of the Higgs boson decaying to a pair of photons are presented. The analysis is performed using proton-proton collisions data recorded with the CMS detector at the LHC at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 137 fb−1. The inclusive fiducial cross section is measured to be {sigma}_{textrm{fid}}={73.4}_{-5.3}^{+5.4}{left(textrm{stat}right)}_{-2.2}^{+2.4}left(textrm{syst}right) fb, in agreement with the standard model expectation of 75.4 ± 4.1 fb. The measurements are also performed in fiducial regions targeting different production modes and as function of several observables describing the diphoton system, the number of additional jets present in the event, and other kinematic observables. Two double differential measurements are performed. No significant deviations from the standard model expectations are observed.

Measurements of production cross sections of the Higgs boson in the four-lepton final state in proton\u2013proton collisions at sqrt{s} = 13,text {TeV}

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.

Measurements of the Higgs boson inclusive and differential fiducial cross sections in the 4ell decay channel at sqrt{s} = 13 TeV

Inclusive and differential fiducial cross sections of the Higgs boson are measured in the H rightarrow ZZ^{*} rightarrow 4ell (ell = e,mu ) decay channel. The results are based on proton-proton collision data produced at the Large Hadron Collider at a centre-of-mass energy of 13 TeV and recorded by the ATLAS detector from 2015 to 2018, equivalent to an integrated luminosity of 139 hbox {fb}^{-1}. The inclusive fiducial cross section for the H rightarrow ZZ^{*} rightarrow 4ell process is measured to be sigma _mathrm {fid} = 3.28 ,{pm }, 0.32 fb, in agreement with the Standard Model prediction of sigma _mathrm {fid, SM} = 3.41 pm 0.18 fb. Differential fiducial cross sections are measured for a variety of observables which are sensitive to the production and decay of the Higgs boson. All measurements are in agreement with the Standard Model predictions. The results are used to constrain anomalous Higgs boson interactions with Standard Model particles.

Measurement of the production cross section of three isolated photons in pp collisions at [formula omitted] TeV using the ATLAS detector

A measurement of the production of three isolated photons in proton–proton collisions at a centre-of-mass energy s=8 TeV is reported. The results are based on an integrated luminosity of 20.2 fb−1 collected with the ATLAS detector at the LHC. The differential cross sections are measured as functions of the transverse energy of each photon, the difference in azimuthal angle and in pseudorapidity between pairs of photons, the invariant mass of pairs of photons, and the invariant mass of the triphoton system. A measurement of the inclusive fiducial cross section is also reported. Next-to-leading-order perturbative QCD predictions are compared to the cross-section measurements. The predictions underestimate the measurement of the inclusive fiducial cross section and the differential measurements at low photon transverse energies and invariant masses. They provide adequate descriptions of the measurements at high values of the photon transverse energies, invariant mass of pairs of photons, and invariant mass of the triphoton system.

Measurement of inclusive and differential cross sections in the H \u2192 ZZ* \u2192 4\u2113 decay channel in pp collisions at sqrt{s}=13 TeV with the ATLAS detector

Inclusive and differential fiducial cross sections of Higgs boson production in proton-proton collisions are measured in the H → ZZ* → 4ℓ decay channel. The proton-proton collision data were produced at the Large Hadron Collider at a centre-of-mass energy of 13 TeV and recorded by the ATLAS detector in 2015 and 2016, corresponding to an integrated luminosity of 36.1 fb−1. The inclusive fiducial cross section in the H → ZZ* → 4ℓ decay channel is measured to be 3.62 ± 0.50(stat)− 0.20+ 0.25 (sys) fb, in agreement with the Standard Model prediction of 2.91 ± 0.13 fb. The cross section is also extrapolated to the total phase space including all Standard Model Higgs boson decays. Several differential fiducial cross sections are measured for observables sensitive to the Higgs boson production and decay, including kinematic distributions of jets produced in association with the Higgs boson. Good agreement is found between data and Standard Model predictions. The results are used to put constraints on anomalous Higgs boson interactions with Standard Model particles, using the pseudo-observable extension to the kappa-framework.

NNLO QCD corrections to Higgs boson production at large transverse momentum

We derive the second-order QCD corrections to the production of a Higgs boson recoiling against a parton with finite transverse momentum, working in the effective field theory in which the top quark contributions are integrated out. To account for quark mass effects, we supplement the effective field theory result by the full quark mass dependence at leading order. Our calculation is fully differential in the final state kinematics and includes the decay of the Higgs boson to a photon pair. It allows one to make next-to-next-to- leading order (NNLO)-accurate theory predictions for Higgs-plus-jet final states and for the transverse momentum distribution of the Higgs boson, accounting for the experimental definition of the fiducial cross sections. The NNLO QCD corrections are found to be moderate and positive, they lead to a substantial reduction of the theory uncertainty on the predictions. We compare our results to 8 TeV LHC data from ATLAS and CMS. While the shape of the data is well-described for both experiments, we agree on the normalization only for CMS. By normalizing data and theory to the inclusive fiducial cross section for Higgs production, good agreement is found for both experiments, however at the expense of an increased theory uncertainty. We make predictions for Higgs production observables at the 13 TeV LHC, which are in good agreement with recent ATLAS data. At this energy, the leading order mass corrections to the effective field theory prediction become significant at large transverse momenta, and we discuss the resulting uncertainties on the predictions.