Higgs Boson Production Cross Section Research Articles

Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at sqrt{mathrm{s}} = 13 TeV

Measurements of Higgs boson production cross sections and couplings in events where the Higgs boson decays into a pair of photons are reported. Events are selected from a sample of proton-proton collisions at sqrt{s} = 13 TeV collected by the CMS detector at the LHC from 2016 to 2018, corresponding to an integrated luminosity of 137 fb−1. Analysis categories enriched in Higgs boson events produced via gluon fusion, vector boson fusion, vector boson associated production, and production associated with top quarks are constructed. The total Higgs boson signal strength, relative to the standard model (SM) prediction, is measured to be 1.12±0.09. Other properties of the Higgs boson are measured, including SM signal strength modifiers, production cross sections, and its couplings to other particles. These include the most precise measurements of gluon fusion and vector boson fusion Higgs boson production in several different kinematic regions, the first measurement of Higgs boson production in association with a top quark pair in five regions of the Higgs boson transverse momentum, and an upper limit on the rate of Higgs boson production in association with a single top quark. All results are found to be in agreement with the SM expectations.

TMD fragmentation functions at N3LO

We compute the unpolarized quark and gluon transverse-momentum dependent fragmentation functions (TMDFFs) at next-to-next-to-next-to-leading order (N3LO) in perturbative QCD. The calculation is based on a relation between the TMDFF and the limit of the semi-inclusive deep inelastic scattering cross section where all final-state radiation becomes collinear to the detected hadron. The required cross section is obtained by analytically continuing our recent computation of the Drell-Yan and Higgs boson production cross section at N3LO expanded around the limit of all final-state radiation becoming collinear to one of the initial states. Our results agree with a recent independent calculation by Luo et al.

Evidence for Higgs boson decays to a low-mass dilepton system and a photon in pp collisions at [formula omitted] TeV with the ATLAS detector

A search for the Higgs boson decaying into a photon and a pair of electrons or muons with an invariant mass mℓℓ<30 GeV is presented. The analysis is performed using 139 fb−1 of proton–proton collision data, produced by the LHC at a centre-of-mass energy of 13 TeV and collected by the ATLAS experiment. Evidence for the H→ℓℓγ process is found with a significance of 3.2 over the background-only hypothesis, compared to an expected significance of 2.1 for the Standard Model prediction. The best-fit value of the signal-strength parameter, defined as the ratio of the observed signal yield to the one expected in the Standard Model, is μ=1.5±0.5. The Higgs boson production cross-section times the H→ℓℓγ branching ratio for mℓℓ<30 GeV is determined to be 8.7−2.7+2.8 fb.

Higgs production in bottom-quark fusion: Matching beyond leading order

We compute the total cross-section for Higgs boson production in bottom-quark fusion using the so-called FONLL method for the matching of a scheme in which the b-quark is treated as a massless parton to that in which it is treated as a massive final-state particle, and extend our previous results to the case in which the next-to-next-to-leading-log five-flavor scheme result is combined with the next-to-leading-order O(αs3) four-flavor scheme computation.

Measurement of the inclusive and differential Higgs boson production cross sections in the leptonic WW decay mode at sqrt{s} = 13 TeV

Measurements of the fiducial inclusive and differential production cross sections of the Higgs boson in proton-proton collisions at sqrt{s} = 13 TeV are performed using events where the Higgs boson decays into a pair of W bosons that subsequently decay into a final state with an electron, a muon, and a pair of neutrinos. The analysis is based on data collected with the CMS detector at the LHC during 2016–2018, corresponding to an integrated luminosity of 137 fb−1. Production cross sections are measured as a function of the transverse momentum of the Higgs boson and the associated jet multiplicity. The Higgs boson signal is extracted and simultaneously unfolded to correct for selection efficiency and resolution effects using maximum-likelihood fits to the observed distributions in data. The integrated fiducial cross section is measured to be 86.5 ± 9.5 fb, consistent with the Standard Model expectation of 82.5 ± 4.2 fb. No significant deviation from the Standard Model expectations is observed in the differential measurements.

Higgs boson production cross-section measurements vand their EFT interpretation in the 4l decay channel at root s =13 TeV with the ATLAS detector (vol 80, 10.1140/epjc/s10052-020-8227-9, 2020)

In the published HTML version of this article, the affiliations of the authors of the National Research Nuclear University MEPhI, Moscow, Russia were unfortunately marked incorrectly.

Higgs boson production cross-section measurements and their EFT interpretation in the 4ell decay channel at sqrt{s}=13\xa0TeV with the ATLAS detector

Higgs boson properties are studied in the four-lepton decay channel (where lepton = e, mu ) using 139 hbox {fb}^{-1} of proton–proton collision data recorded at sqrt{s}=13 TeV by the ATLAS experiment at the Large Hadron Collider. The inclusive cross-section times branching ratio for Hrightarrow ZZ^* decay is measured to be 1.34 pm 0.12 pb for a Higgs boson with absolute rapidity below 2.5, in good agreement with the Standard Model prediction of 1.33 pm 0.08 pb. Cross-sections times branching ratio are measured for the main Higgs boson production modes in several exclusive phase-space regions. The measurements are interpreted in terms of coupling modifiers and of the tensor structure of Higgs boson interactions using an effective field theory approach. Exclusion limits are set on the CP-even and CP-odd ‘beyond the Standard Model’ couplings of the Higgs boson to vector bosons, gluons and top quarks.

Collinear expansion for color singlet cross sections

We demonstrate how to efficiently expand cross sections for color-singlet production at hadron colliders around the kinematic limit of all final state radiation being collinear to one of the incoming hadrons. This expansion is systematically improvable and applicable to a large class of physical observables. We demonstrate the viability of this technique by obtaining the first two terms in the collinear expansion of the rapidity distribution of the gluon fusion Higgs boson production cross section at next-to-next-to leading order (NNLO) in QCD perturbation theory. Furthermore, we illustrate how this technique is used to extract universal building blocks of scattering cross section like the N-jettiness and transverse momentum beam function at NNLO.

N-jettiness beam functions at N3LO

We present the first complete calculation for the quark and gluon N-jettiness ( {mathcal{T}}_N ) beam functions at next-to-next-to-next-to-leading order (N3LO) in perturbative QCD. Our calculation is based on an expansion of the differential Higgs boson and Drell-Yan production cross sections about their collinear limit. This method allows us to employ cutting edge techniques for the computation of cross sections to extract the universal building blocks in question. The class of functions appearing in the matching coefficents for all channels includes iterated integrals with non-rational kernels, thus going beyond the one of harmonic polylogarithms. Our results are a key step in extending the {mathcal{T}}_N subtraction methods to N3LO, and to resum {mathcal{T}}_N distributions at N3LL′ accuracy both for quark as well as for gluon initiated processes.

Search for heavy neutral Higgs bosons produced in association with b -quarks and decaying into b -quarks at s=13 TeV with the ATLAS detector

A search for heavy neutral Higgs bosons produced in association with one or two $b$-quarks and decaying to $b$-quark pairs is presented using 27.8 fb$^{-1}$ of $\sqrt{s}=13$ TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider during 2015 and 2016. No evidence of a signal is found. Upper limits on the heavy neutral Higgs boson production cross-section times its branching ratio to $b\bar{b}$ are set, ranging from 4.0 to 0.6 pb at 95% confidence level over a Higgs boson mass range of 450 to 1400 GeV. Results are interpreted within the two-Higgs-doublet model and the minimal supersymmetric Standard Model.

Approximate four-loop QCD corrections to the Higgs-boson production cross section

We study the soft and collinear contributions to inclusive Higgs-boson production in gluon-gluon fusion at four loops. Using recent progress for the quark and gluon form factors and Mellin moments of splitting functions, we are able to complete the soft-gluon enhanced contributions exactly in the limit of a large number of colours, and to a sufficiently accurate numerical accuracy for QCD. The four-loop soft and virtual contributions increase the QCD cross section at 14 TeV by 2.7% and 0.2% for the standard choices μR=mH and μR=mH/2 of the renormalization scale, and reduce the scale uncertainty to below ±3%. As by-products, we derive the complete δ(1−x) term for the gluon-gluon splitting function at four loops and its purely Abelian contributions at five loops, and provide a numerical result for the single pole of the four-loop gluon form factor in dimensional regularization. Finally we present the closely related fourth-order coefficients D4 for the soft-gluon exponentiation of Higgs-boson and Drell-Yan lepton-pair production.

Triple Higgs production at hadron colliders at NNLO in QCD

In this work we analyse the triple Higgs boson production cross section at hadron colliders via gluon fusion, and present for the first time the full set of QCD NNLO corrections in the heavy top limit. In order to account for finite top mass effects we perform two different reweighting procedures, and study the dependence of the result on the choice of the approximation. Combining the most accurate predictions available to date, we present the following result for the total NNLO cross section for triple Higgs boson production at a 100 TeV collider: {sigma}_{mathrm{NNLO}}={5.56}_{-6%}^{+5%} ± 20% fb, where the first uncertainty is an estimate for higher order effects from scale variations, while the last one is an estimate for the missing finite top mass effects.

Combined measurements of Higgs boson production and decay using up to 80 fb−1 of proton-proton collision data at s=13 TeV collected with the ATLAS experiment

Combined measurements of Higgs boson production cross sections and branching fractions are presented. The combination is based on the analyses of the Higgs boson decay modes $H \to \gamma\gamma$, $ZZ^\ast$, $WW^\ast$, $\tau\tau$, $b\bar{b}$, $\mu\mu$, searches for decays into invisible final states, and on measurements of off-shell Higgs boson production. Up to $79.8$ fb$^{-1}$ of proton-proton collision data collected at $\sqrt{s}=$ 13 TeV with the ATLAS detector are used. Results are presented for the gluon-gluon fusion and vector-boson fusion processes, and for associated production with vector bosons or top-quarks. The global signal strength is determined to be $\mu = 1.11^{+0.09}_{-0.08}$. The combined measurement yields an observed (expected) significance for the vector-boson fusion production process of $6.5\sigma$ ($5.3\sigma$). Measurements in kinematic regions defined within the simplified template cross section framework are also shown. The results are interpreted in terms of modifiers applied to the Standard Model couplings of the Higgs boson to other particles, and are used to set exclusion limits on parameters in two-Higgs-doublet models and in the simplified Minimal Supersymmetric Standard Model. No significant deviations from Standard Model predictions are observed.

Search for a charged Higgs boson decaying into top and bottom quarks in events with electrons or muons in proton-proton collisions at sqrt{mathrm{s}} = 13 TeV

A search is presented for a charged Higgs boson heavier than the top quark, produced in association with a top quark, or with a top and a bottom quark, and decaying into a top-bottom quark-antiquark pair. The search is performed using proton-proton collision data collected by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1. Events are selected by the presence of a single isolated charged lepton (electron or muon) or an opposite-sign dilepton (electron or muon) pair, categorized according to the jet multiplicity and the number of jets identified as originating from b quarks. Multivariate analysis techniques are used to enhance the discrimination between signal and background in each category. The data are compatible with the standard model, and 95% confidence level upper limits of 9.6–0.01 pb are set on the charged Higgs boson production cross section times branching fraction to a top-bottom quark-antiquark pair, for charged Higgs boson mass hypotheses ranging from 200 GeV to 3 TeV. The upper limits are interpreted in different minimal supersymmetric extensions of the standard model.

Search for non-resonant Higgs boson pair production in the bbℓνℓν final state with the ATLAS detector in pp collisions at [formula omitted] TeV

A search for non-resonant Higgs boson pair production, as predicted by the Standard Model, is presented, where one of the Higgs bosons decays via the H→bb channel and the other via one of the H→WW⁎/ZZ⁎/ττ channels. The analysis selection requires events to have at least two b-tagged jets and exactly two leptons (electrons or muons) with opposite electric charge in the final state. Candidate events consistent with Higgs boson pair production are selected using a multi-class neural network discriminant. The analysis uses 139 fb−1 of pp collision data recorded at a centre-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. An observed (expected) upper limit of 1.2 (0.9−0.3+0.4) pb is set on the non-resonant Higgs boson pair production cross-section at 95% confidence level, which is equivalent to 40 (29−9+14) times the value predicted in the Standard Model.

Combination of searches for Higgs boson pairs in pp collisions at [formula omitted] with the ATLAS detector

This letter presents a combination of searches for Higgs boson pair production using up to 36.1fb−1 of proton–proton collision data at a centre-of-mass energy s=13 TeV recorded with the ATLAS detector at the LHC. The combination is performed using six analyses searching for Higgs boson pairs decaying into the bb¯bb¯, bb¯W+W−, bb¯τ+τ−, W+W−W+W−, bb¯γγ and W+W−γγ final states. Results are presented for non-resonant and resonant Higgs boson pair production modes. No statistically significant excess in data above the Standard Model predictions is found. The combined observed (expected) limit at 95% confidence level on the non-resonant Higgs boson pair production cross-section is 6.9 (10) times the predicted Standard Model cross-section. Limits are also set on the ratio (κλ) of the Higgs boson self-coupling to its Standard Model value. This ratio is constrained at 95% confidence level in observation (expectation) to −5.0<κλ<12.0 (−5.8<κλ<12.0). In addition, limits are set on the production of narrow scalar resonances and spin-2 Kaluza–Klein Randall–Sundrum gravitons. Exclusion regions are also provided in the parameter space of the habemus Minimal Supersymmetric Standard Model and the Electroweak Singlet Model.

Search for light pseudoscalar boson pairs produced from decays of the 125 GeV Higgs boson in final states with two muons and two nearby tracks in pp collisions at [formula omitted

A search is presented for pairs of light pseudoscalar bosons, in the mass range from 4 to 15 GeV, produced from decays of the 125 GeV Higgs boson. The decay modes considered are final states that arise when one of the pseudoscalars decays to a pair of tau leptons, and the other one either into a pair of tau leptons or muons. The search is based on proton-proton collisions collected by the CMS experiment in 2016 at a center-of-mass energy of 13 TeV that correspond to an integrated luminosity of 35.9 fb−1. The 2μ2τ and 4τ channels are used in combination to constrain the product of the Higgs boson production cross section and the branching fraction into 4τ final state, σB, exploiting the linear dependence of the fermionic coupling strength of pseudoscalar bosons on the fermion mass. No significant excess is observed beyond the expectation from the standard model. The observed and expected upper limits at 95% confidence level on σB, relative to the standard model Higgs boson production cross section, are set respectively between 0.022 and 0.23 and between 0.027 and 0.19 in the mass range probed by the analysis.

Linearly polarized gluons at next-to-next-to leading order and the Higgs transverse momentum distribution

We calculate the small-b (or large-qT) matching of transverse momentum de- pendent (TMD) distribution for linearly polarized gluons to the integrated gluon distributions at the next-to-next-to-leading order (NNLO). This is the last missing part for the complete NNLO prediction of the Higgs spectrum within TMD factorization. We discuss the numerical impact of the correction so derived to the qT -differential cross-section for Higgs boson production and to the positivity bound for linearly polarized gluon transverse momentum distribution.

Measurement of the production cross section for a Higgs boson in association with a vector boson in the H → WW⁎ → ℓνℓν channel in pp collisions at [formula omitted] TeV with the ATLAS detector

A measurement of the Higgs boson production cross sections via associated WH and ZH production using H→WW⁎→ℓνℓν decays, where ℓ stands for either an electron or a muon, is presented. Results for combined WH and ZH production are also presented. The analysis uses events produced in proton–proton collisions collected with the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The data correspond to an integrated luminosity of 36.1fb−1 recorded at a centre-of-mass energy of 13 TeV. The products of the H→WW⁎ branching fraction times the WH and ZH cross sections are measured to be 0.67−0.27+0.31(stat.)−0.14+0.18(syst.) pb and 0.54−0.24+0.31(stat.)−0.07+0.15(syst.) pb respectively, in agreement with the Standard Model predictions.

Search for Higgs boson pair production in the WW(*)WW(*) decay channel using ATLAS data recorded at sqrt{mathrm{s}} = 13 TeV

A search for a pair of neutral, scalar bosons with each decaying into two W bosons is presented using 36.1 fb−1 of proton-proton collision data at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider. This search uses three production models: non-resonant and resonant Higgs boson pair production and resonant production of a pair of heavy scalar particles. Three final states, classified by the number of leptons, are analysed: two same-sign leptons, three leptons, and four leptons. No significant excess over the expected Standard Model backgrounds is observed. An observed (expected) 95% confidence-level upper limit of 160 (120) times the Standard Model prediction of non-resonant Higgs boson pair production cross-section is set from a combined analysis of the three final states. Upper limits are set on the production cross-section times branching ratio of a heavy scalar X decaying into a Higgs boson pair in the mass range of 260 GeV ≤ mX ≤ 500 GeV and the observed (expected) limits range from 9.3 (10) pb to 2.8 (2.6) pb. Upper limits are set on the production cross-section times branching ratio of a heavy scalar X decaying into a pair of heavy scalars S for mass ranges of 280 GeV ≤ mX ≤ 340 GeV and 135 GeV ≤ mS ≤ 165 GeV and the observed (expected) limits range from 2.5 (2.5) pb to 0.16 (0.17) pb.