Azimuthal correlations of high transverse momentum jets at next-to-leading order in the parton branching method

AbstractThe azimuthal correlation, $$\Delta \phi _{12}$$ Δ ϕ 12 , of high transverse momentum jets in pp collisions at $$\sqrt{s}=13$$ s = 13  TeV is studied by applying PB-TMD distributions to NLO calculations via MCatNLO together with the PB-TMD parton shower. A very good description of the cross section as a function of $$\Delta \phi _{12}$$ Δ ϕ 12 is observed. In the back-to-back region of $${\Delta \phi _{12}}\rightarrow \pi$$ Δ ϕ 12 → π , a very good agreement is observed with the PB-TMD Set 2 distributions while significant deviations are obtained with the PB-TMD Set 1 distributions. Set 1 uses the evolution scale while Set 2 uses transverse momentum as an argument in $$\alpha _\mathrm {s}$$ α s , and the above observation therefore confirms the importance of an appropriate soft-gluon coupling in angular ordered parton evolution. The total uncertainties of the predictions are dominated by the scale uncertainties of the matrix element, while the uncertainties coming from the PB-TMDs and the corresponding PB-TMD shower are very small. The $$\Delta \phi _{12}$$ Δ ϕ 12 measurements are also compared with predictions using MCatNLO together Pythia8, illustrating the importance of details of the parton shower evolution.</jats:p

Azimuthal correlations of high transverse momentum jets at next-to-leading order in the parton branching method

AbstractThe azimuthal correlation, $$\Delta \phi _{12}$$ Δ ϕ 12 , of high transverse momentum jets in pp collisions at $$\sqrt{s}=13$$ s = 13  TeV is studied by applying PB-TMD distributions to NLO calculations via MCatNLO together with the PB-TMD parton shower. A very good description of the cross section as a function of $$\Delta \phi _{12}$$ Δ ϕ 12 is observed. In the back-to-back region of $${\Delta \phi _{12}}\rightarrow \pi$$ Δ ϕ 12 → π , a very good agreement is observed with the PB-TMD Set 2 distributions while significant deviations are obtained with the PB-TMD Set 1 distributions. Set 1 uses the evolution scale while Set 2 uses transverse momentum as an argument in $$\alpha _\mathrm {s}$$ α s , and the above observation therefore confirms the importance of an appropriate soft-gluon coupling in angular ordered parton evolution. The total uncertainties of the predictions are dominated by the scale uncertainties of the matrix element, while the uncertainties coming from the PB-TMDs and the corresponding PB-TMD shower are very small. The $$\Delta \phi _{12}$$ Δ ϕ 12 measurements are also compared with predictions using MCatNLO together Pythia8, illustrating the importance of details of the parton shower evolution.</jats:p

Search for a vector-like quark T′ → tH via the diphoton decay mode of the Higgs boson in proton-proton collisions at s \sqrt{s} = 13 TeV

A search for the electroweak production of a vector-like quark T′, decaying to a top quark and a Higgs boson is presented. The search is based on a sample of proton-proton collision events recorded at the LHC at = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. This is the first T′ search that exploits the Higgs boson decay to a pair of photons. For narrow isospin singlet T′ states with masses up to 1.1 TeV, the excellent diphoton invariant mass resolution of 1–2% results in an increased sensitivity compared to previous searches based on the same production mechanism. The electroweak production of a T′ quark with mass up to 960 GeV is excluded at 95% confidence level, assuming a coupling strength κT = 0.25 and a relative decay width Γ/MT′ < 5%

A search for new physics in central exclusive production using the missing mass technique with the CMS detector and the CMS-TOTEM precision proton spectrometer

A generic search is presented for the associated production of a Z boson or a photon with an additional unspecified massive particle X, pp → pp + Z/γ + X, in proton-tagged events from proton–proton collisions at √s = 13 TeV, recorded in 2017 with the CMS detector and the CMS-TOTEM precision proton spectrometer. The missing mass spectrum is analysed in the 600–1600 GeV range and a fit is performed to search for possible deviations from the background expectation. No significant excess in data with respect to the background predictions has been observed. odelindependent upper limits on the visible production cross section of pp → pp + Z/γ + X are set

Combined searches for the production of supersymmetric top quark partners in proton–proton collisions at √s=13Te

A combination of searches for top squark pair production using proton–proton collision data at a center-of-mass energy of 13TeV at the CERN LHC, corresponding to an integrated luminosity of 137fb$^{-1}$ collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on the model, the combined result excludes a top squark mass up to 1325GeV for a massless neutralino, and a neutralino mass up to 700GeV for a top squark mass of 1150GeV. Top squarks with masses from 145 to 295GeV, for neutralino masses from 0 to 100GeV, with a mass difference between the top squark and the neutralino in a window of 30GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420GeV

Search for new physics in multijet events with at least one photon and large missing transverse momentum in proton-proton collisions at 13 TeV

A search for new physics in final states consisting of at least one photon, multiple jets, and large missing transverse momentum is presented, using proton-proton collision events at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 137 fb−1, recorded by the CMS experiment at the CERN LHC from 2016 to 2018. The events are divided into mutually exclusive bins characterized by the missing transverse momentum, the number of jets, the number of b-tagged jets, and jets consistent with the presence of hadronically decaying W, Z, or Higgs bosons. The observed data are found to be consistent with the prediction from standard model processes. The results are interpreted in the context of simplified models of pair production of supersymmetric particles via strong and electroweak interactions. Depending on the details of the signal models, gluinos and squarks of masses up to 2.35 and 1.43 TeV, respectively, and electroweakinos of masses up to 1.23 TeV are excluded at 95% confidence level

Search for nonresonant Higgs boson pair production in the four leptons plus twob jets final state in proton-proton collisions at s \sqrt{s} = 13 TeV

The first search for nonresonant production of Higgs boson pairs (HH) with one H decaying into four leptons and the other into a pair of b quarks is presented, using proton-proton collisions recorded at a center-of-mass energy of s√ = 13 TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 138 fb−1. A 95% confidence level upper limit of 32.4 is set on the signal strength modifier μ, defined as the ratio of the observed HH production rate in the HH→ZZ∗bb¯¯¯→4ℓbb¯¯¯ decay channel to the standard model (SM) expectation. Possible modifications of the H trilinear coupling λHHH with respect to the SM value are investigated. The coupling modifier κλ, defined as λHHH divided by its SM prediction, is constrained to be within the observed (expected) range −8.8 (−9.8) < κλ < 13.4 (15.0) at 95% confidence level

Measurement of the Higgs boson inclusive and differential fiducial production cross sections in the diphoton decay channel with pp collisions at s \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 $σ_{fid}$=73.4$^{+5.4}_{−5.3}$(stat)$^{+2.4}_{−2.2}$(syst) 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