Search
Results
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The very forward CASTOR calorimeter of the CMS experiment
(2021)Journal of InstrumentationThe physics motivation, detector design, triggers, calibration, alignment, simulation, and overall performance of the very forward CASTOR calorimeter of the CMS experiment are reviewed. The CASTOR Cherenkov sampling calorimeter is located very close to the LHC beam line, at a radial distance of about 1 cm from the beam pipe, and at 14.4 m from the CMS interaction point, covering the pseudorapidity range of -6.6 < eta < - 5.2. It was ...Journal Article -
Measurement of the associated production of a Z boson with charm or bottom quark jets in proton-proton collisions at root s=13 TeV
(2020)Physical Review DRatios of cross sections, sigma(Z + c jets)/sigma(Z + jets), sigma(Z + b jets)/sigma(Z + jets), and sigma(Z + c jets)/sigma(Z + b jets) in the associated production of a Z boson with at least one charm or bottom quark jet are measured in proton-proton collisions at root s = 13 TeV. The data sample, collected by the CMS experiment at the CERN LHC, corresponds to an integrated luminosity of 35.9 fb(-1), with a fiducial volume of p(T) > 30 ...Journal Article -
Study of central exclusive π+π− production in proton-proton collisions at √s=5.02 and 13TeV
(2020)The European Physical Journal CCentral exclusive and semiexclusive production of π+π− pairs is measured with the CMS detector in proton-proton collisions at the LHC at center-of-mass energies of 5.02 and 13 TeV. The theoretical description of these nonperturbative processes, which have not yet been measured in detail at the LHC, poses a significant challenge to models. The two pions are measured and identified in the CMS silicon tracker based on specific energy loss, ...Journal Article -
Mixed higher-order anisotropic flow and nonlinear response coefficients of charged particles in PbPb collisions at root s(NN)=2.76 and 5.02 TeV
(2020)The European Physical Journal CAnisotropies in the initial energy density distribution of the quark-gluon plasma created in high energy heavy ion collisions lead to anisotropies in the azimuthal distributions of the final-state particles known as collective anisotropic flow. Fourier harmonic decomposition is used to quantify these anisotropies. The higher-order harmonics can be induced by the same order anisotropies (linear response) or by the combined influence of ...Journal Article -
Measurement of the cross section for electroweak production of a Z boson, a photon and two jets in proton-proton collisions at √s = 13 TeV and constraints on anomalous quartic couplings
(2020)Journal of High Energy PhysicsA measurement is presented of the cross section for electroweak production of a Z boson and a photon in association with two jets (Zγjj) in proton-proton collisions. The Z boson candidates are selected through their decay into a pair of electrons or muons. The process of interest, electroweak Zγjj production, is isolated by selecting events with a large dijet mass and a large pseudorapidity gap between the two jets. The measurement is ...Journal Article -
Identification of heavy, energetic, hadronically decaying particles using machine-learning techniques
(2020)Journal of InstrumentationMachine-learning (ML) techniques are explored to identify and classify hadronic decays of highly Lorentz-boosted W/Z/Higgs bosons and top quarks. Techniques without ML have also been evaluated and are included for comparison. The identification performances of a variety of algorithms are characterized in simulated events and directly compared with data. The algorithms are validated using proton-proton collision data at root S = 13 TeV, ...Journal Article -
Search for a Narrow Resonance Lighter than 200 GeV Decaying to a Pair of Muons in Proton-Proton Collisions at root s=13 TeV
(2020)Physical Review LettersA search is presented for a narrow resonance decaying to a pair of oppositely charged muons using √ s=13 TeV proton-proton collision data recorded at the LHC. In the 45–75 and 110–200 GeV resonance mass ranges, the search is based on conventional triggering and event reconstruction techniques. In the 11.5–45 GeV mass range, the search uses data collected with dimuon triggers with low transverse momentum thresholds, recorded at high rate ...Journal Article -
Search for new neutral Higgs bosons through the H → ZA → ℓ+ℓ−bb¯ process in pp collisions at s√= 13 TeV
(2020)Journal of High Energy PhysicsThis paper reports on a search for an extension to the scalar sector of the standard model, where a new CP-even (odd) boson decays to a Z boson and a lighter CP-odd (even) boson, and the latter further decays to a b quark pair. The Z boson is reconstructed via its decays to electron or muon pairs. The analysed data were recorded in proton-proton collisions at a center-of-mass energy s√ = 13 TeV, collected by the CMS experiment at the LHC ...Journal Article -
Measurement of top quark pair production in association with a Z boson in proton-proton collisions at √s = 13 TeV
(2020)Journal of High Energy PhysicsA measurement of the inclusive cross section of top quark pair production in association with a Z boson using proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC is performed. The data sample corresponds to an integrated luminosity of 77.5 fb−1, collected by the CMS experiment during 2016 and 2017. The measurement is performed using final states containing three or four charged leptons (electrons or muons), and the Z ...Journal Article -
A multi-dimensional search for new heavy resonances decaying to boosted WW, WZ, or ZZ boson pairs in the dijet final state at 13TeV
(2020)The European Physical Journal CA search in an all-jet final state for new massive resonances decaying to W W , W Z , or Z Z boson pairs using a novel analysis method is presented. The analysis is performed on data corresponding to an integrated luminosity of 77.3 fb−1 recorded with the CMS experiment at the LHC at a centre-of-mass energy of 13 TeV. The search is focussed on potential narrow-width resonances with masses above 1.2 TeV, where the decay products ...Journal Article