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Measurement of the Electron Charge Asymmetry in Inclusive W Production in pp Collisions at √s=7 TeV
(2012)Physical Review LettersA measurement of the electron charge asymmetry in inclusive pp→W+X→eν+X production at √s=7 TeV is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 840 pb−1. The electron charge asymmetry reflects the unequal production of W+ and W− bosons in pp collisions. The electron charge asymmetry is measured in bins of the absolute value of electron pseudorapidity in the range of ...Journal Article -
Measurement of the t-Channel Single Top Quark Production Cross Section in pp Collisions at √s=7 TeV
(2011)Physical Review LettersElectroweak production of the top quark is measured for the first time in pp collisions at √s=7 TeV, using a data set collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb−1. With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from the data. ...Journal Article -
Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV
(2020)Journal of High Energy PhysicsThe parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (𝑑���̂ t) and chromomagnetic (𝜇���̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable 𝐴���(1)FB is used to approximate the asymmetry. Candidate tt⎯⎯ events decaying to a muon or ...Journal Article -
Search for charged Higgs bosons decaying into a top and a bottom quark in the all-jet final state of pp collisions at √s = 13 TeV
(2020)Journal of High Energy PhysicsA search for charged Higgs bosons (H±) decaying into a top and a bottom quark in the all-jet final state is presented. The analysis uses LHC proton-proton collision data recorded with the CMS detector in 2016 at √s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1. No significant excess is observed above the expected background. Model-independent upper limits at 95% confidence level are set on the product of the H± production ...Journal Article -
Determination of the strong coupling constant αS(mZ) from measurements of inclusive W± and Z boson production cross sections in proton-proton collisions at √s = 7 and 8 TeV
(2020)Journal of High Energy PhysicsTwelve measurements of inclusive cross sections of W± and Z boson production, performed in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, are compared with perturbative quantum chromodynamics calculations at next-to-next- to-leading order (NNLO) accuracy obtained with the CT14, HERAPDF2.0, MMHT14, and NNPDF3.0 parton distribution functions (PDFs). Data and theory agree well for all PDF sets, taking into account the ...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 -
Calibration of the CMS hadron calorimeters using proton-proton collision data at √s = 13 TeV
(2020)Journal of InstrumentationMethods are presented for calibrating the hadron calorimeter system of the CMS detector at the LHC. The hadron calorimeters of the CMS experiment are sampling calorimeters of brass and scintillator, and are in the form of one central detector and two endcaps. These calorimeters cover pseudorapidities |η| < 3 and are positioned inside the solenoidal magnet. An outer calorimeter, outside the magnet coil, covers |η| < 1.26, and a steel and ...Journal Article -
Measurements with silicon photomultipliers of dose-rate effects in the radiation damage of plastic scintillator tiles in the CMS hadron endcap calorimeter
(2020)Journal of InstrumentationMeasurements are presented of the reduction of signal output due to radiation damage for two types of plastic scintillator tiles used in the hadron endcap (HE) calorimeter of the CMS detector. The tiles were exposed to particles produced in proton-proton (pp) collisions at the CERN LHC with a center-of-mass energy of 13 TeV, corresponding to a delivered luminosity of 50 fb−1. The measurements are based on readout channels of the HE that ...Journal Article -
Measurements of (tt)over-barH Production and the CP Structure of the Yukawa Interaction between the Higgs Boson and Top Quark in the Diphoton Decay Channel
(2020)Physical Review LettersThe first observation of the (tt) over barH process in a single Higgs boson decay channel with the full reconstruction of the final state (H -> gamma gamma) is presented, with a significance of 6.6 standard deviations (sigma). The CP structure of Higgs boson couplings to fermions is measured, resulting in an exclusion of the pure CP-odd structure of the top Yukawa coupling at 3.2 sigma. The measurements are based on a sample of protonproton ...Journal Article -
The production of isolated photons in PbPb and pp collisions at √sNN = 5.02 TeV
(2020)Journal of High Energy PhysicsThe transverse energy (EγT) spectra of photons isolated from other particles are measured using proton-proton (pp) and lead-lead (PbPb) collisions at the LHC at sNN−−−√ = 5.02 TeV with integrated luminosities of 27.4 pb−1 and 404 μb−1 for pp and PbPb data, respectively. The results are presented for photons with 25 < EγT < 200 GeV in the pseudorapidity range |η| < 1.44, and for different centrality intervals for PbPb collisions. Photon ...Journal Article