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Measurement of the Wγ Production Cross Section in Proton-Proton Collisions at √s=13 TeV and Constraints on Effective Field Theory Coefficients
(2021)Physical Review LettersA fiducial cross section for Wγ production in proton-proton collisions is measured at a center-of-mass energy of 13 TeV in 137 fb-1 of data collected using the CMS detector at the LHC. The W→eν and μν decay modes are used in a maximum-likelihood fit to the lepton-photon invariant mass distribution to extract the combined cross section. The measured cross section is compared with theoretical expectations at next-to-leading order in quantum ...Journal Article -
Long-Term Monitoring of Bright Blazars in the Multi-GeV to TeV Range with FACT
(2017)GalaxiesBlazars like Markarian 421 or Markarian 501 are active galactic nuclei (AGN), with their jets orientated towards the observer. They are among the brightest objects in the very high energy (VHE) gamma ray regime (>100 GeV). Their emitted gamma-ray fluxes are extremely variable, with changing activity levels on timescales between minutes, months, and even years. Several questions are part of the current research, such as the question of the ...Journal Article -
Hard color-singlet exchange in dijet events in proton-proton collisions at √s = 13 TeV
(2021)Physical Review DEvents where the two leading jets are separated by a pseudorapidity interval devoid of particle activity, known as jet-gap-jet events, are studied in proton-proton collisions at √s = 13 TeV. The signature is expected from hard color-singlet exchange. Each of the highest transverse momentum (p(T)) jets must have p(T)(jet) > 40 GeV and pseudorapidity 1.4 < vertical bar eta(jet)vertical bar < 4.7, with eta(jet1)eta(jet2) < 0, where jet1 and ...Journal Article -
Search for singly and pair-produced leptoquarks coupling to third-generation fermions in proton-proton collisions at √s=13 TeV
(2021)Physics Letters BA search for leptoquarks produced singly and in pairs in proton-proton collisions is presented. We consider the leptoquark (LQ) to be a scalar particle of charge −1/3e coupling to a top quark plus a tau lepton (tτ) or a bottom quark plus a neutrino (bν), or a vector particle of charge +2/3e, coupling to tν or bτ. These choices are motivated by models that can explain a series of anomalies observed in the measurement of B meson decays. In ...Journal Article -
Development and validation of HERWIG 7 tunes from CMS underlying-event measurements
(2021)The European Physical Journal CThis paper presents new sets of parameters (“tunes”) for the underlying-event model of the HERWIG7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in HERWIG7, and are obtained from a fit to minimum-bias data collected by the CMS experiment at s=0.9, 7, and 13Te. The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set ...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 -
Search for resonant pair production of Higgs bosons in the bbZZ channel in proton-proton collisions at √s=13 TeV
(2020)Physical Review DA search for the production of a narrow-width resonance decaying into a pair of Higgs bosons decaying into the bbZZ channel is presented. The analysis is based on data collected with the CMS detector during 2016, in proton-proton collisions at the LHC, corresponding to an integrated luminosity of 35.9 fb(-1). The final states considered are the ones where one of the Z bosons decays into a pair of muons or electrons, and the other Z boson ...Journal Article -
Search for Low Mass Vector Resonances Decaying to Quark-Antiquark Pairs in Proton-Proton Collisions at √s=13 TeV
(2017)Physical Review LettersA search is reported for a narrow vector resonance decaying to quark-antiquark pairs in proton-proton collisions at √s=13 TeV, collected with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.7 fb−1. The vector resonance is produced at large transverse momenta, with its decay products merged into a single jet. The resulting signature is a peak over background in the distribution of the invariant ...Journal Article -
Search for colour reconnection effects in e+e- -> W+W- -> hadrons through particle-flow studies at LEP
(2003)Physics Letters BA search for colour reconnection effects in hadronic decays of W pairs is performed with the L3 detector at centre-of-mass energies between 189 and 209 GeV. The analysis is based on the study of the particle flow between jets associated to the sameW boson and between two different W bosons in qqqq events. The ratio of particle yields in the different interjet regions is found to be sensitive to colour reconnection effects implemented in ...Journal Article -
Measurement of differential t t ¯ production cross sections using top quarks at large transverse momenta in pp collisions at s =13 TeV
(2021)Physical Review DA measurement is reported of differential top quark pair (tt¯) production cross sections, where top quarks are produced at large transverse momenta. The data collected with the CMS detector at the LHC are from pp collisions at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 35.9 fb-1. The measurement uses events where at least one top quark decays as t→Wb→qq¯′b and is reconstructed as a large-radius jet with ...Journal Article