Search
Results
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Measurements of production cross sections of WZ and same-sign WW boson pairs in association with two jets in proton-proton collisions at s=13TeV
(2020)Physics Letters BMeasurements of production cross sections of WZ and same-sign WW boson pairs in association with two jets in proton-proton collisions at s=13TeV at the LHC are reported. The data sample corresponds to an integrated luminosity of 137fb−1, collected with the CMS detector during 2016–2018. The measurements are performed in the leptonic decay modes [Formula presented] and [Formula presented], where ℓ,ℓ′=e, [Formula presented]. Differential ...Journal Article -
Observation of the B0s→X(3872)ϕ Decay
(2020)Physical Review LettersUsing a data sample of proton-proton collisions at √s=13 TeV, corresponding to an integrated luminosity of 140 fb−1 collected by the CMS experiment in 2016–2018, the B0s→X(3872)ϕ decay is observed. Decays into J/ψπ+π− and K+K− are used to reconstruct, respectively, the X(3872) and ϕ. The ratio of the product of branching fractions B[B0s→X(3872)ϕ]B[X(3872)→J/ψπ+π−] to the product B[B0s→ψ(2S)ϕ]B[ψ(2S)→J/ψπ+π−] is measured to be ...Journal Article -
Observation of the Production of Three Massive Gauge Bosons at √s=13 TeV
(2020)Physical Review LettersThe first observation is reported of the combined production of three massive gauge bosons (VVV with V = W, Z) in proton-proton collisions at a center-of-mass energy of 13 TeV. The analysis is based on a data sample recorded by the CMS experiment at the CERN LHC corresponding to an integrated luminosity of 137 fb(-1). The searches for individualWWW, WWZ, WZZ, and ZZZ production are performed in final states with three, four, five, and six ...Journal Article -
Search for a light charged Higgs boson in the H±→cs channel in proton-proton collisions at √s=13 TeV
(2020)Physical Review DA search is conducted for a low-mass charged Higgs boson produced in a top quark decay and subsequently decaying into a charm and a strange quark. The data sample was recorded in proton-proton collisions at root s = 13 TeV by the CMS experiment at the LHC and corresponds to an integrated luminosity of 35.9 fb(-1). The search is performed in the process of top quark pair production, where one top quark decays to a bottom quark and a charged ...Journal Article -
Reconstruction of signal amplitudes in the CMS electromagnetic calorimeter in the presence of overlapping proton-proton interactions
(2020)Journal of InstrumentationA template fitting technique for reconstructing the amplitude of signals produced by the lead tungstate crystals of the CMS electromagnetic calorimeter is described. This novel approach is designed to suppress the contribution to the signal of the increased number of out-of-time interactions per beam crossing following the reduction of the accelerator bunch spacing from 50 to 25 ns at the start of Run 2 of the LHC. Execution of the algorithm ...Journal Article -
Performance of the CMS Level-1 trigger in proton-proton collisions at √s = 13 TeV
(2020)Journal of InstrumentationAt the start of Run 2 in 2015, the LHC delivered proton-proton collisions at a center-of-mass energy of 13\TeV. During Run 2 (years 2015–2018) the LHC eventually reached a luminosity of 2.1× 1034 cm-2s-1, almost three times that reached during Run 1 (2009–2013) and a factor of two larger than the LHC design value, leading to events with up to a mean of about 50 simultaneous inelastic proton-proton collisions per bunch crossing (pileup). ...Journal Article -
Studies of Charm Quark Diffusion inside Jets Using Pb-Pb and pp Collisions at root s(NN)=5.02 TeV
(2020)Physical Review LettersThe first study of charm quark diffusion with respect to the jet axis in heavy ion collisions is presented. The measurement is performed using jets with pjetT>60 GeV/c and D0 mesons with pDT>4 GeV/c in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of √sNN=5.02 TeV, recorded by the CMS detector at the LHC. The radial distribution of D0 mesons with respect to the jet axis is sensitive to ...Journal Article -
Measurement of CKM matrix elements in single top quark t-channel production in proton-proton collisions at s=13 TeV
(2020)Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy PhysicsThe first direct, model-independent measurement is presented of the modulus of the Cabibbo–Kobayashi–Maskawa (CKM) matrix elements |η|Vtb, |η|Vtd, and |η|Vts, in final states enriched in single top quark t-channel events. The analysis uses proton-proton collision data from the LHC, collected during 2016 by the CMS experiment, at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1. Processes directly ...Journal Article -
Pileup mitigation at CMS in 13 TeV data
(2020)Journal of InstrumentationWith increasing instantaneous luminosity at the LHC come additional reconstruction challenges. At high luminosity, many collisions occur simultaneously within one proton-proton bunch crossing. The isolation of an interesting collision from the additional "pileup" collisions is needed for effective physics performance. In the CMS Collaboration, several techniques capable of mitigating the impact of these pileup collisions have been developed. ...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