The first evidence for X(3872) production in relativistic heavy ion collisions is reported. The X(3872) production is studied in lead-lead (Pb-Pb) collisions at a center-of-mass energy of sqrt[s_{NN}]=5.02 TeV per nucleon pair, using the decay chain X(3872)→J/ψπ^{+}π^{-}→μ^{+}μ^{-}π^{+}π^{-}.
View Article and Find Full Text PDFMeasurements are presented of the single-diffractive dijet cross section and the diffractive cross section as a function of the proton fractional momentum loss and the four-momentum transfer squared . Both processes and , i.e.
View Article and Find Full Text PDFThe 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 p_{T}^{jet}>60 GeV/c and D^{0} mesons with p_{T}^{D}>4 GeV/c in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=5.02 TeV, recorded by the CMS detector at the LHC.
View Article and Find Full Text PDFEur Phys J C Part Fields
August 2020
Central exclusive and semiexclusive production of pairs is measured with the CMS detector in proton-proton collisions at the LHC at center-of-mass energies of 5.02 and 13TeV. The theoretical description of these nonperturbative processes, which have not yet been measured in detail at the LHC, poses a significant challenge to models.
View Article and Find Full Text PDFA measurement is presented of differential cross sections for -channel single top quark and antiquark production in proton-proton collisions at a centre-of-mass energy of 13 by the CMS experiment at the LHC. From a data set corresponding to an integrated luminosity of 35.9 , events containing one muon or electron and two or three jets are analysed.
View Article and Find Full Text PDFA measurement is reported of the jet mass distribution in hadronic decays of boosted top quarks produced in pp collisions at sqrt[s]=13 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9 fb^{-1}.
View Article and Find Full Text PDFThe polarizations of promptly produced χ_{c1} and χ_{c2} mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at sqrt[s]=8 TeV. The χ_{c} states are reconstructed via their radiative decays χ_{c}→J/ψγ, with the photons being measured through conversions to e^{+}e^{-}, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_{c2} to χ_{c1} yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ→μ^{+}μ^{-} decay, in three bins of J/ψ transverse momentum.
View Article and Find Full Text PDFA search is presented for a narrow resonance decaying to a pair of oppositely charged muons using sqrt[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.
View Article and Find Full Text PDFEur Phys J C Part Fields
March 2020
A search is presented for slepton pairs produced in proton-proton collisions at a center-of-mass energy of 13 . The search is carried out in events containing two leptons in the final state, on the assumption that each slepton decays primarily to a lepton and a neutralino. Events are considered in which each lepton decays to one or more hadrons and a neutrino, or in which one of the leptons decays instead to an electron or a muon and two neutrinos.
View Article and Find Full Text PDFA search in an all-jet final state for new massive resonances decaying to , , or boson pairs using a novel analysis method is presented. The analysis is performed on data corresponding to an integrated luminosity of 77.3 recorded with the CMS experiment at the LHC at a centre-of-mass energy of 13 .
View Article and Find Full Text PDFThe standard model (SM) production of four top quarks ( ) in proton-proton collisions is studied by the CMS Collaboration. The data sample, collected during the 2016-2018 data taking of the LHC, corresponds to an integrated luminosity of 137 at a center-of-mass energy of 13 . The events are required to contain two same-sign charged leptons (electrons or muons) or at least three leptons, and jets.
View Article and Find Full Text PDFPhys Rev Lett
January 2020
The first search for supersymmetry in events with an experimental signature of one soft, hadronically decaying τ lepton, one energetic jet from initial-state radiation, and large transverse momentum imbalance is presented. These event signatures are consistent with direct or indirect production of scalar τ leptons (τ[over ˜]) in supersymmetric models that exhibit coannihilation between the τ[over ˜] and the lightest neutralino (χ[over ˜]_{1}^{0}), and that could generate the observed relic density of dark matter. The data correspond to an integrated luminosity of 77.
View Article and Find Full Text PDFTwo related searches for phenomena beyond the standard model (BSM) are performed using events with hadronic jets and significant transverse momentum imbalance. The results are based on a sample of proton-proton collisions at a center-of-mass energy of , collected by the CMS experiment at the LHC in 2016-2018 and corresponding to an integrated luminosity of 137 . The first search is inclusive, based on signal regions defined by the hadronic energy in the event, the jet multiplicity, the number of jets identified as originating from bottom quarks, and the value of the kinematic variable for events with at least two jets.
View Article and Find Full Text PDFNew sets of CMS underlying-event parameters ("tunes") are presented for the pythia8 event generator. These tunes use the NNPDF3.1 parton distribution functions (PDFs) at leading (LO), next-to-leading (NLO), or next-to-next-to-leading (NNLO) orders in perturbative quantum chromodynamics, and the strong coupling evolution at LO or NLO.
View Article and Find Full Text PDFResults are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at sqrt[s]=13 TeV, and correspond to an integrated luminosity of 35.
View Article and Find Full Text PDFThe average total energy as well as its hadronic and electromagnetic components are measured with the CMS detector at pseudorapidities in proton-proton collisions at a centre-of-mass energy . The results are presented as a function of the charged particle multiplicity in the region . This measurement is sensitive to correlations induced by the underlying event structure over a very wide pseudorapidity region.
View Article and Find Full Text PDFMeasurements are presented of the triple-differential cross section for inclusive isolated-photon+jet events in collisions at TeV as a function of photon transverse momentum ( ), photon pseudorapidity ( ), and jet pseudorapidity ( ). The data correspond to an integrated luminosity of that probe a broad range of the available phase space, for and , , , and jet transverse momentum, , > 25 . The measurements are compared to next-to-leading order perturbative quantum chromodynamics calculations, which reproduce the data within uncertainties.
View Article and Find Full Text PDFA search for narrow low-mass resonances decaying to quark-antiquark pairs is presented. The search is based on proton-proton collision events collected at 13 TeV by the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 35.
View Article and Find Full Text PDFA measurement for inclusive 2- and 3-jet events of the azimuthal correlation between the two jets with the largest transverse momenta, , is presented. The measurement considers events where the two leading jets are nearly collinear ("back-to-back") in the transverse plane and is performed for several ranges of the leading jet transverse momentum. Proton-proton collision data collected with the CMS experiment at a center-of-mass energy of and corresponding to an integrated luminosity of are used.
View Article and Find Full Text PDFA search for a light charged Higgs boson (H^{+}) decaying to a W boson and a CP-odd Higgs boson (A) in final states with eμμ or μμμ is performed using data from pp collisions at sqrt[s]=13 TeV, recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 35.9 fb^{-1}. In this search, it is assumed that the H^{+} boson is produced in decays of top quarks, and the A boson decays to two oppositely charged muons.
View Article and Find Full Text PDFEur Phys J C Part Fields
August 2019
Exclusive photoproduction is measured for the first time in ultraperipheral pPb collisions at with the CMS detector. The cross section is b at for photon-proton centre-of-mass energies between 29 and . The differential cross section is measured in the interval as a function of , where is the squared four-momentum transfer at the proton vertex.
View Article and Find Full Text PDFEur Phys J C Part Fields
July 2019
A search is presented for a heavy pseudoscalar boson decaying to a Z boson and a Higgs boson with mass of 125 . In the final state considered, the Higgs boson decays to a bottom quark and antiquark, and the Z boson decays either into a pair of electrons, muons, or neutrinos. The analysis is performed using a data sample corresponding to an integrated luminosity of 35.
View Article and Find Full Text PDFThe transverse momentum spectra of D^{0} mesons from b hadron decays are measured at midrapidity (|y|<1) in pp and Pb-Pb collisions at a nucleon-nucleon center of mass energy of 5.02 TeV with the CMS detector at the LHC. The D^{0} mesons from b hadron decays are distinguished from prompt D^{0} mesons by their decay topologies.
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