Search
Results
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Measurement of prompt D0 and D‾0 meson azimuthal anisotropy and search for strong electric fields in PbPb collisions at sNN=5.02TeV
(2021)Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy PhysicsThe strong Coulomb field created in ultrarelativistic heavy ion collisions is expected to produce a rapidity-dependent difference (Δv2) in the second Fourier coefficient of the azimuthal distribution (elliptic flow, v2) between D0 (u‾c) and D‾0 (uc‾) mesons. Motivated by the search for evidence of this field, the CMS detector at the LHC is used to perform the first measurement of Δv2. The rapidity-averaged value is found to be ...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 disappearing tracks in proton-proton collisions at s=13TeV
(2020)Physics Letters BA search is presented for long-lived charged particles that decay within the volume of the silicon tracker of the CMS experiment. Such particles can produce events with an isolated track that is missing hits in the outermost layers of the silicon tracker, and is also associated with little energy deposited in the calorimeters and no hits in the muon detectors. The search for events with this “disappearing track” signature is performed in ...Journal Article -
Search for physics beyond the standard model in events with jets and two same-sign or at least three charged leptons in proton-proton collisions at √s=13TeV
(2020)The European Physical Journal CA data sample of events from proton-proton collisions with at least two jets, and two isolated same-sign or three or more charged leptons, is studied in a search for signatures of new physics phenomena. The data correspond to an integrated luminosity of 137fb−1 at a center-of-mass energy of 13TeV, collected in 2016–2018 by the CMS experiment at the LHC. The search is performed using a total of 168 signal regions defined using several ...Journal Article -
Evidence for Top Quark Production in Nucleus-Nucleus Collisions
(2020)Physical Review LettersUltrarelativistic heavy ion collisions recreate in the laboratory the thermodynamical conditions prevailing in the early universe up to 10−6 sec, thereby allowing the study of the quark-gluon plasma (QGP), a state of quantum chromodynamics (QCD) matter with deconfined partons. The top quark, the heaviest elementary particle known, is accessible in nucleus-nucleus collisions at the CERN LHC, and constitutes a novel probe of the QGP. Here, ...Journal Article -
Measurements of the associated production of a Z boson and b jets in pp collisions at √s = 8 TeV
(2017)The European Physical Journal CMeasurements of the associated production of a Z boson with at least one jet originating from a b quark in proton–proton collisions at √s=8TeV are presented. Differential cross sections are measured with data collected by the CMS experiment corresponding to an integrated luminosity of 19.8fb−1. Z bosons are reconstructed through their decays to electrons and muons. Cross sections are measured as a function of observables characterizing ...Journal Article -
Search for a narrow, spin-2 resonance decaying to a pair of Z bosons in the qq¯ℓ+ℓ− final state
(2013)Physics Letters BResults are presented from a search for a narrow, spin-2 resonance decaying into a pair of Z bosons, with one Z-boson decaying into leptons (e+e− or μ+μ−) and the other into jets. An example of such a resonance is the Kaluza–Klein graviton, GKK, predicted in Randall–Sundrum models. The analysis is based on a 4.9 fb−1 sample of proton–proton collisions at a center-of-mass energy of 7 TeV, collected with the CMS detector at the LHC. Kinematic ...Journal Article -
Measurement of the ratio B(t→Wb)/B(t→Wq) in pp collisions at √s = 8 TeV
(2014)Physics Letters BThe ratio of the top-quark branching fractions R = B(t --> Wb)/B(t --> Wq), where the denominator includes the sum over all down-type quarks (q = b, s, d), is measured in the t (t) over bar dilepton final state with proton-proton collision data at root s = 8 TeV from an integrated luminosity of 19.7 fb(-1), collected with the CMS detector. In order to quantify the purity of the signal sample, the cross section is measured by fitting the ...Journal Article -
Search for single production of a vector-like T quark decaying to a Z boson and a top quark in proton-proton collisions at s = 13 TeV
(2018)Physics letters BA search is presented for single production of a vector-like quark (T) decaying to a Z boson and a top quark, with the Z boson decaying leptonically and the top quark decaying hadronically. The search uses data collected by the CMS experiment in proton–proton collisions at a center-of-mass energy of 13 TeV in 2016, corresponding to an integrated luminosity of 35.9 fb-1. The presence of forward jets is a particular characteristic of single ...Journal Article -
Production of Λc+ baryons in proton-proton and lead-lead collisions at sNN=5.02TeV
(2020)Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy PhysicsThe transverse momentum (pT) spectra of inclusively produced Λc + baryons are measured via the exclusive decay channel Λc +→pK−π+ using the CMS detector at the LHC. Spectra are measured as a function of transverse momentum in proton-proton (pp) and lead-lead (PbPb) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The measurement is performed within the Λc + rapidity interval |y|<1 in the pT range of 5–20GeV/c in pp and ...Journal Article