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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 -
Performance of the reconstruction and identification of high-momentum muons in proton-proton collisions at √s = 13 TeV
(2020)Journal of InstrumentationThe CMS detector at the LHC has recorded events from proton-proton collisions, with muon momenta reaching up to 1.8 TeV in the collected dimuon samples. These high-momentum muons allow direct access to new regimes in physics beyond the standard model. Because the physics and reconstruction of these muons are different from those of their lower-momentum counterparts, this paper presents for the first time dedicated studies of efficiencies, ...Journal Article -
Performance of missing transverse momentum reconstruction in proton-proton collisions at root s=13 TeV using the CMS detector
(2019)Journal of InstrumentationThe performance of missing transverse momentum (vec pTmiss) reconstruction algorithms for the CMS experiment is presented, using proton-proton collisions at a center-of-mass energy of 13 TeV, collected at the CERN LHC in 2016. The data sample corresponds to an integrated luminosity of 35.9 fb-1. The results include measurements of the scale and resolution of vec pTmiss, and detailed studies of events identified with anomalous vec pTmiss. ...Journal Article -
Performance of reconstruction and identification of 𝜏 leptons decaying to hadrons and 𝜈𝜏 in pp collisions at √s=13 TeV
(2018)Journal of InstrumentationThe algorithm developed by the CMS Collaboration to reconstruct and identify τ leptons produced in proton-proton collisions at √s=7 and 8 TeV, via their decays to hadrons and a neutrino, has been significantly improved. The changes include a revised reconstruction of π0 candidates, and improvements in multivariate discriminants to separate τ leptons from jets and electrons. The algorithm is extended to reconstruct τ leptons in highly ...Journal Article -
Performance of the CMS muon detector and muon reconstruction with proton-proton collisions at √s=13 TeV
(2018)Journal of InstrumentationThe CMS muon detector system, muon reconstruction software, and high-level trigger underwent significant changes in 2013–2014 in preparation for running at higher LHC collision energy and instantaneous luminosity. The performance of the modified system is studied using proton-proton collision data at center-of-mass energy √s=13 TeV, collected at the LHC in 2015 and 2016. The measured performance parameters, including spatial resolution, ...Journal Article -
Precision measurement of the structure of the CMS inner tracking system using nuclear interactions
(2018)Journal of InstrumentationThe structure of the CMS inner tracking system has been studied using nuclear interactions of hadrons striking its material. Data from proton-proton collisions at a center-of-mass energy of 13 TeV recorded in 2015 at the LHC are used to reconstruct millions of secondary vertices from these nuclear interactions. Precise positions of the beam pipe and the inner tracking system elements, such as the pixel detector support tube, and barrel ...Journal Article -
Measurement of inclusive jet cross-sections in pp and PbPb collisions at √sNN=2.76 TeV
(2017)Physical Review CInclusive jet spectra from pp and PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76TeV, collected with the CMS detector at the CERN Large Hadron Collider, are presented. Jets are reconstructed with three different distance parameters (R=0.2, 0.3, and 0.4) for transverse momentum (pT) greater than 70GeV/c and pseudorapidity |η|<2. Next-to-leading-order quantum chromodynamic calculations with nonperturbative corrections are ...Journal Article -
Pseudorapidity dependence of long-range two-particle correlations in pPb collisions at √sNN=5.02 TeV
(2017)Physical Review CTwo-particle correlations in pPb collisions at a nucleon-nucleon center-of-mass energy of 5.02TeV are studied as a function of the pseudorapidity separation (Δη) of the particle pair at small relative azimuthal angle (|Δϕ|<π/3). The correlations are decomposed into a jet component that dominates the short-range correlations (|Δη|<1), and a component that persists at large Δη and may originate from collective behavior of the produced system. ...Journal Article -
Mechanical stability of the CMS strip tracker measured with a laser alignment system
(2017)Journal of InstrumentationThe CMS tracker consists of 206 m2 of silicon strip sensors assembled on carbon fibre composite structures and is designed for operation in the temperature range from −25 to +25°C. The mechanical stability of tracker components during physics operation was monitored with a few μm resolution using a dedicated laser alignment system as well as particle tracks from cosmic rays and hadron-hadron collisions. During the LHC operational period ...Journal Article -
Observation of charge-dependent azimuthal correlations in pPb collisions and its implication for the search for the chiral magnetic effect
(2017)Physical Review LettersCharge-dependent azimuthal particle correlations with respect to the second-order event plane in p−Pb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range |η|<2.4, and a third particle measured in the hadron ...Journal Article