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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 -
Experimental study of different silicon sensor options for the upgrade of the CMS Outer Tracker
(2020)Journal of InstrumentationDuring the high-luminosity phase of the LHC (HL-LHC), planned to start in 2027, the accelerator is expected to deliver an instantaneous peak luminosity of up to 7.5×1034 cm-2 s-1. A total integrated luminosity of 0300 or even 0400 fb-1 is foreseen to be delivered to the general purpose detectors ATLAS and CMS over a decade, thereby increasing the discovery potential of the LHC experiments significantly. The CMS detector will undergo a ...Journal Article -
Beam test performance of prototype silicon detectors for the Outer Tracker for the Phase-2 Upgrade of CMS
(2020)Journal of InstrumentationA new CMS tracker detector will be installed for operation at the High Luminosity LHC (HL-LHC). This detector comprises modules with two closely spaced parallel sensor plates and front-end ASICs capable of transmitting tracking information to the CMS Level-1 (L1) trigger at the 40 MHz beam crossing rate. The inclusion of tracking information in the L1 trigger decision will be essential for selecting events of interest efficiently at the ...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 -
An embedding technique to determine ττ backgrounds in proton-proton collision data
(2019)Journal of InstrumentationAn embedding technique is presented to estimate standard model ττ backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed μμ events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the ...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 -
Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV
(2018)Journal of InstrumentationMany measurements and searches for physics beyond the standard model at the LHC rely on the efficient identification of heavy-flavour jets, i.e. jets originating from bottom or charm quarks. In this paper, the discriminating variables and the algorithms used for heavy-flavour jet identification during the first years of operation of the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, are presented. ...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