Multijet events at large transverse momentum () are measured at using data recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of . The multiplicity of jets with that are produced in association with a high- dijet system is measured in various ranges of the of the jet with the highest transverse momentum and as a function of the azimuthal angle difference between the two highest jets in the dijet system. The differential production cross sections are measured as a function of the transverse momenta of the four highest jets.
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August 2023
The production of Z bosons associated with jets is measured in collisions at with data recorded with the CMS experiment at the LHC corresponding to an integrated luminosity of 36.3. The multiplicity of jets with transverse momentum is measured for different regions of the Z boson's , from lower than 10 to higher than 100.
View Article and Find Full Text PDFThe double differential cross sections of the Drell-Yan lepton pair (, dielectron or dimuon) production are measured as functions of the invariant mass , transverse momentum , and . The observable, derived from angular measurements of the leptons and highly correlated with , is used to probe the low- region in a complementary way. Dilepton masses up to 1 are investigated.
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July 2023
New sets of parameter tunes for two of the colour reconnection models, quantum chromodynamics-inspired and gluon-move, implemented in the pythia 8 event generator, are obtained based on the default CMS pythia 8 underlying-event tune, CP5. Measurements sensitive to the underlying event performed by the CMS experiment at centre-of-mass energies and 13, and by the CDF experiment at 1.96 are used to constrain the parameters of colour reconnection models and multiple-parton interactions simultaneously.
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July 2023
A search is reported for pairs of light Higgs bosons () produced in supersymmetric cascade decays in final states with small missing transverse momentum. A data set of LHC collisions collected with the CMS detector at and corresponding to an integrated luminosity of 138 is used. The search targets events where both bosons decay into pairs that are reconstructed as large-radius jets using substructure techniques.
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December 2022
Measurements of the associated production of a W boson and a charm ( ) quark in proton-proton collisions at a centre-of-mass energy of 8 are reported. The analysis uses a data sample corresponding to a total integrated luminosity of 19.7 collected by the CMS detector at the LHC.
View Article and Find Full Text PDFUsing a data sample of proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of , the and decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to and , where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of and mesons, .
View Article and Find Full Text PDFA search for low-mass dilepton resonances in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via a pair of beyond the standard model particles, or one such particle and a boson. The search uses proton-proton collision data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 137 , at a center-of-mass energy .
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March 2022
A search for dark matter in the form of strongly interacting massive particles (SIMPs) using the CMS detector at the LHC is presented. The SIMPs would be produced in pairs that manifest themselves as pairs of jets without tracks. The energy fraction of jets carried by charged particles is used as a key discriminator to suppress efficiently the large multijet background, and the remaining background is estimated directly from data.
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February 2022
A search for new long-lived particles decaying to leptons using proton-proton collision data produced by the CERN LHC at is presented. Events are selected with two leptons (an electron and a muon, two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10 and are not required to form a common vertex.
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November 2021
A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 at the CERN LHC, corresponding to an integrated luminosity of 137 collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented.
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September 2021
The measurement of the luminosity recorded by the CMS detector installed at LHC interaction point 5, using proton-proton collisions at in 2015 and 2016, is reported. The absolute luminosity scale is measured for individual bunch crossings using beam-separation scans (the van der Meer method), with a relative precision of 1.3 and 1.
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August 2021
A search is presented for a heavy vector resonance decaying into a boson and the standard model Higgs boson, where the boson is identified through its leptonic decays to electrons, muons, or neutrinos, and the Higgs boson is identified through its hadronic decays. The search is performed in a Lorentz-boosted regime and is based on data collected from 2016 to 2018 at the CERN LHC, corresponding to an integrated luminosity of 137 . Upper limits are derived on the production of a narrow heavy resonance , and a mass below 3.
View Article and Find Full Text PDFA search for charged Higgs bosons produced in vector boson fusion processes and decaying into vector bosons, using proton-proton collisions at at the LHC, is reported. The data sample corresponds to an integrated luminosity of 137 collected with the CMS detector. Events are selected by requiring two or three electrons or muons, moderate missing transverse momentum, and two jets with a large rapidity separation and a large dijet mass.
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April 2021
This paper presents new sets of parameters ("tunes") for the underlying-event model of the event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in , and are obtained from a fit to minimum-bias data collected by the CMS experiment at , 7, and . The tunes are based on the NNPDF 3.
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September 2021
Collinear (small-angle) and large-angle, as well as soft and hard radiations are investigated in three-jet and + two-jet events collected in proton-proton collisions at the LHC. The normalized production cross sections are measured as a function of the ratio of transverse momenta of two jets and their angular separation. The measurements in the three-jet and + two-jet events are based on data collected at a center-of-mass energy of 8 , corresponding to an integrated luminosity of 19.
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July 2021
Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 , corresponding to an integrated luminosity of 35.9 , are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model.
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June 2021
Production cross sections of the Higgs boson are measured in the ( ) decay channel. A data sample of proton-proton collisions at a center-of-mass energy of 13 , collected by the CMS detector at the LHC and corresponding to an integrated luminosity of 137 is used. The signal strength modifier , defined as the ratio of the Higgs boson production rate in the channel to the standard model (SM) expectation, is measured to be at a fixed value of .
View Article and Find Full Text PDFThe rate for Higgs ( ) bosons production in association with either one ( ) or two ( ) top quarks is measured in final states containing multiple electrons, muons, or tau leptons decaying to hadrons and a neutrino, using proton-proton collisions recorded at a center-of-mass energy of by the CMS experiment. The analyzed data correspond to an integrated luminosity of 137 . The analysis is aimed at events that contain , , or decays and each of the top quark(s) decays either to lepton+jets or all-jet channels.
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March 2021
The production of Z boson pairs in proton-proton ( ) collisions, , where or , is studied at a center-of-mass energy of 13 with the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 137 , collected during 2016-2018. The production cross section, , measured for events with two pairs of opposite-sign, same-flavor leptons produced in the mass region is consistent with standard model predictions.
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January 2021
A search for dark matter particles is performed using events with a Z boson candidate and large missing transverse momentum. The analysis is based on proton-proton collision data at a center-of-mass energy of 13 , collected by the CMS experiment at the LHC in 2016-2018, corresponding to an integrated luminosity of 137 . The search uses the decay channels and .
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January 2021
A search is presented for supersymmetric partners of the top quark (top squarks) in final states with two oppositely charged leptons (electrons or muons), jets identified as originating from quarks, and missing transverse momentum. The search uses data from proton-proton collisions at collected with the CMS detector, corresponding to an integrated luminosity of 137 . Hypothetical signal events are efficiently separated from the dominant top quark pair production background with requirements on the significance of the missing transverse momentum and on transverse mass variables.
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December 2020
Measurements 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 PDFA 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 at a center-of-mass energy of , 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 kinematic variables.
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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.
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