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Article Citation - WoS: 13Evidence for Ww/Wz Vector Boson Scattering in the Decay Channel <i>l</I>νqq Produced in Association With Two Jets in Proton-Proton Collisions at √<i>s</I>=13tev(Elsevier, 2022) Karapınar, Güler; CMS Collaboration; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Vetens, W.Evidence is reported for electroweak (EW) vector boson scattering in the decay channel l nu qq of two weak vector bosons WV(V = Wor Z), produced in association with two parton jets. The search uses a data set of proton-proton collisions at 13TeVcollected with the CMS detector during 2016-2018 with an integrated luminosity of 138fb(-1). Events are selected requiring one lepton (electron or muon), moderate missing transverse momentum, two jets with a large pseudorapidity separation and a large dijet invariant mass, and a signature consistent with the hadronic decay of a W/Zboson. The cross section is computed in a fiducial phase space defined at parton level requiring all parton transverse momenta p(T)> 10 GeVand at least one pair of outgoing partons with invariant mass mqq> 100 GeV. The measured and expected EW WVproduction cross sections are 1.90(-0.46)(+0.5)3 pb and 2.23(-0.11)(+0.08)(scale) +/- 0.05(PDF) pb, respectively, where PDF is the parton distribution function. The observed EW signal strength is mu EW= 0.85 +/- 0.12 (stat)(-0.17)(+0.19)(syst), corresponding to a signal significance of 4.4 standard deviations with 5.1 expected, and it is measured keeping the quantum chromodynamics (QCD) associated diboson production fixed to the standard model prediction. This is the first evidence of vector boson scattering in the l nu qq decay channel at LHC. The simultaneous measurement of the EW and QCD associated diboson production agrees with the standard model prediction. (C) 2022 The Author(s). Published by Elsevier B.V.Article Citation - WoS: 20Citation - Scopus: 31Search for Flavor-Changing Neutral Current Interactions of the Top Quark and Higgs Boson in Final States With Two Photons in Proton-Proton Collisions at S =13 Tev(American Physical Society, 2022) Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Bunichev, V.Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks (t) and Higgs bosons (H). The analysis is based on data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb-1. No significant excess above the background prediction is observed. Upper limits on the branching fractions (B) of the top quark decaying to a Higgs boson and an up (u) or charm (c) quark are derived through a binned fit to the diphoton invariant mass spectrum. The observed (expected) 95% confidence level upper limits are found to be 0.019% (0.031%) for B(t→Hu) and 0.073% (0.051%) for B(t→Hc). These are the strictest upper limits yet determined. © 2022 CERN.Article Citation - WoS: 22Citation - Scopus: 25Observation of the Bc+ Meson in Pb-Pb and Pp Collisions at Snn =5.02 Tev and Measurement of Its Nuclear Modification Factor(American Physical Society, 2022) Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Boos, E.The Bc+ meson is observed for the first time in heavy ion collisions. Data from the CMS detector are used to study the production of the Bc+ meson in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a center-of-mass energy per nucleon pair of sNN=5.02 TeV, via the Bc+→(J/ψ→μ+μ-)μ+νμ decay. The Bc+ nuclear modification factor, derived from the Pb-Pb-to-pp ratio of production cross sections, is measured in two bins of the trimuon transverse momentum and of the Pb-Pb collision centrality. The Bc+ meson is shown to be less suppressed than quarkonia and most of the open heavy-flavor mesons, suggesting that effects of the hot and dense nuclear matter created in heavy ion collisions contribute to its production. This measurement sets forth a promising new probe of the interplay of suppression and enhancement mechanisms in the production of heavy-flavor mesons in the quark-gluon plasma. © 2022 CERN.Article Citation - WoS: 51Citation - Scopus: 60Identification of Hadronic Tau Lepton Decays Using a Deep Neural Network(Institute of Physics, 2022) Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Andreev, V.A new algorithm is presented to discriminate reconstructed hadronic decays of tau leptons (τ h) that originate from genuine tau leptons in the CMS detector against τ h candidates that originate from quark or gluon jets, electrons, or muons. The algorithm inputs information from all reconstructed particles in the vicinity of a τ h candidate and employs a deep neural network with convolutional layers to efficiently process the inputs. This algorithm leads to a significantly improved performance compared with the previously used one. For example, the efficiency for a genuine τ h to pass the discriminator against jets increases by 10-30% for a given efficiency for quark and gluon jets. Furthermore, a more efficient τ h reconstruction is introduced that incorporates additional hadronic decay modes. The superior performance of the new algorithm to discriminate against jets, electrons, and muons and the improved τ h reconstruction method are validated with LHC proton-proton collision data at s = 13 TeV. © 2022 CERN.Article Citation - WoS: 13Citation - Scopus: 16Observation of Bs 0 Mesons and Measurement of the Bs 0/B+ Yield Ratio in Pbpb Collisions at [formula Presented] Tev(Elsevier B.V., 2022) Tumasyan, A.; Adam, W.; Ambrogi, F.; Bergauer, T.; Dragicevic, M.; Erö, J.; Kirakosyan, M.The Bs 0 and B+ production yields are measured in PbPb collisions at a center-of-mass energy per nucleon pair of 5.02 TeV. The data sample, collected with the CMS detector at the LHC, corresponds to an integrated luminosity of 1.7 nb−1. The mesons are reconstructed in the exclusive decay channels B→s0J/ψ(μ+μ−)ϕ(K+K−) and B→+J/ψ(μ+μ−)K+, in the transverse momentum range 7–50 GeV/c and absolute rapidity 0–2.4. The Bs 0 meson is observed with a statistical significance in excess of five standard deviations for the first time in nucleus-nucleus collisions. The measurements are performed as functions of the transverse momentum of the B mesons and of the PbPb collision centrality. The ratio of production yields of Bs 0 and B+ is measured and compared to theoretical models that include quark recombination effects. © 2022 The Author(s)Article Citation - WoS: 5Citation - Scopus: 7Search for Wγ Resonances in Proton-Proton Collisions at S=13 TeV Using Hadronic Decays of Lorentz-Boosted W Bosons(Elsevier B.V., 2022) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Alves, G.A.A search for Wγ resonances in the mass range between 0.7 and 6.0 TeV is presented. The W boson is reconstructed via its hadronic decays, with the final-state products forming a single large-radius jet, owing to a high Lorentz boost of the W boson. The search is based on proton-proton collision data at s=13 TeV, corresponding to an integrated luminosity of 137 fb−1, collected with the CMS detector at the LHC in 2016–2018. The Wγ mass spectrum is parameterized with a smoothly falling background function and examined for the presence of resonance-like signals. No significant excess above the predicted background is observed. Model-specific upper limits at 95% confidence level on the product of the cross section and branching fraction to the Wγ channel are set. Limits for narrow resonances and for resonances with an intrinsic width equal to 5% of their mass, for spin-0 and spin-1 hypotheses, range between 0.17 fb at 6.0 TeV and 55 fb at 0.7 TeV. These are the most restrictive limits to date on the existence of such resonances over a large range of probed masses. In specific heavy scalar (vector) triplet benchmark models, narrow resonances with masses between 0.75 (1.15) and 1.40 (1.36) TeV are excluded for a range of model parameters. Model-independent limits on the product of the cross section, signal acceptance, and branching fraction to the Wγ channel are set for minimum Wγ mass thresholds between 1.5 and 8.0 TeV. © 2022 The Author(s)Article Citation - WoS: 86Citation - Scopus: 8Measurement of Single-Diffractive Dijet Production in Proton–proton Collisions at √s=8te With the Cms and Totem Experiments(Springer Nature, 2020) Sirunyan, A.M.; Karapınar, Güler; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Josa, M.I.Measurements are presented of the single-diffractive dijet cross section and the diffractive cross section as a function of the proton fractional momentum loss ξ and the four-momentum transfer squared t. Both processes pp→pX and pp→Xp, i.e. with the proton scattering to either side of the interaction point, are measured, where X includes at least two jets; the results of the two processes are averaged. The analyses are based on data collected simultaneously with the CMS and TOTEM detectors at the LHC in proton–proton collisions at s=8Te during a dedicated run with β∗=90m at low instantaneous luminosity and correspond to an integrated luminosity of 37.5nb-1. The single-diffractive dijet cross section σjjpX, in the kinematic region ξ< 0.1 , 0.03<|t|<1Ge2, with at least two jets with transverse momentum pT>40Ge, and pseudorapidity | η| < 4.4 , is 21.7±0.9(stat)-3.3+3.0(syst)±0.9(lumi)nb. The ratio of the single-diffractive to inclusive dijet yields, normalised per unit of ξ, is presented as a function of x, the longitudinal momentum fraction of the proton carried by the struck parton. The ratio in the kinematic region defined above, for x values in the range - 2.9 ≤ log 10x≤ - 1.6 , is R=(σjjpX/Δξ)/σjj=0.025±0.001(stat)±0.003(syst), where σjjpX and σjj are the single-diffractive and inclusive dijet cross sections, respectively. The results are compared with predictions from models of diffractive and nondiffractive interactions. Monte Carlo predictions based on the HERA diffractive parton distribution functions agree well with the data when corrected for the effect of soft rescattering between the spectator partons. © 2020, CERN for the benefit of the CMS and TOTEM collaborations.Article Citation - WoS: 239Citation - Scopus: 291Performance of the Cms Level-1 Trigger in Proton-Proton Collisions at √s = 13 Tev(Institute of Physics, 2020) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Bunichev, V.At the start of Run 2 in 2015, the LHC delivered proton-proton collisions at a center-of-mass energy of 13 TeV. During Run 2 (years 2015-2018) the LHC eventually reached a luminosity of 2.1 × 1034 cm-2s-1, almost three times that reached during Run 1 (2009-2013) and a factor of two larger than the LHC design value, leading to events with up to a mean of about 50 simultaneous inelastic proton-proton collisions per bunch crossing (pileup). The CMS Level-1 trigger was upgraded prior to 2016 to improve the selection of physics events in the challenging conditions posed by the second run of the LHC. This paper describes the performance of the CMS Level-1 trigger upgrade during the data taking period of 2016-2018. The upgraded trigger implements pattern recognition and boosted decision tree regression techniques for muon reconstruction, includes pileup subtraction for jets and energy sums, and incorporates pileup-dependent isolation requirements for electrons and tau leptons. In addition, the new trigger calculates high-level quantities such as the invariant mass of pairs of reconstructed particles. The upgrade reduces the trigger rate from background processes and improves the trigger efficiency for a wide variety of physics signals. © 2020 CERN for the benefit of the CMS collaboration.Article Citation - WoS: 15Citation - Scopus: 19Study of J/Ψ Meson Production Inside Jets in pp Collisions at S=8 TeV(Elsevier B.V., 2020) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Bergauer, T.; Brandstetter, J.; Hensel, C.A study of the production of prompt J/ψ mesons contained in jets in proton-proton collisions at s=8TeV is presented. The analysis is based on data corresponding to an integrated luminosity of 19.1 fb−1 collected with the CMS detector at the LHC. For events with at least one observed jet, the angular separation between the J/ψ meson and the jet is used to test whether the J/ψ meson is part of the jet. The analysis shows that most prompt J/ψ mesons having energy above 15 GeV and rapidity |y|<1 are contained in jets with pseudorapidity |η<inf>jet</inf>|<1. The differential distributions of the probability to have a J/ψ meson contained in a jet as a function of jet energy for a fixed J/ψ energy fraction are compared to a theoretical model using the fragmenting jet function approach. The data agree best with fragmenting jet function calculations that use a long-distance matrix element parameter set in which prompt J/ψ mesons are predicted to be unpolarized. This technique demonstrates a new way to test predictions for prompt J/ψ production using nonrelativistic quantum chromodynamics. © 2020 Elsevier B.V.Article Citation - WoS: 65Citation - Scopus: 87Measurement of the Higgs Boson Production Rate in Association With Top Quarks in Final States With Electrons, Muons, and Hadronically Decaying Tau Leptons at √s=13tev(Springer, 2021) Karapınar, Güler; CMS Collaboration; Karapınar, Güler; Adam, W.; Bergauer, T.; Dragicevic, M.; Eroe, J.; Vetens, W.The rate for Higgs (H) bosons production in association with either one (tH) or two (t (t) over barH) 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 13 TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 137 fb(-1). The analysis is aimed at events that contain H -> WW, H -> tt, or H -> ZZ decays and each of the top quark(s) decays either to lepton+jets or all-jet channels. Sensitivity to signal is maximized by including ten signatures in the analysis, depending on the lepton multiplicity. The separation among tH, t (t) over barH, and the backgrounds is enhanced through machine-learning techniques and matrix-element methods. The measured production rates for the ttH and tH signals correspond to 0.92 +/- 0.19 (stat)(-0.13)(+0.17) (syst) and 5.7 +/- 2.7 (stat)+/- 3.0 (syst) of their respective standard model (SM) expectations. The corresponding observed (expected) significance amounts to 4.7 (5.2) standard deviations for t (t) over barH, and to 1.4 (0.3) for tH production. Assuming that the Higgs boson coupling to the tau lepton is equal in strength to its expectation in the SM, the coupling y(t) of the Higgs boson to the top quark divided by its SM expectation, kappa(t) = y(t)/y(t)(SM), is constrained to be within -0.9 <kappa(t) < -0.7 or 0.7 <kappa(t) < 1.1, at 95% confidence level. This result is the most sensitive measurement of the ttH production rate to date.