Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
24 results
Search Results
Article Citation - WoS: 20Citation - Scopus: 28Measurement of Ckm Matrix Elements in Single Top Quark T-Channel Production in Proton-Proton Collisions at S=13 Tev(Elsevier B.V., 2020) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Bergauer, T.; Dragicevic, M.; Sobol, A.The first direct, model-independent measurement is presented of the modulus of the Cabibbo–Kobayashi–Maskawa (CKM) matrix elements |η|Vtb, |η|Vtd, and |η|Vts, in final states enriched in single top quark t-channel events. The analysis uses proton-proton collision data from the LHC, collected during 2016 by the CMS experiment, at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1. Processes directly sensitive to these matrix elements are considered at both the production and decay vertices of the top quark. In the standard model hypothesis of CKM unitarity, a lower limit of |η|Vtb>0.970 is measured at the 95% confidence level. Several theories beyond the standard model are considered, and by releasing all constraints among the involved parameters, the values |η|Vtb=0.988±0.024, and |η|Vtd 2+|η|Vts 2=0.06±0.06, where the uncertainties include both statistical and systematic components, are measured. © 2020 The AuthorArticle Citation - WoS: 37Citation - Scopus: 43Search for Heavy Resonances That Decay Into a Vector Boson and a Higgs Boson in Hadronic Final States at √s=13tev(Springer Nature, 2017) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Ruiz-Jimeno, A.A search for heavy resonances with masses above 1TeV, decaying to final states containing a vector boson and a Higgs boson, is presented. The search considers hadronic decays of the vector boson, and Higgs boson decays to b quarks. The decay products are highly boosted, and each collimated pair of quarks is reconstructed as a single, massive jet. The analysis is performed using a data sample collected in 2016 by the CMS experiment at the LHC in proton-proton collisions at a center-of-mass energy of 13TeV, corresponding to an integrated luminosity of 35.9fb-1. The data are consistent with the background expectation and are used to place limits on the parameters of a theoretical model with a heavy vector triplet. In the benchmark scenario with mass-degenerate W′ and Z ′ bosons decaying predominantly to pairs of standard model bosons, for the first time heavy resonances for masses as high as 3.3TeV are excluded at 95% confidence level, setting the most stringent constraints to date on such states decaying into a vector boson and a Higgs boson. © 2017, CERN for the benefit of the CMS collaboration.Article Citation - WoS: 13Citation - Scopus: 19Measurement of Associated Z + Charm Production in Proton–proton Collisions at √s=8tev(Springer Nature, 2018) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; De Gruttola, M.A study of the associated production of a Z boson and a charm quark jet (Z + c), and a comparison to production with a b quark jet (Z + b), in p p collisions at a centre-of-mass energy of 8TeV are presented. The analysis uses a data sample corresponding to an integrated luminosity of 19.7fb-1, collected with the CMS detector at the CERN LHC. The Z boson candidates are identified through their decays into pairs of electrons or muons. Jets originating from heavy flavour quarks are identified using semileptonic decays of c or b flavoured hadrons and hadronic decays of charm hadrons. The measurements are performed in the kinematic region with two leptons with pTℓ>20GeV, | ηℓ| < 2.1 , 71<m111GeV, and heavy flavour jets with pTjet>25GeV and | ηjet| < 2.5. The Z + c production cross section is measured to be σ(pp→Z+c+X)B(Z→ℓ+ℓ-)=8.8±0.5(stat)±0.6(syst)pb. The ratio of the Z + c and Z + b production cross sections is measured to be σ(pp→Z+c+X)/σ(pp→Z+b+X)=2.0±0.2(stat)±0.2(syst). The Z + c production cross section and the cross section ratio are also measured as a function of the transverse momentum of the Z boson and of the heavy flavour jet. The measurements are compared with theoretical predictions. © 2018, CERN for the benefit of the CMS collaboration.Article Citation - WoS: 31Citation - Scopus: 35Electroweak Production of Two Jets in Association With a Z Boson in Proton–proton Collisions at √s= 13 Tev(Springer Nature, 2018) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Albajar, C.A measurement of the electroweak (EW) production of two jets in association with a Z boson in proton-proton collisions at s=13TeV is presented, based on data recorded in 2016 by the CMS experiment at the LHC corresponding to an integrated luminosity of 35.9fb--1. The measurement is performed in the ℓℓjj final state with ℓ including electrons and muons, and the jets j corresponding to the quarks produced in the hard interaction. The measured cross section in a kinematic region defined by invariant masses mℓℓ>50GeV, mjj>120GeV, and transverse momenta pTj>25GeV is σEW(ℓℓjj)=534±20(stat)±57(syst) fb, in agreement with leading-order standard model predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. No evidence is found and limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are -2.6<cWWW/Λ2<2.6TeV-2 and -8.4<cW/Λ2<10.1TeV-2. The additional jet activity of events in a signal-enriched region is also studied, and the measurements are in agreement with predictions. © 2018, CERN for the benefit of the CMS collaboration.Article Citation - WoS: 16Citation - Scopus: 18Studies of Bs2∗(5840)0 and B S 1(5830) 0 Mesons Including the Observation of the Bs2∗(5840)0→b0ks0 Decay in Proton-Proton Collisions at √s=8tev(Springer Nature, 2018) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Bachiller, I.Measurements of Bs2∗(5840)0 and B s 1(5830) 0 mesons are performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of [InlineEquation not available: see fulltext.], collected with the CMS detector at the LHC at a centre-of-mass energy of 8TeV. The analysis studies P-wave Bs0 meson decays into B (∗) +K - and B(∗)0KS0, where the B + and B 0 mesons are identified using the decays B +→ J / ψK + and B 0→ J / ψK ∗(892) 0. The masses of the P-wave Bs0 meson states are measured and the natural width of the Bs2∗(5840)0 state is determined. The first measurement of the mass difference between the charged and neutral B ∗ mesons is also presented. The Bs2∗(5840)0 decay to B0KS0 is observed, together with a measurement of its branching fraction relative to the Bs2∗(5840)0→B+K- decay. © 2018, CERN for the benefit of the CMS collaboration.Article Citation - WoS: 39Citation - Scopus: 49Measurement of Differential Cross Sections for Z Boson Production in Association With Jets in Proton-Proton Collisions at √s=13tev(Springer Nature, 2018) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Fouz, M.C.The production of a Z boson, decaying to two charged leptons, in association with jets in proton-proton collisions at a centre-of-mass energy of 13TeV is measured. Data recorded with the CMS detector at the LHC are used that correspond to an integrated luminosity of 2.19fb-1. The cross section is measured as a function of the jet multiplicity and its dependence on the transverse momentum of the Z boson, the jet kinematic variables (transverse momentum and rapidity), the scalar sum of the jet momenta, which quantifies the hadronic activity, and the balance in transverse momentum between the reconstructed jet recoil and the Z boson. The measurements are compared with predictions from four different calculations. The first two merge matrix elements with different parton multiplicities in the final state and parton showering, one of which includes one-loop corrections. The third is a fixed-order calculation with next-to-next-to-leading order accuracy for the process with a Z boson and one parton in the final state. The fourth combines the fully differential next-to-next-to-leading order calculation of the process with no parton in the final state with next-to-next-to-leading logarithm resummation and parton showering. © 2018, CERN for the benefit of the CMS collaboration.Article Citation - WoS: 27Citation - Scopus: 32Measurement of Differential Cross Sections for Z Boson Pair Production in Association With Jets at S=8 and 13 Tev(Elsevier B.V., 2019) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Okhotnikov, V.This Letter reports measurements of differential cross sections for the production of two Z bosons in association with jets in proton–proton collisions at s=8 and 13 TeV. The analysis is based on data samples collected at the LHC with the CMS detector, corresponding to integrated luminosities of 19.7 and 35.9fb−1 at 8 and 13 TeV, respectively. The measurements are performed in the leptonic decay modes ZZ→ℓ+ℓ−ℓ′+ℓ′−, where ℓ,ℓ′=e,μ. The differential cross sections as a function of the jet multiplicity, the transverse momentum pT, and pseudorapidity of the pT -leading and subleading jets are presented. In addition, the differential cross sections as a function of variables sensitive to the vector boson scattering, such as the invariant mass of the two pT -leading jets and their pseudorapidity separation, are reported. The results are compared to theoretical predictions and found in good agreement within the theoretical and experimental uncertainties. © 2018 The Author(s)Article Citation - WoS: 23Citation - Scopus: 36Measurement of Prompt Ψ(2s) Production Cross Sections in Proton–lead and Proton–proton Collisions at Snn=5.02tev(Elsevier B.V., 2019) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Uzunian, A.Measurements of prompt ψ(2S) meson production cross sections in proton–lead (pPb) and proton–proton (pp) collisions at a nucleon–nucleon center-of-mass energy of sNN=5.02TeV are reported. The results are based on pPb and pp data collected by the CMS experiment at the LHC, corresponding to integrated luminosities of 34.6 nb−1 and 28.0 pb−1, respectively. The nuclear modification factor RpPb is measured for prompt ψ(2S) in the transverse momentum range 4<pT<30GeV/c and the center-of-mass rapidity range −2.4<yCM<1.93. The results on ψ(2S) RpPb are compared to the corresponding modification factor for prompt J/ψ mesons. The results point to different nuclear effects at play in the production of the excited charmonium state compared to the ground state, in the region of backward rapidity and for pT<10GeV/c. © 2019 The AuthorArticle Citation - WoS: 114Citation - Scopus: 132Measurement of Nuclear Modification Factors of ϒ(1s), ϒ(2s), and ϒ(3s) Mesons in Pbpb Collisions at Snn=5.02 Tev(Elsevier B.V., 2019) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Kalinin, A.The cross sections for ϒ(1S), ϒ(2S), and ϒ(3S) production in lead–lead (PbPb) and proton–proton (pp) collisions at sNN=5.02 TeV have been measured using the CMS detector at the LHC. The nuclear modification factors, RAA, derived from the PbPb-to-pp ratio of yields for each state, are studied as functions of meson rapidity and transverse momentum, as well as PbPb collision centrality. The yields of all three states are found to be significantly suppressed, and compatible with a sequential ordering of the suppression, RAA(ϒ(1S))>RAA(ϒ(2S))>RAA(ϒ(3S)). The suppression of ϒ(1S) is larger than that seen at sNN=2.76TeV, although the two are compatible within uncertainties. The upper limit on the RAA of ϒ(3S) integrated over pT, rapidity and centrality is 0.096 at 95% confidence level, which is the strongest suppression observed for a quarkonium state in heavy ion collisions to date. © 2019 The Author(s)Article Citation - WoS: 47Citation - Scopus: 61Measurement of Exclusive Υ Photoproduction From Protons in P Pb Collisions at √snn=5.02tev(Springer Nature, 2019) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Soares, M.S.The exclusive photoproduction of Υ (nS) meson states from protons, γp→Υ(nS)p (with n = 1 , 2 , 3), is studied in ultraperipheral p Pb collisions at a centre-of-mass energy per nucleon pair of sNN=5.02TeV. The measurement is performed using the Υ (nS) → μ+μ- decay mode, with data collected by the CMS experiment corresponding to an integrated luminosity of 32.6nb-1. Differential cross sections as functions of the Υ (nS) transverse momentum squared pT2, and rapidity y, are presented. The Υ (1 S) photoproduction cross section is extracted in the rapidity range | y| < 2.2 , which corresponds to photon–proton centre-of-mass energies in the range 91<Wγp<826GeV. The data are compared to theoretical predictions based on perturbative quantum chromodynamics and to previous measurements. © 2019, CERN for the benefit of the CMS collaboration.
- «
- 1 (current)
- 2
- 3
- »