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Öğe Angular analysis of the decay B+? K*(892)+?+?- in proton-proton collisions at ?s=8 TeV(Springer, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Angular distributions of the decay B+-> K*(892)(+)mu(+)mu(-) are studied using events collected with the CMS detector in root s = 8 TeV proton-proton collisions at the LHC, corresponding to an integrated luminosity of 20.0 fb(-1). The forward-backward asymmetry of the muons and the longitudinal polarization of the K*(892)(+) meson are determined as a function of the square of the dimuon invariant mass. These are the first results from this exclusive decay mode and are in agreement with a standard model prediction.Öğe Correlations of azimuthal anisotropy Fourier harmonics with subevent cumulants in pPb collisions at ?sNN=8.16 TeV(Amer Physical Soc, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (v(n)) in 8.16 TeV pPb data, collected by the CMS experiment at the CERN Large Hadron Collider, are extracted using a subevent four-particle cumulant technique applied to very low multiplicity events. Each combination of four charged particles is selected from either two, three, or four distinct subevent regions of a pseudorapidity range from -2.4 to 2.4 of the CMS tracker, and with transverse momentum between 0.3 and 3.0 GeV. Using the subevent cumulant technique, correlations between v(n) of different orders are measured as functions of particle multiplicity and compared to the standard cumulant method without subevents over a wide event multiplicity range. At high multiplicities, the v(2) and v(3) coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v(2) and v(4) correlation strength is found to depend on the number of subevents used in the calculation. As the event multiplicity decreases, the results from different subevent methods diverge because of different contributions of noncollective or few-particle correlations. Correlations extracted with the four-subevent method exhibit a tendency to diminish monotonically toward the lowest multiplicity region (about 20 charged tracks) investigated. These findings extend previous studies to a significantly lower event multiplicity range and establish the evidence for the onset of long-range collective multiparticle correlations in small system collisions.Öğe Evidence for electroweak production of four charged leptons and two jets in proton-proton collisions at ?s=13 TeV(Elsevier, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Evidence is presented for the electroweak (EW) production of two jets (jj) in association with two Z-bosons and constraints on anomalous quartic gauge couplings are set. The analysis is based on a data sample of proton-proton collisions at root s = 13 TeVcollected with the CMS detector in 2016-2018, and corresponding to an integrated luminosity of 137 fb(-1). The search is performed in the fully leptonic final state ZZ -> lll'l', where l, l' = e, mu. The EW production of two jets in association with two Zbosons is measured with an observed (expected) significance of 4.0 (3.5) standard deviations. The cross sections for the EW production are measured in three fiducial volumes and the result is sigma(EW)(pp -> ZZjj -> lll'l'jj) = 0.33(-0.10)(+0.11)(stat)(-0.03)(+0.04)(syst) fbin the most inclusive volume, in agreement with the standard model prediction of 0.275 +/- 0.021fb. Measurements of total cross sections for jj production in association with two Zbosons are also reported. Limits on anomalous quartic gauge couplings are derived in terms of the effective field theory operators T0, T1, T2, T8, and T9. (C) 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license.Öğe Evidence for Higgs boson decay to a pair of muons(Springer, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Evidence for Higgs boson decay to a pair of muons is presented. This result combines searches in four exclusive categories targeting the production of the Higgs boson via gluon fusion, via vector boson fusion, in association with a vector boson, and in association with a top quark-antiquark pair. The analysis is performed using proton-proton collision data at root s = 13 TeV, corresponding to an integrated luminosity of 137 fb(-1), recorded by the CMS experiment at the CERN LHC. An excess of events over the back- ground expectation is observed in data with a significance of 3.0 standard deviations, where the expectation for the standard model (SM) Higgs boson with mass of 125.38 GeV is 2.5. The combination of this result with that from data recorded at root s = 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.7 fb(-1), respectively, increases both the expected and observed significances by 1%. The measured signal strength, relative to the SM prediction, is 1.19(-0.39)(+0.40)(stat)(-0.14)(+0.15). This result constitutes the first evidence for the decay of the Higgs boson to second generation fermions and is the most precise measurement of the Higgs boson coupling to muons reported to date.Öğe In-medium modification of dijets in PbPb collisions at ?sNN=5.02 TeV(Springer, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Modifications to the distribution of charged particles with respect to high transverse momentum (p(T)) jets passing through a quark-gluon plasma are explored using the CMS detector. Back-to-back dijets are analyzed in lead-lead and proton-proton collisions at root s(NN) = 5.02 TeV via correlations of charged particles in bins of relative pseudorapidity and angular distance from the leading and subleading jet axes. In comparing the lead-lead and proton-proton collision results, modifications to the charged-particle relative distance distribution and to the momentum distributions around the jet axis are found to depend on the dijet momentum balance x(j) , which is the ratio between the subleading and leading jet p(T). For events with x(j) approximate to 1, these modifications are observed for both the leading and subleading jets. However, while subleading jets show significant modifications for events with a larger dijet momentum imbalance, much smaller modifications are found for the leading jets in these events.Öğe Measurement of differential cross sections for Z bosons produced in association with charm jets in pp collisions at ?s=13 TeV(Springer, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Measurements are presented of differential cross sections for the production of Z bosons in association with at least one jet initiated by a charm quark in pp collisions at root s = 13 TeV. The data recorded by the CMS experiment at the LHC correspond to an integrated luminosity of 35.9 fb(-1). The final states contain a pair of electrons or muons that are the decay products of a Z boson, and a jet consistent with being initiated by a charm quark produced in the hard interaction. Differential cross sections as a function of the transverse momentum p(T) of the Z boson and p(T) of the charm jet are compared with predictions from Monte Carlo event generators. The inclusive production cross section 405.4 +/- 5.6 (stat) +/- 24.3 (exp) +/- 3.7 (theo) pb, is measured in a fiducial region requiring both leptons to have pseudorapidity |eta| < 2.4 and p(T)> 10 GeV, at least one lepton with p(T)> 26 GeV, and a mass of the pair in the range 71-111 GeV, while the charm jet is required to have p(T)> 30 GeV and |eta| < 2.4. These are the first measurements of these cross sections in proton-proton collisions at 13 TeV.Öğe Measurement of electroweak production of a W boson and two forward jets in proton-proton collisions at ?s = 8 TeV(Springer Science and Business Media Deutschland GmbH, 2016) Khachatryan, V.; Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.A measurement is presented of the cross section for the electroweak production of a W boson in association with two jets in proton-proton collisions at a center-of-mass energy of 8 TeV. The data set was collected with the CMS detector and corresponds to an integrated luminosity of 19.3 fb?1. The measured fiducial cross section for W bosons decaying to electrons or muons and for pT j1> 60 GeV, pT j2> 50 GeV, |?j| < 4.7, and mjj> 1000 GeV is 0.42 ± 0.04 (stat) ± 0.09 (syst) ± 0.01 (lumi) pb. This result is consistent with the standard model leading-order prediction of 0.50 ± 0.02 (scale) ± 0.02 (PDF) pb obtained with MadGraph5_amc@nlo 2.1 interfaced to pythia 6.4. This is the first cross section measurement for this process. © 2016, The Author(s).Öğe Measurement of prompt D0 and D-0 meson azimuthal anisotropy and search for strong electric fields in PbPb collisions at ?SNN=5.02 TeV(Elsevier, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.The strong Coulomb field created in ultrarelativistic heavy ion collisions is expected to produce a rapiditydependent difference (Av2) in the second Fourier coefficient of the azimuthal distribution (elliptic flow, v2) between D0 (uc) and D0 (uc) mesons. Motivated by the search for evidence of this field, the CMS detector at the LHC is used to perform the first measurement of Av2. The rapidity-averaged value is found to be (Av2) = 0.001 ? 0.001 (stat)? 0.003 (syst) in PbPb collisions at ?sNN = 5.02 TeV. In addition, the influence of the collision geometry is explored by measuring the D0 and D0mesons v2 and triangular flow coefficient (v3) as functions of rapidity, transverse momentum (pT), and event centrality (a measure of the overlap of the two Pb nuclei). A clear centrality dependence of prompt D0 meson v2 values is observed, while the v3 is largely independent of centrality. These trends are consistent with expectations of flow driven by the initial-state geometry. ? 2021 The Author. Published by Elsevier B.V. This is an open access article under the CC BY licenseÖğe Measurement of single-diffractive dijet production in proton-proton collisions at ?s = 8 TeV with the CMS and TOTEM experiments (vol 80, 1164, 2020)(Springer, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.[Abstract Not Available]Öğe Measurement of single-diffractive dijet production in proton-proton collisions at ?s=8 TeV with the CMS and TOTEM experiments(Springer, 2020) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Measurements are presented of the single-diffractive dijet cross section and the diffractive cross section as a function of the proton fractional momentum loss xi 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 root s = 8 TeV during a dedicated run with beta* = 90 m at low instantaneous luminosity and correspond to an integrated luminosity of 37.5 nb(-1). The single-diffractive dijet cross section sigma(pX)(jj), in the kinematic region xi < 0.1, with at least two jets with transverse momentum p(T) > 40GeV, and pseudorapidity vertical bar eta vertical bar < 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 xi, 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(10) x <= -1.6, is R = (sigma(pX)(jj)/Delta xi)/sigma(jj) = 0.025 +/- 0.001(stat) +/- 0.003(syst), where sigma(pX)(jj) and sigma(jj) 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.Öğe Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at ?s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions(Springer, 2020) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Normalised multi-differential cross sections for top quark pair (t (t) over bar) production are measured in proton-proton collisions at a centre-of-mass energy of 13 TeV using events containing two oppositely charged leptons. The analysed data were recorded with the CMS detector in 2016 and correspond to an integrated luminosity of 35.9 fb(-1). The doubledifferential t (t) over bar cross section is measured as a function of the kinematic properties of the top quark and of the t (t) over bar system at parton level in the full phase space. A triple-differential measurement is performed as a function of the invariant mass and rapidity of the t (t) over bar system and the multiplicity of additional jets at particle level. The data are compared to predictions of Monte Carlo event generators that complement next-to-leading-order (NLO) quantum chromodynamics (QCD) calculations with parton showers. Together with a fixed-order NLO QCD calculation, the triple-differential measurement is used to extract values of the strong coupling strength alpha(S) and the top quark pole mass (m(t)(pole)) using several sets of parton distribution functions (PDFs). The measurement of m(t)(pole) exploits the sensitivity of the t (t) over bar invariant mass distribution to m(t)(pole) near the production threshold. Further-more, a simultaneous fit of the PDFs, aS, and m(t)(pole) is performed at NLO, demonstrating that the new data have significant impact on the gluon PDF, and at the same time allow an accurate determination of alpha(S) and m(t)(pole). The values alpha S(mZ) = 0.1135+0.0021-0.0017 and m(t)(pole) = 170.5 +/- 0.8GeV are extracted, which account for experimental and theoretical uncertainties, the latter being estimated from NLO scale variations. Possible effects from Coulomb and soft-gluon resummation near the t (t) over bar production threshold are neglected in these parameter extractions. A rough estimate of these effects indicates an expected correction of m(t)(pole) of the order of +1 GeV, which can be regarded as additional theoretical uncertainty in the current m(t)(pole) extraction.Öğe Measurement of the CP-violating phase ?s in the B0s ? J/??(1020) ? ?+?-K+K- channel in proton-proton collisions at ?s=13 TeV(Elsevier, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.The CP-violating weak phase ?s and the decay width difference ??s between the light and heavy B0s mass eigenstates are measured with the CMS detector at the LHC in a sample of 48 500 reconstructed B0s? J/I) d (1020) ?11+11? K+K? events. The measurement is based on a data sample corresponding to an integrated luminosity of 96.4 fb?1, collected in proton-proton collisions at ?s = 13 TeV in 2017?2018. To extract the values of ?s and ??s, a time-dependent and flavor-tagged angular analysis of the 11+11?K+K? final state is performed. The analysis employs a dedicated tagging trigger and a novel opposite-side muon flavor tagger based on machine learning techniques. The measurement yields ?s = ?11 ?50 (stat) ? 10 (syst) mrad and ??s = 0.114 ? 0.014 (stat)? 0.007 (syst) ps?1, in agreement with the standard model predictions. When combined with the previous CMS measurement at ?s = 8 TeV, the following values are obtained: ?s = ?21 ? 44 (stat) ? 10 (syst) mrad, ??s = 0.1032 ? 0.0095 (stat) ? 0.0048 (syst) ps?1, a significant improvement over the 8 TeV result. ? 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY licenseÖğe Measurement of the WZ production cross section in pp collisions at ?s=13 Tev(Elsevier, 2017) Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.The WZ production cross section in proton-proton collisions at root s = 13 Tev is measured with the CMS experiment at the LHC using a data sample corresponding to an integrated luminosity of 2.3 fb(-1). The measurement is performed in the leptonic decay modes WZ -> lVl'l', where l,l'=e,mu. The measured cross section for the range 60 WZ) = 39.9 +/- 3.2(stat)(2.9)(-3.1)(syst)+/- 0.4(theo)+/- 1.3(lumi)pb, consistent with the standard model prediction.Öğe Measurement of the Z boson differential production cross section using its invisible decay mode (Z ? ?(?)over-bar) in proton-proton collisions at ?s=13 TeV(Springer, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Measurements of the total and differential fiducial cross sections for the Z boson decaying into two neutrinos are presented at the LHC in proton-proton collisions at a center-of-mass energy of 13TeV. The data were collected by the CMS detector in 2016 and correspond to an integrated luminosity of 35.9 fb(-1). In these measurements, events are selected containing an imbalance in transverse momentum and one or more energetic jets. The fiducial differential cross section is measured as a function of the Z boson transverse momentum. The results are combined with a previous measurement of charged-lepton decays of the Z boson. The measured total fiducial cross section for events with Z boson transverse momentum greater than 200 GeV is 3000(-170)(+180) fb.Öğe Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at ?s=13 TeV(Springer, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.Measurements of Higgs boson production cross sections and couplings in events where the Higgs boson decays into a pair of photons are reported. Events are selected from a sample of proton-proton collisions at root s = 13TeV collected by the CMS detector at the LHC from 2016 to 2018, corresponding to an integrated luminosity of 137 fb(-1). Analysis categories enriched in Higgs boson events produced via gluon fusion, vector boson fusion, vector boson associated production, and production associated with top quarks are constructed. The total Higgs boson signal strength, relative to the standard model (SM) prediction, is measured to be 1.12 +/- 0.09. Other properties of the Higgs boson are measured, including SM signal strength modifiers, production cross sections, and its couplings to other particles. These include the most precise measurements of gluon fusion and vector boson fusion Higgs boson production in several different kinematic regions, the first measurement of Higgs boson production in association with a top quark pair in five regions of the Higgs boson transverse momentum, and an upper limit on the rate of Higgs boson production in association with a single top quark. All results are found to be in agreement with the SM expectations.Öğe Observation of electroweak production of W? with two jets in proton-proton collisions at ?s=13 TeV(Elsevier, 2020) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.A first observation is presented for the electroweak production of a W boson, a photon, and two jets in proton-proton collisions. The W boson decays are selected by requiring one identified electron or muon and an imbalance in transverse momentum. The two jets are required to have a high dijet mass and a large separation in pseudorapidity. The measurement is based on data collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). The observed (expected) significance for this process is 4.9 (4.6) standard deviations. After combining with previously reported CMS results at 8 TeV, the observed (expected) significance is 5.3 (4.8) standard deviations. The cross section for the electroweak W gamma jj production in a restricted fiducial region is measured as 20.4 +/- 4.5 fb and the total cross section for W gamma production in association with 2 jets in the same fiducial region is 108 +/- 16 fb. All results are in good agreement with recent theoretical predictions. Constraints are placed on anomalous quartic gauge couplings in terms of dimension-8 effective field theory operators. (C) 2020 The Author(s). Published by Elsevier B.V.Öğe Search for a new scalar resonance decaying to a pair of Z bosons in proton-proton collisions at ?s = 13 TeV (vol 6, 127, 2018)(Springer, 2019) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.In both panels of figure 11, the unit of the z axis was mistakenly written as pb when it should have been fb. The corrected versions are shown in figure 1.Öğe Search for dark matter and unparticles in events with a Z boson and missing transverse momentum in proton-proton collisions at ?s = 13 TeV(Springer, 2017) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.[Abstract Not Available]Öğe Search for dark matter and unparticles in events with a Z boson and missing transverse momentum in proton-proton collisions at ?s = 13 TeV (vol 9, 106, 2017)(Springer, 2018) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.[Abstract Not Available]Öğe search for dark matter in proton-proton collisions at 8 TeV with missing transverse momentum and vector boson tagged jet (vol 12, 083, 2016)(Springer, 2017) Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.[Abstract Not Available]