Browsing by Author "Asilar, E."

Now showing 1 - 20 of 130

Citation - WoS: 146
Citation - Scopus: 194
Angular Analysis of the Decay B0 → K⁎0μ+μ− From Pp Collisions at √s=8 Tev
(Elsevier B.V., 2016) Khachatryan, V.; Karapınar, Güler; Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Puerta Pelayo, J.
The angular distributions and the differential branching fraction of the decay B0→K⁎(892)0μ+μ− are studied using data corresponding to an integrated luminosity of 20.5 fb−1 collected with the CMS detector at the LHC in pp collisions at s=8 TeV. From 1430 signal decays, the forward–backward asymmetry of the muons, the K⁎(892)0 longitudinal polarization fraction, and the differential branching fraction are determined as a function of the dimuon invariant mass squared. The measurements are among the most precise to date and are in good agreement with standard model predictions. © 2015 CERN for the benefit of the CMS Collaboration
Citation - WoS: 13
Citation - Scopus: 21
Azimuthal Correlations for Inclusive 2-Jet, 3-Jet, and 4-Jet Events in Pp Collisions at √s=13tev
(Springer Nature, 2018) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Virto, A.L.
Azimuthal correlations between the two jets with the largest transverse momenta pT in inclusive 2-, 3-, and 4-jet events are presented for several regions of the leading jet pT up to 4Te. For 3- and 4-jet scenarios, measurements of the minimum azimuthal angles between any two of the three or four leading pT jets are also presented. The analysis is based on data from proton–proton collisions collected by the CMS Collaboration at a centre-of-mass energy of 13Te, corresponding to an integrated luminosity of 35.9fb-1. Calculations based on leading-order matrix elements supplemented with parton showering and hadronization do not fully describe the data, so next-to-leading-order calculations matched with parton shower and hadronization models are needed to better describe the measured distributions. Furthermore, we show that azimuthal jet correlations are sensitive to details of the parton showering, hadronization, and multiparton interactions. A next-to-leading-order calculation matched with parton showers in the MC@NLO method, as implemented in herwig 7, gives a better overall description of the measurements than the powheg method. © 2018, CERN for the benefit of the CMS collaboration.
Citation - WoS: 8
Citation - Scopus: 12
Azimuthal Separation in Nearly Back-To Jet Topologies in Inclusive 2- and 3-Jet Events in Pp Collisions at √s=13te
(Springer Nature, 2019) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Goy Lopez, S.
A measurement for inclusive 2- and 3-jet events of the azimuthal correlation between the two jets with the largest transverse momenta, Δϕ12, is presented. The measurement considers events where the two leading jets are nearly collinear (“back-to-back”) in the transverse plane and is performed for several ranges of the leading jet transverse momentum. Proton-proton collision data collected with the CMS experiment at a center-of-mass energy of 13Te and corresponding to an integrated luminosity of 35.9fb-1 are used. Predictions based on calculations using matrix elements at leading-order and next-to-leading-order accuracy in perturbative quantum chromodynamics supplemented with leading-log parton showers and hadronization are generally in agreement with the measurements. Discrepancies between the measurement and theoretical predictions are as large as 15%, mainly in the region 177 ∘< Δϕ12< 180 ∘. The 2- and 3-jet measurements are not simultaneously described by any of models. © 2019, CERN for the benefit of the CMS collaboration.
Citation - WoS: 8
Citation - Scopus: 11
Centrality and Pseudorapidity Dependence of the Transverse Energy Density in Ppb Collisions Ats Root S(nn)=5.02 Tev
(American Physical Society, 2019) Sirunyan, A. M.; Karapınar, Güler; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.
The almost hermetic coverage of the CMS detector is used to measure the distribution of transverse energy, E-T, over 13.2 units of pseudorapidity, eta, for pPb collisions at a center-of-mass energy per nucleon pair of root s(NN) = 5.02 TeV. The huge angular acceptance exploits the fact that the CASTOR calorimeter at -6.6 < eta < -5.2 is effectively present on both sides of the colliding system because of a switch in the proton-going and lead-going beam directions. This wide acceptance enables the study of correlations between well-separated angular regions and makes the measurement a particularly powerful test of event generators. For minimum bias pPb collisions the maximum value of dE(T)/d eta is 22 GeV, which implies an E-T per participant nucleon pair comparable to that of peripheral PbPb collisions at root s(NN) 7 = 2.76 TeV. The increase of dE(T)/d eta with centrality is much stronger for the lead-going side than for the proton-going side. The i dependence of dE(T)/d eta is sensitive to the eta range in which the centrality variable is defined. Several modern generators are compared to these results but none is able to capture all aspects of the eta and centrality dependence of the data and the correlations observed between different eta regions.
Citation - WoS: 632
Citation - Scopus: 532
The Cms Trigger System
(Institute of Physics, 2017) Khachatryan, V.; Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; de Trocóniz, J.F.
This paper describes the CMS trigger system and its performance during Run 1 of the LHC. The trigger system consists of two levels designed to select events of potential physics interest from a GHz (MHz) interaction rate of proton-proton (heavy ion) collisions. The first level of the trigger is implemented in hardware, and selects events containing detector signals consistent with an electron, photon, muon, τ lepton, jet, or missing transverse energy. A programmable menu of up to 128 object-based algorithms is used to select events for subsequent processing. The trigger thresholds are adjusted to the LHC instantaneous luminosity during data taking in order to restrict the output rate to 100 kHz, the upper limit imposed by the CMS readout electronics. The second level, implemented in software, further refines the purity of the output stream, selecting an average rate of 400 Hz for offline event storage. The objectives, strategy and performance of the trigger system during the LHC Run 1 are described. © CERN 2017 for the benefit of the CMS collaboration..
Citation - WoS: 127
Citation - Scopus: 436
Combined Measurements of Higgs Boson Couplings in Proton–proton Collisions at √s=13te
(Springer Nature, 2019) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Bachiller, I.
Combined measurements of the production and decay rates of the Higgs boson, as well as its couplings to vector bosons and fermions, are presented. The analysis uses the LHC proton–proton collision data set recorded with the CMS detector in 2016 at s=13Te, corresponding to an integrated luminosity of 35.9fb-1. The combination is based on analyses targeting the five main Higgs boson production mechanisms (gluon fusion, vector boson fusion, and associated production with a W or Z boson, or a top quark-antiquark pair) and the following decay modes: H → γγ, Z Z , W W , ττ, b b , and μμ. Searches for invisible Higgs boson decays are also considered. The best-fit ratio of the signal yield to the standard model expectation is measured to be μ= 1.17 ± 0.10 , assuming a Higgs boson mass of 125.09Ge. Additional results are given for various assumptions on the scaling behavior of the production and decay modes, including generic parametrizations based on ratios of cross sections and branching fractions or couplings. The results are compatible with the standard model predictions in all parametrizations considered. In addition, constraints are placed on various two Higgs doublet models. © 2019, CERN for the benefit of the CMS collaboration.
Citation - WoS: 5
Citation - Scopus: 7
Correlations of Azimuthal Anisotropy Fourier Harmonics With Subevent Cumulants in Ppb Collisions at Snn =8.16 Tev
(American Physical Society, 2021) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Devetak, D.
Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (vn) 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 vn 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 v2 and v3 coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v2 and v4 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. © 2021 CERN.
Citation - WoS: 59
Citation - Scopus: 72
Cross Section Measurement of T-Channel Single Top Quark Production in Pp Collisions at S=13tev
(Elsevier B.V., 2017) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Rodrigo, T.
The cross section for the production of single top quarks in the t channel is measured in proton–proton collisions at 13TeV with the CMS detector at the LHC. The analyzed data correspond to an integrated luminosity of 2.2fb−1. The event selection requires one muon and two jets where one of the jets is identified as originating from a bottom quark. Several kinematic variables are then combined into a multivariate discriminator to distinguish signal from background events. A fit to the distribution of the discriminating variable yields a total cross section of 238±13(stat)±29(syst) pb and a ratio of top quark and top antiquark production of Rt-ch.=1.81±0.18(stat)±0.15(syst). From the total cross section the absolute value of the CKM matrix element Vtb is calculated to be 1.05±0.07(exp)±0.02(theo). All results are in agreement with the standard model predictions. © 2017 The Author(s)
Citation - WoS: 30
Citation - Scopus: 34
Electroweak 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
Citation - WoS: 16
Citation - Scopus: 7
Erratum To: Measurements of the Z→4ℓ Branching Fraction, and Constraints on Anomalous Triple Gauge Couplings at S=13tev (the European Physical Journal C, (2018), 78, 2, (165), 10.1140/Epjc
(Springer Nature, 2018) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Virto, A.L.
Reference [6]: “Phys. Lett. B 763, 280” should have been corrected into “Phys. Lett. B 763, 280 (2016)”. © 2018, CERN for the benefit of the CMS collaboration.
Erratum: Measurement of Prompt and Nonprompt Charmonium Suppression in Pbpb Collisions at 5.02 Tev (the European Physical Journal C, (2018), 78, 6, (509), 10.1140/Epjc
(Institute for Ionics, 2023) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Brandstetter, J.
In Fig. 3, the y axis titles were mistakenly written showing a single-differential cross section in either dimuon (Formula presented.) or rapidity, when in fact the cross section is normalized by both the (Formula presented.) and rapidity ranges used for a given measurement point. The corrected version is shown in the new Fig. 3 provided below. (Figure presented.) Differential cross section of prompt (Formula presented.) mesons (left) and (Formula presented.) mesons from b hadrons (nonprompt (Formula presented.) ) (right) decaying into two muons as a function of dimuon (Formula presented.) (upper) and rapidity (lower) in pp and (Formula presented.) collisions. The (Formula presented.) cross sections are normalised by (Formula presented.) for direct comparison. The bars (boxes) represent statistical (systematic) point-by-point uncertainties, while global uncertainties are written on the plots. © 2023, CERN for the benefit of the CMS Collaboration.
Citation - WoS: 98
Citation - Scopus: 147
Evidence for Higgs Boson Decay To a Pair of Muons
(Springer, 2021) Karapınar, Güler; CMS Collaboration; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Salama, E.
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.
Citation - WoS: 158
Citation - Scopus: 212
Evidence for Light-By Scattering and Searches for Axion-Like Particles in Ultraperipheral Pbpb Collisions at Snn=5.02tev
(Elsevier B.V., 2019) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Troshin, S.
Evidence for the light-by-light scattering process, γγ→γγ, in ultraperipheral PbPb collisions at a centre-of-mass energy per nucleon pair of 5.02TeV is reported. The analysis is conducted using a data sample corresponding to an integrated luminosity of 390μb−1 recorded by the CMS experiment at the LHC. Light-by-light scattering processes are selected in events with two photons exclusively produced, each with transverse energy ET γ>2GeV, pseudorapidity |ηγ|<2.4, diphoton invariant mass mγγ>5GeV, diphoton transverse momentum pT γγ<1GeV, and diphoton acoplanarity below 0.01. After all selection criteria are applied, 14 events are observed, compared to expectations of 9.0±0.9(theo) events for the signal and 4.0±1.2(stat) for the background processes. The excess observed in data relative to the background-only expectation corresponds to a significance of 3.7 standard deviations, and has properties consistent with those expected for the light-by-light scattering signal. The measured fiducial light-by-light scattering cross section, σfid(γγ→γγ)=120±46(stat)±28(syst)±12(theo)nb, is consistent with the standard model prediction. The mγγ distribution is used to set new exclusion limits on the production of pseudoscalar axion-like particles, via the (Figure presented.) process, in the mass range (Figure presented.). © 2019 The Author(s)
Citation - WoS: 270
Citation - Scopus: 326
Extraction and Validation of a New Set of Cms Pythia8 Tunes From Underlying-Event Measurements
(Springer Nature, 2020) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Fernandez Bedoya, C.
New sets of CMS underlying-event parameters (“tunes”) are presented for the pythia8 event generator. These tunes use the NNPDF3.1 parton distribution functions (PDFs) at leading (LO), next-to-leading (NLO), or next-to-next-to-leading (NNLO) orders in perturbative quantum chromodynamics, and the strong coupling evolution at LO or NLO. Measurements of charged-particle multiplicity and transverse momentum densities at various hadron collision energies are fit simultaneously to determine the parameters of the tunes. Comparisons of the predictions of the new tunes are provided for observables sensitive to the event shapes at LEP, global underlying event, soft multiparton interactions, and double-parton scattering contributions. In addition, comparisons are made for observables measured in various specific processes, such as multijet, Drell–Yan, and top quark-antiquark pair production including jet substructure observables. The simulation of the underlying event provided by the new tunes is interfaced to a higher-order matrix-element calculation. For the first time, predictions from pythia8 obtained with tunes based on NLO or NNLO PDFs are shown to reliably describe minimum-bias and underlying-event data with a similar level of agreement to predictions from tunes using LO PDF sets. © 2019, CERN for the benefit of the CMS collaboration.
Citation - WoS: 207
Citation - Scopus: 478
Identification of Heavy-Flavour Jets With the Cms Detector in Pp Collisions at 13 Tev
(Institute of Physics, 2018) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Sanchez Cruz, S.
Many 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. Heavy-flavour jet identification algorithms have been improved compared to those used previously at centre-of-mass energies of 7 and 8 TeV. For jets with transverse momenta in the range expected in simulated events, these new developments result in an efficiency of 68% for the correct identification of a b jet for a probability of 1% of misidentifying a light-flavour jet. The improvement in relative efficiency at this misidentification probability is about 15%, compared to previous CMS algorithms. In addition, for the first time algorithms have been developed to identify jets containing two b hadrons in Lorentz-boosted event topologies, as well as to tag c jets. The large data sample recorded in 2016 at a centre-of-mass energy of 13 TeV has also allowed the development of new methods to measure the efficiency and misidentification probability of heavy-flavour jet identification algorithms. The b jet identification efficiency is measured with a precision of a few per cent at moderate jet transverse momenta (between 30 and 300 GeV) and about 5% at the highest jet transverse momenta (between 500 and 1000 GeV). © 2018 CERN for the benefit of the CMS collaboration.
Citation - WoS: 26
Citation - Scopus: 35
Inclusive and Differential Measurements of the Tt¯ Charge Asymmetry in Pp Collisions at √s=8 Tev
(Elsevier B.V., 2016) Khachatryan, V.; Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Albajar, C.
The tt¯ charge asymmetry is measured in proton–proton collisions at a centre-of-mass energy of 8 TeV. The data, collected with the CMS experiment at the LHC, correspond to an integrated luminosity of 19.7 fb−1. Selected events contain an electron or a muon and four or more jets, where at least one jet is identified as originating from b-quark hadronization. The inclusive charge asymmetry is found to be 0.0010±0.0068 (stat)±0.0037 (syst). In addition, differential charge asymmetries as a function of rapidity, transverse momentum, and invariant mass of the tt¯ system are studied. For the first time at the LHC, the measurements are also performed in a reduced fiducial phase space of top quark pair production, with an integrated result of −0.0035±0.0072 (stat)±0.0031 (syst). All measurements are consistent within two standard deviations with zero asymmetry as well as with the predictions of the standard model. © 2016 CERN for the benefit of the CMS Collaboration
Citation - WoS: 50
Citation - Scopus: 67
Limits on the Higgs Boson Lifetime and Width From Its Decay To Four Charged Leptons
(American Physical Society, 2015) Khachatryan, V.; Khachatryan, V.; Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Asilar, E.; Soares, M.S.
Constraints on the lifetime and width of the Higgs boson are obtained from H→ZZ→4ℓ events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7fb-1 at a center-of-mass energy of 7 and 8 TeV, respectively. The measurement of the Higgs boson lifetime is derived from its flight distance in the CMS detector with an upper bound of τH<1.9×10-13s at the 95% confidence level (C.L.), corresponding to a lower bound on the width of ΓH>3.5×10-9MeV. The measurement of the width is obtained from an off-shell production technique, generalized to include anomalous couplings of the Higgs boson to two electroweak bosons. From this measurement, a joint constraint is set on the Higgs boson width and a parameter fΛQ that expresses an anomalous coupling contribution as an on-shell cross-section fraction. The limit on the Higgs boson width is ΓH<46MeV with fΛQ unconstrained and ΓH<26MeV for fΛQ=0 at the 95% C.L. The constraint fΛQ<3.8×10-3 at the 95% C.L. is obtained for the expected standard model Higgs boson width. © 2015 CERN, for the CMS. Published by the American Physical Society.
Citation - WoS: 66
Citation - Scopus: 79
Measurement and Interpretation of Differential Cross Sections for Higgs Boson Production at S=13tev
(Elsevier B.V., 2019) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Konstantinov, D.
Differential Higgs boson (H) production cross sections are sensitive probes for physics beyond the standard model. New physics may contribute in the gluon-gluon fusion loop, the dominant Higgs boson production mechanism at the LHC, and manifest itself through deviations from the distributions predicted by the standard model. Combined spectra for the H→γγ, H→ZZ, and H→bb‾ decay channels and the inclusive Higgs boson production cross section are presented, based on proton-proton collision data recorded with the CMS detector at s=13TeV corresponding to an integrated luminosity of 35.9fb−1. The transverse momentum spectrum is used to place limits on the Higgs boson couplings to the top, bottom, and charm quarks, as well as its direct coupling to the gluon field. No significant deviations from the standard model are observed in any differential distribution. The measured total cross section is 61.1±6.0(stat)±3.7(syst)pb, and the precision of the measurement of the differential cross section of the Higgs boson transverse momentum is improved by about 15% with respect to the H→γγ channel alone. © 2019 The Author(s)
Citation - WoS: 11
Citation - Scopus: 18
Measurement 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 , 7125GeV 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.
Citation - WoS: 30
Citation - Scopus: 35
Measurement of B Hadron Lifetimes in Pp Collisions at √s=8tev
(Springer Nature, 2018) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Garcia-Ferrero, J.
Measurements are presented of the lifetimes of the B 0, Bs0, Λb0, and Bc+ hadrons using the decay channels B0→J/ψK∗(892)0, B0→J/ψKS0, Bs0→J/ψπ+π-, Bs0→J/ψϕ(1020), Λb0→J/ψΛ0, and Bc+→J/ψπ+. The data sample, corresponding to an integrated luminosity of 19.7fb-1, was collected by the CMS detector at the LHC in proton–proton collisions at s=8TeV. The B 0 lifetime is measured to be 453.0±1.6(stat)±1.8(syst)μm in J / ψK ∗(892) 0and 457.8±2.7(stat)±2.8(syst)μm in J/ψKS0, which results in a combined measurement of cτB0=454.1±1.4(stat)±1.7(syst)μm. The effective lifetime of the Bs0 meson is measured in two decay modes, with contributions from different amounts of the heavy and light eigenstates. This results in two different measured lifetimes: cτBs0→J/ψπ+π-=502.7±10.2(stat)±3.4(syst)μm and cτBs0→J/ψϕ(1020)=443.9±2.0(stat)±1.5(syst)μm. The Λb0 lifetime is found to be 442.9±8.2(stat)±2.8(syst)μm. The precision from each of these channels is as good as or better than previous measurements. The Bc+ lifetime, measured with respect to the B + to reduce the systematic uncertainty, is 162.3±7.8(stat)±4.2(syst)±0.1(τB+)μm. All results are in agreement with current world-average values. © 2018, CERN for the benefit of the CMS collaboration.