Repository logoGCRIS
  • English
  • Türkçe
  • Русский
Log In
New user? Click here to register. Have you forgotten your password?
Home
Communities
Browse GCRIS
Entities
Overview
GCRIS Guide
  1. Home
  2. Browse by Author

Browsing by Author "Andrejkovic, J. W."

Filter results by typing the first few letters
Now showing 1 - 20 of 239
  • Results Per Page
  • Sort Options
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 5
    Addendum: Measurement and Qcd Analysis of Double-Differential Inclusive Jet Cross Sections in Proton-Proton Collisions at Root S=13 Tev
    (Springer, 2022) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Del Valle, A. Escalante; Gürpınar Güler, Emine; Güler, Yalçın
    The QCD analysis at NNLO is repeated by using the NNLO interpolation grids for the double-differential inclusive jet cross section [1], which were released after the journal publication of the original analysis. The NNLOJET calculation used to derive these grids is based on the leading-colour and leading-flavour-number approximation and does not include the most recent subleading colour contributions. However, these contributions were reported in ref. [2] to be very small in inclusive jet production, in particular for a jet size of R = 0.7. The grids also contain an estimate of the numerical integration uncertainty of around 1% or less. To account for point-to-point fluctuations, this uncertainty, after consultation with the authors of NNLOJET, has been increased by a factor of two; however, its impact in the fit is negligible. A comparison of the measurement with predictions using various PDFs is shown in figure 1. Although the PDF parametrisation remains identical, higher precision in PDF and QCD parameters is expected by using NNLO grids consistently in the QCD analysis. These new results supersede those obtained by using the k-factor technique.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 37
    Citation - Scopus: 46
    Analysis of the Cp Structure of the Yukawa Coupling Between the Higgs Boson and Tau Leptons in Proton-Proton Collisions at Root S=13 Tev
    (Springer, 2022) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Güler, Yalçın; The CMS Collaboration
    The first measurement of the CP structure of the Yukawa coupling between the Higgs boson and tau leptons is presented. The measurement is based on data collected in proton-proton collisions at root s = 13 TeV by the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb(-1). The analysis uses the angular correlation between the decay planes of tau leptons produced in Higgs boson decays. The effective mixing angle between CP-even and CP-odd tau Yukawa couplings is found to be -1 +/- 19 degrees, compared to an expected value of 0 +/- 21 degrees at the 68.3% confidence level. The data disfavour the pure CP-odd scenario at 3.0 standard deviations. The results are compatible with predictions for the standard model Higgs boson.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 1
    Angular Analysis of the B0 → K*(892)0μ+μ- Decay in Proton-Proton Collisions at √s=13 TeV
    (Elsevier, 2025) Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Benato, L.; Bergauer, T.; Kumar, A.
    A full set of optimized observables is measured in an angular analysis of the decay B-0 -> K*(892)(0)mu(+)mu(-) using a sample of proton-proton collisions at root s = 13 TeV, collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 140 fb(-1). The analysis is performed in six bins of the squared invariant mass of the dimuon system, q(2), over the range 1.1 < q(2) < 16 GeV2. The results are among the most precise experimental measurements of the angular observables for this decay and are compared to a variety of predictions based on the standard model. Some of these predictions exhibit tension with the measurements.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Azimuthal Anisotropy of Dijet Events in Pbpb Collisions at √snn=5.02 Tev
    (SPRINGER, 2023) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Gürpınar Güler, Emine; Güler, Yalçın
    The path-length dependent parton energy loss within the dense partonic medium created in lead-lead collisions at a nucleon-nucleon center-of-mass energy of root s(NN) = 5.02TeV is studied by determining the azimuthal anisotropies for dijets with high transverse momentum. The data were collected by the CMS experiment in 2018 and correspond to an integrated luminosity of 1.69 nb(-1). For events containing back-to-back jets, correlations in relative azimuthal angle and pseudorapidity (eta) between jets and hadrons, and between two hadrons, are constructed. The anisotropies are expressed as the Fourier expansion coefficients v(n), n = 2-4 of these azimuthal distributions. The dijet v(n) values are extracted from long-range (1.5 < vertical bar Delta eta vertical bar < 2.5) components of these correlations, which suppresses the background contributions from jet fragmentation processes. Positive dijet v(2) values are observed which increase from central to more peripheral events, while the v(3) and v(4) values are consistent with zero within experimental uncertainties.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 34
    Citation - Scopus: 49
    Combined Searches for the Production of Supersymmetric Top Quark Partners in Proton-Proton Collisions at Root S=13 Tev
    (SPRINGER, 2021) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Vetens, W.; Gürpınar Güler, Emine; Güler, Yalçın; The CMS Collaboration
    A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) 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. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 7
    Citation - Scopus: 5
    Constraints on Anomalous Higgs Boson Couplings From Its Production and Decay Using the Ww Channel in Proton-Proton Collisions at √s=13 Tev
    (Springer, 2024) Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Zhokin, A.
    A study of the anomalous couplings of the Higgs boson to vector bosons, including CP-violation effects, has been conducted using its production and decay in the WW channel. This analysis is performed on proton-proton collision data collected with the CMS detector at the CERN LHC during 2016-2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138 fb(-1). The different-flavor dilepton (e mu) final state is analyzed, with dedicated categories targeting gluon fusion, electroweak vector boson fusion, and associated production with a W or Z boson. Kinematic information from associated jets is combined using matrix element techniques to increase the sensitivity to anomalous effects at the production vertex. A simultaneous measurement of four Higgs boson couplings to electroweak vector bosons is performed in the framework of a standard model effective field theory. All measurements are consistent with the expectations for the standard model Higgs boson and constraints are set on the fractional contribution of the anomalous couplings to the Higgs boson production cross section.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 15
    Citation - Scopus: 24
    Constraints on Anomalous Higgs Boson Couplings To Vector Bosons and Fermions From the Production of Higgs Bosons Using the Tt Final State
    (Amer Physical Soc, 2023) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Gürpınar Güler, Emine; Güler, Yalçın
    A study of anomalous couplings of the Higgs boson to vector bosons and fermions is presented. The data were recorded by the CMS experiment at a center-of-mass energy of pp collisions at the LHC of 13 TeV and correspond to an integrated luminosity of 138 fb-1. The study uses Higgs boson candidates produced mainly in gluon fusion or electroweak vector boson fusion at the LHC that subsequently decay to a pair of z leptons. Matrix-element and machine-learning techniques were employed in a search for anomalous interactions. The results are combined with those from the four-lepton and two-photon decay channels to yield the most stringent constraints on anomalous Higgs boson couplings to date. The pure CP-odd scenario of the Higgs boson coupling to gluons is excluded at 2.4 standard deviations. The results are consistent with the standard model predictions.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 43
    Citation - Scopus: 56
    Constraints on Anomalous Higgs Boson Couplings To Vector Bosons and Fermions in Its Production and Decay Using the Four-Lepton Final State
    (AMER PHYSICAL SOC, 2021) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Vetens, W.; Gürpınar Güler, Emine; Güler, Yalçın; The CMS Collaboration
    Studies of CP violation and anomalous couplings of the Higgs boson to vector bosons and fermions are presented. The data were acquired by the CMS experiment at the LHC and correspond to an integrated luminosity of 137 fb(-1) at a proton-proton collision energy of 13 TeV. The kinematic effects in the Higgs boson's four-lepton decay H -> 4l and its production in association with two jets, a vector boson, or top quarks are analyzed, using a full detector simulation and matrix element techniques to identify the production mechanisms and to increase sensitivity to the tensor structure of the Higgs boson interactions. A simultaneous measurement is performed of up to five Higgs boson couplings to electroweak vector bosons (HVV), two couplings to gluons (Hgg), and two couplings to top quarks (Htt). The CP measurement in the Htt interaction is combined with the recent measurement in the H -> gamma gamma channel. The results are presented in the framework of anomalous couplings and are also interpreted in the framework of effective field theory, including the first study of CP properties of the Htt and effective Hgg couplings from a simultaneous analysis of the gluon fusion and top-associated processes. The results are consistent with the standard model of particle physics.
  • Loading...
    Thumbnail Image
    Article
    Citation - Scopus: 2
    Constraints on Standard Model Effective Field Theory for a Higgs Boson Produced in Association with W or Z Bosons in the H → B(b)over-Bar Decay Channel in Proton-Proton Collisions at √s=13 TeV
    (Springer, 2025) Chekhovsky, V.; Hayrapetyan, A.; Makarenko, V.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Lee, J.
    A standard model effective field theory (SMEFT) analysis with dimension-six operators probing nonresonant new physics effects is performed in the Higgs-strahlung process, where the Higgs boson is produced in association with a W or Z boson, in proton-proton collisions at a center-of-mass energy of 13 TeV. The final states in which the W or Z boson decays leptonically and the Higgs boson decays to a pair of bottom quarks are considered. The analyzed data were collected by the CMS experiment between 2016 and 2018 and correspond to an integrated luminosity of 138 fb(-1). An approach designed to simultaneously optimize the sensitivity to Wilson coefficients of multiple SMEFT operators is employed. Likelihood scans as functions of the Wilson coefficients that carry SMEFT sensitivity in this final state are performed for different expansions in SMEFT. The results are consistent with the predictions of the standard model.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 7
    Constraints on the Higgs Boson Self-Coupling From the Combination of Svingle and Double Higgs Boson Production in Proton-Proton Collisions at √s=13 Tev
    (Elsevier, 2025) Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Lee, J.
    The Higgs boson (H) trilinear self-coupling, lambda(3), is constrained via its measured properties and limits on the HH pair production using the proton-proton collision data collected by the CMS experiment at root s = 13 TeV. The combination of event categories enriched in single-H and HH events is used to measure k(lambda), defined as the value of lambda(3) normalized to its standard model prediction, while simultaneously constraining the Higgs boson couplings to fermions and vector bosons. Values of k(lambda) outside the interval -1.2 < k(lambda) < 7.5 are excluded at 2 sigma confidence level, which is compatible with the expected range of -2.0< k(lambda) < 7.7 under the assumption that all other Higgs boson couplings are equal to their standard model predicted values. Relaxing the assumption on the Higgs couplings to fermions and vector bosons the observed (expected) k(lambda) interval is constrained to be within -1.4 < k(lambda) < 7.8 (-2.3 < k(lambda) < 7.8) at 2 sigma confidence level.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 1
    Determination of the Strong Coupling and Its Running from Measurements of Inclusive Jet Production
    (Elsevier, 2025) Chekhovsky, V.; Hayrapetyan, A.; Makarenko, V.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Lee, J.
    The value of the strong coupling alpha(S) is determined in a comprehensive analysis at next-to-next-to-leading order accuracy in quantum chromodynamics. The analysis uses double-differential cross section measurements from the CMS Collaboration at the CERN LHC of inclusive jet production in proton-proton collisions at centre-of-mass energies of 2.76, 7, 8, and 13 TeV, combined with inclusive deep-inelastic data from HERA. The value alpha(S)(m(Z)) = 0.1176(-0.0016)(+0.0014) is obtained at the scale of the Z boson mass. By using the measurements in different intervals of jet transverse momentum, the running of alpha(S) is probed for energies between 100 and 1600GeV.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 13
    Citation - Scopus: 83
    Development of the Cms Detector for the Cern Lhc Run 3
    (Iop Publishing Ltd, 2024) Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Arnold, B.; Bergauer, H.; Zhokin, A.
    Since the initial data taking of the CERN LHC, the CMS experiment has undergone substantial upgrades and improvements. This paper discusses the CMS detector as it is configured for the third data-taking period of the CERN LHC, Run 3, which started in 2022. The entire silicon pixel tracking detector was replaced. A new powering system for the superconducting solenoid was installed. The electronics of the hadron calorimeter was upgraded. All the muon electronic systems were upgraded, and new muon detector stations were added, including a gas electron multiplier detector. The precision proton spectrometer was upgraded. The dedicated luminosity detectors and the beam loss monitor were refurbished. Substantial improvements to the trigger, data acquisition, software, and computing systems were also implemented, including a new hybrid CPU/GPU farm for the high-level trigger.
  • Loading...
    Thumbnail Image
    Article
    Elliptic Anisotropy Measurement of the F0(980) Hadron in Proton-Lead Collisions and Evidence for Its Quark-Antiquark Composition
    (Nature Portfolio, 2025) Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Zhokin, A.
    Despite the f(0)(980) hadron having been discovered half a century ago, the question about its quark content has not been settled: it might be an ordinary quark-antiquark (q (q) over bar) meson, a tetraquark (q (q) over barq (q) over bar) exotic state, a kaon-antikaon (K (K) over bar) molecule, or a quark-antiquark-gluon (q (q) over barg) hybrid. This paper reports strong evidence that the f(0)(980) state is an ordinary q (q) over bar meson, inferred from the scaling of elliptic anisotropies (v(2)) with the number of constituent quarks (n(q)), as empirically established using conventional hadrons in relativistic heavy ion collisions. The f(0)(980) state is reconstructed via its dominant decay channel f(0)(980) -> pi(+)pi(-), in proton-lead collisions recorded by the CMS experiment at the LHC, and its v(2) is measured as a function of transverse momentum (p(T)). It is found that the n(q) = 2 (q (q) over bar state) hypothesis is favored over n(q) = 4 (q (q) over barq (q) over bar or K (K) over bar states) by 7.7, 6.3, or 3.1 standard deviations in the p(T) < 10, 8, or 6 GeV/c ranges, respectively, and over n(q) = 3 (q<(q)over bar>g hybrid state) by 3.5 standard deviations in the p(T) < 8GeV/c range. This result represents the first determination of the quark content of the f(0)(980) state, made possible by using a novel approach, and paves the way for similar studies of other exotic hadron candidates.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 1
    Citation - Scopus: 2
    Energy-Scaling Behavior of Intrinsic Transverse-Momentum Parameters in Drell-Yan Simulation
    (Amer Physical Soc, 2025) Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Makarenko, V.
    An analysis is presented based on models of the intrinsic transverse momentum (intrinsic k(T)) of partons in nucleons by studying the dilepton transverse momentum in Drell-Yan events. Using parameter tuning in event generators and existing data from fixed-target experiments and from hadron colliders, our investigation spans 3 orders of magnitude in center-of-mass energy and 2 orders of magnitude in dilepton invariant mass. The results show an energy-scaling behavior of the intrinsic k(T) parameters, independent of the dilepton invariant mass at a given center-of-mass energy.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 10
    Evidence for Four-Top Quark Production in Proton-Proton Collisions at √s=13 Tev
    (Elsevier, 2023) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Gürpınar Güler, Emine; Güler, Yalçın
    The production of four top quarks (tt over bar tt over bar ) is studied with LHC proton-proton collision data samples collected by the CMS experiment at a center-of-mass energy of 13 TeV, and corresponding to integrated luminosities of up to 138 fb-1. Events that have no leptons (all-hadronic), one lepton, or two oppositesign leptons (where lepton refers only to prompt electrons or prompt muons) are considered. This is the first tt over bar tt over bar measurement that includes the all-hadronic final state. The observed significance of the tt over bar tt over bar signal in these final states of 3.9 standard deviations (1.5 expected) provides evidence for tt over bar tt over bar production, with a measured cross section of 36+12 signal significance is 4.0 standard deviations (3.2 expected). The combination returns an observed cross section of 17 +/- 4 (stat) +/- 3 (syst) fb, which is consistent with the standard model prediction. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons .org /licenses /by /4 .0/). Funded by SCOAP3.
  • Loading...
    Thumbnail Image
    Article
    Citation - Scopus: 2
    Evidence for Similar Collectivity of High Transverse-Momentum Particles in P-Pb and Pb-Pb Collisions
    (American Physical Society, 2025) Chekhovsky, V.; Hayrapetyan, A.; Makarenko, V.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Druzhkin, D.
    Charged hadron elliptic anisotropies (v(2)) are presented over a wide transverse momentum (p(T)) range for proton-lead (pPb) and lead-lead (PbPb) collisions at nucleon-nucleon center-of-mass energies of 8.16 and 5.02 TeV, respectively. The data were recorded by the CMS experiment and correspond to integrated luminosities of 186 and 0.607 nb(-1) for the pPb and PbPb systems, respectively. A four-particle cumulant analysis is performed using subevents separated in pseudorapidity to effectively suppress noncollective effects. At high pT (p(T) > 8 GeV), significant positive v(2) values that are similar between pPb and PbPb collisions at comparable charged particle multiplicities are observed. This observation suggests a common origin for the multiparticle collectivity for high-p(T) particles in the two systems.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 1
    Citation - Scopus: 4
    Evidence for tWZ Production in Proton-Proton Collisions at S=13 TeV in Multilepton Final States
    (Elsevier B.V., 2024) Hayrapetyan, Aram A.; Tumasyan, A. R.; Adam, Wolfgang; Andrejkovic, J. W.; Bergauer, Thomas; Chatterjee, Suman; Hussain, P. S.
    The first evidence for the standard model production of a top quark in association with a W boson and a Z boson is reported. The measurement is performed in multilepton final states, where the Z boson is reconstructed via its decays to electron or muon pairs. At least one W boson, associated or from top quark decay, decays leptonically, too. The analysed data were recorded by the CMS experiment at the CERN LHC in 2016–2018 in proton-proton collisions at s=13 TeV, and correspond to an integrated luminosity of 138 fb−1. The measured cross section is 354±54(stat)±95(syst) fb, and corresponds to a statistical significance of 3.4 standard deviations. © 2025 Elsevier B.V., All rights reserved.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 13
    Evidence for Ww/Wz Vector Boson Scattering in the Decay Channel L Nu Qq Produced in Association With Two Jets in Proton-Proton Collisions at Root S=13tev
    (Elsevier, 2022) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Del Valle, A. Escalante; Gürpınar Güler, Emine; Güler, Yalçın
    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.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 14
    Citation - Scopus: 21
    First Measurement of the Top Quark Pair Production Cross Section in Proton-Proton Collisions at √s=13.6 Tev
    (Springer, 2023) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Gürpınar Güler, Emine; Güler, Yalçın
    The first measurement of the top quark pair (t (t) over bar) production cross section in proton-proton collisions at root s = 13.6TeV is presented. Data recorded with the CMS detector at the CERN LHC in Summer 2022, corresponding to an integrated luminosity of 1.21 fb(-1), are analyzed. Events are selected with one or two charged leptons (electrons or muons) and additional jets. A maximum likelihood fit is performed in event categories defined by the number and flavors of the leptons, the number of jets, and the number of jets identified as originating from b quarks. An inclusive t (t) over bar production cross section of 881 +/- 23 (stat + syst) +/- 20 (lumi) pb is measured, in agreement with the standard model prediction of 924(-40)(+32) pb.
  • Loading...
    Thumbnail Image
    Article
    Citation - WoS: 4
    Girth and Groomed Radius of Jets Recoiling Against Isolated Photons in Lead-Lead and Proton-Proton Collisions at √snn=5.02 Tev
    (Elsevier, 2025) Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Zhokin, A.
    This Letter presents the first measurements of the groomed jet radius R-g and the jet girth g in events with an isolated photon recoiling against a jet in lead-lead (PbPb) and proton-proton (pp) collisions at the LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The observables R-g and g provide a quantitative measure of how narrow or broad a jet is. The analysis uses PbPb and pp data samples with integrated luminosities of 1.7 nb(-1) and 301 pb(-1), respectively, collected with the CMS experiment in 2018 and 2017. Events are required to have a photon with transverse momentum p(T)(gamma) > 100 GeV and at least one jet back-to-back in azimuth with respect to the photon and with transverse momentum p(T)(jet) such that p(T)(jet)/p(T)(gamma) > 0.4. The measured R-g and g distributions are unfolded to the particle level, which facilitates the comparison between the PbPb and pp results and with theoretical predictions. It is found that jets with p(T)(jet)/p(T)(gamma) > 0.8, i.e., those that closely balance the photon p(T)(gamma), are narrower in PbPb than in pp collisions. Relaxing the selection to include jets with p(T)(jet)/p(T)(gamma) > 0.4 reduces the narrowing of the angular structure of jets in PbPb relative to the pp reference. This shows that selection bias effects associated with jet energy loss play an important role in the interpretation of jet substructure measurements.
  • «
  • 1 (current)
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • »
Repository logo
Collections
  • Scopus Collection
  • WoS Collection
  • TrDizin Collection
  • PubMed Collection
Entities
  • Research Outputs
  • Organizations
  • Researchers
  • Projects
  • Awards
  • Equipments
  • Events
About
  • Contact
  • GCRIS
  • Research Ecosystems
  • Feedback
  • OAI-PMH

Log in to GCRIS Dashboard

Powered by Research Ecosystems

  • Privacy policy
  • End User Agreement
  • Feedback