J B Singh
@puchd.ac.in
Distinguished Professor
UPES,Dehradun,Uttarkhand and Panjab University,Chandigarh
EDUCATION
M.Sc,Ph.D.
RESEARCH INTERESTS
Experimental High Energy Particle Physics
Instrumentations
Radiation Detectors
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
M.I. Abdulhamid, B.E. Aboona, J. Adam, L. Adamczyk, J.R. Adams, I. Aggarwal, M.M. Aggarwal, Z. Ahammed, E.C. Aschenauer, S. Aslam,et al.
Elsevier BV
A. Hayrapetyan, A. Tumasyan, W. Adam, J.W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P.S. Hussain,et al.
Elsevier BV
M. I. Abdulhamid, B. E. Aboona, J. Adam, L. Adamczyk, J. R. Adams, I. Aggarwal, M. M. Aggarwal, Z. Ahammed, E. C. Aschenauer, S. Aslam,et al.
American Physical Society (APS)
A. Tumasyan, W. Adam, J.W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P.S. Hussain, M. Jeitler,et al.
Elsevier BV
A. Hayrapetyan, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P. S. Hussain,et al.
American Physical Society (APS)
D. Kumar, B. Bhuyan, H. Aihara, D. M. Asner, T. Aushev, R. Ayad, V. Babu, Sw. Banerjee, M. Bauer, P. Behera,et al.
American Physical Society (APS)
D. Biswas, Sw. Banerjee, I. Adachi, H. Aihara, D. M. Asner, T. Aushev, R. Ayad, V. Babu, P. Behera, J. Bennett,et al.
American Physical Society (APS)
A dark leptophilic scalar $(\\phi_L)$ is a hypothetical particle that couples only to leptons rather than quarks. We report on a search for $\\phi_L$ in the $e^+e^- \\to \\tau^+ \\tau^- \\phi_L, ~\\phi_L \\to \\ell^+ \\ell^- ~(\\ell = e, \\mu)$ process using 626~\\invfb of data collected by the Belle experiment near the \\Y4S resonance. We validate the backgrounds with multiple control regions in data, using a novel multiclass multivariate event classifier. In absence of a signal, we quote upper limits at the 90\\% confidence level on the coupling between $\\phi_L$ and leptons. Our bounds, obtained in a blinded approach, are 19\\% more constraining than the previous limits, averaged over the mass range $0.04 \\leq m_{\\phi_L} \\leq 6.5~\\gev$. We exclude the parameter space below 4~\\gev favored by measurement of the anomalous magnetic moment of the muon.
A. Hayrapetyan, A. Tumasyan, W. Adam, J.W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P.S. Hussain,et al.
Elsevier BV
, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P. S. Hussain,et al.
Springer Science and Business Media LLC
, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P. S. Hussain,et al.
Springer Science and Business Media LLC
Abstract A search for the production of pairs of heavy Majorana neutrinos (Nℓ) from the decays of Z′ bosons is performed using the CMS detector at the LHC. The data were collected in proton-proton collisions at a center-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV, with an integrated luminosity of 138 fb−1. The signature for the search is an excess in the invariant mass distribution of the final-state objects, two same-flavor leptons (e or μ) and at least two jets. No significant excess of events beyond the expected background is observed. Upper limits at 95% confidence level are set on the product of the Z′ production cross section and its branching fraction to a pair of Nℓ, as functions of Nℓ and Z′ boson masses ($$ {m}_{{\\textrm{N}}_{\\ell }} $$ m N ℓ and $$ {m}_{{\\textrm{Z}}^{\\prime }} $$ m Z ′ , respectively) for $$ {m}_{{\\textrm{Z}}^{\\prime }} $$ m Z ′ from 0.4 to 4.6 TeV and $$ {m}_{{\\textrm{N}}_{\\ell }} $$ m N ℓ from 0.1 TeV to $$ {m}_{{\\textrm{Z}}^{\\prime }} $$ m Z ′ /2. In the theoretical framework of a left-right symmetric model, exclusion bounds in the $$ {m}_{{\\textrm{N}}_{\\ell }} $$ m N ℓ -$$ {m}_{{\\textrm{Z}}^{\\prime }} $$ m Z ′ plane are presented in both the electron and muon channels. The observed upper limit on $$ {m}_{{\\textrm{Z}}^{\\prime }} $$ m Z ′ reaches up to 4.42 TeV. These are the most restrictive limits to date on the mass of Nℓ as a function of the Z′ boson mass.
, A. Hayrapetyan, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle,et al.
Springer Science and Business Media LLC
Abstract A search for high-mass dimuon resonance production in association with one or more b quark jets is presented. The study uses proton-proton collision data collected with the CMS detector at the LHC corresponding to an integrated luminosity of 138 fb−1 at a center-of-mass energy of 13 TeV. Model-independent limits are derived on the number of signal events with exactly one or more than one b quark jet. Results are also interpreted in a lepton-flavor-universal model with Z′ boson couplings to a bb quark pair (gb), an sb quark pair (gbδbs), and any same-flavor charged lepton (gℓ) or neutrino pair (gν), with |gν| = |gℓ|. For a Z′ boson with a mass $$ {m}_{{\\textrm{Z}}^{\\prime }} $$ m Z ′ = 350 GeV (2 TeV) and |δbs| < 0.25, the majority of the parameter space with 0.0057 < |gℓ| < 0.35 (0.25 < |gℓ| < 0.43) and 0.0079 < |gb| < 0.46 (0.34 < |gb| < 0.57) is excluded at 95% confidence level. Finally, constraints are set on a Z′ model with parameters consistent with low-energy b → sℓℓ measurements. In this scenario, most of the allowed parameter space is excluded for a Z′ boson with 350 < $$ {m}_{{\\textrm{Z}}^{\\prime }} $$ m Z ′ < 500 GeV, while the constraints are less stringent for higher $$ {m}_{{\\textrm{Z}}^{\\prime }} $$ m Z ′ hypotheses. This is the first dedicated search at the LHC for a high-mass dimuon resonance produced in association with multiple b quark jets, and the constraints obtained on models with this signature are the most stringent to date.
, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P. S. Hussain,et al.
Springer Science and Business Media LLC
Abstract The second-order (v2) and third-order (v3) Fourier coefficients describing the azimuthal anisotropy of prompt and nonprompt (from b-hadron decays) J/ψ, as well as prompt ψ(2S) mesons are measured in lead-lead collisions at a center-of-mass energy per nucleon pair of $$ \\sqrt{s_{\\textrm{NN}}} $$ s NN = 5.02 TeV. The analysis uses a data set corresponding to an integrated luminosity of 1.61 nb−1 recorded with the CMS detector. The J/ψ and ψ(2S) mesons are reconstructed using their dimuon decay channel. The v2 and v3 coefficients are extracted using the scalar product method and studied as functions of meson transverse momentum and collision centrality. The measured v2 values for prompt J/ψ mesons are found to be larger than those for nonprompt J/ψ mesons. The prompt J/ψ v2 values at high pT are found to be underpredicted by a model incorporating only parton energy loss effects in a quark-gluon plasma medium. Prompt and nonprompt J/ψ meson v3 and prompt ψ(2S) v2 and v3 values are also reported for the first time, providing new information about heavy quark interactions in the hot and dense medium created in heavy ion collisions.
, A. Hayrapetyan, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle,et al.
Springer Science and Business Media LLC
Abstract A search for new physics in final states consisting of at least one photon, multiple jets, and large missing transverse momentum is presented, using proton-proton collision events at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 137 fb−1, recorded by the CMS experiment at the CERN LHC from 2016 to 2018. The events are divided into mutually exclusive bins characterized by the missing transverse momentum, the number of jets, the number of b-tagged jets, and jets consistent with the presence of hadronically decaying W, Z, or Higgs bosons. The observed data are found to be consistent with the prediction from standard model processes. The results are interpreted in the context of simplified models of pair production of supersymmetric particles via strong and electroweak interactions. Depending on the details of the signal models, gluinos and squarks of masses up to 2.35 and 1.43 TeV, respectively, and electroweakinos of masses up to 1.23 TeV are excluded at 95% confidence level.
A. Tumasyan, W. Adam, T. Bergauer, M. Dragicevic, A. Escalante Del Valle, R. Frühwirth, M. Jeitler, N. Krammer, L. Lechner, D. Liko,et al.
Elsevier BV
A. Tumasyan, W. Adam, J.W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P.S. Hussain, M. Jeitler,et al.
Elsevier BV
A. Tumasyan, W. Adam, J.W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P.S. Hussain, M. Jeitler,et al.
Elsevier BV
A. Tumasyan, W. Adam, J.W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P.S. Hussain, M. Jeitler,et al.
Elsevier BV
, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P. S. Hussain,et al.
Springer Science and Business Media LLC
Abstract The first measurement of the top quark pair ($$ \\textrm{t}\\overline{\\textrm{t}} $$ t t ¯ ) production cross section in proton-proton collisions at $$ \\sqrt{s} $$ s = 13.6 TeV 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 $$ \\textrm{t}\\overline{\\textrm{t}} $$ t t ¯ production cross section of 881 ± 23 (stat + syst) ± 20 (lumi) pb is measured, in agreement with the standard model prediction of $$ {924}_{-40}^{+32} $$ 924 − 40 + 32 pb.
, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P. S. Hussain,et al.
Springer Science and Business Media LLC
Abstract A search for a charged Higgs boson H± decaying into a heavy neutral Higgs boson H and a W boson is presented. The analysis targets the H decay into a pair of tau leptons with at least one of them decaying hadronically and with an additional electron or muon present in the event. The search is based on proton-proton collision data recorded by the CMS experiment during 2016–2018 at $$ \\sqrt{s} $$ s = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. The data are consistent with standard model background expectations. Upper limits at 95% confidence level are set on the product of the cross section and branching fraction for an H± in the mass range of 300–700 GeV, assuming an H with a mass of 200 GeV. The observed limits range from 0.085 pb for an H± mass of 300 Ge V to 0.019 pb for a mass of 700 GeV. These are the first limits on H± production in the H±→ HW± decay channel at the LHC.
, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P. S. Hussain,et al.
Springer Science and Business Media LLC
Abstract A search for physics beyond the standard model (SM) in the final state with a hadronically decaying tau lepton and a neutrino is presented. This analysis is based on data recorded by the CMS experiment from proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC, corresponding to a total integrated luminosity of 138 fb−1. The transverse mass spectrum is analyzed for the presence of new physics. No significant deviation from the SM prediction is observed. Limits are set on the production cross section of a W′ boson decaying into a tau lepton and a neutrino. Lower limits are set on the mass of the sequential SM-like heavy charged vector boson and the mass of a quantum black hole. Upper limits are placed on the couplings of a new boson to the SM fermions. Constraints are put on a nonuniversal gauge interaction model and an effective field theory model. For the first time, upper limits on the cross section of t-channel leptoquark (LQ) exchange are presented. These limits are translated into exclusion limits on the LQ mass and on its coupling in the t-channel. The sensitivity of this analysis extends into the parameter space of LQ models that attempt to explain the anomalies observed in B meson decays. The limits presented for the various interpretations are the most stringent to date. Additionally, a model-independent limit is provided.
, A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P. S. Hussain,et al.
Springer Science and Business Media LLC
Abstract A search for supersymmetry is presented in events with a single charged lepton, electron or muon, and multiple hadronic jets. The data correspond to an integrated luminosity of 138 fb−1 of proton-proton collisions at a center-of-mass energy of 13 TeV, recorded by the CMS experiment at the CERN LHC. The search targets gluino pair production, where the gluinos decay into final states with the lightest supersymmetric particle (LSP) and either a top quark-antiquark ($$ \\textrm{t}\\overline{\\textrm{t}} $$ t t ¯ ) pair, or a light-flavor quark-antiquark ($$ \\textrm{q}\\overline{\\textrm{q}} $$ q q ¯ ) pair and a virtual or on-shell W boson. The main backgrounds, $$ \\textrm{t}\\overline{\\textrm{t}} $$ t t ¯ pair and W+jets production, are suppressed by requirements on the azimuthal angle between the momenta of the lepton and of its reconstructed parent W boson candidate, and by top quark and W boson identification based on a machine-learning technique. The number of observed events is consistent with the expectations from standard model processes. Limits are evaluated on supersymmetric particle masses in the context of two simplified models of gluino pair production. Exclusions for gluino masses reach up to 2120 (2050) GeV at 95% confidence level for a model with gluino decay to a $$ \\textrm{t}\\overline{\\textrm{t}} $$ t t ¯ pair (a $$ \\textrm{q}\\overline{\\textrm{q}} $$ q q ¯ pair and a W boson) and the LSP. For the same models, limits on the mass of the LSP reach up to 1250 (1070) GeV.
, I. Adachi, L. Aggarwal, H. Aihara, N. Akopov, A. Aloisio, N. Anh Ky, D. M. Asner, T. Aushev, V. Aushev,et al.
Springer Science and Business Media LLC
Abstract We measure CP asymmetries and branching-fraction ratios for B±→ DK± and Dπ± decays with D →$$ {K}_{\\textrm{S}}^0 $$ K S 0 K±π∓, where D is a superposition of D0 and $$ \\overline{D} $$ D ¯ 0. We use the full data set of the Belle experiment, containing 772 × 106$$ B\\overline{B} $$ B B ¯ pairs, and data from the Belle II experiment, containing 387 × 106$$ B\\overline{B} $$ B B ¯ pairs, both collected in electron-positron collisions at the Υ(4S) resonance. Our results provide model-independent information on the unitarity triangle angle ϕ3.
A. Tumasyan, W. Adam, J. W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P. S. Hussain, M. Jeitler,et al.
American Physical Society (APS)
A search for the standard model Higgs boson decaying to a charm quark-antiquark pair, H→cc[over ¯], produced in association with a leptonically decaying V (W or Z) boson is presented. The search is performed with proton-proton collisions at sqrt[s]=13 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138 fb^{-1}. Novel charm jet identification and analysis methods using machine learning techniques are employed. The analysis is validated by searching for Z→cc[over ¯] in VZ events, leading to its first observation at a hadron collider with a significance of 5.7 standard deviations. The observed (expected) upper limit on σ(VH)B(H→cc[over ¯]) is 0.94 (0.50_{-0.15}^{+0.22})pb at 95% confidence level (C.L.), corresponding to 14 (7.6_{-2.3}^{+3.4}) times the standard model prediction. For the Higgs-charm Yukawa coupling modifier, κ_{c}, the observed (expected) 95% C.L. interval is 1.1<|κ_{c}|<5.5 (|κ_{c}|<3.4), the most stringent constraint to date.
A. Tumasyan, W. Adam, J.W. Andrejkovic, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, A. Escalante Del Valle, P.S. Hussain, M. Jeitler,et al.
Elsevier BV
L. Aggarwal, H. Ahmed, H. Aihara, N. Akopov, A. Aloisio, N. Anh Ky, D. M. Asner, H. Atmacan, T. Aushev, V. Aushev,et al.
American Physical Society (APS)
We present the first measurement of the ratio of branching fractions of inclusive semileptonic B-meson decays, R(X_{e/μ})=B(B→Xeν)/B(B→Xμν), a precision test of electron-muon universality, using data corresponding to 189 fb^{-1} from electron-positron collisions collected with the Belle II detector. In events where the partner B meson is fully reconstructed, we use fits to the lepton momentum spectra above 1.3 GeV/c to obtain R(X_{e/μ})=1.007±0.009(stat)±0.019(syst), which is the most precise lepton-universality test of its kind and agrees with the standard-model expectation.