Papers by Sergei Gninenko
Searches are presented for heavy gauge bosons decaying into a top and a bottom quark in data coll... more Searches are presented for heavy gauge bosons decaying into a top and a bottom quark in data collected by the CMS experiment at $\sqrt{s}$ = 13 TeV that correspond to an integrated luminosity of 2.2 and 2.6 fb$^{-1}$ in the leptonic and hadronic analyses, respectively. Two final states are analyzed, one containing a single electron, or muon, and missing transverse momentum, and the other containing multiple jets and no electrons or muons. No evidence is found for a right-handed W' boson (W'$_R$) and the combined analyses exclude at 95% confidence level W'$_R$ with masses below 2.4 TeV if $M_{{W'}_{R}} \gg M_{{\nu}_{R}}$ (mass of the right handed neutrino), and below 2.6 TeV if $M_{{W'}_{R}} < M_{{\nu}_{R}}$. The results provide the most stringent limits for right-handed W' bosons in the top and bottom quark decay channel.
Journal of High Energy Physics, 2021
A measurement of the top quark mass is performed using a data sample enriched with single top qua... more A measurement of the top quark mass is performed using a data sample enriched with single top quark events produced in the t channel. The study is based on proton- proton collision data, corresponding to an integrated luminosity of 35.9 fb−1, recorded at $$ \sqrt{s} $$ s = 13 TeV by the CMS experiment at the LHC in 2016. Candidate events are selected by requiring an isolated high-momentum lepton (muon or electron) and exactly two jets, of which one is identified as originating from a bottom quark. Multivariate discriminants are designed to separate the signal from the background. Optimized thresholds are placed on the discriminant outputs to obtain an event sample with high signal purity. The top quark mass is found to be $$ {172.13}_{-0.77}^{+0.76} $$ 172.13 − 0.77 + 0.76 GeV, where the uncertainty includes both the statistical and systematic components, reaching sub-GeV precision for the first time in this event topology. The masses of the top quark and antiquark are also determin...
The European Physical Journal C, 2020
The standard model (SM) production of four top quarks ($$\text {t} {}{\overline{\text {t}}} \text... more The standard model (SM) production of four top quarks ($$\text {t} {}{\overline{\text {t}}} \text {t} {}{\overline{\text {t}}} $$tt¯tt¯) in proton–proton collisions is studied by the CMS Collaboration. The data sample, collected during the 2016–2018 data taking of the LHC, corresponds to an integrated luminosity of 137$$\,\text {fb}^{-1}$$fb-1 at a center-of-mass energy of 13$$\,\text {TeV}$$TeV. The events are required to contain two same-sign charged leptons (electrons or muons) or at least three leptons, and jets. The observed and expected significances for the $$\text {t} {}{\overline{\text {t}}} \text {t} {}{\overline{\text {t}}} $$tt¯tt¯ signal are respectively 2.6 and 2.7 standard deviations, and the $$\text {t} {}{\overline{\text {t}}} \text {t} {}{\overline{\text {t}}} $$tt¯tt¯ cross section is measured to be $$12.6^{+5.8}_{-5.2}\,\text {fb} $$12.6-5.2+5.8fb. The results are used to constrain the Yukawa coupling of the top quark to the Higgs boson, $$y_{\text {t}}$$yt, yiel...
Physics Letters B, 2020
The ATLAS Collaboration A search for non-resonant Higgs boson pair production, as predicted by th... more The ATLAS Collaboration A search for non-resonant Higgs boson pair production, as predicted by the Standard Model, is presented, where one of the Higgs bosons decays via the H → bb channel and the other via one of the H → WW * /Z Z * /ττ channels. The analysis selection requires events to have at least two b-tagged jets and exactly two leptons (electrons or muons) with opposite electric charge in the final state. Candidate events consistent with Higgs boson pair production are selected using a multi-class neural network discriminant. The analysis uses 139 fb −1 of pp collision data recorded at a centre-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. An observed (expected) upper limit of 1.2 (0.9 +0.4 −0.3) pb is set on the non-resonant Higgs boson pair production cross-section at 95% confidence level, which is equivalent to 40 (29 +14 −9) times the value predicted in the Standard Model.
Journal of High Energy Physics, 2019
A search for new particles has been conducted using events with two high transverse momentum τ le... more A search for new particles has been conducted using events with two high transverse momentum τ leptons that decay hadronically and at least two energetic jets. The analysis is performed using data from proton-proton collisions at $$ \sqrt{s}=13 $$ s = 13 TeV, collected by the CMS experiment at the LHC in 2016 and corresponding to an integrated luminosity of 35.9 fb−1. The observed data are consistent with standard model expectations. The results are interpreted in the context of two physics models. The first model involves right-handed charged bosons, WR, that decay to heavy right-handed Majorana neutrinos, N ℓ (ℓ = e, μ, τ), arising in a left-right symmetric extension of the standard model. The model considers that Ne and N μ are too heavy to be detected at the LHC. Assuming that the N τ mass is half of the WR mass, masses of the WR boson below 3.50 TeV are excluded at 95% confidence level. Exclusion limits are also presented considering different scenarios for the mass ratio betwe...
Journal of High Energy Physics, 2017
Journal of Instrumentation, 2017
EPJ Web of Conferences, 2016
Physics Letters B, 2015
ABSTRACT
Journal of High Energy Physics, 2016
The European Physical Journal C, 2015
Journal of High Energy Physics, 2011
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Papers by Sergei Gninenko