scholarly journals Measurement of the Top Quark Mass in the All-Hadronic Top-Antitop Decay Channel Using Proton-Proton Collision Data from the ATLAS Experiment at a Centre-of-Mass Energy of 8 TeV

2015 ◽  
Author(s):  
Thomas McCarthy
2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
R. Aaij ◽  
◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
B. Adeva ◽  
...  

Abstract The shape of the $$ {B}_s^0\to {D}_s^{\ast -}{\mu}^{+}{\nu}_{\mu } $$ B s 0 → D s ∗ − μ + ν μ differential decay rate is obtained as a function of the hadron recoil parameter using proton-proton collision data at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.7 fb−1 collected by the LHCb detector. The $$ {B}_s^0\to {D}_s^{\ast -}{\mu}^{+}{\nu}_{\mu } $$ B s 0 → D s ∗ − μ + ν μ decay is reconstructed through the decays $$ {D}_s^{\ast -}\to {D}_s^{-}\gamma $$ D s ∗ − → D s − γ and $$ {D}_s^{-}\to {K}^{-}{K}^{+}{\pi}^{-} $$ D s − → K − K + π − . The differential decay rate is fitted with the Caprini-Lellouch-Neubert (CLN) and Boyd-Grinstein-Lebed (BGL) parametrisations of the form factors, and the relevant quantities for both are extracted.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
T. Bergauer ◽  
...  

Abstract 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 $$ \sqrt{s} $$ 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 $$ \sqrt{s} $$ 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 $$ {1.19}_{-0.39}^{+0.40}{\left(\mathrm{stat}\right)}_{-0.14}^{+0.15}\left(\mathrm{syst}\right) $$ 1.19 − 0.39 + 0.40 stat − 0.14 + 0.15 syst . 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.


2013 ◽  
Vol 28 (26) ◽  
pp. 1330038 ◽  
Author(s):  
SHABNAM JABEEN

This review summarizes the recent results for top quark and Higgs boson measurements from experiments at Tevatron, a proton–antiproton collider at a center-of-mass energy of [Formula: see text], and the Large Hadron Collider, a proton–proton collider at a center-of-mass energy of [Formula: see text]. These results include the discovery of a Higgs-like boson and measurement of its various properties, and measurements in the top quark sector, e.g. top quark mass, spin, charge asymmetry and production of single top quark.


2021 ◽  
Vol 81 (11) ◽  
Author(s):  
G. Aad ◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
K. Abeling ◽  
...  

AbstractA search for R-parity-violating supersymmetry in final states characterized by high jet multiplicity, at least one isolated light lepton and either zero or at least three b-tagged jets is presented. The search uses $${139}\,{\text {fb}^{-1}}$$ 139 fb - 1 of $$\sqrt{s} = {13}\hbox { TeV}$$ s = 13 TeV proton–proton collision data collected by the ATLAS experiment during Run 2 of the Large Hadron Collider. The results are interpreted in the context of R-parity-violating supersymmetry models that feature gluino production, top-squark production, or electroweakino production. The dominant sources of background are estimated using a data-driven model, based on observables at medium jet multiplicity, to predict the b-tagged jet multiplicity distribution at the higher jet multiplicities used in the search. Machine-learning techniques are used to reach sensitivity to electroweakino production, extending the data-driven background estimation to the shape of the machine-learning discriminant. No significant excess over the Standard Model expectation is observed and exclusion limits at the 95% confidence level are extracted, reaching as high as 2.4 TeV in gluino mass, 1.35 TeV in top-squark mass, and 320 (365) GeV in higgsino (wino) mass.


2018 ◽  
Vol 182 ◽  
pp. 02123
Author(s):  
Junquan Tao

The latest results in the search for rare and exotic Higgs boson decays in proton-proton collision events collected with the CMS detector at the LHC are presented. The searches are performed for several decay modes of Higgs boson including H → X(X → 2ℓ)γ (X = Z, γ* and ℓ = e, μ), H → μμ=ee, invisible decays, lepton flavour violating decays and Higgs decay to light scalars or pseudo-scalars. No hint for new physics has been found from the analyzed results with the full LHC run-1 data collected during 2011 and 2012 at √s = 7-8 TeV and with the run-2 data at √s = 13 TeV collected during 2015 and 2016. Limits are set for all the searches which have been performed by CMS.


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