1,722,036 research outputs found
Improved Common Monte-Carlo Settings for ATLAS and CMS
No full textThe ATLAS and CMS Collaborations both use POWHEG+PYTHIA8 for their nominal Monte-Carlo simulations. Presented here is a second iteration of agreed-upon common settings for such a setup, in order to ease comparison and combination of ATLAS and CMS results. Validation of each experiment's ability to reproduce identical samples is shown, and subsequent comparisons are made to publicly available unfolded data. An additional common setup, using the SHERPA Monte-Carlo generation package, is similarly validated and compared
Collection of notes from ATLAS and CMS
No full textAddendum to the report on the Physics at the HL-LHC, and perspectives for the HE-LHC. This addendum collects the original notes from the ATLAS and CMS Collaborations, used as input to the "Workshop on the Physics of HL-LHC, and Perspectives at HE-LHC", which took place between October 2017 and December 2018 at CERN
Combination of the W boson polarization measurements in top quark decays using ATLAS and CMS data at sqrt(s) = 8 TeV
Get PDFThe combination of measurements of the W boson polarization in top quark decays performed by the ATLAS and CMS collaborations is presented. The measurements are based on proton-proton collision data produced at the LHC at a centre-of-mass energy of 8 TeV, and corresponding to an integrated luminosity of about 20 fb−1 for each experiment. The measurements used events containing one lepton and having different jet multiplicities in the final state. The results are quoted as fractions of W bosons with longitudinal (F0), left-handed (FL), or right-handed (FR) polarizations. The resulting combined measurements of the polarization fractions are F0 = 0.693 ± 0.014 and FL = 0.315 ± 0.011. The fraction FR is calculated from the unitarity constraint to be FR = −0.008 ± 0.007. These results are in agreement with the standard model predictions at next-to-next-to-leading order in perturbative quantum chromodynamics and represent an improvement in precision of 25 (29)% for F0 (FL) with respect to the most precise single measurement. A limit on anomalous right-handed vector (VR), and left- and right-handed tensor (gL, gR) tWb couplings is set while fixing all others to their standard model values. The allowed regions are [−0.11, 0.16] for VR, [−0.08, 0.05] for gL, and [−0.04, 0.02] for gR, at 95% confidence level. Limits on the corresponding Wilson coefficients are also derived
Mono-Higgs, Mono-Top searches in the ATLAS and CMS collaborations
No full textMono-X searches in the ATLAS and CMS collaborations, where X= higgs, top
Machine learning in top quark physics at ATLAS and CMS
No full textThis note presents an overview of current and potential future applications of machine-learning-based techniques in the study of the top quark. The research community has developed a diverse set of ideas and tools, including algorithms for the efficient reconstruction of recorded collision events and innovative methods for statistical inference. Recent applications of some techniques by the ATLAS and CMS collaborations are also highlighted
Machine Learning in Top Physics in the ATLAS and CMS Collaborations
Get PDFMachine learning is essential in many aspects of top-quark related physics in
the ATLAS and CMS Collaborations. This work aims to give a brief overview over
current applications in the two collaborations as well as on-going studies for
future applications. Copyright 2023 CERN for the benefit of the ATLAS and CMS
Collaborations. Reproduction of this article or parts of it is allowed as
specified in the CC-BY-4.0 licenseComment: Talk at the 15th International Workshop on Top Quark Physics, Durham,
UK, 4-9 September 202
Review of recent top-quark LHC combinations
No full textA review of recent combinations of top-quark measurements performed at the LHC, by the ATLAS and CMS collaborations, is provided. The typical uncertainty categorisations, and their assumed correlation patterns are presented, together with the results of the combinations of the top-quark pair and single top-quark production cross sections, the top-quark mass, as well as of the boson polarisation and the charge asymmetry in events.A review of recent combinations of top-quark measurements performed at the LHC, by the ATLAS and CMS collaborations, is provided. The typical uncertainty categorisations, and their assumed correlation patterns are presented, together with the results of the combinations of the top-quark pair and single top-quark production cross sections, the top-quark mass, as well as of the boson polarisation and the charge asymmetry in events
Full Run 2 Results from ATLAS and CMS collaborations
No full textBoth ATLAS and CMS collaborations have delivered full Run 2 analysis of . This talk will discuss the details of both analysis, with a focus on the modelling strategies, and finally compare the results of the two analyses
Combination of results from the ATLAS and CMS experiments on anomalous triple gauge couplings in ZZ production from pp collisions at a centre-of-mass energy of 7 TeV at the LHC
No full textA procedure is presented to combine data from the ATLAS and CMS experiments on production to obtain constraints on anomalous neutral triple gauge boson couplings. Statistical and systematic uncertainties and their correlations are taken into account. Data from collisions at a center-of-mass energy of 7 TeV delivered by the LHC are used. The datasets correspond to integrated luminosities of 4.6 and 5.0 for ATLAS and CMS, respectively. The combination is performed in the fully leptonic decay channels ZZ → 2l2ν (ATLAS) and ZZ → 4l (ATLAS, CMS). Combined limits on the coupling parameters are −0.010 < f4γ < 0.011, −0.0087 < f4Z < 0.0091, −0.011 < f5γ < 0.010, and −0.0091 < f5Z < 0.0089 at 95% C.L., where all other parameters are fixed to the standard model values. These results represent the first combined limits of the ATLAS and CMS collaborations for anomalous gauge boson couplings
Photon production in top quark events at ATLAS and CMS
No full textTop quark production in association with a photon offers a unique test ground for the standard model predictions, as it is sensitive to the top-photon coupling. These processes are rare when compared to standard top pair production, however the large amounts of data delivered by the LHC open the window to precise measurements. This talk covered the recent inclusive and differential measurements of top quark single and pair production in association with a photon, by the ATLAS and CMS collaborations. Potential modifications to the top-photon couplings with respect to the standard model predictions are also explored using the standard model effective field theory
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