Complex statistical tools are required for the extraction and interpretation of measurements at the LHC experiments. Tools used by ATLAS and CMS are now public, e.g. Combine and TRExFitter. These can be used for more complex actions such as multi-analysis combinations, unfolding and EFT interpretations. This talk will discuss the underlying statistical methods, including recent developments...
A reinterpretation of four top quark (tttt) production is presented using the full Run 2 dataset recorded by the CMS experiment, corresponding to an integrated luminosity of 138/fb. The analysis targets BSM scenarios using the existing tttt production measurement, including constraints on effective field theory (EFT) operators, top-philic heavy resonances, and the top-Yukawa coupling. The...
A search for charged lepton flavor violation (CLFV) in top quark interactions is presented. The search uses proton-proton collision data collected with the CMS experiment at the LHC during Run2, corresponding to an integrated luminosity of 138 fb^{-1} at a center-of-mass energy of 13 TeV. The study targets both single top production via CLFV interaction and top quark pair production followed...
The LHC produces a vast sample of top quark pairs and single top quarks. Measurements of the inclusive top quark production rates at the LHC have reached a precision of several percent and test advanced Next-to-Next-to-Leading Order predictions in QCD. Differential measurements in several observables are important to test SM predictions and improve Monte Carlo generator predictions. In this...
Effective Field Theory (EFT) provides a universal framework for probing beyond the Standard Model physics at LHC scales. Recent advances in analysis techniques and increased dataset complexity have significantly enhanced the sensitivity of EFT studies. We present the latest results on EFT obtained using ttbar production by the CMS collaboration, probing interactions between the top quark and...
Many-parameter fits to precise measurements in the framework of the Standard Model Effective Field Theory are becoming a standard interpretation of LHC and other collider data. In this contribution an overview is given of state-of-the-art EFT interpretations in ATLAS with particular emphasis on results in the top quark sector.
Many-parameter fits to precise measurements in the framework of the Standard Model Effective Field Theory are becoming a standard interpretation of LHC and other collider data. In this contribution an overview is given of state-of-the-art EFT interpretations in ATLAS with particular emphasis on results in the top quark sector.
The exceptionally large dataset collected by the ATLAS and CMS detectors at the highest proton-proton collision energies provided by the LHC enables precision testing of theoretical predictions using an extensive sample of top quark events. One example of this is the spin correlation of top quarks, which can uniquely be probed due to the decay time being shorter than hadronisation time. This...
A violation of the charge-parity (CP) symmetry can explain the paradox of the baryon asymmetry of the universe. We have studied a forward-backward asymmetry of an angular distribution defined in the top quark sector, which is strongly related to the CP-violation. The measurement is performed in the t-channel production of single top quark in proton-proton collisions, at center-of-mass energy...
The exceptionally large dataset collected by the ATLAS and CMS detectors at the highest proton-proton collision energies provided by the LHC enables precision testing of theoretical predictions using an extensive sample of top quark events. One example of this is the spin correlation of top quarks, which can uniquely be probed due to the decay time being shorter than hadronisation time. This...
We present analytic expressions for the one-loop QCD helicity amplitudes contributing to top-quark pair production in association with a photon or a jet at the Large Hadron Collider (LHC), evaluated through $O(\epsilon^2)$ in the dimensional regularisation parameter, $\epsilon$. These amplitudes are required to construct the two-loop hard functions that enter the NNLO QCD computation. The...
Rare event classification in high-energy physics (HEP) plays a crucial role in probing physics beyond the Standard Model (BSM). Such processes serve as indirect searches for new physics by testing deviations from SM predictions in extreme kinematic regimes. The production of four top quarks in association with a ($W^-$) boson at $(\sqrt{s} = 13)$ $ TeV$ is an exceptionally rare SM process with...
We will report on an extensive survey of rare and exclusive few-body decays of the top quark, defined as those with branching fractions BR≲$10^{-5}$ and two or three final-state particles [1]. Such rare decays probe physics beyond the Standard Model (BSM), constitute a background for exotic decays into new BSM particles, and provide precise information on quantum chromodynamics factorization...
The high center-of-mass energy of proton-proton collisions and the large available datasets at the CERN Large Hadron Collider allow the study of rare processes of the Standard Model with unprecedented precision. Measurements of rare SM processes provide new tests of the SM predictions with the potential to unveil discrepancies with the SM predictions or provide important input for the...
The top-quark mass is one of the key fundamental parameters of the Standard Model that must be determined experimentally. Its value has an important effect on many precision measurements and tests of the Standard Model. The Tevatron and LHC experiments have developed an extensive program to determine the top quark mass using a variety of methods. In this contribution, the top quark mass...
Recent results from the CMS experiment at the Large Hadron Collider indicate the presence of a top-quark pair bound state near the $t\bar{t}$ threshold region. We present a way to reconstruct a toponium state at the ttbar threshold region formed at the Large Hadron Collider using Recursive Jigsaw Reconstruction. We have considered the Non-Relativistic QCD based toponium model implemented in...
This talk is to present new techniques in ATLAS for object reconstruction and identification
A search for the standard model Higgs boson decaying to a cc pair, produced in association with a tt pair (ttH) is presented. The search is performed with the full Run 2 dataset, corresponding to an integrated luminosity of 138/fb. Advanced machine learning techniques are employed for jet flavor identification and event classification. The H->bb decay is measured simultaneously. The...
We present studies of the b_bbar_4l (bb4l) package from the POWHEG BOX RES Monte Carlo generator, used to model top quark productions for the CMS experiment at the LHC. The bb4l package includes next-to-leading order matrix element calculations interfaced to parton shower for top quark pair production, the associated production of a single top quark with a W boson, their interferences, and the...
We present the first analytic results of next-to-next-to-next-to-leading-order (N3LO) QCD corrections to the top-quark decay width. We focus on the dominant leading color contribution, which includes light-quark loops. At next-to-next-to-leading order (NNLO), this dominant contribution accounts for 95% of the total correction. By utilizing the optical theorem, the N3LO corrections are related...
The high center-of-mass energy of proton-proton collisions and the large available datasets at the CERN Large Hadron Collider allow the study of rare processes of the Standard Model with unprecedented precision. Measurements of rare SM processes provide new tests of the SM predictions with the potential to unveil discrepancies with the SM predictions or provide important input for the...
The Future Circular Collider (FCC) programme provides unique opportunities for comprehensive and precise studies of top quark physics. At the FCC-ee, operating at and slightly above the top pair threshold, a precise measurement of the top quark mass with a statistical and systematic accuracy down to the MeV level can be achieved through a threshold scan. Furthermore, the FCC-ee run at 365 GeV...
The current MiNNLOPS technology enables next-to-next-to-leading order (NNLO) QCD predictions matched to parton showers (NNLO+PS) for heavy-quark pair production in arbitrary kinematics (QQF), within the POWHEG framework. Among QQF processes, Higgs production in association with a heavy-quark pair is particularly relevant for LHC phenomenology. In the case of ttH production, the main bottleneck...
We present the calculation of two-loop Feynman integrals contributing to NNLO QCD corrections to the production of a top-quark pair in association with a W boson at hadron colliders, in the leading colour approximation. This process constitutes a key signature at the Large Hadron Collider, and the precise prediction of its cross-section is imperative for comparisons with experimental data. In...
