Description
Conveners:
- Alexander Grohsjean (University of Hamburg)
- Timothรฉe Theveneaux-Pelzer (CPPM, Aix-Marseille Universitรฉ, CNRS/IN2P3)
- Eleni Vryonidou (University of Manchester)
Contact: eps-hep2025-conveners-T06-l@in2p3.fr
The production of an odd number of top quark events is necessarily suppressed in the SM, as it is mediated by the electroweak interactions, but naturally takes place in a number of BSM models, e.g. those involving FCNCs. As a consequence, the study of such processes is a promising tool in the search for new physics. We present a number of studies of such processes, including an observation of...
The exceptionally large dataset collected by the ATLAS detector 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. Recent measurements include total and differential top quark cross sections, as well as measurements of associated top quark production. This contribution presents...
Precision measurements of top quark production cross sections are crucial for validating the Standard Model and investigating potential new physics. In this talk, we present both inclusive and differential measurements of top quark production in association with a photon or a W boson, using CMS data from 13โฏTeV pp collisions. Our results achieve improved precision, and we report, for the first...
We present the first observation of single top quark production in association with a W and a Z boson in proton-proton collisions using 13 and 13.6 TeV data recorded with the CMS detector corresponding to integrated luminosities of 138 and 61.9 fb-1, respectively. Events are selected if they contain three or four charged leptons, which can be electrons or muons. State-of-the-art machine...
A high-precision measurement of luminosity is essential for all ATLAS physics analyses, with the luminosity uncertainty limiting precise cross-section measurements of W, Z, and top-quark processes. The preliminary ATLAS luminosity calibration in Run 3 of the LHC is presented, with a particular focus on measurements using the Inner Detector. Methods exploiting the multiplicity of reconstructed...
Previous studies have shown that a class of observables for massless $e^+e^โ$ colliders producing primary top quarks can be used to measure the top quark mass with a precision smaller than $\Lambda_{\rm QCD}$. The maximal sensitivity to the top mass is attained in the peak of the distribution, where several Effective Field Theories (EFTs) are applicable. The use of EFTs allows 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...
Precision measurements of top quark properties are of paramount importance for our understanding of the SM. We present several measurements of asymmetries in top quark production and of its spin correlations. These measurements allow us to test the fundamentals of quantum mechanics at the highest energies achieved so far and also serve as an excellent probe for physics beyond the Standard Model.
Near the top quark pair production threshold, non-relativistic QCD predicts an enhancement of ttbar production in pseudoscalar states. Color-singlet contributions are expected to produce a distinct resonance just below the tt threshold, offering a unique testable signature at the LHC. In this talk, we present the first observation of such a contribution in the dileptonic final state. In...
The exceptionally large dataset collected by the ATLAS detector 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. This wealth of data has opened the door to new measurements of top quark properties including those particularly sensitive to the ttbar threshold region, such as...
We present the first observation of electroweak production of a photon in association with two forward jets in proton-proton collisions using 13 TeV data recorded by the CMS experiment corresponding to an integrated luminosity of 138 fb-1 The analysis is performed in a region enriched with vector boson fusion (VBF) production, with a requirement on the transverse momentum of the leading photon...
This talk reviews recent measurements of multiboson production using CMS data at sqrt(s) = 13 and 13.6 TeV. Inclusive and differential cross-sections are measured using several kinematic observables.
Precision measurements of Drell-Yan processes, including on-shell and off-shell W- and Z-boson production, offer key input to improve the understanding of QCD and the accuracy of PDFs. In addition, Drell-Yan measurements are instrumental for precision measurements of fundamental electroweak parameters, such as W boson mass measurement. This talk summarizes recent results from ATLAS on this topic.
The Electroweak sector of the Standard Model is currently being scrutinized with a extraordinary level of detail. Many of the Electroweak and QCD processes can be computed nowadays at several orders in perturbation theory, reaching an unprecedented precision. Thanks to the increasing sizes of the data samples collected at LHCb, together with the developments on the theory side, it is possible...
Electronโpositron annihilation into hadrons accompanied by an energetic photon provides a powerful tool to measure the hadronic cross-section across a broad energy range at high-luminosity flavour factories such as DAPHNE, CESR, PEP-II, KEK-B, SuperKEKB, and BESIII. The Monte Carlo event generator PHOKHARA has been widely used and simulates this process with next-to-leading order (NLO)...
The Laser Und XFEL Experiment (LUXE), in planning at DESY Hamburg, is intended to study quantum electrodynamics (QED) in strong electromagnetic fields, and in particular the transition from perturbative to non-perturbative. In the non-perturbative regime, electron-positron pairs tunnel out of the vacuum in a manner akin to the Schwinger process. The experiment will make precision measurements...
A statistical combination of vector boson scattering processes is presented, based on proton-proton collision data at a center-of-mass energy of โs = 13โฏTeV, recorded by the CMS detector during Run 2 of the LHC and corresponding to an integrated luminosity of 138โฏfbโปยน. The analysis includes both fully leptonic and semileptonic decay channels, covering same-sign WW, opposite-sign WW, ZZ, and WZ...
Measurements of rare processes in the electroweak sector provide unprecedented constraints of the SM theory, and unique sensitivity to study the electroweak symmetry breaking (VBS processes) and the quartic boson self-couplings (VBS and triboson processes). In addition to cross-section measurements, studies of boson polarization states in VBS processes are being actively pursued to bring...
Observation of the electroweak production of four charged leptons and a photon, and first evidence at the LHC for the triboson process ZZฮณ with the fully leptonic decays of the Z-bosons using pp collision data collected by the CMS experiment during the LHC Run 2 at 13 TeV, corresponding to an integrated luminosity of 138 /fb.
The MUonE experiment at CERN aims to determine the leading-order hadronic contribution to the muon g-2 by an innovative approach, using elastic scattering of 160 GeV muons on atomic electrons in a low-Z target. The method relies on the measurement of the hadronic contribution to the running of the QED coupling, $\Delta\alpha_{had}(t)$, which can be extracted from a precise measurement of the...
Robust and precise Monte Carlo generators are paramount to the analysis of low-energy $e^+e^-$ scattering experiments at electron-positron colliders, which are essential for precision tests of the Standard Model, such as the dispersive evaluation of the hadronic vacuum polarization contribution to the muon $gโ2$. As part of the community-driven initiative RadioMonteCarlow2, we aim to collect...
PrecisionSM is an annotated database that compiles the available data on low-energy cross sections of electron-positron collisions into hadronic channels. This database organizes and collects data samples from $e^+e^-$ experiments, which are used as input for the data-driven theoretical evaluation of the muon anomalous magnetic moment, $a_{\mu}$, serving as a precise test of the Standard Model...
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...
Thanks to the extended energy range and beam polarization, the linear option for future e+e- collider facility offers unique opportunities for precision electroweak studies and top quark measurements. Beam polarization is not only essential for many observables but also allows better control of background and reduction of systematic uncertainties. The extended energy range of the linear...
The Large Hadron electron Collider (LHeC) is the proposal to deliver electron-proton/nucleus collisions at CERN using the LHC hadron or nuclear beams and a 50 GeV electron beam from an Energy Recovery Linac (ERL) in racetrack configuration. While the 2021 update of its CDR [1] contemplated concurrent operation of electron-hadron and hadron-hadron collisions at the HL-LHC followed by standalone...
High energy photon-photon interactions provide unique opportunity for studying with high precision the electroweak sector of particle physics at future electron-hadron colliders [1]. In particular, facilities such as the LHeC [2, 3], and its proposed phase-one option at a 0.75 TeV centre-of-mass energy [4], FCC-eh, or SppC-eh, will offer very advantageous experimental conditions and at the...
The electron-positron stage of the Future Circular Collider (FCC) will provide measurements of the Z and W bosons couplings and masses 1--3 orders of magnitude better than the present state-of-the-art. With the run around the Z pole, where the integrated luminosity is expected to be about six orders of magnitude larger than at LEP, the Z boson mass and width, as well as the $Z \to b\bar{b}$...
Monte Carlo generators are at the core of LHC data analyses and will remain crucial for future lepton colliders offering unprecedented energies and luminosities. With a Higgs factory on the horizon and ongoing studies on the physics potential of a muon collider, the development of the generators must be continuously supported to meet the anticipated experimental precision.
We give a status...
