Conveners
T07: Top and Electroweak Physics: Part 1
- Elisabetta Gallo-Voss (CMS (CMS-Experiment))
- William Barter (Imperial College London)
T07: Top and Electroweak Physics: Part 2
- Alexander Grohsjean (CMS (CMS Fachgruppe TOP))
- Eleni Vryonidou
T07: Top and Electroweak Physics: Part 3
- Elisabetta Gallo-Voss (CMS (CMS-Experiment))
- Eleni Vryonidou
T07: Top and Electroweak Physics: Part 4
- Francesco Spanò (Royal Holloway University of London)
- Alexander Grohsjean (CMS (CMS Fachgruppe TOP))
T07: Top and Electroweak Physics: Part 5
- William Barter (Imperial College London)
- Elisabetta Gallo-Voss (CMS (CMS-Experiment))
T07: Top and Electroweak Physics: Part 6
- Alexander Grohsjean (CMS (CMS Fachgruppe TOP))
- Eleni Vryonidou
Description
20 Minutes talks are meant as 15'+5'
15 Minutes talks are meant as 12'+3'
Precision measurements of the production cross-sections of W/Z boson at LHC provide important tests of perturbative QCD and information about the parton distribution functions for quarks within the proton. We present measurements of the transverse momentum distribution of the vector boson at 13 TeV. If available differential measurements in the side band of the Z-mass peak are also presented. ...
Recent inclusive W,Z measurements and differential results on DY dilepton productions in a wide range of invariant masses are presented, making use of CMS proton collision data at 13 TeV.
The LHCb experiment covers the forward region of proton-proton collisions, and it can improve the current electroweak landscape by studying the production of W and Z boson in this phase space complementary to ATLAS and CMS. Several preliminary studies have shown the potential of the LHCb experiment to measure the W boson mass with a muon pT based technique, which could yield a statistical...
In this work, we present a new technique to measure the longitudinal and transverse polarization fractions of hadronic decays of boosted $W$ bosons. We introduce a new jet substructure observable denoted as $p_\theta$, which is a proxy for the parton level decay polar angle of the $W$ boson in its rest frame. We show that the distribution of this observable is sensitive to the polarization of...
The European Strategy for Particle Physics ESPP has recommended a financial and technical feasibility of the FCC colliders and their infrastructure to be carried out for its next upgrade around 2025/6. The integral FCC program combines in the same 100km infrastructure a high luminosity Higgs and Electroweak factory e+e- collider, FCC-ee, followed by a 100 TeV hadron collider. With its high...
The Future Circular Collider with electron-positron beams (FCC-ee) should provide improvements of the electroweak precision measurement concerning Z, W, H, and their masses by a large factor over the present status. The unparalleled experimental precision would open, via Electroweak loop corrections, a broad discovery potential for new, at least weakly interacting particles up to high energy...
The associated production of vector bosons and jets originating from heavy-flavour (c or b) quarks is a large background source in measurements of other standard model processes, Higgs boson studies, and many searches for physics beyond the standard model. The study of events with a vector boson accompanied by heavy-flavour jets is crucial to refine the theoretical calculations in perturbative...
I will present an analytic computation of the two-loop QCD corrections to ud->Wbb process for an on-shell W-boson using the leading colour and massless bottom quark approximations. The computation involves integration-by-parts reduction of the unpolarised squared matrix element using finite field reconstruction techniques and identifying an independent basis of special functions that allows an...
Comprehensive measurements of inclusive and differential cross-sections for top-quark production are presented. The cross section for production of top-quark-antiquark pair is measured in the dilepon, lepton+jets and all-hadronic channels as function of kinematic properties the top quarks and of their final decay products, also including final states featuring top quarks with high transverse...
Latest CMS measurements of top quark pair production, inclusive and/or differential is presented. Boosted regime is included in this talk.
We present the first matched computation of top-quark pair production at next-to-next-to-leading order (NNLO) in QCD with all-order radiative corrections as implemented via parton-shower (PS) simulations. This result has been obtained by constructing the MiNNLOPS method for the production of heavy quarks, which constitutes the first NNLO+PS prediction for reactions with colour charges in the...
I discuss recent theoretical results with soft-gluon corrections for various top-quark production processes through approximate N3LO, including soft anomalous dimensions through three loops. I present numerical results for total cross sections as well as single- and double-differential distributions for top-pair and various single-top processes, including three-particle final states, and I...
Measurements in boosted top quark production test the Standard Model in a previously unexplored regime with a strongly enhanced sensitivity to high-scale new phenomena. Dedicated techniques have been developed to reconstruct and identify boosted top quarks. In this contribution measurements of the ATLAS experiment are presented of the differential cross section and asymmetries in this extreme...
The inclusive cross section for production of a single top quark production in association with a W boson is measured in both the dilepton and in the lepton+jets final state. Events are are selected requiring two (one) charged leptons and one or two (at least three) jets with at most two (one) jets (jet) identified as containing b hadrons. Multivariate discriminants are constructed to separate...
Latest CMS measurements of single top quark, inclusive and/or differential is presented. The talk also covers single top production in association with additional bosons.
Processes involving the Higgs boson and the top quark are of high interest in searches for BSM physics because they allow to directly measure the top Yukawa coupling. Although it has a relatively small cross section, the single top and Higgs production process pp → Htj is particularly sensitive to new physics, calling for precise theoretical predictions. For many processes at the LHC, a...
The LUXE experiment (LASER Und XFEL Experiment) is a new experiment in planning at DESY Hamburg using the electron beam of the European XFEL. LUXE is intended to study collisions between a high-intensity optical LASER and 16.5 GeV electrons from the XFEL electron beam, as well as collisions between the optical LASER and high-energy secondary photons. The physics objective of LUXE are processes...
The measurement of exclusive $e^+e^-$ to hadrons processes is a significant part of the physics program of BABAR experiment, aimed to improve the calculation of the hadronic contribution to the muon $g−2$ and to study the intermediate dynamics of the processes. We present the most recent studies performed on the full data set of about 470 fb$^{−1}$ collected at the PEP-II e+e− collider at a...
Vector boson scattering is a key production process to probe the electroweak symmetry breaking of the standard model, since it involves both self-couplings of vector bosons and coupling with the Higgs boson. If the Higgs mechanism is not the sole source of electroweak symmetry breaking, the scattering amplitude deviates from the standard model prediction at high scattering energy. Moreover,...
Measurements that exploit the weak vector-boson scattering and weak vector-boson fusion are fundamental tests of the gauge structure of the Standard Model and are sensitive to anomalous weak boson self interactions. In this talk, we present recent results in this contest performed by the ATLAS experiment using proton-proton collisions at sqrt(s)=13 TeV. Measurements of Zjj final states...
We will discuss the sensitivity to quartic anomalous couplings between photons and W/Z bosons at the LHC using intact protons in the final state. This allows obtaining a negligible background for 300 fb−1 of data and improves the sensitivities to anomalous couplings by two or three orders of magnitude compared to standard methods. We will also discuss the sensitivity to axion-like particles...
We present a systematic interpretation of vector boson scattering (VBS) and diboson measurements from the LHC in the framework of the dimension-six Standard Model Effective Field Theory (SMEFT), based on our results available at https://arxiv.org/abs/2101.03180.
We try to understand what is the interplay between VBS and diboson measurements in order to constrain 16 independent directions in...
Measurements of multiple electroweak bosons production at the LHC constitute an important test of the Standard Model. They are sensitive to the properties of electroweak-boson self-interactions and provide a test of the electroweak theory and of the perturbative quantum chromodynamics. In this talk, we present recent results from the ATLAS experiment for multi-boson production in...
This talk reviews recent measurements of multiboson production using CMS data. Inclusive and differential cross sections are measured using several kinematic observables.
Measurements of the inclusive top-quark pair production cross section and of the W boson polarisation in top quark decays are presented. The most precise results performedd by the ATLAS and CMS collaborations using all the proton-proton collisions data produced at the LHC at center-of-mass energies of 7 and 8 Te. The combined results provide both lower uncertainties than the individual...
The top quark mass is one of the fundamental parameters of the Standard Model that must be determined experimentally. Single measurements of the top quark mass have reached a precision well below the %-level. Different methods - based on a direct reconstruction of the top quark decay or an extraction from (differential) top quark production cross sections - provide complementary handles on the...
The remarkably large integrated luminosity collected by the ATLAS and CMS detectors at the highest proton-proton collision energy provided by LHC allows to use the large sample of top quark events to explore properties of the top quark production and decay and to probe the presence on new physics that might break well established symmetries. The angular properties are explored by illustrating...
The remarkably large integrated luminosity collected by the ATLAS and CMS detector at the highest proton-proton collision energy provided by LHC allows to probe the presence of new physics that might enhance extremely rare processes in the SM. Examples of such studies are presented using data collected in Run2 pp collisions at a center-of-mass of 13 TeV. These involve direct searches for...
We will present our recent calculation of matching NLO QCD corrections
to the production of a top-quark pair in association with a W boson
using the POWHEG-BOX framework. We compare our results with other
Monte Carlo generators for the two same-sign lepton signature
commonly used by the experiments. Special focus will be put on the
assessment of the importance of subleading electroweak...
A comprehensive set of inclusive and differential measurements of top quark pair production in association with light, c- and b-jets is presented and results are compared to theory predictions. The status of the search for four top quark production, to which the LHC experiments are starting to be sensitive, and that has important BSM re-interpretations, is also reported.
Future high-energy $e^{+}e^{-}$ colliders will provide some of the most precise tests of the Standard Model. Statistical uncertainties on electroweak precision observables and triple gauge couplings are expected to improve by orders of magnitude over current measurements.
This provides a new challenge in accurately assessing and minimising the impact of systematic uncertainties. Beam...
The measurements of inclusive deep-inelastic electron-proton scattering (DIS) cross sections at high center-or-mass energies offer a unique opportunity for precision tests of electroweak interactions. In this talk we revisit electroweak effects in DIS and discuss the combined determination of parameters of electroweak theory together with parton distribution functions of the proton [1,2]....
The Large Hadron-Electron Collider (LHeC) will operate at √s = 1.2 TeV and accumulate about 1/ab of integrated electron-proton luminosity [1]. We report here results of a novel study of high energy photon-photon interactions at the LHeC, at the 𝛾𝛾 center-of-mass energy of up to 1 TeV, opening new frontiers in the electroweak physics. Despite very high ep luminosity, the experimental...
Photon-photon fusion is a rare process at hadron and ion colliders. It is particularly interesting as a remarkably clean interaction with little (if any) remnant activity from the interacting particles. In this talk we present the status of photon-photon fusion measurements at the ATLAS detector. We present differential measurements of the light-by-light scattering process, γγ → γγ, in...
A comprehensive set of inclusive and differential measurements of top quark pair production in association with EWK bosons (W, Z or ɣ) , including searches for rare single top production processes (tZq) is presented.
Results are presented of searches in ATLAS for four-top-quark production. This rare process, with a predicted cross section of 12 fb in the Standard Model, has not been observed yet by experiment. The analysis is based on data from proton--proton collisions at a centre-of-mass energy of 13 TeV collected with the ATLAS detector during run 2 of the CERN Large Hadron Collider, and corresponding...
Top quark production can probe physics beyond the SM in different ways. The Effective Field Theory (EFT) framework allows searching for BSM effects in a model independent way. CMS experiment is pioneering EFT measurements that move towards using full potential of the data in the most global way possible. This talk covers various analysis strategies pursued in CMS for constraining top quark EFT...
The top quark has not yet been studied in the extremely favorable and low background environment of e+e- annihilation. This talk will review the opportunities for precision measurements of the top quark properties at the International Linear Collider (ILC). These include the archival measurement of the top quark mass, the search for beyond-Standard Model contributions to the top quark...
The LHeC and the FCC-he offer unique prospects for the measurement of top properties in energy frontier, luminous $ep$ scattering. An update of the 2012 Conceptual Design Report was produced last year [1]. In this talk we will revisit the determination of the top mass through inclusive measurements. In addition, we will address the possibilities for precise measurements of $Wtq$ and $\gamma...
As the heaviest particle of the model, with a mass close to the electroweak scale, the top quark is an interesting candidate to look for hints of new physics. The electroweak couplings of the top quarks are specially relevant in many extensions of the Standard Model. Indeed, as the top quark was not produced in the previous generation of electron-positron colliders most of its electro-weak...
The correct identification of b-initiated jets (b-jets) against c-initiated (c-jets), hadronic tau-initiated (tau-jets) and u-, d-, s-initiated jets (light-jets) is primordial for ATLAS Collaboration searches and precision measurements e.g. ttbar and single-top measurements, supersymmetry, Higgs boson. In consequence, the ATLAS Collaboration has developed several so-called b-tagging...
We consider the top-pair production through pp annihilation, followed by the semileptonic decay of the top-quark. We study the new physics contributions to the Wtb vertex at the Large Hadron Collider. In particular, we estimate the limits on anomalous couplings for the pre-existing data of 13 TeV LHC energy with integrated luminosities of 36.1 fb^{-1} and 140 fb^{-1}. Prediction of limits on...
We explore a new energy regime, 5 TeV, for the diboson and top quark pair productions in proton-proton collisions using 304/pb of data collected in 2017 by the CMS experiment at the LHC. The diboson, WW, WZ, and ZZ, cross sections are measured analyzing events with two, three or four charged leptons in the final state. The cross sections are compared with NNLO predictions and across other...
Top quark pair production in association with a vector boson (photon or Z boson) provides an experimental probe for the electroweak couplings of the top quark. To improve the sensitivity to possible new physics modifications of these couplings, the CMS experiment performs differential cross section measurements using proton-proton collisions data collected at 13 TeV. To correct for detector...
Single top quark production in association with a Z boson (tZq) was recently observed for the first time by both the CMS and ATLAS experiments. This rare process provides experimental access to the coupling of the top quark to the Z boson and is interesting as a probe for several new physics scenarios. We report on an inclusive tZq cross-section measurement that has been improved with respect...
An inclusive and normalised differential cross sections measurements are presented for the production of single top quarks in association with a W boson, in proton-proton collisions at a centre-of-mass energy of 13 TeV. Events containing one muon and one electron in the final state are analysed. For the inclusive measurement, a multivariate discriminant, exploiting the kinematic properties of...
New results are presented corresponding to the measurement of several properties of WZ production in the CMS experiment. The measurements profit from the high purity of the three lepton final state and the whole luminosity of the Run II of the LHC to provide precisions never reached before on this diboson process.
Inclusive and differential cross section measurements are complemented with...
The associated production of a single top quark and a Z boson includes the tZ coupling as well as the coupling of three vector bosons (WWZ) and is therefore a unique process to study the couplings of heavy particles in the SM. The top quark in this process is polarized due to its production through the weak interaction. Since the top quark decays before it hadronizes, the spin information is...
Measurements of cross sections for the production of pairs of oppositely charged -bosons (WW) provide an important test of the Standard Model (SM), in particular electroweak theory and perturbative quantum chromodynamics. WW production can additionally be a dominant background for measurements of Higgs boson production, and in searches for physics beyond the SM. In contrast to most previous...
Top anti-top (tt) pair production at the Large Hadron Collider (LHC) is
often observed in the presence of additional high energy radiation. Similarly
the abundant tt production at the LHC allows us to probe high transverse momentum (p_{T} )
top quarks. This poster compares the latest measurements, using data recorded
by the ATLAS detector from 2015 to 2018, with different QCD...
The production of a top-quark-antiquark pair in association with a Z boson (ttZ) is a rare process that directly probes the neutral coupling of the top quark to the electroweak gauge bosons. A better understanding of this process also benefits precision measurements of other Standard Model processes and beyond the Standard Model searches where ttZ is an important background. The ttZ process...
The $t$-channel process provides a unique phase space with lower colour reconnection probability as compared to the $t\bar{t}$ which has been exploited to make a precision measurement of the top quark and antiquark mass. Single top quark production via $t$-channel is the most dominant production process at the LHC. The final state comprises a single top along with a light quark giving rise to...
Photon fusion is a rare and interesting process at proton colliders, with a remarkably clean signature that has little (if any) remnant activity from the interacting particles. A particularly interesting photon-induced process, the production of W-boson pairs (yy->WW), was recently observed using the 139/fb of proton-proton collision data collected by ATLAS at √s=13TeV during LHC Run-2. In...
The full Run II CMS dataset (137.1 fb$^{-1}$) of proton-proton collisions at a center-of-mass energy of 13 TeV is analyzed, to search for the electroweak VBS production of an opposite sing pair of W bosons plus two jets in the fully leptonic channel. Events are selected requiring two leptons (electrons or muons) and two jets with large pseudorapidity separation and high invariant mass; they...
A search for flavor-changing neutral current interactions between the top quark and the Higgs boson is presented. The search is based on a data sample corresponding to an integrated luminosity of 137 /fb recorded by the CMS experiment at the LHC in proton-proton collisions at the center of mass energy of 13 TeV. Events containing exactly one lepton (electron or muon) and at least three jets,...
The methodology and results are presented for the search for four-top production at the ATLAS detector. An integrated luminosity of 139 fb-1 of proton-proton collision data at sqrt(s) = 13 TeV was analyzed to measure the cross section of the four-top production, specifically for decays containing 1 lepton or 2 oppositely-charged leptons. For these largely hadronic decay channels, signal...
A search for the electroweak VBS production of a VW pair plus two jets, in the semi-leptonic channel, at a centre-of-mass energy of 13 TeV is reported. The data sample corresponds to the full Run-II CMS dataset of proton-proton collisions at 13 TeV including an integrated luminosity of 137.1 fb−1. Events are analyzed in two energy regimes: either the hadronically decaying W/Z boson is...
We work on the improvement of theoretical predictions for Standard Model electroweak pseudo-observables at the $e^+e^-$ Z-resonance peak. This study is mandatory for example for the new Future Circular Collider (FCC). The missing higher-order computations involve many Feynman diagrams at three-loop order including all possible Standard Model particles. We make progress in completing the...
In nowadays theoretical approach to describe the physics behind scattering experiment we use elementary particles as degrees of freedom. These stand in remarkably agreement with experimental data but encounter an existential dilemma from the quantum field theoretical point of view, since these states are gauge dependent. The solution to this problem for a non-perturbative theory is provided by...
We present high-precision predictions for $\ell^-\ell^+$ production ($\ell=\mu,\tau$) at $\gamma\gamma$ collisions by considering a complete set of one-loop-level scattering amplitudes, i.e., full electroweak (EW) $\mathcal{O}(\alpha)$ corrections together with soft and hard QED radiation. We perform detailed numerical discussion of the one-loop EW radiative corrections, particularly the pure...
The study of the $Z$-boson decay was crucial for the success of the LEP experiment. In $e^+ e^-$ collisions, with the centre of mass energy matched to its mass, i.e. $\sim$ 91 GeV, a huge number of $Z$-bosons was produced ($\sim10^6$). Significant statistics allowed for precise measurements of its decay products along with the Standard Model (SM) parameters. The precision of LEP was so high...
We compute the top quark contribution to the two-loop amplitude for on-shell W/Z boson pair production in gluon fusion. Exact dependence on the top quark mass is retained. For each phase space point the integral reduction is performed numerically and the master integrals are evaluated using the auxiliary mass flow method, allowing fast computation of the amplitude with very high precision....
In this talk we present the analytic evaluation of the two-loop QED correction
to the mu-e elastic scattering, retaining the full dependence on
the muon mass and considering the electron as a massless particle.
We discuss the generation of integrands from Feynman
diagrams as well as the evaluation of the latter by recalling
the analytic expressions of the two-loop master...
