Conveners
Top quark and EW Physics
- Martijn Mulders (CERN)
- Maria Aldaya (DESY)
Top quark and EW Physics
- Matteo Negrini (Istituto Nazionale di Fisica Nucleare)
- Malgorzata Worek (RWTH Aachen University)
Top quark and EW Physics
- Malgorzata Worek (RWTH Aachen University)
- Ken Mimasu (King's College London)
Top quark and EW Physics
- Ken Mimasu (King's College London)
- Martijn Mulders (CERN)
Top quark and EW Physics
- Federica Fabbri (University of Glasgow)
- Maria Aldaya (DESY)
Top quark and EW Physics
- Maria Aldaya (DESY)
- Federica Fabbri (University of Glasgow)
Top quark and EW Physics
- Martijn Mulders (CERN)
- Matteo Negrini (Istituto Nazionale di Fisica Nucleare)
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. This talk will present recent differential Z+jets results in extreme phase-spaces with high pT jets. The measurement is compared to the state-of-the-art NNLO theoretical predictions. If...
The large amount of data collected by the CMS experiment at the CERN LHC provides unprecedented opportunities to perform precision measurements of the standard model, which allow an accurate validation of the theory and might potentially reveal hints of new physics. Thanks to their leptonic decays, W and Z bosons guarantee a clean final state, and their relatively high production cross section...
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...
Recent measurements of top quark pair production inclusive and differential cross sections are presented using the data collected by the CMS detector. The differential cross sections are measured multi-differentially as a function of various kinematic observables of top quarks, jets, leptons of the event final state. Results are compared to precise theory calculations, among them also...
The LHCb experiment covers the forward region of proton-proton collisions, and it can improve the current electroweak landscape by studying W and Z bosons in this phase space complementary to ATLAS and CMS. Thanks to the excellent detector performance, fundamental parameters of the Standard Model can be precisely measured by studying the properties of the electroweak bosons. In this talk an...
The Precision Proton Spectrometer (PPS) is a subdetector of CMS introduced for the LHC Run 2, which provides a powerful tool for advancing BSM searches. The talk will discuss the key features of proton reconstruction (PPS alignment and optics calibrations), validation chain with physics data (using exclusive dilepton events), and finally the new results on exclusive diphoton, ttbar, Z+X, and...
In many BSM theories the top quark is hypothesized to have an enhanced non-standard or extremely rare interaction with other SM particles. This presentation covers the latest CMS results in this regard, either from direct searches or precise measurements, including flavor-changing neutral current (FCNC) and tests of discrete symmetries with top quark.
The large integrated luminosity collected by the ATLAS detector at the highest proton-proton collision energy provided by LHC allows to probe the presence of new physics that could enhance the rate of rare processes in the SM. The LHC can therefore gain considerable sensitivity for Flavour Changing Neutral Current (FCNC) interactions of the top quark. In the SM, FCNC involving the top-quark...
KKMChh adapts the CEEX (Coherent Exclusive Exponentiation) of the Monte Carlo Program KKMC for Z boson production and decay to hadron scattering. Amplitude-level soft photon exponentiation of initial and final state radiation, together with initial-final interference, is matched to a perturbative calculation to second order next-to-leading logarithm, and electroweak corrections to the hard...
The weak mixing angle is a probe of the vector-axial coupling structure of electroweak interactions. It has been measured precisely at the Z-pole by experiments at the LEP and SLD colliders, but its energy dependence above $m_Z$ remains unconstrained.
In this contribution we propose to exploit measurements of Neutral-Current Drell-Yan production at the Large Hadron Collider at large...
In this talk, we present the analytic evaluation of the virtual corrections
to the di-muon production in electron-positron collision in QED, up to the second order in fine structure constant, retaining the full dependence on
the muon mass and considering the electron as a massless particle.
We discuss the computational details, and the high-level of automation it required,
from the...
For both the FCC-ee and the ILC, to exploit properly the respective precision physics program, the theoretical precision tag on the respective luminosity will need to be improved from the analogs of the 0.054 % (0.061%) results at LEP at $M_Z$, where the former (latter) LEP result has (does not have) the pairs correction. At the FCC-ee at $M_Z$ one needs improvement to 0.01%, for example. We...
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 of multiboson production at the LHC are important probes of the electroweak gauge structure of the Standard Model. for contributions from anomalous couplings. In this talk we present recent ATLAS results on Zy production in association with jet activity. These differential measurements provide inputs and constraints on modeling of the Standard Model. Using di-boson processes to...
This talk reviews recent measurements of multiboson production using CMS data. Inclusive and differential cross sections are measured using several kinematic observables.
Vector boson scattering (VBS) plays a central role in the search for new physics at collider experiments such as ATLAS and CMS at the LHC. Usually predictions for this kind of process are obtained using mainly perturbative approaches in fixed gauges.
In our work we investigate VBS in a manifestly fully gauge-invariant setup. To analyse the differences to gauge-fixed perturbation theory we are...
We present a parton-level study of electro-weak production of vector-boson pairs at the Large Hadron Collider, establishing the sensitivity to a set of dimension-six operators in the Standard Model Effective Field Theory (SMEFT). Different final states are statistically combined, and we discuss how the orthogonality and interdependence of different analyses must be considered to obtain the...
Top quark production can probe physics beyond the SM in different ways. The Effective Field Theory (EFT) framework allows searching for beyond the SM effects in a model independent way. The CMS experiment is pioneering EFT measurements that move towards using the full potential of the data in the most global way possible.
We perform a complete study of four top quarks production at the LHC in the context of the Standard Model Effective Field Theory (SMEFT). Our analysis is conducted at the tree-level yet investigating all possible QCD- and EW-couplings orders for the contributing dimension-six SMEFT operators. We observe that the formally dominating contributions do not necessarily provide the largest...
The mass of the W boson, one of the most important fundamental parameters in particle physics, is tightly constrained by the symmetries of the standard model. Following the observation of the Higgs boson and obtaining its measured mass, the standard model prediction of the W boson mass can be constrained to better than 10 MeV. An experimental measurement of the W boson mass to that level of...
A significant displacement both from the electroweak fit predictions and previous experimental results has been observed in the recent measurement of the W boson mass at CDF. This confirms the importance of measuring this fundamental parameter of the Standard Model. The LHCb experiment has a fundamental role in this topic: it has recently measured the W boson mass by using a part of its...
The determination of the W-boson mass is a slowly evolving field, with new results only every few years. The available measurements reflect the theoretical state of the art at the time of their preparation; at hadron colliders, determining factors are the theoretical description of the W boson production and decay, and the modelling of the proton structure. We present the status of the ongoing...
We present results from the global fit of the Standard Model (SM) to electroweak precision measurements. The fit uses the latest theoretical calculations for observables on the Z pole and the W boson mass, yielding precise SM predictions for the effective weak mixing angle and the masses of the W and Higgs bosons, as well as the top quark. We study the impact of the latest measurements on the...
In this talk we will review the most recent global analysis of electroweak data in the Standard Model as obtained in the HEPfit framework (based on arXiv:2112.07274). Moreover, we will discuss the impact of the recent measurements of the top-quark mass (CMS collaboration) and of the W-boson mass (CDF collaboration) on the fit of electroweak data in the Standard Model and beyond with particular...
We use the Fitmaker tool to incorporate the recent CDF measurement of $m_W$ in a global fit to electroweak, Higgs, and diboson data in the Standard Model Effective Field Theory (SMEFT) including dimension-6 operators at linear order. We find that including any one of the SMEFT operators ${\cal O}_{HWB}$, ${\cal O}_{HD}$, ${\cal O}_{\ell \ell}$ or ${\cal O}_{H \ell}^{(3)}$ with a non-zero...
The FCC-ee offers powerful opportunities for direct or indirect evidence for physics beyond the Standard Model, via a combination of high precision measurements and searches for forbidden and rare processes and feebly coupled particles. The precision measurement program benefits from an extraordinary conjunction of circumstances: (i) very clean experimental conditions and excellent...
The Circular Electron Positron Collider (CEPC) project aims to build a circular electron-positron collider capable of precision physics measurements. The CEPC offers the possibility of dedicated low-energy runs at the Z pole and WW threshold with a high instantaneous luminosity. The expected integrated luminosity for the CEPC Z pole runs (WW threshold runs ) is 100 $ {\rm ab}^{-1}$ (6 $ {\rm...
I will present our recent study of modeling uncertainties for fiducial signatures of the ttW process in the 3 lepton decay channel by comparing various approaches, such as full off-shell fixed-order NLO predictions and parton shower matched predictions based on on-shell ttW production. Finally, we provide a simple prescription to combine both approaches.
The large integrated luminosity accumulated by the ATLAS detector at the highest proton-proton collision energy provided by LHC allows the study of rare SM top quark production processes. The observation of associated production of top quarks has provided the first direct measurement of the top quark EW couplings with neutral gauge bosons and the first access to the four-top-quark interaction...
A comprehensive set of measurements of top quark production in association with vector bosons (W, Z, gamma) using data collected by the CMS experiment is presented. Differential cross sections are measured as functions of several kinematic observables from the final state physics objects and compared to standard model predictions.
Since its discovery at the Large Hadron Collider in 2012 the Higgs boson has arguably become the most famous of the Standard Model particles and many measurements have been performed in order to asses its properties. Among others, these include measurements of the Higgs boson's ${\cal CP}$-state which is predicted to be ${\cal CP}$-even. Even though a pure ${\cal CP}$-odd state has been ruled...
One of the greatest achievements of the LHC has been the discovery of the Higgs boson in 2012. Since then, the properties of this newly discovered particle have been widely tested. For instance, we need to understand how this particle couples to the other fundamental particles. The coupling of the Higgs boson to the heaviest of the quarks, the top quark, has been probed first indirectly and,...
In this talk we show our results for the soft-gluon threshold resummation of the four-top production process. This is the first time threshold resummation is applied to a 2$\rightarrow$4 type hadronic process. By matching the next-to-leading logarithmic (NLL) result to the available next-to-leading order (NLO) result, we achieve NLO+NLLโ precision for the total cross section, where we take...
The top-quark mass is one of the key fundamental parameters of the Standard Model that must be determined experimentally. Its value has an important effect on many precision measurements and tests of the Standard Model. The Tevatron and LHC experiments have developed an extensive program to determine the top quark mass using a variety of methods. In this contribution, the top quark mass...
In this talk, we will present NNLO QCD predictions for several differential distributions of B-hadrons in top-pair events at the LHC. In an extension of previous work, the decay of the produced B-hadron to a muon or a J/$\psi$ meson has been incorporated, allowing us to make predictions for distributions involving those decay products as well. Additionally, a new set of B-hadron fragmentation...
Studies of top quark properties using data collected by the CMS experiment are presented, including direct measurements of properties or extractions using differential cross section measurements. The latest results on top mass using multiple kinematic distributions in a likelihood technique as well as the top quark pole mass derived from tt+jet cross section will be discussed.
Due to its high mass top quarks decay before top-flavoured hadrons can be formed. This feature yields experimental access to the top quark polarization and production asymmetries. The large top quark sample moreover enables measurements of other properties, such as the W-boson branching ratios and helicity, and fragmentation functions of the bottom quarks. In this contribution, recent...
The LHC has unlocked a previously unexplored energy regime. Dedicated techniques have been developed to reconstruct and identify boosted top quarks. Measurements in boosted top quark production test the Standard Model in a region with a strongly enhanced sensitivity to high-scale new phenomena. In this contribution, several new measurements of the ATLAS experiment are presented of the...
Due to its genuine relativistic behavior, exotic character of interactions and symmetries, and fundamental nature, high-energy colliders are attractive systems for the experimental study of fundamental aspects of quantum mechanics. We propose the detection of entanglement between the spins of top-antitop-quark pairs at the LHC, representing the first proposal of entanglement detection in a...
Quantum information observables, such as entanglement measures, provide a powerful way to characterize the properties of quantum states. In this talk, I propose to use them to probe the structure of fundamental interactions and to search for new physics at high energy.
Inspired by recent proposals to measure entanglement of top quark pairs produced at the LHC, I examine how...
The Drell-Yan process offers an interesting opportunity to test the Standard Model (SM) and possibly reveal New Physics beyond it.
Indeed, dilepton production at high invariant masses is sensitive to beyond SM effects, while also being extremely well controlled both theoretically and experimentally and producing sufficient events for in-depth analyses.
In this talk I will present the recent...
The LUXE experiment (LASER Und XFEL Experiment) is an 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 pulse and 16.5 GeV electrons from the XFEL electron beam, as well as collisions between the LASER pulse and high-energy secondary photons. This will elucidate Quantum...
The process ee->qq with qq=ss,cc,bb,tt plays a central role in the physics programs of high energy electron-positron colliders operating from the O(100GeV) to O(1TeV) center of mass energies. Furthermore, polarised beams as available at the International Linear Collider (ILC) are an essential input for the complete measurement of the helicity amplitudes that govern the production cross...
In this talk, we will present state-of-the-art results for the QED Parton Distribution Functions (PDFs), which have been recently pushed up to next-to-leading logarithmic (NLL) accuracy. NLL PDFs properly take into account the mixing between the electron/positron with the photon and the other fermions, running-$\alpha$ effects and the dependence on the renormalisation and factorisation scheme....
Belle II is considering upgrading SuperKEKB with a polarized electron beam. The introduction of beam polarization to the experiment would significantly expand the physics program of Belle II in the electroweak, dark, and lepton flavor universality sectors. For all of these future measurements a robust method of determining the average beam polarization is required to maximize the level of...
The LHeC and the FCC-he offer singular possibilities for measurement of top properties and EW parameters in DIS, both due to their large centre-of-mass energies and high luminosities. In this talk we will review the most recent studies. We will revisit the determination of the top mass through inclusive measurements. In addition, we will address the possibilities for precise measurements of...
