Measurements of single W and Z boson inclusive and differential production cross sections and their ratios with the CMS detector are presented. The results are compared to predictions from different Monte Carlo generators. A comparison of the results to predictions using different pardon distribution functions (PDF) tests the performance of PDFs.
Measurements of the Drell-Yan production of W and Z/gamma bosons at the LHC provide a benchmark of our understanding of perturbative QCD and probe the proton structure in a unique way. The ATLAS collaboration has performed new high precision measurements at center-of-mass energies of 7. The measurements are performed for W+, W- and Z/gamma bosons integrated and as a function of the boson or...
Measuring the scattering of longitudinally-polarized vector bosons will represent a fundamental test of
Electroweak Symmetry Breaking.
In addition to the challenges provided by low rates and large backgrounds,
there are conceptual issues which remain unresolved for the definition of a suitable signal.
Since vector bosons are unstable and can only be observed through their decay products,
the...
Precision measurements of the Drell-Yan production of W and Z bosons at the LHC provide a benchmark of our understanding of perturbative QCD and electroweak processes and probe the proton structure in a unique way.
The ATLAS collaboration has performed a new precise triple differential cross-section measurement as a function of M(ll), dilepton rapidity and cosฮธโ defined in the Collins-Soper...
We present the measurements of forward-backward charge asymmetry $A_{FB} $ in
$p\bar{p}\rightarrow Z/\gamma^{*} \rightarrow \mu^+\mu^- $ events using $9.7 \ $fb$^{-1}$ of $ p\bar p$ data collected at $\sqrt s=1.96\ $TeV by the D0 detector at the Fermilab Tevatron collider. $A_{FB}$ is measured as a function of the invariant mass of the dimuon system to extract the effective weak mixing...
We present four measurements of forward-backward charge asymmetry $A_{FB} $ in
$p\bar{p}\rightarrow Z/\gamma^{*} \rightarrow e^+ e^-/\mu^+\mu^- + X$ events using $\sim 10\ $fb$^{-1}$ of $ p\bar p$ data collected at $\sqrt s=1.96\ $TeV by the D0 and CDF detectors at the Fermilab Tevatron collider. $A_{FB}$ is measured as a function of the invariant mass of the dilepton system to extract the...
We report on the status of the precision measurements of electroweak parameters with W and Z bosons with the CMS detector. The effective electroweak mixing angle sin^{2}_{\theta} is extracted by measuring the forward-backward asymmetry in dilepton events near the Z boson mass region. Experimental and theoretical challenges needed for a high-precision W boson mass measurement are reported using...
A precise measurement of the mass of the W boson represents an important milestone to test the overall consistency of the Standard Model. Since the discovery of a Higgs Boson, the the W boson mass is predicted to 7 MeV precision, while the world average of all measurements is 15 MeV, making the improved measurement an important goal.
The ATLAS experiment at the LHC represents an ideal...
We review the status of the global electroweak fit in the Standard Model (SM), including the latest theoretical and experimental updates. We discuss in detail the consistency of the SM with current experimental data, and derive constraints on general new physics scenarios. These are compared and combined with the bounds obtained using Higgs boson observables measured at the LHC. Finally, we...
We present the status of the global fit to electroweak precision data. The fit includes the latest available hadron collider measurements of the top-quark and the W-boson masses, as well as newest higher-order theoretical calculations. A large set of numerical and graphical results as well as Standard Model compatibility tests are presented. The global electroweak fit is also used to constrain...
The discovery of the Higgs physics together with the excellent performance of the LHC allow to make precision tests of Brout-Englert-Higgs Physics.
At this level, it becomes important to fully understand the theory behind this physics. As was already pointed out more than 35 years ago, there is a paradox in the standard model: The elementary fields should not be the particles we observe, as...
We discuss the constraints on the Standard Model Effective Field Theory inferred from global fits to electroweak data. In particular, we focus on two unconstrained combinations of Wilson coefficients that are present when the analysis is restricted to measurements of $\bar\psi\psi\rightarrow \bar\psi\psi$ scatterings. We show how these unconstrained directions arise due to a...
A simultaneous fit of parton distribution functions (PDFs) and electroweak
parameters to HERA data on deep inelastic scattering is presented. The input
data are the neutral current and charged current inclusive cross sections
which were previously used in the QCD analysis leading to the HERAPDF2.0
PDFs. In addition, the polarisation of the electron beam was taken into
account for the ZEUS data...
Using inclusive DIS cross sections measured with the H1 experiment at HERA, electroweak parameters of the Standard Model are probed. The cross sections were determined using longitudinally polarized lepton beams, which enhances the sensitivity to the vector couplings of the light quarks. The quark couplings and the electroweak mixing angle are probed through the $\gamma/Z$ interference. This...
We present the most recent inclusive and differential measurements of multiboson production (VV, VVV) with data collected by the CMS during Run I & II.
Measurements of the cross sections of the production of pairs of electroweak gauge bosons at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale.
The ATLAS collaboration has performed new measurements of integrated and differential cross sections of the production of heavy di-boson...
Measurements of the cross sections of the production of three electroweak gauge bosons and of vector-boson scattering processes at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has recently searched for the production of three W bosons or of a W boson...
The production of massive vector boson pairs is a key process for the understanding of the non-abelian gauge structure of the standard model and for the comprehension of the electroweak symmetry breaking mechanism. The study of the production of vector boson pairs with the presence of two jets in the event allows to measure the electroweak production of vector bosons in association with jets,...
I will discuss the structure of the loop corrections in the case of the non-linear EW effective theory and compare it with the low-energy contributions from the exchange of heavy resonances. The convenience of using either the non-linear HEFT or the linear SMEFT will depend on the interplay of the scales that control these two types of contributions.
We study electroweak baryogenesis driven by up-type heavy quarks in
a general two Higgs doublet model with $CP$ invariant Higgs potential.
With Higgs sector couplings and an additional top Yukawa coupling $\rho_{tt}$
all of $\mathcal{O}(1)$ in strength, one naturally has sizable $CP$ violation
that fuels a cosmic baryon asymmetry. Even if $\rho_{tt}$ vanishes, the flavor violating...
The large equivalent-photon fluxes accompanying Pb ion beams at the LHC initiate photon-photon and photo-nuclear interactions which dominate when the colliding nuclei have large impact parameter (ultra-peripheral collisions). These electromagnetically-induced processes are sensitive to the nuclear wave-function and in particular the nuclear modifications of the nucleon parton distribution...
We will report on our results for light-by-light scattering in
ultraperipheral Pb-Pbcollisions at the LHC.
We calculate cross section for the elementary $\gamma \gamma \to \gamma \gamma$
subprocess taking into account the following contributions:
(a) box mechanisms with leptons and quarks in the loops,
(b) VDM-Regge mechanism (fluctuation of both photons to vector mesons
and their...
LHCb, while purpose built for b-physics, also functions as a general purpose forward detector, covering the pseudo-rapidity range 2.0 to 5.0. LHCb has measured forward top production using final states accessible from both single top and top pair production processes. Measurements in the LHCb acceptance have particular sensitivity to high and low values of Bjorken-x when compared to other LHC...
Measurements of the inclusive and differential top-quark pair and single-top production cross sections in proton-proton collisions with the ATLAS detector at the Large Hadron Collider at center-of-mass energies of 8 TeV and 13 TeV are presented. The inclusive measurements reach high precision and are compared to the best available theoretical calculations. Differential measurements of the...
Measurements of the inclusive and differential top quark pair production cross section in proton-proton collisions at 5.02 TeV, 7 TeV, 8 TeV and 13 TeV are presented using the CMS detector. The total cross section is measured using the lepton+jets, dilepton and fully hadronic channels, including the tau-dilepton and tau+jets modes. Indirect constraints on both the top quark mass and ษS are...
We present state-of-the-art, high-precision predictions for top-quark pair production in the di-lepton channel at the LHC.
Our results are based on the narrow-width approximation and include approximate NNLO corrections in the production subprocess, exact NNLO corrections in the decay sub-process as well as exact NLO-production/NLO-decay interferences.
We will briefly outline the structure...
Measurements of single top-quark production in proton-proton collisions are presented based on the 8 TeV and 13 TeV ATLAS datasets. For the production of single top-quarks and single anti-top-quarks in the t-channel, the total production cross sections, their ratio, as well as measurements of inclusive and differential cross-sections are presented. Measurements of the inclusive and...
Several measurements of single top quark production in proton-proton collisions at the LHC at centre-of-mass energies of 7, 8 and 13 TeV, using data collected with the CMS experiment, are presented. The analyses investigate separately the productions of top via t-channel exchange, in association with a W boson (tW) or via the s-channel. Final states with at least one charged lepton and one...
I will discuss the top-quark mass determination at the LHC, according to the
different methods used by the experimental collaborations.
In particular, I will investigate the theoretical uncertainty on the measured mass,
once interpreted in terms of the top-quark pole mass, taking particular
care about non-perturbative corrections due to bottom fragmentation in top decays.
We report the most recent measurements of the mass of the the top quark, performed by the D0 experiment at the Fermilab Tevatron collider using the full Run II (2001--2011) data set corresponding to an integrated luminosity of $9.7\ $fb$^{-1}$. This includes measurements in the dilepton channels using the matrix element and neutrino weighting approaches, as well as measurements in the...
Measurements of the top quark mass and width using proton-proton collisions at the LHC at centre-of-mass energies of 7, 8 and 13 TeV are presented. The analyses used different decay channels and production modes of the top quark. Several techniques are investigated based on the reconstruction of the top kinematics from final state products, using leptonic decays with a J/psi, the shapes of top...
The top quark mass is one of the fundamental parameters of the Standard Model. The latest ATLAS measurements of the top quark mass in top quark pair and single top final states are presented. A measurement using lepton+jets top-quark pair events is presented, where a multi-dimensional template fit is used to constrain the uncertainties on the energy measurements of jets. The measurement is...
We present an alternative approach to the direct measurements of the top quark mass using D0 data. We discuss extractions of the pole mass of the top quark based on measurements of the inclusive and unfolded differential $p\bar p \to t\bar t$ production cross section as a function of $p_T(t)$ and $t\bar t$ mass.. We use the full Run II data set of $p \bar p$ collisions collected by the D0...
I review the status of the top quark couplings studies. The discussion is focused on anomalous electroweak interactions, which are largely unconstrained by hadron collider experiments. Possible anomalous interactions in Quantum Chromodynamics are reviewed, as well. In addition to hadron collider experiments, I discuss constraints from B-physics experiments and future colliders.
Several measurements of top quark properties are presented using data collected by the CMS experiment at different centre-of-mass-energies. The properties are mostly probed in the decay of the top quarks. The Wtb couplings are probed by measuring the helicity fractions in single top and ttbar topologies or by inspecting a V-A vertex structure of the coupling. Furthermore, searches for...
Several measurements of top quark properties are presented using data collected by the CMS experiment at different centre-of-mass-energies. The properties are mostly probed in production of the top quarks. The charge asymmetry is measured inclusively and differentially probing anomalous couplings to the gluons at production mode. These measurements are extended searching for asymmetries in...
Precise measurements of the properties of the top quark test the Standard Model (SM) and can be used to constrain new physics models. As it may be significantly enhanced by the presence of new physics, the ttbar production charge asymmetry is measured inclusively and differentially using the 8 TeV ATLAS dataset using both the lepton+jets and dilepton channels, including a dedicated measurement...
We discuss the complete overview of the forward-backward asymmetry measurements in the angular distributions of $p\bar p \to t\bar t$ events at the Tevatron collider. These measurements use the full Run II data set in lepton plus jets and dilepton channels, recorded in the D0 and CDF detectors, corresponding to an integrated luminosity of $\approx 2\times10\ $fb$^{-1}$ . The combinations of...
The top quark is the heaviest known fundamental particle and probing its couplings with the other fundamental particle may open a window to physics beyond the Standard Model. Single top-quark production provides a unique window to study the coupling between the top quark, the W boson and the b quark, since it involves the Wtb vertex in both production and decay. Measurements of angular...
The large centre-of-mass energy available at the proton-proton collider LHC allows for the copious production of top quark pairs in association with other final state particles at high transverse momenta. The ATLAS experiment has measured several final state observables that are sensitive to additional radiation in top anti-top quark final states. Results on the top production in association...
A comprehensive set of measurements of top quark pair production in association with EWK bosons (W, Z or ษฃ) is presented at different centre-of-mass energies. The results are compared to the theory predictions and re-interpreted as searches for new physics inducing deviations from the standard model predictions using an effective field theory approach. The status of the search for double-ttbar...
The measurements of associated production of a massive gauge boson with
a top-antitop quark pair at the LHC provide an important test of the
Standard Model, in particular of the top quark couplings.
To increase the precision of the theoretical predictions beyond NLO, a class of
logarithmic corrections can be taken into account with the help of
resummation methods.
In this talk results for soft...
State-of-the-art theoretical predictions accurate to next-to-leading order QCD interfaced with Pythia8 and Herwig++ event generators are tested by comparing the unfolded ttbar differential data collected with the CMS detector at 8 and 13 TeV. These predictions are also compared with the underlying event activity distributions in ttbar events using CMS proton-proton data collected at a center...
In order to fully exploit the abundance of hadronically decaying high momentum top quarks, and W, Z or Higgs bosons produced at LHC, jet substucture has become crucial to a wide array of searches and measurements. The latest ATLAS results in terms of optimisation and performance of large radius jets taggers are presented. The calibration of large radius jets energy and mass and their...
We evaluate the Michel parameters of $\tau$ decays using the full data
sample of Belle. This is important to reveal the Lorentz structure of
$\tau$ leptonic decays, which includes not only the V โ A interaction but
also contributions from scalar, tensor and others that may arise from
New Physics, thus testing lepton universality as well. We use both
$\tau^+ \to l^+ \nu \bar{\nu}$ and $\tau^+...
The BABAR Collaboration has an intensive programย studying hadronic cross sections in low-energy $e^+e^-$ annihilations, which are accessible with data taken near the $\Upsilon$(4S) via initial-state radiation.
Our measurements allow significant improvements in the precision of the
predicted value of the muon anomalous magnetic moment. These improvements are necessary for shedding light on...
The proposed upgrade of the LHC, the High-Luminosity LHC (HL-LHC) is expected to deliver data corresponding to a luminosity of up to 3 ab-1 under severe pileup conditions with up to 200 additional interactions per bunch crossing. The pileup effects are expected to be mitigated by upgraded detectors, which allow to study rare physics processes up to large rapidities, as well as precision...
In the next decades the Large Hadron Collider and its luminosity upgrade
are expected to yield a wealth of increasingly sensitive searches and
measurements in hadro-production of top quarks and electro-weak gauge
bosons. Several projects are being prepared for energy-frontier lepton
(ILC, CLIC, FCCee, CEPC, mC), electron-proton (LHeC), hadron colliders
(FCChh, SPPC) that are to continue this...
This talk presents a review of precision top quark measurements at
linear e+e- colliders, with results from the ILC detector concepts and
the CLIC detector and physics group. After a brief overview of
established elements of the top physics programme, the contribution
focuses on new developments in the full-simulation studies of key
measurements. These include improvements in the...
The future circular hadron-hadron collider FCC-hh is expected to produce collisions at the unrivaled center of mass energy of sqrt(s) = 100 TeV and to deliver an integrated luminosity of few tens of ab-1. As a result, trillions of top quarks and electroweak gauge bosons will be produced. Having at disposal such humongous samples opens a wide range of possibilities in the realm of electroweak...
The Large Hadron-electron Collider LHeC and the Future Circular Collider in electron-hadron mode FCC-eh will provide electron-proton collisions with center-of-mass energies in the range 1.3-3.5 TeV and instantaneous luminosities larger than $10^{34}$ cm$^{-2}$s$^{-1}$. The talk presents an overview on novel and unique top physics through single and pair production in ep collisions, including...
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...
