Related papers: Cross section ratios as a precision tool for $t\ba…
Inclusive and differential cross-sections are measured at particle level for the associated production of a top quark pair and a photon ($t\bar{t}\gamma$). The analysis is performed using an integrated luminosity of 140 fb$^{-1}$ of…
The measurement of the $t\bar{t}$ inclusive production cross section $\sigma_{t\bar{t}}$ is crucial to probe QCD predictions, constrain new physic scenarios, proton PDFs, top quark pole mass, $\alpha_S$ and many other parameters from the…
We present new theoretical predictions for the t bar t production cross section at NNLO at the Tevatron and the LHC. We discuss the scale uncertainty and the errors due to the parton distribution functions (PDFs). For the LHC, we present a…
We explore in detail the physics potential of a measurement of the ttbar invariant mass distribution. First, we assess the accuracy of the best available predictions for this observable and find that in the low invariant mass region, the…
We calculate the $pp\rightarrow t\bar t\gamma+X\rightarrow W\gamma + X$ cross section at SSC energies. Approximately 40\% of the total cross section originates from photon bremsstrahlung off the final state jet in $t\bar tj$ production.…
We demonstrate that the use of on-shell methods, involving calculation of the discontinuity across the t-channel cut associated with the exchange of a pair of massless particles, can be used to evaluate loop contributions to both the…
NLO QCD corrections to the process $pp \rightarrow e^+\nu_e \mu^- \bar{\nu}_{\mu} \tau^+\tau^- b \bar{b}+X$ are presented with the full off-shell effects included. The calculation includes all resonant and non-resonant Feynman diagrams,…
Normalized double-differential cross sections for top quark pair (t t-bar) production are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS experiment at the LHC. The analyzed data correspond to an integrated…
Precision predictions for phenomenologically interesting observables such as the t-tbar invariant mass distribution and forward-backward asymmetry in top-quark pair production at hadron colliders require control over the differential cross…
Toponium production at future hadron colliders is investigated. Perturbative QCD corrections to the production cross section for gluon fusion are calculated as well as the contributions from gluon-quark and quark-antiquark collisions to the…
Predictions for the total cross section for e+e- -> t tbar near threshold are reviewed. The renormalization group improved results at NNLL order have improved convergence and reduced scale dependence relative to fixed order results at NNLO.…
We measure the ttbar production cross section in ppbar collisions at sqrt{s}=1.96 TeV in the lepton+jets channel. Two complementary methods discriminate between signal and background, b-tagging and a kinematic likelihood discriminant. Based…
In this proceedings we briefly report on the state-of-the-art NLO QCD computation for the $pp\to t\bar{t}\gamma$ process in the di-lepton channel. We describe higher-order corrections to the $e^+\nu_e \, \mu^- \bar{\nu}_\mu \,…
We give the amplitude for $\gamma\gamma \rightarrow \pi^+\pi^-\pi^0$ in leading order chiral perturbation theory. For the case of real photons we calculate the total and differential cross section. Furthermore, we give the dependence of the…
I review the predictions of the total cross section for many models, and point out that some of them lead to the conclusion that the standard experimental analysis may lead to systematic errors much larger than expected.
Triggered by ongoing experimental analyses, we report on a study of the cross section ratio sigma(pp -> ttbb)/sigma(pp -> ttjj) at the next-to-leading order in QCD, focusing on both present and future collider energies: sqrt{s}= 7, 8, 13…
We review some of the major progress in the accurate calculation of the cross section for the production of a charged Higgs boson in a generic two-Higgs double model, by focussing on the high-mass region, for which new calculations have…
Measurements of normalized differential cross sections for top quark pair production are performed in the dilepton decay channels in proton-proton collisions at a center-of-mass energy of 13 TeV. The differential cross sections are measured…
A measurement is reported of differential top quark pair ($\mathrm{t\bar{t}}$) production cross sections, where top quarks are produced at large transverse momenta. The data collected with the CMS detector at the LHC are from pp collisions…
In this contribution we present a systematic comparison of the full off-shell calculation for pp -> ttj in the dileptonic decay channel with a description based on the narrow width approximation. The aim of this study is to estimate the…