Related papers: Beyond the Narrow-Width Limit for Off-Shell and Bo…
We consider the exclusive decay $B\to J/\psi K$ using the QCD-improved factorization method in the heavy quark limit. It is shown that the decay amplitude is factorizable in this limit and nonfactorizable contributions are calculable from…
We discuss possible non-standard contributions to the top-quark width, particularly the virtual effects on the standard decay $t\rightarrow W^+\,b$ within the context of the MSSM. We also place a renewed emphasis on the unconventional mode…
We briefly report on NLO QCD corrections to the $pp \to t\bar{t} B +X$ process, where $B$ stands for $H,\,W^\pm$ or $Z$. In the calculation all double-, single and non-resonant Feynman diagrams, interferences and finite-width effects are…
We consider QCD radiative corrections to $W^+W^-b {\bar b}$ production with leptonic decays and massive bottom quarks at the LHC. We perform an exact next-to-leading order (NLO) calculation within the $q_T$-subtraction formalism and…
We exploit offshell regions in the process $e^+e^-\rightarrow W^+W^-b\bar{b}$ to gain access to the top-quark width. Working at next-to-leading order in QCD we show that carefully selected ratios of offshell regions to onshell regions in…
We present details of a calculation of the cross section for hadronic top-antitop production in next-to-leading order (NLO) QCD, including the decays of the top and antitop into bottom quarks and leptons. This calculation is based on matrix…
We discuss top-quark physics at the ILC with a focus on the full off-shell processes for $t\bar{t}$ and $t\bar{t}H$ production, including top-quark decays and also leptonic $W$ decays. A special focus is on the matching of the resummed…
A brief summary of the calculation of the NLO QCD corrections to the process pp -> e+ ve mu- v_mu bb~ j + X is reported. This provides a complete description of the process of t-tbar + jet production with leptonic decays beyond the…
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…
We derive a factorization formula for boosted double resonant top-antitop pair production in $e^+e^-$ annihilation with a semileptonic top quark decay in the phase space region where the $b$-jet invariant mass is small. The decaying top…
Motivated by ongoing new physics searches in the top-quark sector at the Large Hadron Collider we report on the calculation of NLO QCD corrections to the Standard Model $pp\to t\bar{t}Z+X$ process in the tetra-lepton decay channel. This…
In these proceedings we explore the possibility of new physics manifesting itself in rare top quark decays. In particular, we adopt an effective theory description of FCNC t -> q V top quark decays and possible deviations from the SM form…
The narrow width approximation is used in high energy physics to reduce the complexity of scattering calculations. It is a fortunate accident that it works so well for the Standard Model, but in general it will fail in the context of new…
We develop a new nonrelativistic effective field theory of $\rho$NRQCD [1] to describe the finite lifetime effects in the threshold production of top quark-antiquark pairs. The theory is based on the expansion in a parameter…
We present numerical calculations of the partial width of the charged Higgs boson decay into a top quark, $H^- \rightarrow \bar{t} + b + X$, and the partial width of the top quark decay into a light charged Higgs boson $t \rightarrow H^+ +…
In top quark production, the polarization of top quarks, decided by the chiral structure of couplings, is likely to be modified in the presence of any new physics contribution to the production. Hence the same is a good discriminator for…
Using unfolded top-quark decay data we can measure the top quark mass, as well as search for unexpected kinematic effects. We present a new generative unfolding method for the two tasks and show how they both benefit from unbinned,…
The one-loop induced top quark decay $t\to u_1\bar{u}_2u_2$ ($u_i=u,c$) is calculated in the context of the standard model. The dominant contribution to this top quark decay arises from the Feynman diagrams induced by the off-shell…
Exclusive, non-leptonic, two-body decays of B mesons simplify greatly in the heavy quark limit. In this talk I discuss the factorized structure that holds in this limit and some of its consequences: (a) naive factorization is recovered in a…
This letter details and discusses the next-to-leading order QCD corrections to $t$-channel electro-weak $W^+ b j$ production, where finite top-width effects are consistently taken into account. The computation is done within the aMC@NLO…