Related papers: Quark-Loop Amplitudes for W^+- H^-+ Associated Had…
In view of a recently renewed interest to production of multiple Higgs bosons the amplitude for such process at the threshold of $n$ particles is considered. An explicit calculation is done for the loop corrections to the amplitude arising…
We present the two-loop virtual QCD corrections to the production of heavy quarks in the quark--anti-quark--annihilation channel in the limit when all kinematical invariants are large compared to the mass of the heavy quark. Our result is…
We present complete analytical ${\mathcal O}(\epsilon^2)$ results on the one-loop amplitudes relevant for the NNLO quark-parton model description of the hadroproduction of heavy quarks as given by the so-called loop-by-loop contributions.…
Presented are complete next-to-leading order electroweak (NLO EW) corrections to top-squark pair production at the Large Hadron Collider (LHC) within the Minimal Supersymmetric Standard Model (MSSM). At this order, also effects from the…
In this paper, we show how to calculate analytically the one-loop helicity amplitudes for the process $q\bar{q} rightarrow t\bar{t}$ induced by KK gluon, using the spinor-helicity formalism. A minimal set of Feynman rules which are uniquely…
We compute the helicity amplitudes for the processes $gg\to Zg$ and $gg\to Z\gamma$ to two loops in massless QCD. The perturbative expansion of these processes starts only at the one-loop level, such that our results are a crucial…
This paper explores the effects of both finite width and interference (with background) in the pair production and decay of extra heavy quarks with charge 2/3 at the Large Hadron Collider (LHC). This dynamics is normally ignored in standard…
We consider forward inclusive production of several quarks in the high energy p-A collisions in the CGC formalism. For three particle production we provide a complete expression in terms of multipole scattering amplitudes on the nucleus and…
We calculate the complete NLO QCD corrections to loop-induced $gg \rightarrow ZZ$ production including full top-quark mass effects. The two-loop virtual corrections are obtained by combining analytic results for the massless,…
The search for Higgs bosons and extensions of the Standard Model of Elementary Particle Physics are main tasks of the Large Hadron Collider (LHC) at CERN which will start operation mid-2008. In this thesis processes which can be used to…
Quarkonium production in proton-proton collision is interesting in profiling the partons inside the nucleon. Recently, the impact of double parton scatterings (DPSs) was suggested by experimental data of associated quarkonium production…
We investigate exclusive electroproduction of $\pi^-\Delta^{++}$ within the handbag approach in which the helicity amplitudes factorize into generalized parton distributions (GPDs) and hard partonic subprocesses. We define the $p-\Delta$…
We combine the six-dimensional helicity formalism of Cheung and O'Connell with D-dimensional generalized unitarity to obtain a new formalism for computing one-loop amplitudes in dimensionally regularized QCD. With this procedure, we…
Particle production mechanisms in proton+proton and heavy-ion collisions at the LHC energies are discussed. An attempt is made to connect p+p to heavy-ion collisions in understanding the final state observables. New emerging phenomena like…
Single top quark production in association with vector bosons provides a unique way to probe the electroweak sector of the standard model at the Large Hadron Collider. In this talk the latest experimental results of the ATLAS and CMS…
The production of a Higgs boson in association with a top-antitop quark pair ($t\bar{t}H$) holds significant importance in directly probing the top-quark Yukawa coupling, which is related to various fundamental questions in high energy…
In order to solve the hierarchy problem, several extra-dimensional models have received considerable attention. We have considered a process where a Higgs boson is produced in association with a KK-graviton ($G_{\rm KK}$) at the LHC. At the…
We compute the one-loop QCD amplitudes for the processes HqqQQ and Hqqgg, the latter restricted to the case of opposite-helicity gluons. Analytic expressions are presented for the color- and helicity-decomposed amplitudes. The coupling of…
We review heavy quark and quarkonium production in high energy hadronic collisions. We discuss the status of the theoretical calculations and their uncertainties. We then compare the current theoretical results with the most recent…
We employ the recently developed method of generalized $D$-dimensional unitarity to compute one-loop virtual corrections to all scattering amplitudes relevant for the production of a $W$ boson in association with three jets in hadronic…