Andreas van Hameren

Complete off-shell effects in top quark pair hadroproduction with leptonic decay at next-to-leading order

Results for next-to-leading order QCD corrections to the

Single-parton scattering versus double-parton scattering in the production of two

pp\left( {p\bar{p}} \right) \to t\bar{t} \to {W^{+} }{W^{-} }b\bar{b} \to {e^{+} }{\nu_e}{\mu^{-} }{\bar{\nu }_\mu }b\bar{b} + X

c \bar c

processes with complete off-shell effects are presented for the first time. Double-, single-and non-resonant top contributions of the order

pairs and charmed meson correlations at the LHC

\mathcal{O}\left( {\alpha_s^3{\alpha^4}} \right)

BCFW recursion for TMD parton scattering

are consistently taken into account, which requires the introduction of a complex-mass scheme for unstable top quarks. Moreover, the intermediate W bosons are treated off-shell. Comparison to the narrow width approximation for top quarks, where non-factorizable corrections are not accounted for is performed. Besides the total cross section and its scale dependence, several differential distributions at the TeVatron run II and the LHC are given. In case of the TeVatron the forward-backward asymmetry of the top is recalculated afresh. With inclusive selection cuts, the forward-backward asymmetry amounts to

Four-jet production in single- and double-parton scattering within high-energy factorization

A_{FB}^t = 0.051\pm 0.0013

Production of two charm quark–antiquark pairs in single-parton scattering within the kt -factorization approach

. Furthermore, the corrections with respect to leading order are positive and of the order 2.3% for the TeVatron and 47% for the LHC. A study of the scale dependence of our NLO predictions indicates that the residual theoretical uncertainty due to higher order corrections is 8% for the TeVatron and 9% for the LHC.

Search for optimal conditions for exploring double-parton scattering in four-jet production: kT-factorization approach

We compare results of exact calculations of single parton scattering (SPS) and double parton scattering (DPS) for production of

Three jet production and gluon saturation effects in p-p and p-Pb collisions within high-energy factorization

c \bar c c \bar c

QCD amplitudes with 2 initial spacelike legs via generalised BCFW recursion

and for