Related papers: Combining parton showers and NNLO matrix elements
We implement the recently-calculated analytic expressions for the next-to-leading order QCD corrections to $gg\to ZH$ in ggxy. This provides a flexible framework for investigating partonic and hadronic cross sections for various top quark…
We consider $W^\pm Z$ production in hadronic collisions and present high-precision predictions in QCD and electroweak (EW) perturbation theory matched to parton showers. To this end, we match next-to-next-to-leading order QCD corrections to…
We formulate a collinear partonic shower algorithm that achieves next-to-single-logarithmic (NSL, $\alpha_s^n L^{n-1}$) accuracy for collinear-sensitive non-singlet fragmentation observables. This entails the development of an algorithm for…
I briefly discuss some theoretical aspects of top mass measurements at the LHC. In particular, I illustrate a recent theoretical study performed using next-to-leading order (NLO) calculations interfaced to shower generators (NLO+PS) of…
A framework to include triple collinear splitting functions into parton showers is presented, and the implementation of flavor-changing NLO splitting kernels is discussed as a first application. The correspondence between the Monte-Carlo…
In this short note, I introduce to essential conceptual features and main building blocks of matrix element merging algorithms, operating on fixed order calculations both at leading order and next-to-leading order. The intention is purely…
We present a calculation of the next-to-leading order (NLO) QCD corrections to the hadroproduction process $gg\to ZZ \to e^+e^- \mu^+ \mu^-$, matched to the parton shower in the POWHEG framework. We take advantage of the POWHEG BOX tool for…
We present a phenomenological study of the current status of the application of our approach of {\it exact} amplitude-based resummation in quantum field theory to precision QCD calculations, by realistic MC event generator methods, as…
A modified version of the CKKW matrix element merging algorithm is presented, suitable for use in an angular-ordered parton shower, using truncated showers and forced splittings. The algorithm is implemented in the Herwig++ Monte Carlo…
In this paper we study the theoretical uncertainties in the determination of the top-quark mass using next-to-leading-order (NLO) generators interfaced to parton showers (PS) that have different levels of accuracy. Specifically we consider…
We extend the lowest-order matching of tree-level matrix elements with parton showers to give a complete description at the next higher perturbative accuracy in alpha_s at both small and large jet resolutions, which has not been achieved so…
A method for incorporating information from next-to-leading order QCD matrix elements for hadronic diboson production into showering event generators is presented. In the hard central region (high jet transverse momentum) where perturbative…
We compare a NLO W gamma matrix element generator with the leading order calculation in Pythia . A matching scheme between a next-to-leading order W gamma matrix element generator by Baur et. al. and the Pythia parton shower is presented.…
A new method for combining QCD matrix elements and parton showers in Monte Carlo simulations of hadronic final states is outlined. The aim is to provide at least a leading-order description of all hard multi-jet configurations together with…
After an introduction to event generators we give an overview of developments in the field of joining matrix elements with parton showers. Starting with matrix element corrections, we also discuss implementations that match LO and NLO…
We present the matching between a next-to-leading order computation in QCD and the PYTHIA parton shower Monte Carlo, according to the MC@NLO formalism. We study the case of initial-state radiation, and consider in particular single vector…
We outline a new technique for the fully-differential matching of final-state parton showers to NNLO calculations, focussing here on the simplest case of leptonic collisions with two final-state jets. The strategy is facilitated by working…
We present a calculation of the next-to-leading order QCD corrections to slepton pair production in association with a jet at the LHC together with their implementation in the POWHEG BOX. For the simulation of parton-shower effects and the…
Standard dipole parton showers are known to yield incorrect subleading-colour contributions to the leading (double) logarithmic terms for a variety of observables. In this work, concentrating on final-state showers, we present two simple,…
With Run-II of the LHC starting its final year of data-taking, high precision theoretical predictions through Monte-Carlo event generators whose uncertainties match that of the recorded data are of highest importance. This talk summarises…