Tt̄ pair hadroproduction in association with a heavy boson at the NLO QCD accuracy + Parton Shower

M V Garzelli,Z Trócsányi,A Kardos,C G Papadopoulos

doi:10.1088/1742-6596/452/1/012046

Abstract

The PowHel framework allows to make predictions of total and differential cross-sections of multiparticle hadroproduction processes at both NLO QCD accuracy and NLO QCD matched to Parton Shower, on the basis of the interface between the P0WHEG-B0X and HELAC-NL0 codes. It has already been applied to study several processes involving a tt̄ pair in association with a third particle or hadronic jet. Our most recent predictions concern tt̄V hadroproduction (with V = W or Z), at both parton and hadron level, by considering different decay channels (hadronic and leptonic) of the heavy particles. In particular, we show the results of our phenomenological analyses under the same system of cuts also recently adopted by the CMS collaboration at LHC.

Highlights

In recent years significant effort was devoted to increase the accuracy of theoretical predictions for p-p collision processes, in order to match the experimental capabilities of the LHC detectors
In this paper we concentrate on the case of tt-pair hadroproduction in association with an heavy gauge boson, ttW and ttZ, that we have recently studied extensively in Ref. [9, 10], leaving the reader interested in our predictions for other tt-X associated processes, like ttj, ttH and ttA, to previous works including PowHel predictions [11, 12, 13]
Results ttZ and ttW ± LO and NLO inclusive cross-sections as predicted by PowHel were already presented in Ref. [9, 10]

Summary

Introduction

In recent years significant effort was devoted to increase the accuracy of theoretical predictions for p-p collision processes, in order to match the experimental capabilities of the LHC detectors. One line of development aims at providing refined automatic computations of fixed-order total and differential cross-sections with increased accuracy, leading to predictions of the final products of hard-scattering processes at the parton level.

Results

Conclusion