W-Boson Production in Association with a Jet at Next-to-Next-to-Leading Order in Perturbative QCD

Abstract

We present the complete calculation of W-boson production in association with a jet in hadronic collisions through next-to-next-to-leading order (NNLO) in perturbative QCD. To cancel infrared divergences, we discuss a new subtraction method that exploits the fact that the N-jettiness event-shape variable fully captures the singularity structure of QCD amplitudes with final-state partons. This method holds for processes with an arbitrary number of jets and is easily implemented into existing frameworks for higher-order calculations. We present initial phenomenological results for W+jet production at the LHC. The NNLO corrections are small and lead to a significantly reduced theoretical error, opening the door to precision measurements in the W+jet channel at the LHC.

NNLO QCD predictions for fully-differential top-quark pair production at the Tevatron

“…This has been possible thanks to the development of subtraction schemes [62][63][64][65][66][67][68][69][70], slicing methods [60,61,71] and the calculation of several two-to-two virtual amplitudes [72][73][74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91]. As far as top-quark pair production is concerned, besides our own calculation [10,92] only partial results are known at the differential level [93,94]; there is also progress at the level of total crosssection [95] obtained with slicing methods.…”

A complete basis of helicity operators for subleading factorization

“…Subtraction schemes based on factorization theorems include the recently introduced N -jettiness subtraction scheme [137][138][139], based on the N -jettiness event shape [140], as well as the SCET based subtraction scheme for NNLO semileptonic top quark decays of ref. [141].…”

Color-singlet production at NNLO in MCFM

“…However, no initial collinear singularities appear in this calculation. A powerful generalization of this idea applicable to general initial and final states was introduced in [4,16]. It is obtained by replacing the q T variable with the event-shape N -jettiness variable [66].…”

“…The corresponding two-loop soft functions are also known for zero-jettiness [71,72] and for general Njettiness [73]. The first process calculated at NNLO using this method was pp → W +jet [16], followed by calculations of the pp → Higgs+jet [8] and pp → Z +jet [18] processes, and by detailed phenomenological studies of these processes at this order [74][75][76]. pp → H and pp → Z were also calculated using this method [4].…”