Single-jet inclusive rates with exact color at $$ \mathcal{O} $$ ($$ {\alpha}_s^4 $$)

Abstract

Next-to-next-to-leading order QCD predictions for single-, double-and even triple-differential distributions of jet events in proton-proton collisions have recently been obtained using the NNLOjet framework based on antenna subtraction. These results are an important input for Parton Distribution Function fits to hadron-collider data. While these calculations include all of the partonic channels occurring at this order of the perturbative expansion, they are based on the leading-color approximation in the case of channels involving quarks and are only exact in color in the pure-gluon channel. In the present publication, we verify that the sub-leading color effects in the single-jet inclusive doubledifferential cross sections are indeed negligible as far as phenomenological applications are concerned. This is the first independent and complete calculation for this observable. We also take the opportunity to discuss the necessary modifications of the sector-improved residue subtraction scheme that made this work possible.

Higgs decay into massive b-quarks at NNLO QCD in the nested soft-collinear subtraction scheme

“…A number of methods have been developed to accomplish that. Here, we follow the nested soft-collinear subtraction scheme [17,[25][26][27] which is closely related to the sectorimproved residue subtraction scheme [28][29][30][31]. As with all subtraction schemes, the general idea is to introduce subtraction terms for each singular limit which regulate the integrand and to add back these subtraction terms integrated over the unresolved phase space.…”

“…Throughout the article, we describe calculations only for the region with E 4 > E 5 ; the other region can easily be covered by performing the same steps with the gluon momenta swapped, q 4 ↔ q 5 . 2 Hence, we parametrise the gluon energies as [31]…”

Four-particle scattering amplitudes in QCD at NNLO to higher orders in the dimensional regulator

“…The observables associated with the production of two jets were computed at next-toleading order (NLO) [4][5][6][7] and even at NNLO [8][9][10][11] in perturbative QCD. The importance of this process and the wealth of data collected by the LHC is inspiring to go beyond the existing accuracy and perform a calculation at N 3 LO in QCD perturbation theory.…”

“…11) In the above equation the a i now simply label the colour of an external gluon. The 16 helicity configurations are represented by the following structures,…”

Measurements of inclusive jet spectra in pp and central Pb-Pb collisions at sNN=5.02TeV

“…The inclusive jet cross section in pp collisions contains important QCD physics itself. In recent years, the inclusive jet cross section in pp collisions was computed at NLO with resummation of logarithms of the jet resolution parameter [26][27][28][29] and threshold logarithms [30,31], and also to NNLO both with and without the leading color approximation [32,33]. Measurements of the inclusive pp jet cross section have been made at the SPS [34,35], the Tevatron [36,37], RHIC [38], and the LHC [39][40][41][42][43][44][45][46][47], and the latest comparisons of these measurements with theoretical predictions demonstrate the importance of contributions beyond NLO fixedorder calculations, namely resummations or matched parton showers.…”