Approximate Next-to-Next-to-Leading Order Corrections to Hadronic Jet Production

Abstract

We determine dominant next-to-next-to-leading order QCD corrections to single-inclusive jet production at the LHC and Tevatron, using the established threshold resummation framework. In contrast to previous literature on this topic, our study incorporates all of the following features: (1) It properly accounts for the way a jet is defined in experiment and treated in available full next-to-leading order calculations, (2) It includes the three leading classes of logarithmic terms in the perturbative expansion, and (3) It is adapted to the full kinematics in jet transverse momentum and rapidity relevant for experiments. A recent full next-to-next-to-leading order calculation in the purely gluonic channel allows us to assess the region where our approximate corrections provide an accurate description. We expect our results to be important on the way to precision jet phenomenology at the LHC and as benchmark for further full next-to-next-to-leading order calculations.PACS numbers: 12.38.Bx, 13.85.-t, 13.87.-aIntroduction. -The production of high-transversemomentum hadron jets plays a fundamental role at the LHC [1] and at Tevatron [2]. Jets are produced very copiously, making them precision probes of the physics of the Standard Model and beyond. Theoretical calculations whose precision matches that achievable in experiment are of critical importance. The efforts made in this context have spanned more than three decades now, culminating so far with the recent calculation of the next-tonext-to-leading order (NNLO) perturbative corrections to jet production in the "gluon-only" channel [3,4].As complete NNLO calculations of jet production are probably still a few years away, it is useful to determine approximate NNLO results, at least in certain kinematical regimes. This is possible thanks to the fact that the perturbative series for the partonic cross sections contains classes of logarithmic terms that often dominate. Resummation techniques in QCD [5] allow to determine the all-order structure of these logarithmic terms, and one therefore also obtains the logarithms present at NNLO. Knowledge of approximate NNLO expressions is very useful, since it potentially offers an avenue toward more precise phenomenology than available on the basis of the presently known full next-to-leading order (NLO) corrections. It also serves as benchmark for future full NNLO calculations.The logarithms just mentioned arise near a threshold from which the production of a jet becomes possible in a partonic collision. They are hence known as "threshold logarithms". The threshold is set by a vanishing invariant mass √ s 4 of the partonic system that recoils against

Nuclear parton density functions from dijet photoproduction at the EIC

“…The implementation of jet mass corrections [34] to our aNNLO formalism is left for future work. Although they will in particular introduce a dependence on the jet radius R, the impact of these additional corrections is expected to be even smaller than the one of the aNNLO contributions as a whole, in particular when R ¼ 1 as in this study, where terms ln R obviously disappear.…”

“…More important is the reduction of the scale uncertainty in particular at large p T , which strengthens our confidence in the perturbative calculation. Strictly speaking, the aNNLO formalism described above applies to massless jets [34], whereas experimentally jets are defined with an algorithm and have nonvanishing mass. Work on implementing the jet mass corrections is currently in progress.…”

Parton distributions for the LHC run II

“…Specifically, NNLO corrections are not available for two datasets included in our fit: the vector boson transverse momentum distribution and the W + c rapidity distribution (since there are no NNLO calculations for V +jets and V +heavy quarks). For the jet inclusive cross section, only the gg-channel has been recently computed at NNLO [82,99], while for the full cross section only an approximate NNLO prediction based on threshold resummation is available [100]. For all other observables included in the fit the cross sections are known up to NNLO.…”

Effects of cold nuclear matter energy loss on inclusive jet production inp+Acollisions at energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider

“…[36]. In principle, a LO calculation of single inclusive jet production has certain limitations since only at next-to-leading order (NLO) the QCD structure of the jet starts to play a role in the theoretical description of physical observables [37,38], for example a LO calculation cannot be used to study the dependence of CNM effects on the jet cone radius R. Unlike final-state quark-gluon plasma effects, however, the dependence of initial-state effects on the jet cone radius is expected to be very small [39]. Furthermore, quantitatively the NLO and LO cross sections are very similar for intermediate jet radii R ∼ 0.4.…”