One-Loop Matching and Next-to-Next-to-Leading Log Resummation for all Partonic 2→2 Processes in QCD
نویسنده
چکیده
The Wilson Coefficients for all 4-parton operators which arise in matching QCD to Soft-Collinear Effective Theory (SCET) are computed at 1-loop. Any dijet observable calculated in SCET beyond leading order will require these results. The Wilson coefficients are separated by spin and color, although most applications will involve only the spin-averaged hard functions. The anomalous dimensions for the Wilson coefficients are given to 2-loop order, and the renormalization group equations are solved explicitly. This will allow for analytical resummation of dijet observables to next-to-next-to-leading logarithmic accuracy. For each channel, there is a natural basis in which the evolution is diagonal in color space. The same basis also diagonalizes the color evolution for the soft function. Even though soft functions required for SCET calculations are observable dependent, it is shown that their renormalization group evolution is almost completely determined by a universal structure. With these results, it will be possible to calculate hadronic event shapes or other dijet observables to next-to-leading order with next-tonext-to-leading log resummation.
منابع مشابه
Two-loop anomalous-dimension matrix for soft-gluon exchange.
The resummation of soft-gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions. We compute this matrix directly for arbitrary 2-->n massless processes for the first time at two loops. Using color-generator notation, we show that it is proportional to the one-loop matrix. This result reproduces all pole terms in dimensional regularization of the explicit calculations of...
متن کاملTwo-Loop Soft Corrections and Resummation of the Thrust Distribution in the Dijet Region
The thrust distribution in electron-positron annihilation is a classical precision QCD observable. Using renormalization group (RG) evolution in Laplace space, we perform the resummation of logarithmically enhanced corrections in the dijet limit, T → 1 to next-to-next-to-leading logarithmic (NNLL) accuracy. We independently derive the two-loop soft function for the thrust distribution and extra...
متن کاملStatus of Eikonal Two-Loop Calculations with Massive Quarks
The calculation of threshold corrections to hard scattering cross sections beyond leading logarithms requires the calculation of loop diagrams in the eikonal approximation [1]. One-loop calculations have been performed for all 2 → 2 partonic processes in heavy quark [2] and jet [3] production. The soft anomalous dimension matrix ΓS at one-loop allows the resummation of soft-gluon corrections at...
متن کاملThreshold resummation for high-transverse-momentum Higgs production at the LHC
We study the resummation of large logarithmic QCD corrections for the process pp → H + X when the Higgs boson H is produced at high transverse momentum. The corrections arise near the threshold for partonic reaction and originate from soft gluon emission. We perform the all-order resummation at next-to-leading logarithmic accuracy and match the resummed result with the next-to-leading order per...
متن کاملThreshold Resummation and the Total Cross Section for Top Quark Production
We discuss the motivation for resummation of the effects of initialstate soft gluon radiation, to all orders in the strong coupling strength, for processes in which the near-threshold region in the partonic subenergy is important. We summarize our calculation of the total cross section for top quark production at hadron colliders. Comments are included on the differences between our treatment o...
متن کامل