Precision direct photon and W-boson spectra at high pT and comparison to LHC data

The differential p(T) spectrum for vector boson production is computed at next-to-leading fixed order and including the resummation of threshold logarithms at next-to-next-to-leading logarithmic accuracy. A comparison is made to ATLAS data on direct photon and W production at high transverse momentum p(T), finding excellent agreement. The resummation is achieved by factorizing contributions associated with different scales using soft-collinear effective theory. Each part is then calculated perturbatively and the individual contributions are combined using renormalization group methods. A key advantage of the effective theory framework is that it indicates a set of natural scale choices, in contrast to the fixed-order calculation. Resummation of logarithms of ratios of these scales leads to better agreement with data and reduced theoretical uncertainties.