Thomas Becher, Christian Lorentzen, Matthew D. Schwartz
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 pertubatively 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.
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http://arxiv.org/abs/1206.6115
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