2009/11/30 by Thomas Becher, Matthew D. Schwartz · 1 citation
Physics and Astronomy · #Effective field theory #Factorization #Gluon #Hadron #High-Energy Particle Collisions Research #Jet (fluid) #Observable #Particle physics theoretical and experimental studies #Parton #Photon #Quantum Chromodynamics and Particle Interactions #Resummation #Tevatron #hep-ph
paper · pdf · doi:10.1007/jhep02(2010)040
published as JHEP 1002:040,2010 · 42 pages, 9 figures; v2: references added, minor changes; v3: typos; v4: typos, corrections in (16), (47), (72)
openalex publication_date 2010/02/01 · arxiv created 2012/02/09 · arxiv updated 2012/02/10 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The production of hard photons in hadronic collisions is studied using Soft-Collinear Effective Theory (SCET). This is the first application of SCET to a physical, observable cross section involving energetic partons in more than two directions. A factorization formula is derived which involves a non-trivial interplay of the angular dependence in the hard and soft functions, both quark and gluon jet functions, and multiple partonic channels. The relevant hard, jet and soft functions are computed to one loop and their anomalous dimensions are determined to three loops. The final resummed inclusive direct photon distribution is valid to next-to-next-to-leading logarithmic order (NNLL), one order beyond previous work. The result is improved by including non-logarithmic terms and photon isolation cuts through matching, and compared to Tevatron data and to fixed order results at the Tevatron and the LHC. The resummed cross section has a significantly smaller theoretical uncertainty than the next-to-leading fixed-order result, particularly at high transverse momentum.