Resummation and NLO Matching of Event Shapes with Effective Field Theory

 Title: Resummation and NLO Matching of Event Shapes with Effective Field Theory Author: Schwartz, Matthew D Citation: Schwartz, Matthew D. 2008. Resummation and NLO Matching of Event Shapes with Effective Field Theory. Physical Review D 77(1): 014026. Full Text & Related Files: 0709.2709v2.pdf (245.5Kb; PDF) Abstract: The resummed differential thrust rate in $$e^+e^-$$ annihilation is calculated using Soft-Collinear Effective Theory (SCET). The resulting distribution in the two-jet region $$(T \sim 1)$$ is found to agree with the corresponding expression derived by the standard approach. A matching procedure to account for finite corrections at $$T < 1$$ is then described. There are two important advantages of the SCET approach. First, SCET manifests a dynamical seesaw scale $$q = p^2/Q$$ in addition to the center-of-mass energy $$Q$$ and the jet mass scale $$p \sim Q\sqrt{(1 - T)}$$. Thus, the resummation of logs of $$p/q$$ can be cleanly distinguished from the resummation of logs of $$Q/p$$. Second, finite parts of loop amplitudes appear in specific places in the perturbative distribution: in the matching to the hard function, at the scale $$Q$$, in matching to the jet function, at the scale p, and in matching to the soft function, at the scale $$q$$. This allows for a consistent merger of fixed order corrections and resummation. In particular, the total NLO $$e^+e^-$$ cross section is reproduced from these finite parts without having to perform additional infrared regulation. Published Version: doi://10.1103/PhysRevD.77.014026 Other Sources: http://arxiv.org/abs/0709.2709 Terms of Use: This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:8064443 Downloads of this work: