# Threshold Hadronic Event Shapes with Eﬀective Field Theory

 Title: Threshold Hadronic Event Shapes with Eﬀective Field Theory Author: Kelley, Randall; Schwartz, Matthew D Note: Order does not necessarily reflect citation order of authors. Citation: Kelley, Randall and Matthew D. Schwartz. 2011. Threshold hadronic event shapes with eﬀective field theory. Physical Review D 83(3): 033001. Full Text & Related Files: Hadronic Event Shapes.pdf (421.1Kb; PDF) Abstract: Hadronic event shapes, that is, event shapes at hadron colliders, could provide a great way to test both standard and nonstandard theoretical models. However, they are significantly more complicated than event shapes at e$$^+$$e$$^-$$ colliders, involving multiple hard directions, multiple channels, and multiple color structures. In this paper, hadronic event shapes are examined with soft-collinear effective theory (SCET) by expanding around the dijet limit. A simple event shape, threshold thrust, is defined. This observable is global and has no free parameters, making it ideal for clarifying how resummation of hadronic event shapes can be done in SCET. Threshold thrust is calculated at next-to-leading fixed order (NLO) in SCET and resummed to next-to-next-to-leading logarithmic (NNLL) accuracy. The scale-dependent parts of the soft function are shown to agree with what is expected from general observations, and the factorization formula is explicitly shown to be renormalization group invariant to 1-loop. Although threshold thrust is not itself expected to be phenomenologically interesting, it can be modified into a related observable which allows the jet p$$_T$$ distribution to be calculated and resummed to NNLL+NLO accuracy. As in other processes, one expects resummation to be important even for moderate jet momenta due to dynamical threshold enhancement. A general discussion of threshold enhancement and nonglobal logs in hadronic event shapes is also included. Published Version: doi:10.1103/PhysRevD.83.033001 Other Sources: http://arxiv.org/abs/1008.4355 Terms of Use: This article is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#OAP Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:8063807 Downloads of this work: