One-Loop Angularity Distributions with Recoil using SCET

Jet angularities are a class of event shapes that are designed to measure the energy- flow into angular regions of phase space between energetic jets. Angularity description relies on a free parameter b (b >-1) such that varying the exponent b changes the sensitivity of the observable to the substructure of the jet. When measured with respect to the standard thrust axis, this class of QCD observables is a generalization to the well known jet observables thrust (b = 1) and jet broadening (b = 0), where the former is insensitive to the recoil of soft against collinear radiation while the latter being maximally sensitive to it. Presently available analytic results for angularity distributions with b ≠ 0 can be applied only close to the thrust limit (i.e.  b ≳ 1), since recoil effects have so far been neglected. In this talk, I will discuss a universal field theoretic framework based on Soft-Collinear Effective Theory (SCET) which can be utilized over the whole range of angularity exponents. This comprehensive framework allows for novel and more detailed understanding of the recoil effects and our analytic results smoothly unify the one-loop differential distributions for thrust and jet broadening, which have typically been described in terms of different effective theories so far. I will discuss these results in detail in my talk.

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