NNLO beam functions for angularity distributions

arXiv (Cornell University)

Abstract

The popular class of angularity event shapes provides a wealth of information on the hadronic final-state distribution in collider events. While initially proposed for $e^+ e^-$ collisions, angularities have more recently attracted considerable interest as a jet substructure observable at hadron colliders. Moreover, angularities can be measured as a global event shape in deep inelastic electron-nucleon scattering (DIS), and the respective factorisation theorem contains a beam function that parametrises the collinear initial-state radiation. In the present work, we compute the quark and gluon beam functions for seven different angularities to next-to-next-to-leading order (NNLO) in the strong-coupling expansion. Our calculation is based on an automated framework that was previously developed for SCET-2 observables, and which we transfer in the current work to the generic SCET-1 case. Our results are relevant for resumming DIS angularity distributions at NNLL$'$ accuracy.

Authors 4

1. Guido Bell

   University of Siegen

   Affiliation as printed

   Theoretische Physik 1 , Center for Particle Physics Siegen , Universität Siegen , 57068 Siegen , Germany

2. Kevin Brune

   University of Siegen

   Affiliation as printed

   Theoretische Physik 1 , Center for Particle Physics Siegen , Universität Siegen , 57068 Siegen , Germany

3. Goutam Das Aachen Institut für Theoretische Teilchenphysik und Kosmologie

   RWTH Aachen University

   Affiliation as printed

   Institut für Theoretische Teilchenphysik und Kosmologie , RWTH Aachen University , 52056 Aachen , Germany

4. Marcel Wald

   University of Siegen

   Affiliation as printed

   Theoretische Physik 1 , Center for Particle Physics Siegen , Universität Siegen , 57068 Siegen , Germany