Higher-order non-global logarithms from jet calculus

• Published in: The journal of high energy physics Vol. 2022; no. 3; pp. 135 - 34
• Main Authors: Banfi, Andrea, Dreyer, Frédéric A., Monni, Pier Francesco
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2022; Springer Nature B.V; SpringerOpen
• Subjects: Algorithms; Angular distribution; Classical and Quantum Gravitation; Coherent scattering; Elementary Particles; Energy distribution; High energy physics; Jets; Logarithms; Mathematical analysis; Nonlinear differential equations; Physics; Physics and Astronomy; QCD Phenomenology; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Radiation; Regular Article - Theoretical Physics; Relativity Theory; String Theory; Jets; QCD Phenomenology
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP03(2022)135

A bstract Non-global QCD observables are characterised by a sensitivity to the full angular distribution of soft radiation emitted coherently in hard scattering processes. This complexity poses a challenge to their all-order resummation, that was formulated at the leading-logarithmic order about two decades ago. In this article we present a solution to the long-standing problem of their resummation beyond this order, and carry out the first complete next-to-leading logarithmic calculation for non-global observables. This is achieved by solving numerically the recently derived set of non-linear differential equations which describe the evolution of soft radiation in the planar, large- N c limit. As a case study we address the calculation of the transverse energy distribution in the interjet rapidity region in e + e − → dijet production. The calculation is performed by means of an algorithm that we formulate in the language of jet-calculus generating functionals, which also makes the resummation technique applicable to more general non-global problems, such as those that arise in hadronic collisions. We find that NLL corrections are substantial and their inclusion leads to a significant reduction of the perturbative scale uncertainties for these observables. The computer code used in the calculations is made publicly available.