We use an abelian model to study linear power corrections which arise from infrared renormalons and affect event shapes in e(+)e(-) annihilation into hadrons. While previous studies explored power corrections in the two-jet region, in this paper we focus on the three-jet region, which is the most relevant one for the determination of the strong coupling constant. We show that for a broad class of shape variables, linear power corrections can be written in a factorised form, that involves an analytically-calculable function, that characterises changes in the shape variable when a soft parton is emitted, and a constant universal factor. This universal factor is proportional to the so-called Milan factor, introduced in earlier literature to describe linear power corrections in the two-jet region. We find that the power corrections in the two-jet and in the three-jet regions are different, a result which is bound to have important consequences for the determination of the strong coupling constant from event shapes. As a further illustration of the power of the approach developed in this paper, we provide explicit analytic expressions for the leading power corrections to the C-parameter and the thrust distributions in the N -jet region for arbitrary N, albeit in the abelian model.

Caola, F., Ravasio, S., Limatola, G., Melnikov, K., Nason, P., Ozcelik, M. (2022). Linear power corrections to e + e – shape variables in the three-jet region. JOURNAL OF HIGH ENERGY PHYSICS, 2022(12) [10.1007/JHEP12(2022)062].

Linear power corrections to e + e – shape variables in the three-jet region

Limatola G.;Nason P.;
2022

Abstract

We use an abelian model to study linear power corrections which arise from infrared renormalons and affect event shapes in e(+)e(-) annihilation into hadrons. While previous studies explored power corrections in the two-jet region, in this paper we focus on the three-jet region, which is the most relevant one for the determination of the strong coupling constant. We show that for a broad class of shape variables, linear power corrections can be written in a factorised form, that involves an analytically-calculable function, that characterises changes in the shape variable when a soft parton is emitted, and a constant universal factor. This universal factor is proportional to the so-called Milan factor, introduced in earlier literature to describe linear power corrections in the two-jet region. We find that the power corrections in the two-jet and in the three-jet regions are different, a result which is bound to have important consequences for the determination of the strong coupling constant from event shapes. As a further illustration of the power of the approach developed in this paper, we provide explicit analytic expressions for the leading power corrections to the C-parameter and the thrust distributions in the N -jet region for arbitrary N, albeit in the abelian model.
Articolo in rivista - Articolo scientifico
Factorization; Renormalization Group; Higher-Order Perturbative Calculations; Specific QCD Phenomenology;
English
12-dic-2022
2022
2022
12
62
open
Caola, F., Ravasio, S., Limatola, G., Melnikov, K., Nason, P., Ozcelik, M. (2022). Linear power corrections to e + e – shape variables in the three-jet region. JOURNAL OF HIGH ENERGY PHYSICS, 2022(12) [10.1007/JHEP12(2022)062].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/531183
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