SciPost Submission Page

The pion-photon transition form factor at two loops in QCD

by Jing Gao, Tobias Huber, Yao Ji, Yu-Ming Wang

Submission summary

As Contributors:	Tobias Huber
Arxiv Link:	https://arxiv.org/abs/2110.14776v1 (pdf)
Date accepted:	2022-02-28
Date submitted:	2021-10-29 16:20
Submitted by:	Huber, Tobias
Submitted to:	SciPost Physics Proceedings
Proceedings issue:	RADCOR 2021 (15th International Symposium on Radiative Corrections: Applications of Quantum Field Theory to Phenomenology)
Academic field:	Physics
Specialties:	High-Energy Physics - Phenomenology
Approaches:	Theoretical, Phenomenological

Abstract

We report on the fully analytic calculation of the leading-power contribution to the photon-pion transition form factor $\gamma \, \gamma^{\ast} \to \pi^0$ at two loops in QCD. The applied techniques are based on hard-collinear factorization, together with modern multi-loop methods. We focus both, on the technical details such as the treatment of evanescent operators, and the phenomenological implications. Our results indicate that the two-loop correction is numerically comparable to the one-loop effect in the same kinematic domain. We also demonstrate that our results will play a key role in disentangling various models for the twist-two pion distribution amplitude thanks to the envisaged precision at Belle II.

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