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

### 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.

###### Current status:
Publication decision taken: accept

Editorial decision: For Journal SciPost Physics Proceedings: Publish
(status: Editorial decision fixed and (if required) accepted by authors)

### Submission & Refereeing History

Submission 2110.14776v1 on 29 October 2021

## Reports on this Submission

### Strengths

The article reports on the work presented at RADCOR/LoopFest 2021. It fulfills all the requirements for publication in SciPost Proceedings.

None.

### Report

The article reports on the work presented at RADCOR/LoopFest 2021. It fulfills all the requirements for publication in SciPost Proceedings and therefore we recommend its publication.

### Requested changes

None.

• validity: high
• significance: high
• originality: good
• clarity: high
• formatting: excellent
• grammar: excellent