Document Type

Article

Publication Date

2016

DOI

10.1103/PhysRevD.93.114508

Publication Title

Physical Review D

Volume

93

Issue

11

Pages

114508 (1-20)

Abstract

We present a determination of the P-wave πœ‹πœ‹ β†’ πœ‹π›Ύβ‹† transition amplitude from lattice quantum chromodynamics. Matrix elements of the vector current in a finite volume are extracted from three-point correlation functions, and from these we determine the infinite-volume amplitude using a generalization of the Lellouch-LΓΌscher formalism. We determine the amplitude for a range of discrete values of the πœ‹πœ‹ energy and virtuality of the photon and observe the expected dynamical enhancement due to the ρ resonance. Describing the energy dependence of the amplitude, we are able to analytically continue into the complex energy plane and from the residue at the ρ pole extract the ρ β†’ πœ‹π›Ύβ‹† transition form factor. This calculation, at mπœ‹ β‰ˆ 400  MeV, is the first to determine the form factor of an unstable hadron within a first principles approach to QCD.

Comments

Β© 2016 American Physical Society

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An Erratum to this article was published on April 27, 2022.

Original Publication Citation

BriceΓ±o, R.A., Dudek, J.J., Edwards, R.G., Shultz, C.J., Thomas, C.E. & Wilson, D.J. (2016) πœ‹πœ‹ β†’ πœ‹π›Ύ* amplitude and the resonant 𝜌 β†’ πœ‹π›Ύ* transition from lattice QCD Physical Review D. 93(11), 1-20, Article 114508. https://doi.org/10.1103/PhysRevD.93.114508

ORCID

0000-0003-1109-1473 (BriceΓ±o), 0000-0003-4327-2121 (Dudek)

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