Improved Standard-Model Prediction for π0→e+e-

Author(s): Martin Hoferichter, Bai-Long Hoid, Bastian Kubis, Jan Lüdtke
Abstract: We present an improved standard-model (SM) prediction for the dilepton decay of the neutral pion. The loop amplitude is determined by the pion transition form factor for p0**, for which we employ a dispersive representation that incorporates both spacelike and timelike data as well as short-distance constraints. The resulting SM branching fraction, Br[p0?e+e-]=6.25(3)×10-8, sharpens constraints on physics beyond the SM, including pseudoscalar and axial-vector mediators.
Organisation(s): Particle Physics
External organisation(s): Universität Bern, Rheinische Friedrich-Wilhelms-Universität Bonn
Journal: Physical Review Letters
Volume: 128
No. of pages: 7
ISSN: 0031-9007
DOI: https://doi.org/10.1103/PhysRevLett.128.172004
Publication date: 04-2022
Peer reviewed: Yes
Austrian Fields of Science 2012: 103034 Particle physics
Keywords
ASJC Scopus subject areas: General Physics and Astronomy
Portal url: https://ucrisportal.univie.ac.at/en/publications/6fc61aab-9c7a-4339-9070-bd73f0a57bf1

Improved Standard-Model Prediction for π<sup>0</sup>→e<sup>+</sup>e<sup>-</sup>