Two-photon decays and transition form factors of π0 , η , and η′ in large- Nc chiral perturbation theory
Year: 2020
Type: article
Abstract: We present a calculation of $P\ensuremath{\rightarrow}{\ensuremath{\gamma}}^{(*)}{\ensuremath{\gamma}}^{(*)}$ processes, where $P={\ensuremath{\pi}}^{0},\ensuremath{\eta},{\ensuremath{\eta}}^{\ensuremath{'}}$, at the one-loop level up to and including next-to-next-to-leading order (NNLO) in large-${N}_{c}$ chiral perturbation theory. The results are numerically evaluated successively at LO, NLO, and NNLO. The appearing low-energy constants are determined through fits to the available experimental data. We investigate the decay widths to real photons, the single-virtual transition form factors, and the widths of $P\ensuremath{\rightarrow}\ensuremath{\gamma}{l}^{+}{l}^{\ensuremath{-}}$, where $l=e$, $\ensuremath{\mu}$. Furthermore, we provide results for the slopes and curvatures of the transition form factors.
Authors: P. Bickert, S. Scherer
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Funder: Deutsche Forschungsgemeinschaft
Award: G3795454412
OpenAlex ID: W3024313618