Year: 2000
Type: article
Abstract: The differential cross sections for ${\ensuremath{\pi}}^{\ensuremath{-}}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\gamma}n$ and ${\ensuremath{\pi}}^{+}\stackrel{\ensuremath{\rightarrow}}{n}\ensuremath{\gamma}p$ are computed up to ${O(p}^{3})$ in heavy baryon chiral perturbation theory (HBChPT). The expressions at $O(p)$ and ${O(p}^{2})$ have no free parameters. There are three unknown parameters at ${O(p}^{3}),$ low energy constants of the HBChPT Lagrangian, which are determined by fitting to experimental data. Two acceptable fits are obtained, which can be separated by comparing with earlier dispersion relation calculations of the inverse process. Expressions for the multipoles, with emphasis on the p-wave multipoles, are obtained and evaluated at threshold. Generally the results obtained from the best of the two fits are in good agreement with the dispersion relation predictions.
Source: Physical Review C
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2047583993