Formula_17561

\[\frac{1}{g_{\mathrm{A}}^{2}}=1+\frac{2 m_{\mathrm{N}}^{2}}{\pi g_{\pi \mathrm{N}}^{2}} \int_{m_{\pi}}^{\infty} \frac{q d v}{v^{2}}\left[\sigma_{\pi-\mathrm{p}}(v)-\sigma_{\pi+\mathrm{p}}(v)\right] .\]