Beyond the wave function at the origin: Some momentum-dependent effects in the nonrelativistic quark model

Although the $u$, $d$, and $s$ quarks of nonrelativistic potential models are moving at high speeds, the approximation $\frac{p}{m}\simeq 0$ is used not only in spectroscopy (where its effects may be hidden), but also in calculating transition amplitudes. We have considered a simple scheme for going beyond the static approximation and found that many discrepancies disappear, including those for $\frac{g_A}{g_V}$ and $〈0\left|A^{\mu }\right|A_1〉$.