Derivation of the Balitsky-Kovchegov Equation for Quark-Quark Scattering

We derived the BK equation for quark-quark scattering, extending the dipole-hadron scattering framework. This derivation reveals that the quark-quark scattering amplitude grows with increasing quark rapidity. Since the momentum dot product is Lorentz invariant, the coupling constant plays a crucial role in accounting for it.