The result, Quantum Collision Theory (North-Holland, 1983; later reprinted by Elsevier), is a towering achievement. It bridges the gap between the abstract formalism of scattering theory and the practical calculations needed to predict experimental outcomes.

After all, in quantum collision theory, respecting the wavefunction’s boundary conditions is essential. Respecting copyright while seeking knowledge is no less a virtue.

– Introduces advanced formalisms, including S-matrix theory and cross-section determination.

As the table shows, Joachain occupies the sweet spot: formal enough to be correct, applied enough to be useful.

While modern research leans heavily on numerical solutions, a physicist cannot debug a code without understanding the underlying approximations. Joachain’s feature here is its of perturbation and non-perturbation methods: