Hadronic production of P-wave charmonium states

Hadronic production of P-wave charmonium states ( χ_J) is discussed. Particular emphasis is put on the contribution from valence quark annihilation. Different models give striking differences for the relative abundance of the various χ_J states and for the angular distribution of the cascade photons. The magnitude of the production cross section is calculated. Dominance of χ₁ production in K^-p, overlinepp and π^-p collisions is predicted.