Repulsive KAr potentials from differential optical collisions

Experimental differential cross sections for the optical collision process K(4s)2S + Ar + hν → K(4p)2P + Ar are reported. The characteristic interference structures are used to determine the repulsive parts of the KAr X2Σ and B2Σ potential curves by comparison with the results of exact quantum coupled-channel scattering calculations. By a least-squares procedure we obtain potentials with a relative accuracy of typically 1% in the range 0 ≤ V ≤ 1000-1500 cm-1, corresponding to absolute values of 2-4 cm-1 for the larger and 10-15 cm-1 for the smaller distances sampled by the experiment