SEARCH FOR COLOR VAN-DER-WAALS FORCE IN PB-208+PB-208 MOTT SCATTERING

In a high precision experiment, Mott scattering of the [sup 208]Pb+[sup 108]Pb system was measured at [ital E][sub lab]=873.40 MeV and 1129.74 MeV with kinematic coincidences for angle pairs around [theta][sub lab]=30[degree], 60[degree] and [theta][sub lab]=45[degree], 45[degree]. The observed Mott oscillations exhibit an angular shift with respect to pure Mott scattering. A comparison with the angular shift produced by a color van der Waals force including nuclear polarizability, vacuum polarization, relativistic effects, and electronic screening provides a new upper limit for the strength of this force. Influence of atomic effects other than screening were identified for the first time.