Exclusive Vector Meson Production
One of the nuclei emits a photon. The photon fluctuates into a vector meson, which scatters off the other nucleus.
– Vector Meson Dominance Model
– The probability of finding the photon in the vector
meson state is of the order of ? ? 1/137
– The lifetime of the fluctuation: ? 2E? /(M2+Q2) ?
For high E? , the distance the vector meson travels is
large compared with the nuclear dimensions
– The reaction is mediated by a colorless exchange