On the narrow dip structure at 1.9 GeV/c${}^2$ in diffractive photoproduction

Abstract

The narrow dip observed at 1.9 GeV/c${}^2$ by the Fermilab experiment E687 in diffractive photoproduction of $3{\pi }^{+}3{\pi }^{-}$ is examined. The E687 data are refitted, a mechanism is proposed to explain why this resonance appears as a dip, and possible interpretations are discussed.

Comments: 13 pages, 3 figures. Accepted by Phys. Lett. B