2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/207327The narrow dip observed at 1.9 GeV/c$^2$ by the Fermilab experiment E687 in diffractive photoproduction of $~3π^+3π^-$ 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.13 pages, 3 figures. Accepted by Phys. Lett. BHigh Energy Physics - ExperimentHigh Energy Physics - Phenomenologytext