Coherent production of theK −π+π− system inK −d interactions at 4.5 GeV/c

The reactionK−d→K−π+π−d has been studied at an incidentK−-momentum of 4.5 GeV/c. A fractional analysis has been performed. A spin density matrix analysis and a partial wave analysis indicate that the events in theQ-region mainly originate from\(\bar K*\) production in aJPℓmη=(1+S0+) wave state. A comparison has been made with the reactionK+d→K+π−π+d at 4.6 GeV/c and the combined results have been compared toK+/−p→K+/−π+π−p at 13 GeV/c. It is found that theKππ-mass spectra produced on a proton or deuteron target can be described by one single Deck type mechanism on which directQ-meson production is superimposed.