PIONIC DECAY OF A POSSIBLE D' DIBARYON

The pionic decay of a possible d' dibaryon in the process d' --> N + N + pi is studied in the microscopic quark shell. model and with a sing le-quark transition operator describing the transition q --> q + pi. F or the d' with quantum numbers J(p) = 0(-), T = 0, we employ a six-qua rk shell-model wave function with a spatial s(5)p[51](X) configuration and with N = 1 harmonic oscillator quanta. It is shown that the pioni c decay width depends strongly on the mass and size of the d'. In the case that the calculated d' mass is close to the experimental one, a s mall pionic decay width of Gamma(pi) approximate to 0.04 MeV is obtain ed. This is an order of magnitude smaller than the experimental I-pi(e xp) similar or equal to 0.5 MeV. Two possibilities to improve the calc ulated width are suggested. The effect of the non-static correction te rm in the transition operator and the influence of the form factor at the decay vertex on the decay width are also discussed.