Wandering in Color-Space -- why the life of pentaquark is so long ? --

摘要

The problem of the long life time of the pentaquark $\Theta^+$ isinvestigated on the basis of the color molecular dynamics simulation. We findthat it takes a long time (typically of 50-100 fm/c) for the initialpentaquark-state to rearrange its color and spatial positions to decay into thenucleon + kaon final state. Structure of the potential surface in the color andposition spaces also supports this picture. Pentaquark wanders on the potentialsurface to find a narrow channel to decay.