qanti q pair production in expanding hadronic flux tubes

The qanti q pair production probability per unit time and unit volume is calculated for a hadronic flux tube with constant radius, expanding longitudinally with the speed of light. We find that the pair production rate is suppressed for short times in comparison to that in a static flux tube of infinite length. Consequently, the half life of the longitudinally expanding flux tube is sufficiently large, so that the assumption of the formation of a flux-tube like gluon-field configuration between a qanti q pair receding with the speed of light seems to be justified. The results support a flux tube radius of 0.5 fm. (orig.)