Search for anomalous interaction mean free paths of charge, 2?Z?18 projectile fragments in emulsions exposed to 1.8 A GeV40Ar ions

Abstract

4~interactions are studied, to investigate the question of anomalons, in two G-5 emulsion stacks. In about 4600 primary interactions, projectile fragments of Z > 2 for all generations have been followed until they interact or leave the stack. After careful estimation of charges of these fragments, variation of their mean free paths is studied as a function of distance from the preceding interaction. Generation effect, Nh dependence and production angle effect are investigated. In addition multi-chain events are analysed separately. Our results do not show anomalons at the 6% level and are consistent with non-occurrence of anomalons. However, this experiment is not sensitive enough to rule out anomalons (with a mfp of the order of 2 to 3 cm) produced at about 1% (or less) level.