Projectile fragmentation of 6,7Li nuclei in photoemulsion at Dubna energy

Abstract

Stripping and diffraction dissociation processes of 6 Li at incident momentum 4.5AGeV/c and 7 Li at incident momentum 3AGeV/c, provided by the JINR Synchrophastron, were studied using the photoemulsion technique. The two stable isotopes of 6 Li and 7 Li were treated as two weakly-bound systems composed of (4 He+d) and (4 He+t) cluster configurations, respectively. Along the track double scanning method was carried out in order to search for 6,7 Li interactions in emulsion (Em). For 6 Li-Em about 1050 inclusive events were recorded with mean free path 14.5 ± 0.5 cm while about 1015 events were detected for 7 Li-Em with mean free path 15.1 ± 0.6 cm. The type of momentum distribution inside the projectile according to which the features of each mechanism can be correctly explained and the difference between the angular distributions of these processes are theoretically discussed. The total cross sections of both stripping and dissociation are estimated theoretically as well as experimentally. The measured angular distributions of the outgoing fragments were compared with that calculated theoretically and good agreement between the experimental and theoretical values is obtained. This agreement supported the presence of 6,7 Li nuclei in a cluster mode at high energy reactions.