Emission of projectile helium fragments in 14N interactions at 2.1 GeV/nucleon: A test of factorization and limiting fragmentation

Some general properties of projectile fragments in40Ar interactions in nuclear emulsions at 1.8 A GeV

“…In a heavy projectile like 4"Ar, most of the interactions have at least one heavy fragment emitted along with alphas. This situation is quite different to that of the relatively less massive beam such as 14N, where, in almost all the cases [23], only alphas are emitted. The average emission angle of helium fragments in various channels for events from different target groups is shown in table 4.…”

“…In figure 2, we show the frequency of emission of Z = 2 projectile fragments ( n e ) as a function of (fi,) (which is the average of n h grouped over definite intervals conveniently chosen). It is clear that the emission frequency decreases as (A,,) increases, but not as markedly as was the case in I4N-Em [23] interactions. The reason could be that here we are dealing with events where most collisions are between nearly equal-sized nuclei, for which the strict geometrical criterion is not the only condition for central collision.…”

Multiparticle Production in Nucleus-Nucleus Interactions at High Energh

“…CNO events: 2 ≤ N h ≤ 8 and no track with range ≤ 10 µm AgBr events: (i) N h > 8 , (ii) N h ≤ 8 and at least one track with range ≤ 10 µm and no track with 10 ≤ R ≤ 50 µm H events: N h ≤ 1, but do not fall in the above categories. Table 1 gives the results using the above criteria along with the results of other similar efforts [4,[9][10][11]. It may be seen from the table that the probability of events due to AgBr nuclei increases with increasing projectile mass.…”

Limiting Fragmentation Behavior of Projectile Helium (Z= 2) Fragments in Nucleus–Nucleus Interactions at 14.6 A GeV

“…Because of the large separation between the projectile and target fragments, limiting fragmentation admits no correlation between projectile and target fragments. 5) The hypothesis of limiting fragmentation, an asymptotic property of the nucleus-nucleus collisions at relativistic high energies, has been observed experimentally for a variety of collision processes such as hadron-hadron, 6,7) hadron-nucleus, 7,8) and nucleus-nucleus interactions [9][10][11][12][13][14][15][16][17][18][19] for produced charged hadrons at different energies and also for photons at forward pseudo-rapidity. 15,16,20) Apart from the multitude of produced charged hadrons, the light, intermediate and heavy fragments (which are mainly the decay products of the projectile spectator and found near the beam rapidity region) are also emitted in a substantial amount in these heavy-ion collision experiments.…”

“…In this perspective, the study of limiting fragmentation phenomenon for these projectile helium fragments needs some more attention to be paid in order to understand the underlying physics of the fragmentation mechanism involved in such nuclear collisions at relativistic high energies. The projectile helium fragments with charge Z ¼ 2, have been studied earlier in nuclear emulsion experiments from the point of view of limiting fragmentation by Heckman et al 22) and by Bhanja et al 5) at 2.1 A GeV energy. In this sequence, some other authors [23][24][25] further confirmed this hypothesis experimentally for projectile helium fragments in nucleus-nucleus interactions in later years.…”