Backward-forward analysis of fast and slow hadrons in⁶Li interactions with emulsion nuclei at 3.7 A GeV

Abstract

A comparison of the recent experimental results on yields of s, g and b-particles (fast and slow hadrons) emitted in the forward (θ < 90 • ) and backward (θ 90 • ) hemispheres resulting from the interactions of 6 Li (3.7 A GeV) with emulsion nuclei is made with two theoretical models: a typical intranuclear cascade model and a modified FRITIOF model. The latter consists of two main ingredients: (i) the distribution of the nucleons knocked out by hard collisions based on a classical Glauber approach and (ii) the description of the secondary interactions by a soft process which amounts to a cascade on the plane of impact parameter. Particles taking part in the hard processes become excited strings as in the original FRITIOF model. From such comparison it is found that, while the cascade model applies well in the region of limited cascading (backward hemispheres), it becomes less applicable in the forward hemisphere (where cascading becomes more branched). The modified FRITIOF model, on the other hand, could reproduce the experimental observations in both hemispheres.

System size dependence of final state hadron sources atElab= 3.7 A GeV

“…The pion source varies according to the energy, system size, centrality, and emission zone. Our lab group has concerned it [10,[16][17][18][19][20][24][25][26][27][28][29][30][31][32][33]. The present interactions are 3.7 A GeV 4 He, 16 O, and 32 S with emulsion nuclei.…”

Forward-backward multiplicity correlations of target fragments in nucleus-emulsion collisions at a few hundred MeV/u

“…The backward emission of protons and pions in hadron-nucleus [1][2][3][4][5][6][7] and nucleus-nucleus [8][9][10][11][12][13][14][15][16][17][18] at relativistic energies have been investigated exclusively. It is found that the backward proton production was attributed to the absorption of secondary pions by a nucleon pair in the target nucleus, and the backward pions production shown to be consistent with the cumulative effect [19].…”

“…The study of the production of backward particles in hadron-nucleus and nucleus-nucleus interactions at high energies has received considerable experimental and theoretical attention because the fact that the backward emission of relativistic particles in high energy hadronnucleon collisions is kinematically restricted. The backward emission of protons and pions in hadron-nucleus [1][2][3][4][5][6][7] and nucleus-nucleus [8][9][10][11][12][13][14][15][16][17][18] at relativistic energies have been investigated exclusively. It is found that the backward proton production was attributed to the absorption of secondary pions by a nucleon pair in the target nucleus, and the backward pions production shown to be consistent with the cumulative effect [19].…”

Multiplicities of forward-backward particles in16O-emulsion interactions at 4.5AGeV/c

“…In this paper, we analyze the data on shower and grey particles produced in the backward (90 • θ 180 • , where θ is the emission angle in the laboratory system) hemisphere and forward (0 • θ 90 • ) hemisphere from the interaction of 16 O projectile with emulsion nuclei at 4.5 AGeV/c. This research focused on the general characteristics of multiplicity distributions of backward shower and grey particles and compared them systematically with the corresponding ones obtained for other projectiles at nearly the same incident momentum per nucleon [16][17][18][19][20][21][22][23][24][25] . Furthermore, the multiplicity correlations between dif-…”