Projectile spectator proton production in 84Kr-emulsion interactions at 1.7 A GeV

The multiplicity distribution of projectile protons and multiplicity correlations between black particles, grey particles, shower particles, compound particles, heavily ionized track particles, projectile helium fragments and projectile spectator protons in <'84>Kr-emulsion collisions at 1.7 A GeV are investigated. It is found that the projectile spectator proton multiplicity distribution becomes broader with increasing target mass. The average multiplicity of shower particles and compound particles strongly depends on the number of projectile spectator protons, but the average multiplicity of black particles, grey particles and heavily ionized track particles weakly depends on the number of projectile spectator protons. The average multiplicity of projectile helium fragments increases linearly with increasing numbers of projectile spectator protons. Finally, the multiplicity distribution of projectile spectator protons obeys a KNO type of scaling law.     

Evidence of self-affine multiplicity fluctuation of particle production in 84Kr--emulsion interactions at 1.7 A GeV

Self-affine multiplicity fluctuation is investigated by using the two-dimensional factorial moment methodology and the concept of the Hurst exponent (H). Investigation on the experimental data of compound particles and target fragments emitted in 84 Kr-AgBr interactions at 1.7 A GeV reveals that the best power law behaviours are exhibited at H=0.7 and 0.6 respectively, and the data for shower particles produced in 84 Kr-emulsion interactions at 1.7 A GeV indicate that the best power law behaviour occurs at H=0.6, all of which show the self-affine multiplicity fluctuation patterns. The multifractality and the non-thermal phase transition occurring during producing the compound particles, the target fragments, and the shower particles in the 84 Kr-AgBr interaction and the 84 Kr-emulsion interaction are also discussed. The multifractality is observed during producing compound particles, target fragments, and shower particles. In the target fragment production, an evidence of non-thermal phase transition is observed, but in the shower particle production and the compound particle production, no evidence of non-thermal phase transition is observed.     

Projectile spectator proton production in 84Kr- emulsion interactions at 1.7 A GeV

The multiplicity distribution of projectile protons and multiplicity correlations between black particles, grey particles, shower particles, compound particles, heavily ionized track particles, projectile helium fragments and projectile spectator protons in ⁸⁴Kr-emulsion collisions at 1.7 A GeV are investigated. It is found that the projectile spectator proton multiplicity distribution becomes broader with increasing target mass. The average multiplicity of shower particles and compound particles strongly depends on the number of projectile spectator protons, but the average multiplicity of black particles, grey particles and heavily ionized track particles weakly depends on the number of projectile spectator protons. The average multiplicity of projectile helium fragments increases linearly with increasing numbers of projectile spectator protons. Finally, the multiplicity distribution of projectile spectator protons obeys a KNO type of scaling law.     

Evidence of intermittent fluctuation of target fragments in ^84Kr-AgBr interactions at 1.7 A GeV

Intermittency and fractal behaviour have been studied of emission spectra of target associated fragments from ^84Kr-AgBr interactions at 1.7 A GeV in emission angle space and azimuthal angle space separately. The intermittent behaviour is observed in the two spaces separately. Prom the intermittency exponent, the anomalous fractal dimension dq is calculated and the variation of dq with the order q is investigated. It is found that the anomalous dimensions are found to increase with the order of moments q, thereby indicating the relation of multifractality to production mechanism of target associated fragments.     

Investigation of self-affine multiplicity fluctuations of proton emission in 84Kr-AgBr interactions at 1.7 A GeV

Self-affine multiplicity scaling is investigated in the framework of a two-dimensional factorial mo-ment methodology using the concept of the Hurst exponent (H). Investigation of the experimental data of medium-energy knocked-out target protons in SaKr-AgBr interactions at 1.7 AGeV reveals that the best power law behavior is exhibited for H = 0.4, indicating a self-affine multiplicity fluctuation pattern. Multifractalit yamong the knocked-out target protons is also observed in the data.     

Investigation of self-affine multiplicity fluctuations of proton emission in ^84Kr-AgBr interactions at 1.7 A GeV

Self-affine multiplicity scaling is investigated in the framework of a two-dimensional factorial moment methodology using the concept of the Hurst exponent （H）. Investigation of the experimental data of medium-energy knocked-out target protons in ^84Kr-AgBr interactions at 1.7 AGeV reveals that the best power law behavior is exhibited for H=0.4, indicating a self-affine multiplicity fluctuation pattern. Multifractality among the knocked-out target protons is also observed in the data.     

Fragmentation in ^16 O-emulsion interactions at 3.7 A GeV

The topology of ¹⁶O fragmentation at 3.7 A GeV in reactions with emulsion nuclei is presented. The multiplicity distributions of projectile fragments,charged secondaries and their dependences on the projectile residues are discussed.     

Intermittency in 3.7 A GeV ^16O-emulsion interactions

The intermittency effect has been studied for an interaction of 3.7 A GeV ^16O with emulsion using the distributions of both the pseudorapidity intervals and the azimuthal angle intervals of the shower particles emitted in a central rapidity region. The scaled factorial moments, reduced scaled factorial moments and multifractal moments as functions of the bin size in pseudorapidity and in azimuthal angle have been calculated and have revealed the presence of an intermittent behaviour which may be due to the random cascading property of the reaction. The anomalous fractal dimension has been found to increase with the increase of rank of the moment.     

Evidence of self-affine multiplicity fluctuation of target residues in 84Kr-AgBr interactions at 1.7 AGeV

Self-afline multiplicity scaling is investigated in the framework of a two-dimensional factorial mo-ment methodology using the concept of the Hurst exponent (H). Analyzing the experimental data of target evaporated fragments emitted in84Kr-AgBr interactions at 1.7 AGeV revealed that the best power law behav-ior is exhibited for H = 0.3 indicating a self-affine multiplicity fluctuation pattern. A signal of multifractality is also observed from knowledge of the anomalous fractal dimension dq extracted from the intermittency exponent aq of the anisotropic phase space scenario.     

Evidence of self-affine multiplicity fluctuation of target residues in ^84Kr-AgBr interactions at 1.7 AGeV

Self-affine multiplicity scaling is investigated in the framework of a two-dimensional factorial moment methodology using the concept of the Hurst exponent （H）. Analyzing the experimental data of target evaporated fragments emitted in ^84Kr-AgBr interactions at 1.7 AGeV revealed that the best power law behavior is exhibited for H = 0.3 indicating a self-arlene multiplicity fluctuation pattern. A signal of multifractality is also observed from knowledge of the anomalous fractal dimension dq extracted from the intermittency exponent aq of the anisotropic phase space scenario.     

Forward-backward multiplicity correlations 4.5 A GeV/c ^16O-emulsion interactions

A detailed study of the mechanisms of the emissions of pions and protons in the forward and backward hemispheres in 4.5 A GeV/c oxygen-emulsion interactions has been carried out. The correlations between the multiplicities of secondary charged particles in the backward and forward hemispheres are investigated.     

Helium production from 84Kr-- and 197Au--emulsion interactions at high energies

The properties of the relativistic helium fragments produced in interactions of 84 Kr at 1.8 A GeV and 197 Au at 10.7 A GeV in emulsion are investigated. The experimental results are compared with those obtained from various projectiles with emulsion collisions at different energies. It is found that the multiplicity distribution of helium projectile fragments (HPFs) is well described by the Koba-Nielsen-Olesen (KNO) scaling presentation. The second Mueller moment f 2 of the HPF multiplicity distribution is independent of the projectile energy for the same projectile, but it is dependent on the projectile mass number. The value of f 2 increases with the increase of projectile mass number A p . The negative value of f 2 , when A p < 69, means that the emission of HPFs is anticorrelated, but positive value of f 2 , when A p > 69, refers to that the emission of HPFs is correlated. The non-zero f 2 moment in this experiment implies the strong correlation existing between the HPFs.     

Study of compound particle production in ~（84）Kr-emulsion interactions at 1.7 A GeV

The characteristics of compound particle multiplicity distribution and multiplicity correlations between the compound particle and the grey particle, black particle, shower particle and heavily ionized track particle are investigated in this paper. It is found that the average multiplicities of the grey particle, black particle, shower particle and heavily ionized track particle increase with an increase in the number of compound particles, which can be explained by the impact geometrical model. The compound multiplicity distribution is observed to obey a Koba-Nielson-Olesen (KNO) type of scaling law.     

Features of the total disintegration events of heavyemulsion targets caused by 4.5A GeV/c16O

Total disintegration events produced by 4.5\,A GeV/c $^{16}$O--AgBr interactions are analysed to investigate the characteristics of secondary charged particles produced in such collisions. The multiplicity distributions of grey, black, and relativistic charged particles can be well represented by Gaussian distribution. The average multiplicity of grey particles is found to increase with the mass of projectile increasing, while that of black particles is found to decrease with the mass of projectile increasing. This result is in good agreement with the prediction of fireball model. Finally, the linear dependence between grey and black particles is observed, but there is no distinct dependence between the production of relativistic charged particles and the target excitation.     

3.7 A GeV 16O与乳胶作用相对论性α粒子的双源发射

对3.7 A GeV 16O与原子核乳胶作用α射弹碎片的发射进行了研究, 发现α射弹碎片的角分布不能用单一的旁观体-反应体模型来解释，所以假设α射弹碎片来源于两个温度不同的发射源。     

The production of slow particles in 16O－Em interactions at 4.5 A GeV/c

A sample of 1233 events is used to study the general characteristics of {}^{16}O－Em interactions at 4.5 A GeV/c. Multiplicity and angular distributions of slow particles and correlations among them are discussed. The present data are compared with the corresponding results from the interactions of other projectiles at the same energy and also the same projectile at different energies. The results indicate that black particle production is independent of the energy and mass of the projectile, but for grey particles it is dependent on the mass of projectile.     

Fragmentation of ^16O nuclei in nuclear emulsion

We present the topology of 16O fragmentation at 60A GeV in reactions with emulsion nuclei.We discuss the multiplicity distributions of projectile fragments.charged secondaries and their dependence on the target residues.     

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

An exclusive study of the characteristics of interactions accompanied by backward emission (θlab≥ 90°) of shower and grey particles in collisions of a 4.5 AGeV/c 16O beam with emulsion nuclei is carried out. The experimental multiplicity distributions of different particles emitted in the forward (θlab<90°) and backward hemispheres due to the interactions with the two emulsion components (CNO, AgBr) are presented and analyzed. The correlations between the different emitted particles are also investigated. The results indicate that there are signatures for a collective mechanism, which plays a role in the production of particles in the backward hemisphere. Hence, the backward multiplicity distribution of the emitted shower and grey particles at 4.5 AGeV/c incident momentum can be represented by a decay exponential law formula independent of the projectile size. The exponent of the power was found to increase with decreasing target size. The experimental data favor the idea that the backward particles were emitted due to the decay of the system in the latter stages of the reactions.     

Multiplicities of forward-backward particles in ^16O-emulsion interactions at 4.5 AGeV/c

An exclusive study of the characteristics of interactions accompanied by backward emission（θlab 90°） of shower and grey particles in collisions of a 4.5 AGeV/c ^16O beam with emulsion nuclei is carried out. The experimental multiplicity distributions of different particles emitted in the forward（θlab 〈 90°） and backward hemispheres due to the interactions with the two emulsion components（CNO,AgBr） are presented and analyzed. The correlations between the different emitted particles are also investigated. The results indicate that there are signatures for a collective mechanism,which plays a role in the production of particles in the backward hemisphere. Hence,the backward multiplicity distribution of the emitted shower and grey particles at 4.5 AGeV/c incident momentum can be represented by a decay exponential law formula independent of the projectile size. The exponent of the power was found to increase with decreasing target size. The experimental data favor the idea that the backward particles were emitted due to the decay of the system in the latter stages of the reactions.