Multiplicity in proton-nucleus interactions in emulsion at 800 GeV

The experimental data on multiplicities of charged particles of different type produced in incoherent interactions of 800 GeV proton with emulsion nuclei are reported and discussed. The data are compared with the results of other experiments on protonnucleus collisions at lower energies. It is shown that the Lund model describes well the data on multiplicities of relativistic particles.     

Transverse momenta of helium fragments in gold fragmentation at 10.6 GeV/nucleon

The transverse momentum (p_t) distributions of helium fragments from gold fragmentation on different nuclei of nuclear emulsion have been measured and a clear increase of average p _t with target mass is seen. The p _t distributions can be parameterized by a sum of three exponential functions of the form $\sim {\rm exp}(-p_{t}^{2}/B_{i})$ . The differences in p _t distributions in interactions on different targets can be explained by different contributions of the three exponential functions. These contributions depend on the projectile breakup in the collision, and for a given degree of the projectile breakup do not depend on the target mass.     

Fragmentation and particle production in interactions of 10.6 GeV/N gold nuclei with hydrogen, light and heavy targets

We have investigated the interactions of 10.6 GeV/n Au in nuclear emulsion. Two methods of separating interactions into those with hydrogen, light (C,N,O) and heavy (Ag,Br) target nuclei were used, giving almost identical results, which strengthened our confidence in the correctness of these methods. We also measured the angular distributions of singly and multiply charged relativistic particles emitted from the interaction vertices and the charges of the multiply charged projectile fragments. The fragmentation of the projectile Au nuclei and of the target nuclei were analyzed. The multiparticle production was studied as a function of the mass of the target nucleus. The multiplicity and the pseudorapidity distributions of relativistic singly charged particles were compared with the predictions of the RQMD Model. Received: 22 April 1998 / Published online: 8 September 1998     

Baryonic loops and confinement in the three quark channel

The expectation value of three Wilson lines is used for exploring the confinement in the baryonic channel of static quarks. Preliminary results are in good agreement with the $\text{q}\text{q}$ data.     

Critical angle in the parton cascade

The angular correlation function of partons in a jet as derived from perturbative QCD is nonanalytic at a critical angle which separates a multiparticle regime with scaling properties from a regime with few particles near the hadronisation scale. Some phenomenological consequences are discussed.     

Backward emitted protons in interactions of neutrinos with nuclei in photoemulsion

Backward emitted protons with momentump>0.3 GeV/c in interactions of neutrino in the energy range 10–200 GeV with photoemulsion nuclei were investigated. Energy spectrum slope parameter of backward protons was measured to beT ₀=48.9±7.9 MeV. TheA-dependence power index of relative mean yield of backward protons was found to bea=0.68±0.12. A drop in the mean yield of backward protons at the four momentum squared over ～15 (GeV/c)² (the neutrino energy over ～50 GeV) was observed.