Transverse momentum distribution of secondary gamma-ray in air jet

Analysis was performed on the transverse momentum distribution of secondary γ ray in air jet. The analysed distribution types were linear exponential distribution (LD), Boltzmann distribution (BD), two Gaussian distribution (two BD), exponential integral distribution (ED), and quadratic distribution (QD). A list of γ-ray family obtained with an emulsion chamber exposed at Mt. Norikura was used for the present purpose. The conditions of selection of events were number of γ-ray of five or more, and the secondary γ-ray due to π0 decay. The criterion of the analysis was ΣP sub(tγ)=2.5 GeV/C. Data were classified to two groups, namely a group of Nγ>5, ΣE sub(γ)<=20 TeV, ΣP sub(tγ)<=2.5 GeV/C and a group of Nγ>5, ΣP sub(tγ)>2.5 GeV/C. Obtained average value of the transverse momentum of the group of ΣP sub(tγ)<=2.5 GeV/C was =0.142+-0.037 GeV/C, and that of the group of ΣP sub(tγ)>2.5 GeV/C was =0.229+-0.038 GeV/C. For the region of Nγ>5, ΣE sub(γ)<=20TeV, ΣP sub(tγ)<=2.5GeV/C, the LD showed the best fit. For the region of Nγ>5, ΣP sub(tγ)>2.5GeV/C, the two BD showed the best fit. The present results show that small fire ball region is different from large fire ball region. The results were compared with the data by M. Akashi et al. taken at Mt. Norikura, and the data by C.P. Babayan et al. (Kato, T.)