Investigation of Nuclear Interactions around 20 TeV

Nuclear interactions at a mean energy of about 20 TeV are studied by means of a nuclear emulsion chamber with jet producer. In the present analysis, particular emphasis is placed on the experimental condition. The transverse momentum spectrum of secondary γ rays is approximated by a single exponential in a range of 0.3< p tγ <1.2 GeV/c. The mean transverse momentum of π 0 mesons is estimated to be 0.44±0.02 GeV/c. The fractional energy spectrum of γ rays, E γ / Σ E γ , in the range of 0.003< E γ / Σ E γ <0.7, is not represented by a single exponential, but by a spectrum expected on the assumption that the fractional energy spectrum of the parent π 0 mesons, f = E π 0 / Σ E π 0 , becomes f (d N /d f )∝exp (- f / f 0 ). These results are compared with those of other similar experiments and accelerator experiments.