CHACALTAYA Emulsion Chamber Experiment

This is a publication of results obtained by the collaboration experiment of the Brazil and Japan Emulsion Group over a period of nearly ten years since 1962. It is divided into five parts. I. Introduction gives a short description of the emulsion chambers exposed at Mt. Chacaltaya Laboratory (5200 m), Bolivia, ranging from Câmara No. 1 of 0.4 m2 up to Câmara No. 15 of 44.2m2, with a brief historical review of the collaboration experiment. Main part of the present results are obtained with Câmara No. 12 (6m2) and No. 13 (9.8m2), both of which have the producer layer for nuclear interactions in the chamber itself. II. Morphological Strides on Cosmic-ray Components give the results on frequency, energy spectrum and zenith angle distribution of the electromagnetic and the nuclear-active components at Chacaltaya. The vertical flux for the electromagnetic component is (2.66·10-9/cm2 sec sterad)·(E/1012 eV)- β with β= 2.07 ± 0.10, covering energy region of 2·1011 eV ∼ 5 · 1013 eV. Ratio of a flux value of the electromagnetic component to that of the nuclear-active component of the same visible energy is ∼ 0.56, constant over the concerned energy region. III. Fire-ball Studies on C-jets give detailed analysis on 85 events of local nuclear interactions with Σ Eγ ≥ 3 TeV occurred in the producer layer. High energy r-rays produced in the interaction are described in the integral form as Nγ exp(-NγEγ/ΣEγ) with Nγ = 8 ± 1. All of the results on energy spectrum, angular distribution, pT distribution and pT - θγ correlation show that those γ-rays are products of an isotropic intermediate state (a fire-ball) with momentum distribution, Nγ exp(-pγ*/p0)(pγ*/p02)dpγ* with Nγ = 8 ± 1, p0 = 82 ± 15 MeV in its rest system. A fire-ball analysis is made on individual 75 C-jets with the observed γ-ray multiplicity equal to or greater than 4. Seventy one events are found to show emission of a fire-ball. Their experimental mass spectrum has a peak at \mathfrakMγ ∼ 1.2 GeV, giving the average value as ≪\mathfrakMγ> = 1.28 ± 0.35 GeV where \mathfrakMγ is a part of the rest energy liberated into γ-rays. IV. Atmospheric Interactions be concerned with analysis of 41 γ-ray families which are selected by the imposed criteria as representing directly the parent atmospheric interactions. The events are divided into two groups according to their value of a sum of transverse momenta of γ-rays as: (A) ΣpT γ ≲ 2.5 GeV/c and (B) Σ pT γ > 2.5 GeV/c. Fire-ball analysis on 28 events of the group (A) shows that they are emissions of a fire-ball of identical properties with that found in the C-jets. Whereas, 13 events of the group (B) are found to exhibit emission of a larger fire-ball, named as “super heavy quantum (SH quantum)”. The experimental data give its mass as \mathfrakMγ = 8 ± 2 GeV and isotropic emission of γ-rays with average multiplicity ≪Nγ> = 30 ± 8. It total rest energy will be 20 ∼ 25 GeV. The momentum distribution of γ-rays from the SH-quantum is not of a simple exponential form but has a less steep tail on the higher momentum regions. V. Conclusion gives a summary of the results and comparisons with other experiments. Emission of a small fire-ball with \mathfrakMγ = 1.31 ± 0.28 GeV (average over 99 events) is confirmed in multiple production process over a wide energy region starting the accelerator region of ∼ 10 GeV up to cosmic-ray region of Σ Eγ ∼ 100 TeV. Its total rest energy is estimated to be 2.2 ∼ 2.6 GeV. This is identified as “H-quantum” proposed by Hasegawa. Re-analysis of the Bristol-Bombay experiment of a ballon emulsion chamber confirmed the existence of the H- and SH-quanta. Fire-ball analysis on the Texas Lone Star of the Bristol group shows a fire-ball of still larger mass, its \mathfrakMγ being about 78 ± 10 GeV. A large air shower event called Andromeda with Σ Eγ ∼ 3·1016 eV suggests the existence of a large fire-ball of the same property. Thus, as a conclusion, we have the three types of a fire-ball with its total rest energy expressed as Mn = m0an with m0 ∼ 230MeV, a ∼ 10 and n = 1, 2 and 3. Because of this particular nature, we call all of such fire-balls as new states of matter connecting directly with the stratum of the sub-elementary particles.