Summary
About 700 interactions were found by following 6.2 GeV protons « along the track ». An interaction mean free path of (38.2±1.5) cm was obtained. 42 possible proton-free proton collisions were separated and the cross section for meson production was found to be 23 +7−6 mb. We found an average multiplicity for charged secondary tracks in inelastic p-p collisions of 2.8±0.3 and the branching ratio of 2 prong to 4 prong events was about 2. These values were compared with the predictions of the statistical theory and with a modification of it. The results of this investigation would be consistent with a model which assumes that at these energies about 50% of all collisions are « peripheral » ones which lead to (nucleon) isobar (NN* orN*N*) formation only. The angular distribution of all thin secondary tracks in theL system have been measured and the formula of Castagnoliet al. has been applied to a reasonably selected sample of stars. This gave an overestimation by a factor of about 2 for the primary energy. Other investigators have obtained a similar value at 1012 eV.
Riassunto
Si sono trovate 700 interazioni seguendo protoni di 6.2 GeV « lungo la traccia ». Si ottenne un percorso libero medio di interazione di (38.2±1.5) cm. Si separarono 42 possibili collisioni protone-protone libero trovando che la sezione trasversale per la produzione di mesoni è 23 +7−6 mb. Abbiamo trovato una molteplicità media per tracce di secondari carichi in collisione anelastiche p-p di 2.8±0.9 ed il rapporto di branching fra eventi a 2 e 4 rami era circa 2. Questi valori vennero paragonati a quelli predetti dalla teoria statistica e da una sua modificazione. I risultati di queste ricerche sarebbero in accordo con un modello che suppone che a queste energie circa il 50% di tutte le collisioni sono « periferiche » portano solo alla formazione di isobare (di nucleoni) (N* oN*N*). Si sono misurate le distribuzioni angolari di tutte le tracce secondarie sottili nel sistemaL e si è applicata la formula di Castagnoliet al. ad un campione di stelle ragionevolmente selezionato. Questo porta ad una stima per eccesso dell’energia primaria per un fattore di circa 2. Altri ricercatori hanno ottenuto a 1012 eV un valore simile.
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Winzeler, H., Klaiber, B., Koch, W. et al. Interactions of 6.2 GeV protons in emulsions. Nuovo Cim 17, 8–34 (1960). https://doi.org/10.1007/BF02860212
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DOI: https://doi.org/10.1007/BF02860212