I. Photometric Determination of Ionization of Cloud Chamber Tracks. II. Cloud Chamber Study of Charged V-Particles

Citation

Björnerud, Egil Kristoffer (1955) I. Photometric Determination of Ionization of Cloud Chamber Tracks. II. Cloud Chamber Study of Charged V-Particles. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/JZH8-0240. https://resolver.caltech.edu/CaltechETD:etd-12092003-113707

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. A photoelectric method for the measurement of ionization of cloud chamber tracks has been developed. The principal feature of the method is the use of a comparison track of known ionization in the same part of the chamber. A microphotometer slit is made to scan the track perpendicular to its direction and a tracing of the transmission of the track relative to the background transmission is obtained. A calibration curve is established and the method is used to measure the ionization of various tracks. The error of measurement is of the order of 10 per cent. A theoretical treatment of the problem is carried out to show the effects of various physical parameters not easily ascertained experimentally. An analysis of 101 charged V-particles decays, observed with a double cloud chamber, is presented. The events in the upper chamber appear to have markedly different properties from those in the lower. The particles in the upper chamber have measured properties which are in every respect consistent with those of the kappa meson: (a) lifetime 5 x 10[^-10] to 2 x 10[^-10] sec; (b) mass 1000m[subscript e], and (c) transverse momentum distribution consistent with a three-body decay scheme. The majority of the particles in the lower chamber, on the other hand, are tentatively identified as charge hyperons with the aid of two cases which appear to have proton secondaries: (a) lifetime 10[^-10] to 3 x 10[^-10] sec; and (b) transverse momentum distribution consistent with a two-body decay scheme.

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