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Type of Document	Dissertation
Author	Alford, William Lumpkin
URN	etd-04212003-085844
Persistent URL	http://resolver.caltech.edu/CaltechETD:etd-04212003-085844
Title	The mean lifetime of V-particles
Degree	PhD
Option	Physics
Advisory Committee	Advisor Name Title Unknown Committee Member
Keywords	None
Date of Defense	1953-01-01
Availability	unrestricted
Abstract NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. A maximum-likelihood procedure for determining mean lifetimes of V-particles from cloud chamber data is discussed and applied to samples taken from a group of 134 neutral V-particle decays. For 74 events which were consistent with a decay into a proton and a negative pi meson, a lifetime of (2.5[...]0.7) x 10(superscript -10) sec is obtained. Dividing the data into "low-Q" and "high-Q" groups on the basis of the calculated energy release in the decay, a value of [tau][subscript L] = (2.9) [...] 0.8) x 10[superscript -10] sec is found for those cases with 0 < Q <= 50 Mev and a value of [tau][subscript H] = (1.6 [...] 0.5) x 10[superscript -10] sec is found for those cases with 50 < Q < 150 Mev. While no significant difference exists between these two values, the difference is greater than for other plausible division schemes which are considered. A qualitative discussion of lifetimes is given for the case of 23 charged V-particle decays. For the charged V-particles these data suggest either a lifetime less than that of the neutral V-particles, provided the sample is homogeneous, or a more likely an apparent average lifetime less than that of the neutral V-particles, if the sample is a mixture of two or more types of particles. The possibility of kappa mesons making up a part of these decays is considered and data indicating lifetimes approximately equal to or longer than 10[superscript -9] sec for both the kappa and tau mesons are briefly discussed.
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