@article{eeeb1fe5ee6c48778117ec0bb9a1588b,
title = "Experimental study on the τ± decay matrix element",
abstract = "In a wire spark-chamber experiment the squared matrix element |M|2 has been measured for the processes τ± (K± → π±π±π∓). Our previous results showed no significant difference between τ+ and τ-. The final results, based on ∼1.5 million τ± decays, are expressed in the form |M|2 ∝ 1 + aY + bX2 + cY2 + ..., where X and Y are the Dalitz variables. The data are adequately fitted by a quadratic expansion where a = 0.2752 ± 0.0033; b = -0.038 ± 0.009; c = 0.025 ± 0.010. Results are also given for τ+ and τ- separately. Finally we have determined the difference between the Q values of τ+ and τ- to be: Q+ - Q- = -60±55 keV.",
author = "Ford, {W. T.} and Pirou{\'e}, {P. A.} and Remmel, {R. S.} and Smith, {A. J.S.} and Souder, {P. A.}",
note = "Funding Information: The results we now report are based on a combined sample of ~ 1.5 million ~-events, ~ 0.75 million of each charge. This sample size is sufficiently large that the systematic errors inherent in the experiment are comparable to the statistical uncertainty. A Monte-Carlo simulation, in which 1.3 million events were generated, was used to calculate the apparatus efficiency. The data and Monte Carlo events were reconstructed by the same analysis program. This * Work supported by the Office of Naval Research Contract No. N0014-67-A-0151, and by the US Atomic Energy Commission Contracts AT(30-1) -2137 andAT(30-1)-4159. Extensive use was made of the Princeton University Computer Center, sponsored in part by the National Science Founda-tion. ** Permanent address: California Institute of Techno-logy, Pasadena, California, USA. *** Permanent address: Yale University, New Haven, Connecticut, USA.",
year = "1972",
month = mar,
day = "6",
doi = "10.1016/0370-2693(72)90260-2",
language = "English (US)",
volume = "38",
pages = "335--338",
journal = "Physics Letters B",
issn = "0370-2693",
publisher = "Elsevier",
number = "5",
}