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Title: Recent tau results from CLEO

Abstract

A data sample of 4.5x10{sup 6} tau pairs has been analyzed to obtain a limit on the mass of the tau neutrino and also to search for CP violation in tau decay. The neutrino mass study utilizes a two-dimensional extended likelihood analysis that includes the dependence of the end-point population on m{sub {nu}{sub {tau}}} and also, for the first time, incorporates an explicit background contribution. We use the the decays {tau}{yields}5{pi}{nu}{sub {tau}} and {tau}{yields}3{pi}2{pi}{sup 0}{nu}{sub {tau}} to obtain an upper limit of 30 MeV/c{sup 2} at 95% C.L. In addition, we have performed the first search for CP violation in tau lepton decay. CP violation could appear as an asymmetry in the angular distribution of the decay {tau}{sup -}{yields}K{sup 0}{pi}{sup -}{nu}{sub {tau}} relative to the charge conjugate decay. We define and measure an observable assymetry parameter and find no evidence for CP violation in this decay.

Authors:
 [1]
  1. Cornell University, Ithaca, New York 14853 (United States)
Publication Date:
OSTI Identifier:
21202149
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 444; Journal Issue: 1; Conference: 1. tropical workshop on particle physics and cosmology; 2. Latin American symposium on high energy physics, San Juan (Puerto Rico), 1-11 Apr 1998; Other Information: DOI: 10.1063/1.56619; (c) 1998 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANGULAR DISTRIBUTION; ASYMMETRY; CESR STORAGE RING; CP INVARIANCE; ELECTRON-POSITRON INTERACTIONS; KAONS NEUTRAL; MEV RANGE; MULTIPARTICLE SPECTROMETERS; PARTICLE DECAY; PARTICLE IDENTIFICATION; PARTICLE PRODUCTION; PIONS MINUS; PIONS NEUTRAL; PIONS PLUS; REST MASS; TAU NEUTRINOS; TAU PARTICLES; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Baker, Richard G. Recent tau results from CLEO. United States: N. p., 1998. Web. doi:10.1063/1.56619.
Baker, Richard G. Recent tau results from CLEO. United States. doi:10.1063/1.56619.
Baker, Richard G. Mon . "Recent tau results from CLEO". United States. doi:10.1063/1.56619.
@article{osti_21202149,
title = {Recent tau results from CLEO},
author = {Baker, Richard G.},
abstractNote = {A data sample of 4.5x10{sup 6} tau pairs has been analyzed to obtain a limit on the mass of the tau neutrino and also to search for CP violation in tau decay. The neutrino mass study utilizes a two-dimensional extended likelihood analysis that includes the dependence of the end-point population on m{sub {nu}{sub {tau}}} and also, for the first time, incorporates an explicit background contribution. We use the the decays {tau}{yields}5{pi}{nu}{sub {tau}} and {tau}{yields}3{pi}2{pi}{sup 0}{nu}{sub {tau}} to obtain an upper limit of 30 MeV/c{sup 2} at 95% C.L. In addition, we have performed the first search for CP violation in tau lepton decay. CP violation could appear as an asymmetry in the angular distribution of the decay {tau}{sup -}{yields}K{sup 0}{pi}{sup -}{nu}{sub {tau}} relative to the charge conjugate decay. We define and measure an observable assymetry parameter and find no evidence for CP violation in this decay.},
doi = {10.1063/1.56619},
journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 444,
place = {United States},
year = {1998},
month = {10}
}