35 research outputs found
Precision Measurement of the π+→e+νe Branching Ratio in the PIENU Experiment
The PIENU experiment at TRIUMF aims to measure the branching ratio of the pion decay modes Rπ=[π+→e+νe(γ)]/[π+→μ+νμ(γ)] with precision of <0.1%.
Precise measurement of RÏ€ provides a stringent test of electron-muon universality in weak interactions. The current status of the PIENU experiment and future prospects are presented
Status of the TRIUMF PIENU Experiment
The PIENU experiment at TRIUMF aims to measure the pion decay branching ratio
with precision % to provide a sensitive test of electron-muon
universality in weak interactions. The current status of the PIENU experiment
is presented.Comment: Talk presented CIPANP2015. 8 pages, LaTeX, 4 eps figure
Improved Search for Heavy Neutrinos in the Decay
A search for massive neutrinos has been made in the decay . No evidence was found for extra peaks in the positron energy spectrum
indicative of pion decays involving massive neutrinos (). Upper limits (90 \% C.L.) on the neutrino mixing matrix element
in the neutrino mass region 60--135 MeV/ were set, which are
%representing an order of magnitude improvement over previous results
Search for the rare decays and
The rare pion decays
and are allowed in the
Standard Model but highly suppressed. These decays were searched for using data
from the PIENU experiment. A first result for
,
and an improved measurement
were obtained.Comment: 6 figure
Search for three body pion decays
The three body pion decays , where
is a weakly interacting neutral boson, were searched for using the full
data set from the PIENU experiment. An improved limit on
in
the mass range MeV/ and a first result for
in the region MeV/ were obtained. The Majoron-neutrino
coupling model was also constrained using the current experimental result of
the branching ratio.Comment: 8 pages, 7 figures. arXiv admin note: text overlap with
arXiv:2006.0038
Precision Measurement of the π+→e+νe Branching Ratio in the PIENU Experiment
The PIENU experiment at TRIUMF aims to measure the branching ratio of the pion decay modes Rπ=[π+→e+νe(γ)]/[π+→μ+νμ(γ)] with precision of <0.1%.
Precise measurement of RÏ€ provides a stringent test of electron-muon universality in weak interactions. The current status of the PIENU experiment and future prospects are presented
Search for heavy neutrinos in pi > mu nu decay
In the present work of the PIENU experiment, heavy neutrinos were sought in pion decays pi(+) -> mu(+)nu at rest by examining the observed muon energy spectrum for extra peaks in addition to the expected peak for a light neutrino. No evidence for heavy neutrinos was observed. Upper limits were set on the neutrino mixing matrix vertical bar U-mu i vertical bar(2) in the neutrino mass region of 15.7-33.8 MeV/c(2), improving on previous results by an order of magnitude. (C) 2019 The Authors. Published by Elsevier B.V
Improved search for two body muon decay
Charged lepton flavor violating muon decay ,
where is a massive neutral boson, was sought by searching for extra peaks
in the muon decay energy spectrum in
the mass region MeV/. No signal was found and 90%
confidence level upper limits were set on the branching ratio
at the level of for this region.Comment: 3 pages, 2 figure