991 research outputs found
Prospects for observing ultra-compact binaries with space-based gravitational wave interferometers and optical telescopes
Space-based gravitational wave interferometers are sensitive to the galactic
population of ultra-compact binaries. An important subset of the ultra-compact
binary population are those stars that can be individually resolved by both
gravitational wave interferometers and electromagnetic telescopes. The aim of
this paper is to quantify the multi-messenger potential of space-based
interferometers with arm-lengths between 1 and 5 Gm. The Fisher Information
Matrix is used to estimate the number of binaries from a model of the Milky Way
which are localized on the sky by the gravitational wave detector to within 1
and 10 square degrees and bright enough to be detected by a magnitude limited
survey. We find, depending on the choice of GW detector characteristics,
limiting magnitude, and observing strategy, that up to several hundred
gravitational wave sources could be detected in electromagnetic follow-up
observations.Comment: 6 pages, 3 figures Updated to include new results. Submitted to MNRA
Rare Kaon Decays
The current status of rare kaon decay experiments is reviewed. New limits in
the search for Lepton Flavor Violation are discussed, as are new measurements
of the CKM matrix.Comment: 8 pages, 3 figures, LaTeX, presented at the 3rd International
Conference on B Phyiscs and CP Violation, Taipei December 3-7, 199
Flavor-Changing Processes in Extended Technicolor
We analyze constraints on a class of extended technicolor (ETC) models from
neutral flavor-changing processes induced by (dimension-six) four-fermion
operators. The ETC gauge group is taken to commute with the standard-model
gauge group. The models in the class are distinguished by how the left- and
right-handed components of the quarks and charged leptons transform
under the ETC group. We consider and other pseudoscalar
meson mixings, and conclude that they are adequately suppressed if the and
components of the relevant quarks are assigned to the same (fundamental or
conjugate-fundamental) representation of the ETC group. Models in which the
and components of the down-type quarks are assigned to relatively conjugate
representations, while they can lead to realistic CKM mixing and intra-family
mass splittings, do not adequately suppress these mixing processes. We identify
an approximate global symmetry that elucidates these behavioral differences and
can be used to analyze other possible representation assignments.
Flavor-changing decays, involving quarks and/or leptons, are adequately
suppressed for any ETC-representation assignment of the and components
of the quarks, as well as the leptons. We draw lessons for future ETC model
building.Comment: 25 page
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 Rπ provides a stringent test of electron-muon universality in weak interactions. The current status of the PIENU experiment and future prospects are presented
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
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
Is it still worth searching for lepton flavor violation in rare kaon decays?
Prospective searches for lepton flavor violation (LFV) in rare kaon decays at
the existing and future intermediate-energy accelerators are considered. The
proposed studies are complementary to LFV searches in muon-decay experiments
and offer a unique opportunity to probe models with approximately conserved
fermion-generation quantum number with sensitivity superior to that in other
processes. Consequently, new searches for LFV in kaon decays are an important
and independent part of the general program of searches for lepton flavor
violation in the final states with charged leptons.Comment: 30 pages, 10 figures. An extended version of the talk given at the
Chicago Flavor Seminar, February 27, 2004. In the new version some misprints
were corrected and some new data for LFV-processes were added. The main
content of the paper was not changed. The paper is published in Yad. Fiz. 68,
1272 (2005
Study of a Large NaI(Tl) Crystal
Using a narrow band positron beam, the response of a large high-resolution
NaI(Tl) crystal to an incident positron beam was measured. It was found that
nuclear interactions cause the appearance of additional peaks in the low energy
tail of the deposited energy spectrum
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