J. A. Macdonald

Study of the decay K+→π+νν̄ in the momentum region 140<Pπ<199MeV/c

Experiment E949 at Brookhaven National Laboratory has observed three new events consistent with the decay K+ => pi+,nu,nubar in the pion momentum region 140 pi+,nu,nubar events to seven. Combining this observation with previous results, assuming the pion spectrum predicted by the standard model, results in a branching ratio of (1.73+1.15-1.05)e-10. An interpretation of the results for alternative models of the decay K^ => pi+,nothing is also presented.

Radiative Muon Capture on Hydrogen and the Induced Pseudoscalar Coupling

Next to the hydrogen atom, the µ − p system is the most fundamental lepton-hadron system; therefore it can be used to test and extend our basic knowledge of the weak semi-leptonic interaction between leptons and quarks. Radiative muon capture (RMC) is much more sensitive than ordinary muon capture (OMC) to the induced pseudoscalar coupling constant of the weak semi-leptonic current because of the much larger range of momentum transfers which can occur in RMC. A status report on TRIUMF E452, Radiative Muon Capture on Hydrogen, which is anticipating a 10% measurement of this coupling constant, is presented.

The spatial resolution of the time projection chamber at triumf

Abstract The spatial resolution of the time projection chamber at TRIUMF has been investigated. The best resolution, σ ⋍ 200 μ m , occurs at the minimum drift length and for an optimum track to anode crossing angle determined by the magnetic field. The resolution worsens for tracks crossing at larger or smaller angles and for longer drift lengths. The observed resolution is quantitatively reproduced by considering the diffusion of the drifting electrons, the track to anode crossing angle, E × B effects near the anode wire and the discrete nature of the ionization process.

Apparatus for a search for T-violating muon polarization in stopped-kaon decays

Abstract The detector built at KEK to search for T-violating transverse muon polarization in K + → π 0 μ + ν μ ( K μ 3 ) decay of stopped kaons is described. Sensitivity to the transverse polarization component is obtained from reconstruction of the decay plane by tracking the μ+ through a toroidal spectrometer and detecting the π0 in a segmented CsI(Tl) photon calorimeter. The muon polarization was obtained from the decay positron asymmetry of muons stopped in a polarimeter. The detector included features which minimized systematic errors while maintaining high acceptance.

A detector to search for K+ → π+ νν

Abstract The detector built for experiment 787 to measure the decay K + → π + ν ν at Brookhaven National Laboratory is describe

Search for the decay in the momentum region Pπ<195 MeV/c

Abstract We have searched for the decay K + →π + ν ν in the kinematic region with pion momentum below the K + → π + π 0 peak. One event was observed, consistent with the background estimate of 0.73±0.18. This implies an upper limit on B(K + →π + ν ν ) −9 (90% C.L.), consistent with the recently measured branching ratio of 1.57 +1.75 −0.82 ×10 −10 , obtained using the standard model spectrum and the kinematic region above the K + → π + π 0 peak. The same data were used to search for K + → π + X 0 , where X 0 is a weakly interacting neutral particle or system of particles with 150 M X 0 c 2 .We have searched for the decay

Test of exotic scalar and tensor couplings in K+→π0e+ν decay

K^+ to pi^+ nu barnu

A study on the use of lead fluoride for electromagnetic calorimetry

in the kinematic region with pion momentum below the

Measurement of Γ(Kμ3)/Γ(Ke3) ratio using stopped positive kaons

K^+ to pi^+ pi^0

CsI(Tl) photon detector with PIN photodiode readout for a Kμ3 T-violation experiment

peak. One event was observed, consistent with the background estimate of