Liquid Argon HEC Wheel Assembly Database

This document describes the details of the contents of the LAr Hadronic EndCap Wheel Assembly Database. This database contains the important data from the wheel assembly: mechanical alignment, electrical properties, cabling, and a summary of the readout gap failures. This document describes the final database that is intended mainly for archival purposes. This database should be viewed in conjunction with the HEC module production database that describes the modules that form the wheel and the Feedthrough database that describes the signal feedthroughs. This wheel database lists for instance the location of the modules, the amplifiers to which they are connected, and the details of the alignment measurements. It also details all non-conformances. It is important that for all non-conformances, whether they occurred during wheel assembly or in the B180 cold tests, that a single table be produced of all the non-conformances listing the non-conformance in a format suitable for making offline corrections to the data. This non-conformance table will be derived from a set of queries of this database

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

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

High Purity Pion Beam at TRIUMF

An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay pi+ --> e+ nu is also described.Comment: 5 page

Improved Search for Heavy Neutrinos in the Decay π→eν\pi\rightarrow e\nu

A search for massive neutrinos has been made in the decay $\pi\rightarrow e^+ \nu$. No evidence was found for extra peaks in the positron energy spectrum indicative of pion decays involving massive neutrinos ($\pi\rightarrow e^+ \nu_h$). Upper limits (90 \% C.L.) on the neutrino mixing matrix element $|U_{ei}|^2$ in the neutrino mass region 60--135 MeV/$c^2$ were set, which are %representing an order of magnitude improvement over previous results