S. Stanislaus

Atomic capture ratios for muons in oxides

Abstract Using the lifetime technique, atomic capture ratios of negative muons have been measured in 41 oxides. The results, though a little different from the earlier TRIUMF findings, are consistent with the mesic X-ray measurements. It has been noticed that the atomic capture ratios have an approximately linear dependence on density, whereas the Z -dependence is periodic.

Search for T = 2 dibaryons via π−d→γX

Abstract A search has been made for possible dibaryons using the reaction π − d→ γ X, starting from the mesic atom. Previously observed candidates had a mass of about 2002 MeV and would produce γ-rays of about 13 MeV. No such transitions have been observed with a branching ratio limit of about 2 × 10 −4 with 90% CL.

Atomic capture of muons and density

Abstract Including a density dependence, as well as a Z -dependence, an empirical expression was formulated for atomic capture ratios of negative muons in oxides, chlorides and fluorides, using a chi-squared minimization method. The overall chi-square per point produced by this expression is lower than the same obtained from any of the present atomic capture models.

Gamma-ray coincidence measurements for studies of pion chemistry

No entirely satisfactory model has yet been established for describing the processes of molecular and atomic capture of negative pions in organic materials. One major point of dispute between theories is the manner in which pions captured by hydrogen are transferred to other nuclei. The two suggested mechanisms are tunneling by the pion through the potential barrier to the atom bound to the hydrogen or the collision of the small neutral π− p system with some other nucleus after leaving the parent molecule. Experiments were conducted at TRIUMF to attempt to clarify this point. The nuclear capture of pions by hydrogen were measured using the charge exchange reaction: pπ− → nπ0, π0 →γγ. The coincident γ-rays were detected by two large NaI detectors, TINA and MINA. Measurements were made of acid anhydrides, sugars, simple hydrides and some nitrogen compounds. The implications of these measurements for the various theoretical models are discussed.

Transfer of π- from hydrogen to deuterium in H2O+D2O mixtures

Abstract The transfer of stopping π− mesons from hydrogen to deuterium has been investigated in mixtures of H2O+D2O as a function of D2O concentration. The concentration dependence of the transfer probability is similar to that observed for the gas mixtures of H2 and D2 but slightly more transfer is found for H2O+D2O.

Progress report on muon catalyzed fusion studies in H2+D2 and HD gaseous targets

Gamma yields from the decay of the muonic molecule pdμ produced in muon‐catalyzed fusion studies in H2+D2 and HD gaseous targets have been measured. The experiments have been performed at TRIUMF and the data is presented in this report. (AIP)