1982/04/19 by S. H. Aronson, Robert Bernstein, G. J. Bock +7 · 1 citation
Physics and Astronomy · #Particle physics theoretical and experimental studies #High-Energy Particle Collisions Research #Quantum Chromodynamics and Particle Interactions
paper · doi:10.1103/physrevlett.48.1078
openalex publication_date 1982/04/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Hydrogenlike atoms consisting of a pion and a muon can be formed in KL0\ensuremath→\ensuremathπ\ensuremathμ\ensuremathν decays. In an intense, high-energy KL0 beam, 320 pi-mu atoms were detected and simultaneously the KL0 flux was monitored by recording ordinary KL0\ensuremath→\ensuremathπ\ensuremathμ\ensuremathν decays. The first measurement is reported of the branching ratio R=\frac\ensuremathΓ(KL0\ensuremath→pi\ensuremath-mu\phantom\rule0ex0exatom+\ensuremathν)\ensuremathΓ(KL0\ensuremath→\ensuremathπ\ensuremathμ\ensuremathν)=(3.88\ifmmode±\else\textpm\fi0.41)\ifmmode×\else\texttimes\fi10^\ensuremath-7, using a subset of 155 atoms. This ratio may be sensitive to anomalous interactions between the pion and the muon. In the absence of such interactions, theory predicts R=(4.43\ifmmode±\else\textpm\fi0.12)\ifmmode×\else\texttimes\fi10^\ensuremath-7.