OBSERVATION OF INTERFERENCE BETWEEN POSITIVE-PION NEGATIVE-PION AMPLITUDES FROM K-L DECAY AND COHERENT REGENERATION.
Abstract
A spark chamber - magnetic spectrometer search for interference between positive-pion negative-pion decay amplitudes produced in free K-L decay, in apparent violation of CP invariance in the weak interactions, and from coherent regeneration was performed. Using diffuse beryllium regenerators of different mean densities, evidence was found for maximal constructive interference, independent of the K-S - K-L mass difference. Additional data using a solid beryllium regenerator provides good evidence that the magnitude of the mass difference lies in the interval 0.4 < delta < 0.7 in units of h/S. Data were also taken on regeneration in liquid hydrogen and can be understood on the basis of large constructive interference with no anomalous effects. Optical model calculations of the phase of the regeneration scattering amplitude in beryllium indicate it is largely imaginary, so that the dominant contributions to CP violation are expected to come from the mass matrix and/or Delta I = 3/2 currents. Implications of interference for CP conserving models are discussed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 16, 1966
- Accession Number
- AD0634496
Entities
People
- James S. Russ
Organizations
- Princeton University