Measurement of epsilon'/epsilon

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6261744

Schmidt, M P; Adair, R K; Black, J K; Blatt, S R; Campbell, M K; Kasha, H; Mannelli, M; Schwarz, C B; Larsen, R C; Leipuner, L B

After twenty years of intense scrutiny CP violation is apparently still well described, if not explained, by the superweak hypothesis, in which absolute values ..delta..S = 2 (T-violating) transitions between the K/sup 0/, anti K/sup 0/ states induce CP violating impurities in the K/sub L//sup 0/, K/sub S//sup 0/ states. CP-violating effects observed in the K/sup 0/ - anti K/sup 0/ system can be described in terms of one parameter, absolute values epsilon approx. = 2 x 10/sup -3/, which defines the portion of the CP-even state K/sub 1//sup 0/ found in the predominantly CP-odd K/sub L//sup 0/ state: K/sub L//sup 0/ proportional to K/sub 2//sup 0/ + epsilon K/sub 1//sup 0/. A precise measurement of the relative rates for the CP-violating decays K/sub L//sup 0/ ..-->.. ..pi../sup +/..pi../sup -/ and K/sub S//sup 0/ ..-->.. ..pi../sup 0/..pi../sup 0/ in principle provides a test for absolute values ..delta..S = 1 CP-violating amplitudes which result in deviations from the superweak predictions: eta /sup 00/ = eta /sup + -/ = epsilon, where eta /sup + -/ and eta /sup 00/ are the ratios of K/sub L/ to K/sub S/ decay amplitudes into ..pi../sup +/..pi../sup -/ and ..pi../sup 0/..pi../sup 0/ final states. Gauge theory models of CP-violation are in general constructed to nearly mimic superweak predictions by having the dominant contribution to CP-violation arise from complex terms in the K/sup 0/ - anti K/sup 0/ mixing amplitudes. However, there are usually additional contributions in the form of direct CP violating absolute values ..delta..S = 1 decay amplitudes, parametrized by epsilon', which are not identical for the weak transitions into isospin I = 0 and 2 ..pi pi.. final states. The Yale-BNL group has recently completed a measurement of R and thus epsilon'/epsilon at the Brookhaven AGS. Results are presented.

• Research Organization: Yale Univ., New Haven, CT (USA). Dept. of Physics; Brookhaven National Lab., Upton, NY (USA)
• DOE Contract Number: AC02-76ER03075; AC02-76CH00016
• OSTI ID: 6261744
• Report Number(s): BNL-35841; CONF-8410222-3; ON: DE85006687
• Country of Publication: United States
• Language: English

Related Subjects

645102 -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Weak Interactions & Properties
645302* -- High Energy Physics-- Particle Invariance Principles & Symmetries-- Applications to Electromagnetic & Weak Interactions-- (-1987)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BOSONS
CP INVARIANCE
DECAY
ELEMENTARY PARTICLES
HADRONS
INVARIANCE PRINCIPLES
KAONS
KAONS NEUTRAL
KAONS NEUTRAL LONG-LIVED
KAONS NEUTRAL SHORT-LIVED
MESONS
PARTICLE DECAY
PIONS
PIONS MINUS
PIONS PLUS
PSEUDOSCALAR MESONS
STRANGE PARTICLES
VIOLATIONS
WEAK HADRONIC DECAY
WEAK PARTICLE DECAY