A search for the decay K sup 0 yields e sup + e sup minus

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5246640

Schaffner, S F

Due to perceived deficiencies in the Standard Model, many extensions have been proposed to it. One promising experimental area for exploring such theories is in the search for flavor-changing neutral currents; these currents are highly suppressed in the Standard Model, but are present at substantially higher rates in a wide range of new models. As part of an experiment at the Alternating Gradient Synchrotron (Brookhaven experiment E780), a search for the flavor-changing neutral currents K{sub L}{sup 0} {yields} e{sup +}e{sup {minus}} and K{sub S}{sup 0} {yields} e{sup +}e{sup {minus}} was carried out. The detector for the search consisted of a single-magnet spectrometer equipped with mini-drift chambers, and, for electron identification, an atmospheric pressure hydrogen Cerenkov counter and a lead glass electromagnetic calorimeter; the kaons were produced by a 28 GeV primary proton beam on a nine-inch copper target. The normalization was determined by the simultaneous observation of the CP-violating decay K{sub L}{sup 0} {yields} {pi}{sup +}{pi}{sup {minus}}; effectively {approximately}3 {times} 10{sup 5} such event were collected. No candidate K{sup 0} {yields} e{sup +}e{sup {minus}} events were observed in the search. Based on the normalization sample, the author has therefore set limits, at the 90% confidence level, of BR(K{sub L}{sup 0} {yields} e{sup +}e{sup {minus}}) {ge} 9.59 {times} 10{sup {minus}9} and BR(K{sub S}{sup 0} {yields} e{sup +}e{sup {minus}}) {ge} 4.22 {times} 10{sup {minus}6} (where radiative corrections have been taken into account).

• Research Organization: Yale Univ., New Haven, CT (United States)
• OSTI ID: 5246640
• Country of Publication: United States
• Language: English

Related Subjects

645102* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Weak Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCELERATORS
ALGEBRAIC CURRENTS
BOSONS
BROOKHAVEN AGS
CHERENKOV COUNTERS
CORRECTIONS
CP INVARIANCE
CURRENTS
CYCLIC ACCELERATORS
DECAY
DRIFT CHAMBERS
ELECTRON PAIRS
ELEMENTARY PARTICLES
HADRONS
INTERACTIONS
INVARIANCE PRINCIPLES
KAONS
KAONS NEUTRAL
LIMITING VALUES
MAGNETIC SPECTROMETERS
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MESONS
MULTIWIRE PROPORTIONAL CHAMBERS
NEUTRAL CURRENTS
PAIR PRODUCTION
PARTICLE DECAY
PARTICLE IDENTIFICATION
PARTICLE MODELS
PARTICLE PRODUCTION
PROPORTIONAL COUNTERS
PSEUDOSCALAR MESONS
RADIATION DETECTORS
RADIATIVE CORRECTIONS
SHOWER COUNTERS
SPECTROMETERS
STANDARD MODEL
STRANGE MESONS
STRANGE PARTICLES
SYNCHROTRONS
UNIFIED GAUGE MODELS
WEAK PARTICLE DECAY