Search For the Rare Decay K_L → π⁰π⁰γ

Thesis/Dissertation · Tue Aug 01 04:00:00 EDT 2006

DOI:https://doi.org/10.2172/897170· OSTI ID:897170

Smith, David Edward ^[1]

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1. Univ. of Virginia, Charlottesville, VA (United States)

This thesis describes a search for the rare decay K_L → π⁰π⁰γ using data from the KTeV experiment, using the topology K_L → π⁰π$$0\atop{D}$$γ (where π$$0\atop{D}$$ → γe⁺e^-). Due to Bose statistics and the real nature of the photon, the K_L → π⁰π⁰γ decay can proceed at lowest order only by the Cp conserving direct emission of an E2 photon. The decay vanishes to O(p⁴) in chiral perturbation theory and is a probe of the theory to the sixth order. The primary background to this decay consists of K_L → π⁰π$$0\atop{D}$$ events with one lost photon. The upper limit for the decay K_L π⁰π⁰γ presented in this thesis is 2.32 x 10^-7 at the 90% confidence level. This upper limit was derived from both 1997 and 1999 data, using a blind analysis. The upper limit was derived from a Feldman-Cousins method, based on a weighted total of 0.53 data events in the signal region with an expected K_L → π⁰π⁰π$$0\atop{D}$$ background of 0.37 ± 0.28 events. The previous upper limit for this decay was 5.6 x 10^-6 at the 90% confidence level.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 897170
• Report Number(s): FERMILAB-THESIS--2006-20
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DECAY
Experiment-HEP
PERTURBATION THEORY
PROBES
STATISTICS
TOPOLOGY