A Measurement of the Branching Ratio of the π⁰ Dalitz Decay using K(L) → 3 π⁰ Decays from KTeV

Thesis/Dissertation · Wed Aug 01 00:00:00 EDT 2007

DOI:https://doi.org/10.2172/935238· OSTI ID:935238

Abouzaid, Erin E. ^[1]

---

1. Univ. of Chicago, IL (United States)

The authors present a measurement of B(π⁰ → e⁺e^-γ)/B(π⁰ → γγ) using data taken in 1999 by the E832 KTeV experiment at Fermilab. The π⁰s were produced by K_L decays in flight that are fully reconstructed. They find 63,693 K_L → 3π⁰ → γγ γγ e⁺e^-γ decays in KTeV data (an increase of a factor of ~ 20 in event statistics over previous experiments), and normalize to K_L → 3π⁰ → 6γ, to extract B(π⁰ → e⁺e^-γ, m_e⁺e^- > 15 MeV/c²⁰ → γγ) = (3.920 ± 0.016 ± 0.036) x 10^-3, where the first error is statistical and the second is systematic. Using the Mikaelian and Smith prediction for the e⁺e^- mass spectrum as implemented in the KTeV Monte Carlo to correct to the full e⁺e^- mass range yields B(π⁰ → e⁺e^-γ)/B(π⁰ → γγ) = (1.1559 ± 0.0046 ± 0.0107)%. This result is consistent with previous measurements and with theoretical predictions, and the uncertainty is a factor of three smaller than any previous measurement.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 935238
• Report Number(s): FERMILAB-THESIS-2007-68; TRN: US0804157
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BRANCHING RATIO
DECAY
FERMILAB
FORECASTING
STATISTICS
Experiment-HEP