O IF - Instituto de Física, da Universidade Federal de Goiás, oferece Graduação em: Bacharelado em Física; Licenciatura em Física; Física Médica; e, Engenharia Física.
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Navegando IF - Instituto de Física por Autor "Abouzaid, Erin Elizabeth"
We present a measurement of Bðπ0 → eþe−γÞ=Bðπ0 → γγÞ, the Dalitz branching ratio, using data taken in
1999 by the E832 KTeV experiment at Fermi National Accelerator Laboratory. We use neutral pions from
fully reconstructed KL decays in flight; the measurement is based on ∼60 thousand KL → π0π0π0 →
γγγγeþe−γ decays. We normalize to KL → π0π0π0 → 6γ decays. We find Bðπ0 → eþe−γÞ=Bðπ0 → γγÞ ðmeþe− > 15 MeV=c2Þ¼½3.920 0.016ðstatÞ 0.036ðsystÞ × 10−3. Using the Mikaelian and Smith
prediction for the eþe− mass spectrum, we correct the result to the full eþe− mass range. The corrected
result is Bðπ0 → eþe−γÞ=Bðπ0 → γγÞ¼½1.1559 0.0047ðstatÞ 0.0106ðsystÞ %. This result is consistent
with previous measurements, and the uncertainty is a factor of 3 smaller than any previous measurement.