First Observation of the decay KL -> pi0 e e gamma

Abstract

We report on the first observation of the decay KL -> pi0 ee gamma by the KTeV E799 experiment at Fermilab. Based upon a sample of 48 events with an estimated background of 3.6 +/- 1.1 events, we measure the KL -> pi0 ee gamma branching ratio to be (2.34 +/- 0.35 +/- 0.13)x10^{-8}. Our data agree with recent O(p^6) calculations in chiral perturbation theory that include contributions from vector meson exchange through the parameter a_V. A fit was made to the KL -> pi0 ee gamma data for a_V with the result -0.67 +/- 0.21 +/- 0.12, which is consistent with previous results from KTeV.

Submitted to Physical Review Letters, 5 pages, 5 figures

References in corpus (1)

• Experimental search for the decay mode K_L -> pi^0 gamma e^+ e^-

Cited by in corpus (5)

• Extracting short-distance physics from K_{L,S} -> pi0 e+ e- decays
• Anatomy of kaon decays and prospects for lepton flavour universality violation
• Beyond the Standard Model prospects for kaon physics at future experiments
• Measurement of the Decay KL -> pi0 e+ e- gamma
• On the electron-positron energy asymmetry in K_L --> pi0 e+ e-