APS » PROLA » Phys. Rev. Lett. » Volume 87 » Issue 2

Phys. Rev. Lett. 87, 021801 (2001) [5 pages]

First Observation of the Decay KL → π0e+e-γ
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A. Alavi-Harati et al. (The KTeV Collaboration)
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Received 28 November 2000; published 25 June 2001

We report on the first observation of the decay KL→π0e+e-γ 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→π0e+e-γ branching ratio to be (2.34±0.35±0.13)×10-8. Our data agree with recent O(p6) calculations in chiral perturbation theory that include contributions from vector meson exchange through the parameter aV. A fit was made to the KL→π0e+e-γ data for aV with the result -0.67±0.21±0.12, which is consistent with previous results from KTeV.


©2001 The American Physical Society

URL: http://link.aps.org/abstract/PRL/v87/e021801
DOI: 10.1103/PhysRevLett.87.021801
PACS: 13.20.Eb, 11.30.Er, 12.39.Fe, 13.40.Gp

* Current address: National Technical University, 175 73, Athens, Greece.
† Current address: Montana State University, Bozeman, Montana 59717.
‡ Current address: Fermi National Accelerator Laboratory, Batavia, Illinois 60510.
§ To whom correspondence should be addressed.
** Current address: Princeton University, Princeton, New Jersey 08544.
†† Current address: C.P.P. Marseille/C.N.R.S., France.
‡‡ Current address: Kyoto University, 606-8502 Japan.
Current address: Stanford Linear Accelerator Center, Stanford, California 94309.
a Current address: Nagoya University, Nagoya 464-8602 Japan.
b Current address: California Institute of Technology, Pasadena, California 91125.
c
d
e Current address: Columbia University, New York, New York 10027.

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