@article{6527381fb5bd44b7bba40816c4372d89,
title = "Measurement of the decay KL → π0γγ",
abstract = "We report on a new measurement of the decay KL → π0γγ by the KTeV experiment at Fermilab. We determine the KL → π0γγ branching ratio to be (1.68 ±0.07 ± 0.08) × 10-6. Our data show the first evidence for a low-mass γγ signal as predicted by recent O(p6) chiral perturbation calculations which include vector meson exchange contributions. From our data, we extract a value for the effective vector coupling aV = -0.72 ± 0.05 ± 0.06.",
author = "\{KTeV Collaboration\} and A. Alavi-Harati and Albuquerque, \{I. F.\} and T. Alexopoulos and M. Arenton and K. Arisaka and S. Averitte and Barker, \{A. R.\} and L. Bellantoni and A. Bellavance and J. Belz and R. Ben-David and Bergman, \{D. R.\} and E. Blucher and Bock, \{G. J.\} and C. Bown and S. Bright and E. Cheu and S. Childress and R. Coleman and Corcoran, \{M. D.\} and G. Corti and B. Cox and Crisler, \{M. B.\} and Erwin, \{A. R.\} and R. Ford and A. Golossanov and G. Graham and J. Graham and K. Hagan and E. Halkiadakis and K. Hanagaki and S. Hidaka and Hsiung, \{Y. B.\} and V. Jejer and J. Jennings and Jensen, \{D. A.\} and R. Kessler and Kobrak, \{H. G.E.\} and \{La Due\}, J. and A. Lath and A. Ledovskoy and \{Mc Bride\}, \{P. L.\} and \{Mc Manus\}, \{A. P.\} and P. Mikelsons and E. Monnier and T. Nakaya and U. Nauenberg and Nelson, \{K. S.\} and H. Nguyen and V. O{\textquoteright}dell",
year = "1999",
doi = "10.1103/PhysRevLett.83.917",
language = "English (US)",
volume = "83",
pages = "917--921",
journal = "Physical review letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "5",
}