@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",
}