Precise measurement of the decay KL → π0γγ

Precise measurement of the decay KL → π0γγ

The decay rate of KL → π0 γγ has been measured with the NA48 detector at the CERN SPS. A total of 2558 KL π0γγ candidates have been observed with a residual background of 3.2%. The branching ratio is determined to be (1.36 ± 0.03(stat) ± 0.03(syst) ± 0.03(norm)) × 10-6 and the vector coupling consta...

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Bibliographic Details
Main Authors: Lai, A, Marras, D, Bevan, A, Dosanjh, R, Gershon, T, Hay, B, Kalmus, G, Lazzeroni, C, Munday, D, Needham, MD, Olaiya, E, Parker, M, White, T, Wotton, SA, Barr, G, Bocquet, G, Ceccucci, A, Cuhadar-Dönszelmann, T, Cundy, D, D'Agostini, G, Doble, N, Falaleev, V, Gatignon, L, Gonidec, A, Gorini, B
Format: Journal article
Language:English
Published: 2002
Description
Summary:The decay rate of KL → π0 γγ has been measured with the NA48 detector at the CERN SPS. A total of 2558 KL π0γγ candidates have been observed with a residual background of 3.2%. The branching ratio is determined to be (1.36 ± 0.03(stat) ± 0.03(syst) ± 0.03(norm)) × 10-6 and the vector coupling constant av = -0.46 ± 0.03(stat) ± 0.04(syst). This result suggests that the CP-violation effects are dominating in the KL → π0e+e- decay. An upper limit for the KL → π0γγ decay rate in the two photon mass region mγγ < mπ0 is also given. © 2002 Published by Elsevier Science B.V.

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