We have searched for the decay K(S) --> gamma gamma in a sample of similar to 2 x 10(9) phi --> K(S)K(L) decays collected at DA Phi NE with an integrated luminosity of 1.9 fb(-1). K(S) are tagged by the K(L) interaction in the calorimeter. Two prompt photons must also be detected. Kinematic constraints reduce the initial 6 x 10(5) events to 2740 candidates, from which a signal of 711 +/- 35 events is extracted. By normalizing to the K(S) --> 2 pi(0) decays counted in the same sample, we measure BR (K(S) --> gamma gamma) = (2.26 +/- 0.12(stat) +/- 0.06(syst)) x 10(-6), in agreement with O(p(4)) Chiral Perturbation Theory predictions.

Ambrosino, F., Antonelli, A., Antonelli, M., Archilli, F., Beltrame, P., Bencivenni, G., et al. (2008). Measurement of the K(S) -> gamma gamma branching ratio using a pure K(S) beam with the KLOE detector. JOURNAL OF HIGH ENERGY PHYSICS(5), 1-11 [10.1088/1126-6708/2008/05/051].

Measurement of the K(S) -> gamma gamma branching ratio using a pure K(S) beam with the KLOE detector

CERADINI, Filippo;DI MICCO, Biagio;
2008-01-01

Abstract

We have searched for the decay K(S) --> gamma gamma in a sample of similar to 2 x 10(9) phi --> K(S)K(L) decays collected at DA Phi NE with an integrated luminosity of 1.9 fb(-1). K(S) are tagged by the K(L) interaction in the calorimeter. Two prompt photons must also be detected. Kinematic constraints reduce the initial 6 x 10(5) events to 2740 candidates, from which a signal of 711 +/- 35 events is extracted. By normalizing to the K(S) --> 2 pi(0) decays counted in the same sample, we measure BR (K(S) --> gamma gamma) = (2.26 +/- 0.12(stat) +/- 0.06(syst)) x 10(-6), in agreement with O(p(4)) Chiral Perturbation Theory predictions.
2008
Ambrosino, F., Antonelli, A., Antonelli, M., Archilli, F., Beltrame, P., Bencivenni, G., et al. (2008). Measurement of the K(S) -> gamma gamma branching ratio using a pure K(S) beam with the KLOE detector. JOURNAL OF HIGH ENERGY PHYSICS(5), 1-11 [10.1088/1126-6708/2008/05/051].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/114164
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