Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10723194 | Physics Letters B | 2007 | 7 Pages |
Abstract
We have measured the ratio RÏ=BR(Ïâηâ²Î³)/BR(Ïâηγ) by looking for the radiative decays Ïâηâ²Î³ and Ïâηγ into the final states Ï+Ïâ7γ and 7γ, respectively, in a sample of â¼1.4Ã109Ï mesons produced at the Frascati Ï factory. We obtain RÏ=(4.77±0.09stat±0.19syst)Ã10â3, from which we derive BR(Ïâηâ²Î³)=(6.20±0.11stat±0.25syst)Ã10â5. Assuming the ηⲠhas zero gluonium content, we extract the pseudoscalar mixing angle in the quark-flavor basis, ÏP=(41.4±0.3stat±0.7syst±0.6th)°. Combining the value of RÏ with other constraints, we estimate the fractional gluonium content of the ηⲠto be Z2=0.14±0.04 and the mixing angle to be ÏP=(39.7±0.7)°.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Nuclear and High Energy Physics
Authors
KLOE Collaboration KLOE Collaboration, F. Ambrosino, A. Antonelli, M. Antonelli, C. Bacci, P. Beltrame, G. Bencivenni, S. Bertolucci, C. Bini, C. Bloise, S. Bocchetta, V. Bocci, F. Bossi, D. Bowring, P. Branchini, R. Caloi, P. Campana, G. Capon, G. Xu,