The first observation of the B s 0 → η ′ η ′ decay is reported. The study is based on a sample of proton-proton collisions corresponding to 3.0 fb - 1 of integrated luminosity collected with the LHCb detector. The significance of the signal is 6.4 standard deviations. The branching fraction is measured to be [3.31 ± 0.64 (stat) ± 0.28 (syst) ± 0.12 (norm)] × 10 - 5, where the third uncertainty comes from the B ± → η ′ K ± branching fraction that is used as a normalization. In addition, the charge asymmetries of B ± → η ′ K ± and B ± → Φ K ±, which are control channels, are measured to be (- 0.2 ± 1.3) % and (+ 1.7 ± 1.3) %, respectively. All results are consistent with theoretical expectations.
Observation of the B-s(0) -> eta 'eta ' Decay
COGONI, VIOLETTA;Dettori, F.;MANCA, GIULIA;OLDEMAN, RUDOLF GERHARD CHRISTIAAN;SAITTA, BIAGIO;VACCA, CLAUDIA;
2015-01-01
Abstract
The first observation of the B s 0 → η ′ η ′ decay is reported. The study is based on a sample of proton-proton collisions corresponding to 3.0 fb - 1 of integrated luminosity collected with the LHCb detector. The significance of the signal is 6.4 standard deviations. The branching fraction is measured to be [3.31 ± 0.64 (stat) ± 0.28 (syst) ± 0.12 (norm)] × 10 - 5, where the third uncertainty comes from the B ± → η ′ K ± branching fraction that is used as a normalization. In addition, the charge asymmetries of B ± → η ′ K ± and B ± → Φ K ±, which are control channels, are measured to be (- 0.2 ± 1.3) % and (+ 1.7 ± 1.3) %, respectively. All results are consistent with theoretical expectations.File | Dimensione | Formato | |
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PhysRevLett.115.051801.pdf
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