This paper reports the observation of the decays B(s)0 → Ds1(2536)∓ K ± using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb −1. The branching fractions of these decays are measured relative to the normalisation channel B 0 → D¯ 0 K + K −. The Ds1(2536) − meson is reconstructed in the D¯ *(2007)0 K − decay channel and the products of branching fractions are measured to be B(Bs0→Ds1(2536)∓K±)×B(Ds1(2536)−→D¯∗(2007)0K−)=(2.49±0.11±0.12±0.25±0.06)×10−5,B(B0→Ds1(2536)∓K±)×B(Ds1(2536)−→D¯∗(2007)0K−)=(0.510±0.021±0.036±0.050)×10−5. The first uncertainty is statistical, the second systematic, and the third arises from the uncertainty of the branching fraction of the B 0 → D¯ 0 K + K − normalisation channel. The last uncertainty in the Bs0 result is due to the limited knowledge of the fragmentation fraction ratio, fs/fd. The significance for the Bs0 and B 0 signals is larger than 10 σ. The ratio of the helicity amplitudes which governs the angular distribution of the Ds1(2536) − → D¯ *(2007)0 K − decay is determined from the data. The ratio of the S- and D-wave amplitudes is found to be 1.11 ± 0.15 ± 0.06 and the phase difference between them 0.70 ± 0.09 ± 0.04 rad, where the first uncertainty is statistical and the second systematic. [Figure not available: see fulltext.].
Observation of the decays B(s)0 → Ds1(2536)∓ K ±
De Serio M.;Galati G.;Pappagallo M.;Simone S.;
2023-01-01
Abstract
This paper reports the observation of the decays B(s)0 → Ds1(2536)∓ K ± using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb −1. The branching fractions of these decays are measured relative to the normalisation channel B 0 → D¯ 0 K + K −. The Ds1(2536) − meson is reconstructed in the D¯ *(2007)0 K − decay channel and the products of branching fractions are measured to be B(Bs0→Ds1(2536)∓K±)×B(Ds1(2536)−→D¯∗(2007)0K−)=(2.49±0.11±0.12±0.25±0.06)×10−5,B(B0→Ds1(2536)∓K±)×B(Ds1(2536)−→D¯∗(2007)0K−)=(0.510±0.021±0.036±0.050)×10−5. The first uncertainty is statistical, the second systematic, and the third arises from the uncertainty of the branching fraction of the B 0 → D¯ 0 K + K − normalisation channel. The last uncertainty in the Bs0 result is due to the limited knowledge of the fragmentation fraction ratio, fs/fd. The significance for the Bs0 and B 0 signals is larger than 10 σ. The ratio of the helicity amplitudes which governs the angular distribution of the Ds1(2536) − → D¯ *(2007)0 K − decay is determined from the data. The ratio of the S- and D-wave amplitudes is found to be 1.11 ± 0.15 ± 0.06 and the phase difference between them 0.70 ± 0.09 ± 0.04 rad, where the first uncertainty is statistical and the second systematic. [Figure not available: see fulltext.].I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
