Observation of the decays 𝐵0(𝑠) → Ds1(2536)∓K±

Observation of the decays 𝐵0(𝑠) → Ds1(2536)∓K±

Abstract This paper reports the observation of the decays B s...

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Bibliographic Details
Main Authors:	Aaij, R., Abdelmotteleb, A. S. W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adeva, B., Adinolfi, M., Adlarson, P., Afsharnia, H., Agapopoulou, C., Aidala, C. A., Ajaltouni, Z., Akar, S., Akiba, K., Albicocco, P., Albrecht, J.
Other Authors:	Massachusetts Institute of Technology. Department of Physics
Format:	Article
Language:	English
Published:	Springer Berlin Heidelberg 2023
Online Access:	https://hdl.handle.net/1721.1/152520

Description
Summary:	Abstract This paper reports the observation of the decays B s 0 $$ {B}_{(s)}^0 $$ → 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 B0 → D ¯ $$ \overline{D} $$ 0K+K−. The Ds1(2536)− meson is reconstructed in the D ¯ $$ \overline{D} $$ (2007)0K− decay channel and the products of branching fractions are measured to be B B s 0 → D s 1 2536 ∓ K ± × B D s 1 2536 − → D ¯ ∗ 2007 0 K − = 2.49 ± 0.11 ± 0.12 ± 0.25 ± 0.06 × 10 − 5 , B B 0 → D s 1 2536 ∓ K ± × B D s 1 2536 − → D ¯ ∗ 2007 0 K − = 0.510 ± 0.021 ± 0.036 ± 0.050 × 10 − 5 . $$ {\displaystyle \begin{array}{c}\mathcal{B}\left({B}_s^0\to {D}_{s1}{(2536)}^{\mp }{K}^{\pm}\right)\times \mathcal{B}\left({D}_{s1}{(2536)}^{-}\to {\overline{D}}^{\ast }{(2007)}^0{K}^{-}\right)\\ {}=\left(2.49\pm 0.11\pm 0.12\pm 0.25\pm 0.06\right)\times {10}^{-5},\\ {}\mathcal{B}\left({B}^0\to {D}_{s1}{(2536)}^{\mp }{K}^{\pm}\right)\times \mathcal{B}\left({D}_{s1}{(2536)}^{-}\to {\overline{D}}^{\ast }{(2007)}^0{K}^{-}\right)\\ {}=\left(0.510\pm 0.021\pm 0.036\pm 0.050\right)\times {10}^{-5}.\end{array}} $$ The first uncertainty is statistical, the second systematic, and the third arises from the uncertainty of the branching fraction of the B0 → D ¯ $$ \overline{D} $$ 0K+K− normalisation channel. The last uncertainty in the B s 0 $$ {B}_s^0 $$ result is due to the limited knowledge of the fragmentation fraction ratio, fs/fd. The significance for the B s 0 $$ {B}_s^0 $$ and B0 signals is larger than 10 σ. The ratio of the helicity amplitudes which governs the angular distribution of the Ds1(2536)− → D ¯ $$ \overline{D} $$ (2007)0K− 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.