2008/09/07 by Belle collaboration, Belle Collaboration
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.48550/arxiv.0809.1224
10 pages, 5 figures, Contributed to the 34th International Conference On High Energy Physics (ICHEP 2008)
arxiv created 2008/09/07 · openalex publication_date 2008/09/07 · arxiv updated 2012/08/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present results on the X(3872), produced in B+ → X(3872) K+ and B0 → X(3872) K0S decays where X(3872) → J/ψπ+ π-. We report the first statistically significant observation of B0 → X(3872) K0S and measure the ratio of branching fractions to be \frac\cal B(B0 → X(3872)K0) \cal B(B+ → X(3872)K+) = 0.82 ± 0.22 ± 0.05, consistent with unity. The mass difference between the X(3872) states produced in B+ and B0 decay is found to be δM ≡ MXK+ - MXK0 = (+0.18 ± 0.89 ± 0.26) MeV/c2, consistent with zero. In addition, we search for the X(3872) in the decay B0 → X(3872)K+π-, X(3872) → J/ψπ+ π-. We measure \cal B(B0 → X(3872) (K+ π-)NR) × \cal B(X(3872) → J/ψπ+ π-) = (8.1 ± 2.0 +1.1-1.4)× 10-6 and we set the 90% C.L. limit, \cal B(B0 → X(3872)K*(892)0) × \cal B(X(3872) → J/ψπ+ π-) < 3.4 × 10-6. The analysis is based on a 605 fb-1 data sample collected at the Υ(4S) with the Belle detector at the KEKB collider.