Measurement of branching fractions for B \\to J/\\psi \\eta K decays and search for a narrow resonance in the J/\\psi \\eta final state
Journal
PTEP
Journal Volume
2014
Journal Issue
4
Pages
043C01
Date Issued
2013-10
Author(s)
Iwashita, T. et al.
Abstract
We report an observation of the B J/K and B 0 J/K 0 S decays using 772 10 6 B B pairs collected at the (4S) resonance with the Belle detector at the KEKB asymmetric-energy e + e -collider. We obtain the branching fractions B(B J/K ) = (1.27 0.11(stat.) 0.11(syst.)) 10 -4 and B(B 0 J/K 0 S ) = (5.22 0.78(stat.) 0.49(syst.)) 10 -5 . We search for a new narrow charmonium(-like) state X in the J/ mass spectrum and find no significant excess. We set upper limits on the product of branching fractions, B(B X K )B(X J/), at 3872 MeV c -2 where a C-odd partner of X (3872) may exist, at (4040) and (4160) assuming their known mass and width, and over a range from 3.8 to 4.8 GeV c -2 . The obtained upper limits at 90% confidence level for X C-odd (
Type
journal article