Observation of X(3872)J/ψγX(3872)\to J/\psi \gamma and search for X(3872)ψγX(3872)\to\psi'\gamma in B decays

Collaboration
May, 2011

Citations per year

201120142017202020230510152025
Abstract: (arXiv)
We report a study of B(J/ψγ)KB\to (J/\psi \gamma) K and B(ψγ)KB\to (\psi' \gamma)K decay modes using 772×106772\times 10^{6} BBˉB\bar{B} events collected at the \Upsilon(4S)resonancewiththeBelledetectorattheKEKBenergyasymmetric resonance with the Belle detector at the KEKB energy-asymmetric e^+ e^-collider.Weobserve collider. We observe X(3872) \to J/\psi \gammaandreportthefirstevidencefor and report the first evidence for \chi_{c2} \to J/\psi \gammain in B\to (X_{c\bar{c}}\gamma) Kdecays,whileinasearchfor decays, while in a search for X(3872) \to \psi' \gammanosignificantsignalisfound.Wemeasurethebranchingfractions, no significant signal is found. We measure the branching fractions, \mathcal{B}(B^{\pm} \to X(3872) K^{\pm}) \mathcal{B}(X(3872) \to J/\psi\gamma) = (1.78^{+0.48}_{-0.44}\pm 0.12)\times 10^{-6},, \mathcal{B} (B^{\pm} \to\chi_{c2} K^{\pm})$$=$ $(1.11^{+0.36}_{-0.34} \pm 0.09) \times 10^{-5}$, $\mathcal{B}(B^{\pm} \to X(3872) K^{\pm}) \mathcal{B}(X(3872) \to \psi'\gamma)$ $<$ $3.45\times 10^{-6}$ (upper limit at 90% C.L.) and also provide upper limits for other searches.
Note:
  • 6 pages, 3 figures
  • 13.20.He
  • 13.20.Gd
  • 14.40.Nd
  • B: cascade decay
  • X(3872): radiative decay
  • BELLE
  • KEK-B
  • electron positron: annihilation
  • B: pair production
  • chi/c2(3555): radiative decay