Evidence for X(3872)-->gamma J/psi and the sub-threshold decay X(3872)-->omega J/psi

We report the first evidence for $X(3872)$ production in two-photon interactions by tagging either the electron or the position in the final state, exploring the highly virtual photon region. The search is performed in $e^+e^- \rightarrow e^+e^-J/\psi\pi^+\pi^-$, using 825 fb$^{-1}$ of data collected by the Belle detector operated at the KEKB $e^+e^-$ collider. We observe three $X(3872)$ candidates with an expected background of $0.11\pm 0.10$ events, with a significance of 3...

We report on the search for a charged partner of the X(3872) in the decay $B \to X^\pm K$, $X^\pm \to J/\psi \pi^\pm \pi^0$, using 213 million $B\bar B$ events collected at the $\Upsilon(4S)$ resonance with the BaBar detector at the PEP-II $e^+ e^-$ asymmetric-energy storage ring. The resulting product branching fraction upper limits are $BR (\bar{B}^0/B^0 \to X^\pm K^\mp$, $X^\pm \to J/\psi \pi^\pm \pi^0)$ $< 5.8 \times 10^{-6}$ and $BR (B^\pm \to X^\pm K^0_S$, $X^\pm \to J/...

I report recent results on hidden charm spectroscopy from Belle. These include: observation of a near-threshold enhancement in the omega-J/psi invariant mass distribution for exclusive B-->K omega J/psi decays; evidence for the decay X(3872)-->pi+pi-pi0 J/psi, where the pi+pi-pi0 invariant mass distribution has a strong peak between 750 MeV and the kinematic limit of 775 MeV, suggesting that the process is dominated by the sub-threshold decay X-->omega J/psi; and the observat...

In a study of B+ --> J/psi gamma K+ decays, we find evidence for the radiative decay X(3872) --> J/psi gamma with a statistical significance of 3.4 sigma. We measure the product of branching fractions BF(B+ --> X(3872) K+).BF(X(3872) --> J/psi gamma) = (3.3 +/- 1.0 +/- 0.3) x 10^-6, where the uncertainties are statistical and systematic, respectively. We also measure the branching fraction BF(B+ --> chi_c1 K+) = (4.9 +/- 0.2 +/- 0.4) x 10^-4. These results are obtained from (...

In a search for B --> ccbar gamma K decays with the BaBar detector, where ccbar includes J/psi and psi(2S), and K includes K+, Ks, and K*(892), we find evidence for X(3872) --> J/psi gamma and X(3872) --> psi(2S) gamma with 3.6 sigma and 3.5 sigma significance, respectively. We measure the product of branching fractions BR(B+ --> X(3872) K+) x BR(X(3872) --> J/psi gamma) = (2.8 +/- 0.8(stat.) +/- 0.2(syst.)) x 10^(-6) and BR(B+ --> X(3872) K+) x BR(X(3872) --> psi(2S) gamma) ...

We present results of a search for the X(3872) in B0-->X(3872)KS0,X(3872)-->J/psi pi+ pi-, improved measurements of B-->X(3872)K-, and a study of the J/psi pi+ pi- mass region above the X(3872). We use 232x106 B[overline B] pairs collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II e+e- asymmetric-energy storage rings. The results include the 90% confidence interval 1.34x10-6<BR(B0-->X(3872)K0,X-->J/psi pi+ pi-)<10.3x10-6 and the branching fraction BR(...

We report the observation of the $B$ meson decay $B^\pm\to J/\psi \eta K^\pm$ and evidence for the decay $B^0\to J/\psi \eta K^0_S$, using {90} million $BBbar$ events collected at the $\ensuremath{\Upsilon{(4S)}}\xspace$ resonance with the $BaBar$ detector at the PEP-II $e^+ e^-$ asymmetric-energy storage ring. We obtain branching fractions of $\cal{B}$$(B^\pm\to J/\psi \eta K^{\pm}$)=$(10.8\pm 2.3(\rm{stat.})\pm 2.4(\rm{syst.}))\times 10^{-5}$ and $\cal{B}$$(B^0\to J/\psi\et...

We study the $\rho$ and $\omega$ meson contribution to the radiative decays $X(3872)\rightarrow J/\psi \pi \gamma$ and $X(3872)\rightarrow J/\psi \pi\pi \gamma$. The $X(3872)\rightarrow J/\psi \pi \gamma$ is dominated by the $\omega$ meson. As for the $X(3872)\rightarrow J/\psi \pi\pi \gamma$, the contributions of the cascade decays through the $\rho$ and $\omega$ mesons are strongly suppressed with respect to the diagrams which proceed either through the $\psi(2S)$ or the th...

We report the observation of the X(3872) in the J/psi pi+pi- channel, with J/psi decaying to mu+mu- in p-p(bar) collisions at sqrt(s) = 1.96 TeV. Using approximately 230 pb^-1 of data collected with the Run II D0 detector, we observe 522 +/- 100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9 +/- 3.1 (stat.) +/- 3.0 (syst.) MeV/c^2. We have investigated the production and decay characteristics of the X(3872), and find th...

We report a search for $X(3872)$ and $X(3915)$ in $B^+ \to \chi_{c1} \pi^0 K^+$ decays. We set an upper limit of $\mathcal{B}(B^+ \to X(3872) K^+) \times \mathcal{B}(X(3872) \to \chi_{c1} \pi^0)$ $ < 8.1 \times 10^{-6}$ and $\mathcal{B}(B^+ \to X(3915) K^+) \times \mathcal{B}(X(3915) \to \chi_{c1} \pi^0)$ $ < 3.8 \times 10^{-5}$ at 90\% confidence level. We also measure $\mathcal{B}(X(3872) \to \chi_{c1} \pi^0)/\mathcal{B}(X(3872) \to J/\psi \pi^+ \pi^-) < 0.97$ at 90\% confi...