No Arabic abstract
One of the most intriguing puzzles in hadron spectroscopy are the numerous charmonium-like states observed in the last decade, including charged states that are manifestly exotic. The $BABAR$ and Belle experiments have extensively studied those in B meson decays, initial state radiation processes and two photon reactions. We can question what we have understood after 11 year search in this field, and try to combine results to conclude on what these new unpredicted resonant states are, and how they can be accommodated in the theory. Big effort has been made from theoretical and experimental point of view, as the potential models unlikely explain the presence of so many enhancements, for mass values above the $D bar D$ threshold. In this report the $BABAR$ and Belle results of the two invariant mass systems of $J/psi phi$ and $J/psi omega$ are put in comparison in a search for non-conventional charmonium states. This involves the study of the systems of $J/psi K^+ K^-$ and $J/psi pi^+ pi^- pi^0$, respectively. There are strong theoretical arguments in favor of the presence of hybrids or exotic states, in those invariant mass distributions. Remarks on these data analyses are given, based on the $BABAR$ and Belle experimental results.
In this short review we present and discuss all the experimental information about the charged exotic charmonium states, which have been observed over the last five years. We try to understand their properties such as masses and decay widths with QCD sum rules. We describe this method, show the results and compare them with the experimental data and with other theoretical approaches.
The latest results of CMS in the area of exotic quarkonium decays will be presented: observation of a peaking structure in $J/psiPhi$ mass spectrum in the decay $B^pm rightarrow J/psi Phi K^pm$, search for new bottomonium states in $Upsilon(1mathrm{S})pi^+pi^-$ mass spectrum, measurement of prompt $J/psi$ pair production.
A search for centrally produced charmonium states has been presented. There is no significant evidence for any charmonium production. An upper limit of 2 nb is found for the cross section of chic production using the decay chic(1P)-> J/psi gamma.
We present recent results on charmonium and charmonium-like states from the BaBar B-factory located at the PEP-II asymmetric energy $e^{+}e^{-}$ storage ring at the SLAC National Accelerator Laboratory.
New results of the Belle experiment at the KEKB asymmetric e^+e^- collider are presented, in particular (a) measurement of the mass and width of the $eta_c$ and $eta_c$ in B meson decays, (b) measurement of the mass, width and quantum numbers of the X(3872) and (c) observation of the $chi_{c2}$ in $B$ meson decays.