No Arabic abstract
We report BELLE measurements of the exclusive cross sections for the processes e+e-->DD*, e+e-->DD, e+e-->DDpi, the first observation of psi(4415)-> DD*2(2460)bar decay and new state, Y(4660), using ISR. In addition, another cluster of events at around 4.05GeV/c2 is reported.
We report measurements of the branching fractions for the decays B->D_s1(2536)+ anti-D(*), where anti-D(*) is anti-D0, D- or D*-, and study of B->X(3872) K with X(3872) decaying to D*0 anti-D0 using a sample of 657 million B anti-B pairs recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.
Using the CLEO-c detector at the Cornell Electron Storage Ring, we have measured inclusive and exclusive cross sections for the production of D+, D0 and Ds+ mesons in e+e- annihilations at thirteen center-of-mass energies between 3.97 and 4.26 GeV. Exclusive cross sections are presented for final states consisting of two charm mesons (DD, D*D, D*D*, Ds+Ds-, Ds*+Ds-, and Ds*+Ds*-) and for processes in which the charm-meson pair is accompanied by a pion. No enhancement in any final state is observed at the energy of the Y(4260).
The cross section for $e^+ e^- to pi^+ pi^- J/psi$ between 3.8 GeV and 5.5 GeV is measured with a 967 fb$^{-1}$ data sample collected by the Belle detector at or near the $Upsilon(nS)$ ($n = 1, 2, ..., 5$) resonances. The Y(4260) state is observed, and its resonance parameters are determined. In addition, an excess of $pi^+ pi^- J/psi$ production around 4 GeV is observed. This feature can be described by a Breit-Wigner parameterization with properties that are consistent with the Y(4008) state that was previously reported by Belle. In a study of $Y(4260) to pi^+ pi^- J/psi$ decays, a structure is observed in the $M(pi^pmjpsi)$ mass spectrum with $5.2sigma$ significance, with mass $M=(3894.5pm 6.6pm 4.5) {rm MeV}/c^2$ and width $Gamma=(63pm 24pm 26)$ MeV/$c^{2}$, where the errors are statistical and systematic, respectively. This structure can be interpreted as a new charged charmonium-like state.
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.
The cross sections of $e^+e^- rightarrow omegachi_{cJ(J=0,1,2)}$ have been measured by BESIII. We try to search for vector charmonium(-like) states $Y(4220)$, $Y(4360)$, $psi(4415)$ and $Y(4660)$ in the $e^+e^- rightarrow omegachi_{cJ(J=0,1,2)}$ line shapes. The $omegachi_{c0}$ mainly comes from $Y(4220)$, $omegachi_{c1}$ mainly comes from $Y(4660)$ and $omegachi_{c2}$ mainly comes from $psi(4415)$, maybe partly comes from $Y(4360)$ or $Y(4660)$. For the charmonium(-like) states that are not significant in the $e^+e^- rightarrow omegachi_{cJ(J=0,1,2)}$ line shape, we also give the $90%$ confidence level upper limits on the electron partial width multiplied by branching fraction. These results are helpful to study the nature of charmonium(-like) states in this energy region.