9 research outputs found
Measurements of the Mass and Full-Width of the Meson
In a sample of 58 million events collected with the BES II detector,
the process J/ is observed in five different decay
channels: , , (with ), (with
) and . From a combined fit of all five
channels, we determine the mass and full-width of to be
MeV/ and
MeV/.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.
Evidence of psi(3770) non-DD-bar Decay to J/psi pi+pi-
Evidence of decays to a non- final state is
observed. A total of \psi(3770) \to \PPJP events are
obtained from a data sample of 27.7 taken at center-of-mass
energies around 3.773 GeV using the BES-II detector at the BEPC. The branching
fraction is determined to be BF(\psi(3770) \to \PPJP)=(0.34\pm 0.14 \pm
0.09)%, corresponding to the partial width of \Gamma(\psi(3770) \to \PPJP) =
(80 \pm 33 \pm 23) keV.Comment: 8 pages, 7 figures, Submitted to Physics Letters
Theoretical investigation on the structure and electronic properties of bimetallic gold-zinc cluster cations and their monocarbonyls
Using the first principles calculations, the mixed AunZn \hbox{} (n + m ≤ 6) cluster cations and their
monocarbonyls AunZnmCO+
have been investigated at the PW91 level. For the small AunZn \hbox{}, most ground-state isomers are planar structures. A significant odd-even
oscillation of the highest occupied-lowest unoccupied molecular orbital energy gaps with
the number of Au atoms is observed. Upon CO adsorption, the top site and C head-on
adsorptions are most favorable in energy. Moreover, the optimized geometries indicate that
the CO molecule prefers binding to Au atom of the AunZn \hbox{} clusters, which can be understood by the frontier molecular orbital
theory in detail. From the theoretical calculations, the CO charge population, CO binding
energy (BE) and the Gibbs free-energy change ΔG generally decrease with
the increase of the Zn content. It is found that the BE is highly related to the electron
transfer between CO and the cluster cations. Furthermore, a linear correlation between
ΔG and the CO BE is found. The red shift in the CO stretching frequency
is sensitive to the cluster size and composition. Our calculation suggests that CO
reactive collision on Au3Zn+ and Au2Zn \hbox{} may lead to the dissociation of the clusters with a Zn atom loss