41,140 research outputs found
Hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells
We study the hybrid exciton-polaritons in a bad microcavity containing the
organic and inorganic quantum wells. The corresponding polariton states are
given. The analytical solution and the numerical result of the stationary
spectrum for the cavity field are finishedComment: 3 pages, 1 figure. appear in Communications in Theoretical Physic
Measurement of the branching fractions of psi(2S) -> 3(pi+pi-) and J/psi -> 2(pi+pi-)
Using data samples collected at sqrt(s) = 3.686GeV and 3.650GeV by the BESII
detector at the BEPC, the branching fraction of psi(2S) -> 3(pi+pi-) is
measured to be [4.83 +- 0.38(stat) +- 0.69(syst)] x 10^-4, and the relative
branching fraction of J/psi -> 2(pi+pi-) to that of J/psi -> mu+mu- is measured
to be [5.86 +- 0.19(stat) +- 0.39(syst)]% via psi(2S) -> (pi+pi-)J/psi, J/psi
-> 2(pi+pi-). The electromagnetic form factor of 3(pi+pi-) is determined to be
0.21 +- 0.02 and 0.20 +- 0.01 at sqrt(s) = 3.686GeV and 3.650GeV, respectively.Comment: 17pages, 7 figures, submitted to Phys. Rev.
Observation of p pbar pi^0 and p pbar eta in psi' decays
The processes psi'-->p pbar pi^0 and psi'-->p pbar eta are studied using a
sample of 14 million psi' decays collected with the Beijing Spectrometer at the
Beijing Electron-Positron Collider. The branching fraction of psi'-->p pbar
pi^0 is measured with improved precision as (13.2\pm 1.0\pm 1.5)\times 10^{-5},
and psi'-->p pbar eta is observed for the first time with a branching fraction
of (5.8\pm 1.1\pm 0.7)\times 10^{-5}, where the first errors are statistical
and the second ones are systematic.Comment: 15 pages, 8 figures and 3 table
Measurements of J/psi decays into phi pi^0, phi eta, and phi eta^prime
Based on 5.8x10^7 J/psi events detected in BESII, the branching fractions of
J/psi--> phi eta and phi eta^prime are measured for different eta and eta^prime
decay modes. The results are significantly higher than previous measurements.
An upper limit on B(J/psi--> phi pi^0) is also obtained.Comment: 9 pages, 10 figure
Measurement of the chi_{c2} Polarization in psi(2S) to gamma chi_{c2}
The polarization of the chi_{c2} produced in psi(2S) decays into gamma
chi_{c2} is measured using a sample of 14*10^6 psi(2S) events collected by
BESII at the BEPC. A fit to the chi_{c2} production and decay angular
distributions in psi(2S) to gamma chi_{c2}, chi_{c2} to pi pi and KK yields
values x=A_1/A_0=2.08+/-0.44 and y=A_2/A_0=3.03 +/-0.66, with a correlation
rho=0.92 between them, where A_{0,1,2} are the chi_{c2} helicity amplitudes.
The measurement agrees with a pure E1 transition, and M2 and E3 contributions
do not differ significantly from zero.Comment: 6 pages, 4 figures, 1 tabl
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