Measurement of the chi_{c2} Polarization in psi(2S) to gamma chi_{c2}

Abstract

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.

6 pages, 4 figures, 1 table

References in corpus (5)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• Charmless Final States and S--D-wave mixing in the ${\psi }^{\prime \prime }$
• Measuring psi(3770) --> rho pi in e+e- experiment
• Study of psi(2S) decays to X J/psi
• Measuring psi(3770) -> Kshort Klong as a test of the S- and D-wave mixing of charmonia

Cited by in corpus (10)

• Charmonium spectrum and their electromagnetic transitions with higher multipole contributions
• Radiative Decays of the Upsilon(1S) to a Pair of Charged Hadrons
• Two-Photon Widths of the chi_cJ States of Charmonium
• Higher-order multipole amplitudes in charmonium radiative transitions
• Higher-order multipole amplitude measurement in $\psi (2S)\to \gamma {\chi }_{c2}$
• Physics Accomplishments and Future Prospects of the BES Experiments at the BEPC Collider
• Measurement of higher-order multipole amplitudes in $\psi (3686)\to \gamma {\chi }_{c1,2}$ with ${\chi }_{c1,2}\to \gamma J/\psi$ and search for the transition ${\eta }_c(2S)\to \gamma J/\psi$
• Improved measurements of two-photon widths of the ${\chi }_{cJ}$ states and helicity analysis for ${\chi }_{c2}\to \gamma \gamma$
• M2 signatures in psi(2S) radiative decays
• Precision dispersive approaches versus unitarized Chiral Perturbation Theory for the lightest scalar resonances $\sigma /f_0(500)$ and $\kappa /K_0^{\ast }(700)$