Physical Review D 73,7 (2006) 071101(R);
The two-photon width of chi(c2)(P-3(2)) state of charmonium has been measured using 14.4 fb(-1) of e(+)e(-) data taken at root s=9.46-11.30 GeV with the CLEO III detector. The gamma gamma-fusion reaction studied is e(+)e(-)-> e(+)e(-)gamma gamma, gamma gamma ->chi(c2)->gamma J/psi ->gamma e(+)e(-)(mu(+)mu(-)). We measure Gamma(gamma gamma)(chi(c2))B(chi(c2)->gamma J/psi)B(J/psi -> e(+)e(-)+mu(+)mu(-))=13.2 +/- 1.4(stat)+/- 1.1(syst) eV, and obtain Gamma(gamma gamma)(chi(c2))=559 +/- 57(stat)+/- 48(syst)+/- 36(br) eV. This result is in excellent agreement with the result of gamma gamma-fusion measurement by Belle and is consistent with that of the (p) over barp ->chi(c2)->gamma gamma measurement, when they are both reevaluated using the recent CLEO result for the radiative decay chi(c2)->gamma J/psi.
heavy quarkonia;; decay-rates;; cleo;; resonance;; detector
Date of this Version