Results from a detailed study using the Crystal Ball detector at the SLAC e+e storage ring SPEAR of the inclusive photon spectra from 1.8 X 106 i(t' and 2.2&& 106 J/P decays are presented. Radiative transitions from the P to the 1'2~o states are observed with photon energies of 126.0+0.2+4, 169.6+0.3 +4, and 258.4+0.4+4 Mev and branching ratios 8(i('~y X2, &, p) =(8.0%0.5+0.7)%, (9.0+0.5+0.7)%, and (9.9+0.5+0.8)%, respectively. Values for the natural linew'idths of the p states are obtained: I (p2 l 0)=0.8-4.9, &3.8, and 13-21 MeV, respectively (90% C.L.). Improved values are found for the branchmg ratios 8(g'~yg,) =(0.28+0.06)% and B(J//~yes,) =(1.27+0.36)%, and for the natural width I (g,) =11.524.5 MeV.

The Crystal Ball detector at SPEAR has been used to investigate the decays '#'+YYJ/9,J/J~(ete-or b+v') resulting from production of 8x105 .#f. From this selection of the data we measure the branching ratios for the processes q'-'(7) or T~)J/$ and.$'+yx,x-+yJ/+. An analysis of the angular correlations in the latter process furnishes measurements of the x(3.55) and x(3.51) spins and of the multipole structure of the radiative transitions.

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100 and 3000 MeV. Formation of~, g, and g' mesons is observed, and the following meson partial widths are obtained: I 0-7.7+0.5+0.5 eV, I "»-0.514+0.017+0.035 keV, and 'tl I "yy=4. 7+0.5+0.5 keV. No other narrow resonances are observed, and upper limits are given for the product I p yyB& yy. 38 1365 Q~1988 The American Physical Society 1366 D. A. WILLIAMS et al. 38 the range 10 '-10 ' sec which is difficult to measure: they have both a short decay length and a small natural width. The best determinations of the q and g' lifetimes are obtained by using measurements of I & and the branching ratio for X~yy to derive the full width. ' A precise measurement of the m. lifetime using the decaylength technique was recently achieved by Atherton et al. In this paper we describe a study of the reaction e+e~e+e yy~e+e yy, where each y* is a quasireal photon radiated from one of the beam particles. The virtual photons scatter to produce a final state consisting of two real photons. The final-state leptons scatter at very small angles and are not detected. The sum of the transverse momenta of the final-state photons with respect to the beam axis is essentially zero. %e observe three peaks in the invariant-yy-mass spectrum corresponding to the formation of m, g, and g' mesons. This is the first observation of n. production using this technique, first suggested by Low in 1960. The data used for this analysis were collected with the Crystal Ball detector running at the DORIS II e+e storage ring at DESY. The e+e center-of-mass energy varied from 9.4 to 10.6 GeV, with most of the data taken on the Y(1S), Y(2S), and Y(4S) resonances. The sample used for the study of g and g' production has an integrated luminosity of 114 pb ', of which about 40% has

An r\ c ' candidate state is observed at a mass M~ 3592 ± 5 MeV and with a natural linewidth T< 8 MeV (95% confidence level), by using the "crystal ball" Nal(Tl) detector at the Stanford Linear Accelerator Center (SPEAR). The evidence is found in the inclusive photon spectrum in decays of the */>'(3684), where a signal is observed corresponding to a radiative transition to this state with branching ratio between 0.2% and 1.3% (95% confidence interval, including an uncertainty due to correlation with width).