- Published 1980

Mark II results from SPEAR on radiative transitions from the $(3095) and $~'(3684) to ordinary hadrons (i.e., hadrons which do not contain charmed quarks to first order) are reviewed. I. INCLUSIVE $ RADIATIVE TRANSITIONS First order QCD calculations predict that a significant fraction of the hadronic decays of heavy quark-antiquark 3S1 resonances (such as the $> result in the production of direct photons (i.e., photons not coming from secondary decays of TO'S and n's).l The direct hadronic decay of the Jo must proceed via an intermediate state consisting of at least three color-octet gluons. The dominant contribution to direct photon production arises by replacement of one of the outgoing gluon lines by a photon. It is expected that approximately 8% of all $ decays should contain a direct photon. This direct photon production is expected to peak at x=1, where x is the fraction of the beam energy taken by the photon, and hence should be experimentally observable. IO’ Figure 1 shows the inclusive y momentum distribution at the $I (solid circles) compared with the y distribution predicted from the measured TO and n momentum distributions (open circles).2 Whereas ITO and n decays can account for the measured y spectrum at low x, there is clearly an excess in the spectrum for x 2 0.5. The direct photon contribution, which was obtained by subtracting the predicted distribution from the measured distribution, is shown in Fig. 2. Also shown in the figure is the theoretical distribution (convoluted with the Mark II photon energy resolution) from lowest order in QCD. The observed integrated rate of direct photon I00

@inproceedings{HADRONS1980RadiativeTF,
title={Radiative Transitions from The},
author={ORDINARY HADRONS and Daniel L. Scharre},
year={1980}
}