RESULTS ON HADRON PRODUCTION AT CESR

No abstract availabl

Experiments on few-electron very high-Z ions

The measurement of the Lamb shift in heliumlike uranium and outlines future experimental tests of QED using few-electron very high atomic number (Z) ions are presented. A discussion of the possibility of using ultrarelativistic atomic collisions to produce very heavy leptons is also presented. 38 refs., 4 figs., 1 tab

Diffractive production of #rho#"0(770) mesons in muon-proton interactions at 470 GeV

The diffractive production of #rho#"0(770) mesons in muon-proton interactions is studied in the kinematic region 0.15 GeV"2 < Q"3 < 20 GeV"2 and 20 GeV < #nu# < 420 GeV. The data were obtained in the Fermilab fixed-target experiment E665 with primary muons of 470 GeV energy. Results are presented on the Q"2, x and #nu# dependence of the cross section, on the shape of the #pi#"+#pi#"- mass spectrum, on the slope of the diffraction peak and on the production and decay angular distributions of the #rho#"0(770). The cross section for diffractive production of #rho#"0 by virtual photons on protons depends mainly on Q"2. At fixed Q"2, no significant dependence on x or #nu# is observed. The extrapolation to Q"2 = 0 yields a photoproduction cross section of (10.30 #+-# 0.33) #mu#b. The slope of the t' distribution has a value of (7.0#+-#0.2) GeV"-"2, with a tendency to decrease as Q"2 increases. The production and decay angular distributions of the #rho#"0 depend strongly on Q"2 and are consistent with s-channel helicity conservation. The ratio R #sigma#_L/#sigma#_T deduced from the decay angular distributions rises strongly with Q"2, passing the value of 1 at Q"2 #approx# 2 GeV"2. (orig.)SIGLEAvailable from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman