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 intera ctions is studied in the kinematic region 0.15 GeV2 < Q(2) < 20 GeV2 a nd 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, o n the share of the pi(+)pi(-) mass spectrum, on the slope of the diffr action peak and on the production and decay angular distributions of t he 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) m u 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 = sig ma(L)/sigma(T) deduced from the decay angular distributions rises stro ngly with Q(2), passing the value of I at Q(2) approximate to 2 GeV2.