Evidence for a spin 1 gluon in three jet events

SIGLEDEGerman

Rho rho production by two photon scattering

SIGLEDEGerman

RAPID GROWTH OF CHARGED-PARTICLE MULTIPLICITY IN HIGH-ENERGY E+E- ANNIHILATIONS

Hadron production by e+e- annihilation has been studied for c.m. energies W between 13 and 31.6 GeV. As a function of 1n W the charged particle multiplicity grows faster at high energy than at lower energies. This is correlated with a rise in the plateau of the rapidity distribution. The cross section sdσ/dx is found to scale within ±30% for x > 0.2 and 5 ≤ W ≤ 31.6 GeV. © 1980

The hadronic final state in e+e−e^{+}e^{-} annihilation at c.m. energies of 13, 17 and 27.4 GeV

Results on the hadronic final state in e/sup +/e/sup -/ annihilation at 13, 17 and 27.4 GeV are presented. There is no compelling evidence for the existence of the t quark in these data, which are in general agreement with a simple quark parton model. Some tentative indications of QCD effects are observed in the p/sub T//sup 2/ distributions

Evidence for planar events in e⁺e^- annihilation at high energies

Hadron jets produced in e+e- annihilation between 13 GeV and 31.6 GeV in c.m. at PETRA are analyzed. The transverse momentum of the jets is found to increase strongly with c.m. energy. The broadening of the jets is not uniform in azimuthal angle around the quark direction but tends to yield planar events with large and growing transverse momenta in the plane and smaller transverse momenta normal to the plane. The simple qq collinear jet picture is ruled out. The observation of planar events shows that there are three basic particles in the final state. Indeed, several events with three well-separated jets of hadrons are observed at the highest energies. This occurs naturally when the outgoing quark radiates a hard noncollinear gluon, i.e., e+e- → qqg with the quarks and the gluons fragmenting into hadrons with limited transverse momenta. © 1979

Properties of hadron final states in e⁺e^- annihilation at 13 GeV and 17 GeV center of mass energies

We have observed e+e- hadrons at C.M. energies of 13 GeV and 17 GeV at PETRA using the TASSO detector. We find R(13 GeV) = 5.6 ± 0.7 and R(17 GeV) = 4.0 ± 0.7. The additional systematic uncertainty is 20%. Comparing inclusive charged hadron spectra we observe scaling between 5 GeV and 17 GeV for x = p/pbeam > 0.2; however the 13 GeV cross section is above the 17 GeV cross section for smaller x. This may be due to copious bb̄ production. The events become increasingly jet like at high energies as evidenced by a shrinking sphericity distribution with increasing energy. © 1979

e⁺ e^- annihilation at high energies and search for the t-quark continuum contribution

Measurements of R, sphericity and thrust are presented for c.m. energies between 12 and 31.6 GeV. A possible contribution of a t {Mathematical expression} continuum can be ruled out for c.m. energies between 16 and 31 GeV. © 1980 Springer-Verlag