TEST OF QED IN E+E- ANNIHILATION AT ENERGIES BETWEEN 12 AND 31.6 GEV
PHYSICS LETTERS B 94:2 (1980) 259-265
Energy scan for narrow states in e+e- annihilation at C.M. energies between 29.90 and 31.46 GeV
Physics Letters B 88:1-2 (1979) 199-202
Abstract:
A fine energy scan has been performed to search for narrow states in e+e- annihilation at c.m. energies between 29.90 and 31.46 GeV. No such state has been observed. The 90% confidence upper limit on the leptonic decay width times the hadronic decay branching ratio is ΓeeBh<1.6 keV. © 1979.Evidence for planar events in e+e- annihilation at high energies
Physics Letters B 86:2 (1979) 243-249
Abstract:
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.Backward axial vector meson production at intermediate energy
Nuclear Physics, Section B 157:1 (1979) 153-169
Abstract:
We analyse the recent data on backward axial vector meson production which come predominantly from a large K-p bubble chamber experiment at 4.2 GeV/c. In an attempt to understand the production mechanisms, we study the isospin and SU(3) structure of A1, B, D(1285) and C(1280) production and compare this with the corresponding production of pseudoscalar, vector and tensor mesons in the backward direction. The isospin and SU(3) study shows that octet exchange is dominant but there are indications that other exchanges, lower-lying than the nucleon (Nα) trajectory, must also be important. We show that a consistent description of backward resonance production is possible, but further experiments are required to confirm this. © 1979.SU(3) implications of the observation of the A1 and C mesons
Nuclear Physics, Section B 156:3 (1979) 532-547