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We present a study of 43 000 3-jet events from Z° boson decays. Both the measured jet energy distributions and the event orientation are reproduced by second order QCD. An alternative model with scalar gluons fails to describe the data.

In a study of photoproduction at photon energies between 0.3 and 5.8 GeV in a hydrogen bubble chamber, approximately 1.7 million pictures containing about 31 000 events with three or more outgoing charged particles were analyzed. This is the second of two final reports on this experiment. Distributions of effective masses are given for the reactions yp -> N3ir, N4TT, N57r. Cross sections for the production of A (1236) and p via yp -> Ap, A2ir, A37r, A47r, Nirp, and N2irp and of various other reactions are reported. From the reaction yp -» A ++ p~, an upper limit for the radiative decay width of p~, r(p~ -• > ir~~y) <0.24 MeV, is obtained (90% confidence). For the four-pion decay mode of the p°, an upper limit of r (p° -> 7r + 7r + 7r~7r~)/T(p° -» ir + ir~) <0.0015 is found (90% confidence). The photoproduction of strange particles is discussed and cross sections for yp -> AK + , 2K, AKTT, XKTT, and KK-KTV are presented. Production of 2 (1385) was observed.

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