The results of a high-statistics study of inclusive muon spectra at PETRA are reported. Improved mass limits have been obtained for heavy quarks, heavy leptons, and charged Higgs particles. It is shown that the fragmentation properties of b quarks and c quarks are different, with the mean fragmentation variables 〈zb〉=0.75±0.03±0.06, 〈zc〉=0.46±0.02±0.05 and the average semileptonic branching ratio for the B and C hadrons R(B)=(10.5±1.5±1.3)%, R(C)=(11.5±1.0±1.7)%.
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The inclusive production of Σ + (1385) and Σ − (1385) has been studied in K − p interactions at 10 and 10 and 16 GeV/ c . It is found that the cross sections for the reactions K − p → Σ ± (1385) + anything are approximately constant in the energy range form 10 to 32 GeV/ c , being ≈ 350 μ b for Σ + (1385) and ≈ 250 μ b for Σ − (1385). The d σ d p ⊥ 2 distributions for Σ ± (1385) fall off exponentially with increasing p ⊥ 2 , with sloped of about 3 (GeV/ c ) −2 . The d σ /d x distributions for Σ + (1385) and Σ − (1385) are markedly different: the production of Σ − (1385) is symmetrical forwards and backwards in the c.m.s.; for Σ + (1385), the distribution is the same as for Σ − (1385) in the forward direction, but presents a large excess of events in the backward direction. This indicates that for the production of both Σ + (1385) and Σ − (1385) the fragmentation of the incoming kaon is negligible. The fragmentation of the target proton is negligible for Σ − (1385), but it is important for Σ + (1385) and is responsible for the excess (∼100 μ b) of its cross section over that for Σ − (1385).
Axis error includes +- 0.0/0.0 contribution (?////RES-DEF(RES=SIG(1385P13) ,BACK=CORRECTED)//CORRECTED FOR UNSEEN DECAY MODES (PDG 1974)).
Axis error includes +- 0.0/0.0 contribution (?////RES-DEF(RES=SIG(1385P13) ,BACK=CORRECTED)//CORRECTED FOR UNSEEN DECAY MODES (PDG 1974)).
Axis error includes +- 0.0/0.0 contribution (?////RES-DEF(RES=SIG(1385P13) ,BACK=CORRECTED)//CORRECTED FOR UNSEEN DECAY MODES (PDG 1974)).