The results of a measurement of the ratio R = Y(phi pi+ pi-) / Y(omega pi+ pi-) for antiproton annihilation at rest in a gaseous and in a liquid hydrogen target are presented. It was found that the value of this ratio increases with the decreasing of the dipion mass, which demonstrates the difference in the phi and omega production mechanisms. An indication on the momentum transfer dependence of the apparent OZI rule violation for phi production from the 3S1 initial state was found.
(C=CORRECTED) the ratio with phase space correctio. The annihilation in liquid hydrogen (C=LIQUID) and in hydrogen at 3 atm (C=P).
The cross sections for the reaction p¯+p→K++K−+π++π− were measured at six momenta from 400 to 670 MeV/c. Various effective mass distributions indicate that about 37% of the reaction involves K*0 or K¯*0, 16% proceeds via the intermediate state K*0+K¯*0, about 21% involves ρ, 5% proceeds via the ϕ+ρ state, and the rest follows phase space.
No description provided.
Fraction obtained from the effective mass distribution.
Fraction obtained from the effective mass distribution.
Experimental results on antiproton-proton annihilations at 5 incident momenta in the range 1.22–1.35 GeV/ c into final states with at least one visible K 1 0 meson are presented. Based on a total of 5855 events, cross sections and resonance fractions for all experimentally accessible final states are determined. The total cross section for annihilation into strange particles with at least one visible K 1 0 is 2069 ± 45 ub. Copious resonance production is observed but there is no significant evidence for the formation of a resonance in the s -channel.
No description provided.
RESONANCE FRACTIONS AND CROSS SECTIONS FOR AP P --> KS (K+ PI- + K- PI+).
RESONANCE FRACTIONS AND CROSS SECTIONS FOR AP P --> KS (K+ PI- + K- PI+) PI0.
An analysis of a data sample of 1296 events of the reaction p p → K + K − π + π − at 2.32 GeV/ c is presented. The reaction cross section is 300 ± 20 μb . A number of tests of C conservation were made with careful attention to possible systematic errors, yielding no clear evidence of C violation. Various quasi two-body and quasi three-body final states contributing to this reaction were studied. The final state φπ + π − appears to be produced via a Zweig's rule violating mechanism. An analysis of the quasi three-body final state, K ∗0 K − π + (with K ∗0 → K + π − ) plus charge conjugate, whose cross section is 84 ± 12 μ b, is given. The properties of this final state are compared with expectations based on a simple baryon exchange model, and poor agreement is found. A quark model allows a successful qualitative interpretation of the properties of this three-body final state.
INCOHERENT BREIT-WIGNER PLUS PHASE SPACE FIT TO RESONANCE MASS SPECTRA. THE EQUAL CROSS SECTIONS FOR CHARGE CONJUGATE FINAL STATES ARE NOT TABULATED.
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