Cross sections for various channels in 3 prong + V 0 final states of K − n interactions are obtained at 8.25 GeV/ c . An energy dependence study of the quasi two-body reactions Σ − (1385) + vector meson and ΛB − seem to imply the presence of cuts in the Regge exchange formalism, whereas the reaction Δ(1236) K ∗ (890) does not require such cuts. Upper limits of 1 and 2 μb are found for the reactions K − n → Λ A 1 and K − n → Λ A 2 .
CROSS SECTIONS ARE CORRECTED FOR ALL RESONANCE DECAY MODES EXCEPT FOR K*- DEL0 PRODUCTION WHICH IS ONLY CORRECTED FOR UNSEEN AK0 DECAYS. NO EVIDENCE FOR NON-DIFFRACTIVE A1 AND A2 PRODUCTION.
MAXIMUM LIKELIHOOD EXPONENTIAL FITS TO DIFFERENTIAL CROSS SECTIONS.
Annihilation of e + e − into final states with a single electron has been studied with the PLUTO detector at the DORIS storage ring at CMS energies from 3.6 to 5 GeV. In the sample of 4-prong events without any detected photon we observe 21 events which we assign to the reaction e + e − → τ + τ − → νν e + νϱ 0 π . We obtain a branching ratio for τ + → νϱ 0 π + of 0.050 ± 0.015 with an overall systematic uncertainty of 30%. The data are consistent with the ϱπ coming from an A 1 meson.
No description provided.
The production of φ mesions is studied in the reaction π+p→π+p K+K− and π+→π+p K0K¯0 at 3.75 GeV/c. A large isotropic component is seen in the production angular distribution for the reaction π+p→π+pφ. The cross sections for the φπ+p and φΔ++ final states are compared with the cross sections for ωπ+p and ωΔ++ at the same momentum.
NORMALIZED TO THE CROSS SECTION FOR PI+ P --> PI+ P PI+ PI-.
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Data on the reaction π − p → π + π − π 0 have been taken at 12 and 15 GeV/ c with the CERN Omega multiparticle spectrometer. In a 3-pion partial-wave analysis strong production of A 2 0 (1310) and ω ∗ (1675) is observed. Total and differential cross sections are determined and density matrix elements presented as a function of t in the t - and s -channel frames. The energy dependence of A 2 0 production is studied, and a comparison of ω(780), A 2 0 (1310) and ω ∗ (1675) production is made.
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The production of the f 0 (1270) has been studied in the reaction π − p → π + π − n at 12 and 15 GeV/ c in the momentum transfer range 0.02 to 0.80 GeV 2 . Differential and total cross sections for the reaction π − p → f 0 n have been determined. The f 0 decay density matrix elements have been evaluated requiring all the matrix eigenvalues to be non-negative. The relative unnatural and natural parity exchange contributions to the f 0 production have been studied. The results are compared with a Regge exchange model formulated in terms of the pion and A 2 exchanges including cut contributions.
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The reaction π − p → ω n has been studied at 8 and 12 GeV / c incident momenta with the CERN Omega spectrometer using a neutron time of flight trigger. The differential cross sections and the ω-decay density matrix elements are presented as functions of the momentum transfer squared − t in the range of 0.02 to 0.80 GeV 2 . The data are used to evaluate the intercept and slope of both the natural and unnatural parity exchange trajectories. Regge exchange amplitude factorisation tests involving the reaction π N → ω N are investigated.
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'FIT'.
'FIT'.
A 7.5 GeV linearly polarized photon beam was used to study ϱ 0 production on d, n and p in the SLAC 82 inch bubble chamber. The production of ϱ 0 is found to proceed mainly via t -channel natural parity exchange and to conserve s -channel c.m.s. helicity for small t . The I = 1 contribution to the γ N → ϱ 0 t -channel amplitude is found to be small at 7.5 GeV.
ERRORS QUOTED INCLUDE BOTH STATISTICAL AND SYSTEMATIC UNCERTAINTIES.
THE FOURTH REACTION IS THE SUM OF THE FIRST THREE, NAMELY THE CLOSURE DIFFERENTIAL CROSS SECTION.
DIPION EVENTS IN THE RHO0 MASS REGION (600 TO 880 MEV).
The K L o p → K S o p differential and total cross-section and the forward scattering amplitude phase φ have been measured in the 1.5 to 2.3 GeV centre of mass energy range. The data is compared with predictions based on recent K ± N phase shift solutions. Best agreement is found for K + N solutions which do not warrant an I=0 P 1 2 exotic Z ∗ o (1800) baryon.
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The total and differential cross sections of the K¯0p→Λπ+ and K¯0p→∑0π+ reactions have been measured in the centre-of-mass energy range of l.5 to 2.3 GeV. Using our K¯0p→∑0π+ data as well as available cross-section data of isospin related channels, we have calculated the total I=0K¯N→∑π cross section as function of energy. The results are compared with predictions obtained from K¯N phase-shift analyses.
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We have measured the total and differential cross-sections for coherently photoproduced ϱ, ω and ϱ′ on deuterium at 7.5 GeV. Using VDM relations, we have obtained γ ω 2 / γ ϱ 2 = 7.1 ± 1.5, σ T ( ϱ d) = (54 ± 2) mb and σ T ( ω d) = (56 ± 5) mb. Assuming the amplitude for ϱ′ production via an intermediate ϱ 0 to be small and that the amplitudes for ϱp and ϱ′p elastic scattering are comparable, we found γ ϱ ′ 2 / γ ϱ 2 = 6.0 ± 1.2 and σ T ( ϱ ′d) = (47 ± 6) mb.
No description provided.
FROM AN EXPONENTIAL FIT WITH DEUTERON FORM FACTOR.