Differential cross sections for $K^-$ radiative capture in flight on the proton, leading to the $\gamma\Lambda$ and $\gamma\Sigma^0$ final states, have been measured at eight $K^-$ momenta between 514 and 750 MeV/$c$. The data were obtained with the Crystal Ball multiphoton spectrometer installed at the separated $K/\pi$ beam line C6 of the BNL Alternating Gradient Synchrotron. The results substantially improve the existing experimental data available for studying radiative decays of excited hyperon states. An exploratory theoretical analysis is performed within the Regge-plus-resonance approach. According to this analysis, the $\gamma\Sigma^0$ final state is dominated by hyperonresonance exchange and hints at an important role for a resonance in the mass region of 1700 MeV. In the $\gamma\Lambda$ final state, on the other hand, the resonant contributions account for only half the strength, and the data suggest the importance of a resonance in the mass region of 1550 MeV.
Differential cross section for the K- P --> GAMMA LAMBDA reaction at thelower beam momenta.
Differential cross section for the K- P --> GAMMA LAMBDA reaction at thehigher beam momenta.
Differential cross section for the K- P --> GAMMA SIGMA0 reaction at thelower beam momenta.
The observation of 70 000 K 0 p π + events produced with K + incident momenta of 1.21, 1.29, 1.38 and 1.69 GeV/ c allows a detailed description of the production and decay of the Δ(1236) and K ∗ (892) resonances which dominate the K 0 p π + final state. No striking variations with energy are observed. The associated production of Δ and K ∗ near threshold shows striking similarities with the same production at higher energy.
INCLUDING 1 PCT SYSTEMATIC ERROR ON CORRECTIONS.
FIT 'A', ALLOWING FOR DELTA-K* INTERFERENCE (TWO OTHER FITS GIVEN IN PAPER).
S-CHANNEL HELICITY FRAME.
The angular distributions of the reactions K - p → K - p and K - p → K K 0 n have been measured at 23 incident K - momenta between 1.136 and 1.798 ifGeV/c using the bubble chamber technique. These data, together with other published data on the same reactions, including K - p polarisations, K̄N total cross sections, and measurements of Re ƒ(0)/ Im ƒ(0) , have been analysed in terms of partial-wave amplitudes. Resonance behaviour is confirmed for the P 03 partial wave at 1890 MeV. The resonance parameters of the F 15 (1915), F 17 (2030) and G 07 (2100) have been redetermined. No evidence has been found for new resonances coupling significantly to K K N in the energy region explored.
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Measurements are reported of the differential cross section for the reaction π − +p→ ω +n from threshold to a final-state c.m. momentum P ∗ of 200 MeV /c . The previously reported fall in total cross section σ/P ∗ below about 100 MeV/ c is again seen. The differential cross section remains close to isotropic over the entire range. A paralle experiment on the variation in the elastic differential cross section across the threshold shows evidence of this threshold. The elastic data cover a range of incident moments from 1010 to 1180 MeV/ c in steps of 5 MeV/ c .
CROSS SECTION DEPENDENCE ON FINAL STATE CENTRE OF MASS MOMENTUM.
ANGULAR DISTRIBUTIONS ARE ALMOST ISOTROPIC.
LEGENDRE POLYNOMIAL COEFFICIENTS NORMALIZED SUCH THAT SIG = 4*PI*LEG(L=0).
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