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Axis error includes +- 0.0/0.0 contribution (?////The errors include an uncertainties in solid angle, efficiency, and background).
The measurements on the polarization of the recoil protons from the process γ+p→π0+p have been extended to higher γ-ray energies, at 90° in the center-of-mass system. We have found at 910 Mev a polarization, P=−0.45±0.07; at 800 Mev, P=−0.42±0.10. The rather high values of P agree with the hypothesis that the neutral photoproduction in the 500-1000 Mev range can be described by the well-known three resonant states, and strongly indicate that the second and third resonance have opposite parity. The probable quantum numbers are: T=12, J=32, D pion wave for the second resonance; T=12, J=52, F wave for the third resonance.
No description provided.
Total cross sections for negative pions on protons were measured at laboratory energies of 230, 290, 370, 427, and 460 Mev. The measurements were made in the same pion beams as and at energies identical with those of our π−−p differential scattering experiments. Comparisons of the total and differential scattering can be made with the dispersion theory at a given energy without introducing the systematic errors that would normally enter due to uncertainties in the parameters of more than one pion beam. The measured total cross sections are found to agree within statistics with other measured values, and with the sums of elastic, inelastic, and charge-exchange cross sections measured at this laboratory. The results are:
No description provided.
The differential cross section for charge-exchange scattering of negative pions by hydrogen has been observed at 230, 260, 290, 317, and 371 Mev. The reaction was observed by detecting one gamma ray from the π0 decay with a scintillation-counter telescope. A least-squares analysis was performed to fit the observations to the function dσdω=Σl=15alPl−1(cosθ) in the c.m. frame. The best fit to our experimental measurements requires only s- and p-wave scattering. The results (in mb) are: The least-squares analysis indicates that d-wave scattering is not established in this energy range.
No description provided.
No description provided.
No description provided.