Coulomb Interference Region Research Articles

A method for studies of small-angle hadron-proton elastic scattering in the coulomb interference region

A hydrogen-filled ionization chamber used as a target and as a detector of the recoil protons was proposed to be applied for studies of small-angle hadron-proton elastic scattering. The analysis of signals from the chamber electrodes and delay times of the signals made it possible to determine the energy and the emission angle of the recoils, as well as to separate the target volume inside the volume of the chamber. The protons were detected in the energy range 1.0–4.0 MeV, with the energy resolution fwhm = 40 keV. The method can be used in a wide range of incident particle momenta at beam intensities of 104–105 particles/s.

Elastic pp-scattering in the coulomb interference region in the momentum range 1.1 to 1.7 GeV/c

Differential cross-sections for pp elastic scattering in the transfer momentum range 2 x 10 −3 ⩽ | t| ⩽ x8 10 −3 (GeV/ c) 2 were studied with a hydrogen filled ionization chamber which was used as a target and as a detector of the recoiled protons. The measurements have been done at P lab. = 1.11 GeV/ c, 1.28 GeV/ c, 1.34 GeV/ c, 1.40 GeV/ c and 1.70 GeV/ c. The real part of the spin independent forward scattering amplitude has been determined, the results being in agreement with the dispersion relation calculations.

A phenomenological comparison of certain high-energy scattering models

On the basis of χ 2 evaluation, using total cross section data up to 70 GeV/ c including that recently reported at the Amsterdam Conference, it is difficult to distinguish between many phenomenological models which have been proposed for its explanation. In particular it is shown, that on the basis of the data, that models which violate the Pomeranchuk theorem, are no more likely than the others. Interesting consequences of violation of the Pomeranchuk theorem are examined for a particular model, and pion nucleon differential cross sections are predicted in the Coulomb interference region. The possibility of decisive tests of the Pomeranchuk theorem violating models in this region is examined.

The real part of the elastic scattering amplitude in the Coulomb interference region of 4.2 GeV/ c K − mesons on protons and a comparison with K +p scattering at 5 GeV/ c.

Using the same method as applied before to 5 GeV/ c K +p scattering we analyzed 4.2 GeV/ c K −p elastic scattering down to | t| values of 0.01 (GeV/ c) 2. About 5500 events yielded the following results: the ratio of real to imaginary part of the nuclear amplitude α = 0.20 ± 0.07, the slope of the exponential A = 8.6 ± 0.2 (GeV/ c) −2, the total elastic nuclear cross-section σ el = 4.3 ± 0.1 mb and the total cross-section σ T = 25.0 ± 0.7 mb.

Small angle pp scattering in the momentum range 1.3 to 1.5 GeV/ c

Elastic pp scattering in the Coulomb interference region has been studied using sonic spark chambers with a magnetic spectrometer. Measurements were made at 1.29, 1.39 and 1.54 GeV/ c and the data were analysed to determine the real part of the spin independent forward scattering amplitude. Disagreement with the predictions of dispersion relation calculations was found.

The real part of the spin-independent forward scattering amplitude in elastic nucleon-nucleon collisions

Elastic pp and pd scattering in the Coulomb interference region have been studied using a sonic spark chamber technique. Analyses of these data yield αp = 0.10 ± 0.16 and n = −0.50 ± 0.15 at 1.69 GeV/c in good agreement with dispersion relation calculations, the value of αp = −0.30 ± 0.09 obtained at 1.54 GeV/c is however not consistent with these calculations.

Measurement of the real part of π −p elastic scattering amplitude in the coulomb interference region at 3.5 GeV/ c

The π−p elastic scattering differential cross section has been measured for 1.22 × 10 −3 ⩽ − t ⩽ 4.22 × 10 −3 (GeV/ c) 2 using recoil protons. The real part of the nuclear amplitude determined from the Coulomb and the nuclear scattering interference is in agreement with dispersion-relation calculations.