Neutron-proton Polarization Research Articles

Measurement of the neutron-proton polarization transfer coefficient Kyy′ at 17.4 MeV

The polarisation transfer coefficient Kyy′ has been measured for neutron-proton scattering at 17.4 MeV and θc.m. = 132.9°. Using a neutron beam produced via the 2H(ovvbar|d, n) pd reaction with an average polarization of 50% and a liquid-helium proton polarimeter, a value of Kyy′ = 0.155±0.026 has been obtained. Unlike our recent result at 25.8 MeV, this is smaller than the predictions of modern nucleon-nucleon potentials.

Neutron-proton polarization at 50 MeV

Data are presented for the polarization parameter $P(\ensuremath{\theta})$ in $n\ensuremath{-}p$ scattering at 50.0 MeV. The results confirm the overall trend of previous data and are in good agreement with phase shift predictions.

Relevance of some recent neutron-proton polarization data toTviolation at intermediate energies

We comment on some neutron-proton polarization data taken by Leung, Kerth, and Surko at 520 and 600 MeV, and compare these data with $n\ensuremath{-}p$ asymmetry measurements taken by Cheng, MacDonald, Helland, and Ogden at 500 and 600 MeV. The two sets of data agree within experimental error, thus ruling out any $T$ asymmetry in $n\ensuremath{-}p$ scattering at intermediate energies greater than a few percent. We point out the relevance of this to a $T$-asymmetric nucleon-nucleon potential model developed by Bryan and Gersten.

Neutron-proton polarization measurements near 20-MeV incident neutron energy

Neutron-proton polarization measurements near 20-MeV incident neutron energy

Measurement of Neutron-Proton Polarization at 126 MeV

The n-p polarization at 126 Mev was measured between 33 and 82 deg c.m. by scattering a 41% polarized neutron beam from liquid hydrogen. The energy threshold and angle of scattering were determined by a range-threshold neutron counter. By the use of a conjugate counter to detect the recoil protons in coincidence with the scattered neutrons, the background rate was held to about 10%. Many systematic errors were eliminated by the use of precession magnets to reverse the sign of the neutron polarization. The maximum polarization was found to be 0.580 plus or minus 0.040 at 56 deg c.m. This maximum is higher than that obtained in any of the Yale phase-shift predictions. (auth) of the angular distribution of the dipion decay with respect

Significance of Neutron-Proton Polarization Measurements in the 20-Mev Energy Range

Neutron-proton polarizations were calculated theoretically and observed experimentally at 16 and 24 Mev. It was found that combinations of parameters determining proton-proton polarization enter the calculations. The validity of charge independence is assumed by the employment of T = 1 phase parameters determined from p-p scattering in the analysis of n-p scattering data. Effects of magnetic scattering are negligible. (L.N.N.)

Neutron-Proton Polarization and Differential Cross Section at 128 Mev

A 42% polarized neutron beam of 128 Mev average energy has been used to measure the $n\ensuremath{-}p$ differential cross section and polarization. A range telescope detected recoil protons from a liquid hydrogen target placed in the beam. The following values were obtained: The errors quoted do not include the 7% uncertainty in the normalization of the cross-section data or the 8% uncertainty in the normalization of the polarization data.

Polarization in neutron proton scattering at 95 MeV

The free neutron-proton polarization has been measured at centre-of-mass angles from 20° to 160°. The asymmetries were obtained using fixed detectors and by rotating the plane of polarization of the neutron beam with respect to the scattering plane by means of a long solenoid. The polarization cross-section was found to be strongly non-antisymmetrical about 90° centre-of-mass and evidence forD-wave interaction was obtained.