Polarization transfer in

Review of quasi-elastic charge-exchange data in the nucleon-deuteron breakup reaction

“…The longitudinal polarisation transfer in the forward direction was measured later at LAMPF at 318 and 494 MeV [75] with neutron flight paths of, re-spectively, 200 and 400 m so that the energy resolution was typically 750 keV (FWHM). This allowed the authors to use the 14 C( p, n) 14 N 2.31 reaction to calibrate the neutron polarimeter, a technique that was taken up afterwards at PSI [68]. Including these results, we now have reliable values of either K LL (0) or K N N (0) from low energies up to 800 MeV.…”

“…Because the (d, 2p) results were obtained under the clean 1 S 0 conditions of E pp < 200 keV, the problem must be laid at the door of the much poorer energy resolution associated with the detection of neutrons. It was only the later PSI experiment [68] which showed that the spin-transfer parameter varied very strongly with E pp and, as argued in section 4, this is probably the resolution of the discrepancy.…”

“…This must go a long way to explain the anomalous results found by the RCNP group [65]. At 54 MeV both K N N and K LL were measured and, when extrapolated to the 1 S 0 limit of maximum neutron energy, the values gave The subsequent PSI measurement at 70.4 MeV made significant refinements in two separate areas [68]. The extension of the flight path to 11.6 m improved the resolution in the neutron energy by about a factor of three, which allowed a much more detailed study to the E pp dependence of K N N to be undertaken.…”

“…A strong variation of the polarisation transfer parameter with E pp is predicted when using the Faddeev equations [68,70], though these do not give a perfect description of the data. These calculations represent full multiple scattering schemes with all binding corrections and off-shell dependence of the nucleon-nucleon amplitudes.…”

“…The most precise measurements of the polarisation transfer parameters at low energies were accomplished in experiments at PSI at 56 and 70 MeV [67,68]. One of the advantages of their setup was the time structure of the PSI injector cyclotron, where bursts of width 0.7 ns, separated by 20 ns, were obtained at 72 MeV, increasing to about 1.2 ns, separated by 70 ns, at 55 MeV.…”