Absolute calibration of the transverse analyzing power in proton-carbon elastic scattering at 50.24 MeV

Abstract

To provide an accurately calibrated polarization analyzer, the analyzing power for elastic scattering of protons from natural carbon at El,b =50.24 MeV and O"b=50. 0' was measured by scattering protons of very high and precisely known polarization (0.9965+0.0007) from a graphite target. The result of the calibration is A =0.9277+0. 0036, where the error is the quadratic sum of the statistical error +0.0033 and systematic uncertainties which total +0.0016. PACS number(s): 25.40.Cm, 24.70.+ s

Partial-wave analysis of all nucleon-nucleon scattering data below 350 MeV

“…There it is shown that the magnetic-moment interaction has to be included in order to describe these data properly. A recent absolute calibration measurement of the transverse analyzing power in proton-carbon elastic scattering [42] implied that these 50.04 MeV A y data should be renormalized by a factor 1.0069, where the previous overall scale uncertainty of 2% should be reduced to 0.39%. We use the renormalized data.…”

“…Recently, very accurate pp analyzing-power data at 50.04 MeV [38,42] have become available, as well as an np longitudinal total cross section [110] and a set of np spin-correlation data at 67. The influence of these data in the s.e.…”

“…Including this latter experimental value we find N th,1 = 1.0133 (67). Later in a separate experiment [42] there was a new determination of the normalization, yielding N ex,2 = 1.0069(39). When we compare this with our determination N fl,1 we see again the consistency, but now the error in N ex,2 is smaller than our error in N fl,1 .…”

“…One should realize, however, that this very accurate experimental determination of the normalization is only applicable at a small selected set of energies (for details, see Refs. [39,42]). At any other energy, it is extremely difficult or even impossible to achieve this high accuracy, whereas our m.e.…”