Nuclear force studies in the proton-deuteron break-up channel at 135 MeV

Abstract

In this contribution, vector analyzing powers, Ax and Ay, are presented for the proton-deuteron break-up reaction studied using a polarised-proton beam at 135 MeV impinging on a liquid-deuterium target. For the experiment we used the Big Instrument for Nuclear-polarisation Analysis (BINA) at KVI, the Netherlands. With this setup, we expanded our measurements of analyzing powers compared to earlier published result (Kalantar-Nayestanaki N. et al., Rep. Prog. Phys. 75 (2012)). In particular, we determined, for the first time, Ax for a large range in the kinematical S, polar and azimuthal angles of the two outgoing protons. Analyzing power data are compared to predictions from Faddeev calculations. Our data are reasonably well described by calculations for kinematical configurations at which the three-nucleon force effect is predicted to be small. However, striking discrepancies are observed at specific configurations, in particular in cases where the relative azimuthal angle between the two protons becomes small. In this contribution, some of these configurations along with the analysis techniques will be presented.