Study of the $\vec{p}d \to n\{pp\}_{s}$ charge-exchange reaction using a polarised deuterium target

TL;DR

This study measures analyzing powers in the proton-deuteron charge-exchange reaction at 600 MeV using a polarised deuterium target, providing data that supports impulse approximation models and extends previous results.

Contribution

First measurement of analyzing powers in the $ar{p}d o n ext{ extlangle}pp ext{ extrangle}_{s}$ reaction at 600 MeV using a polarised deuterium target, extending previous data and testing theoretical models.

Findings

Data agree with impulse approximation predictions.

No significant signs of multiple scattering effects.

Results extend the momentum transfer range of previous measurements.

Abstract

The vector and tensor analysing powers, $A_y$ and $A_{yy}$, of the $\vec{p}d \to n\{pp\}_{s}$ charge-exchange reaction have been measured at a beam energy of 600 MeV at the COSY-ANKE facility by using an unpolarised proton beam incident on an internal storage cell target filled with polarised deuterium gas. The low energy recoiling protons were measured in a pair of silicon tracking telescopes placed on either side of the target. Putting a cut of 3 MeV on the diproton excitation energy ensured that the two protons were dominantly in the $^{1}S_{0}$ state, here denoted by $\{pp\}_{s}$. The polarisation of the deuterium gas was established through measurements in parallel of proton-deuteron elastic scattering. By analysing events where both protons entered the same telescope, the charge-exchange reaction was measured for momentum transfers $q\geq 160$ MeV/$c$. These data provide a good continuation of the earlier results at $q\leq 140$ MeV/$c$ obtained with a polarised deuteron beam. They are also consistent with impulse approximation predictions with little sign evident for any modifications due to multiple scatterings.