A precise extraction of the induced polarization in the 4He(e,e'p)3H reaction

TL;DR

This study precisely measures the induced polarization in the 4He(e,e'p)3H reaction at specific momentum transfers, providing insights into reaction mechanisms beyond impulse approximation and constraining charge-exchange effects.

Contribution

It offers the most precise measurement of induced polarization in this reaction and compares results with theoretical models to refine understanding of charge-exchange contributions.

Findings

Results agree with relativistic distorted-wave impulse approximation

Over-estimation by models with strong charge-exchange effects

Data constrains charge-exchange interaction strength

Abstract

We measured with unprecedented precision the induced polarization Py in 4He(e,e'p)3H at Q^2 = 0.8 (GeV/c)^2 and 1.3 (GeV/c)^2. The induced polarization is indicative of reaction-mechanism effects beyond the impulse approximation. Our results are in agreement with a relativistic distorted-wave impulse approximation calculation but are over-estimated by a calculation with strong charge-exchange effects. Our data are used to constrain the strength of the spin independent charge-exchange term in the latter calculation.