Equality of Analyzing Power and Polarization in the ReactionH3(p,n)3He

Abstract

The quantities $A_y$ and $P^y$ were remeasured for $E_p<4\mathrm{}$ MeV in the reaction ${}_{}{}^3{}_{}{}^{}H{(p,n)}^3\mathrm{He}$. Although our $A_y$ data confirm previous data, our $P^y$ values are appreciably larger than earlier results and in fact agree well with those for $A_y$. Elimination of the previously reported $A_y-P^y$ difference has important consequences. Charge-symmetry-breaking effects must be small or nonexistent in this reaction; and the previously required $f$-wave admixture to the lowest $J^{\pi }=2^{-}$ state of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ is no longer necessary.