Evidence for a2+Resonance inHe4at 40 MeV

The fore-aft asymmetry in the angular distribution of the reaction ${}_{}{}^3{}_{}{}^{}\mathrm{H}$($p$,${\gamma }_0$)${}_{}{}^4{}_{}{}^{}\mathrm{He}$ has been measured as a function of energy for protons from 17 to 31 MeV. The same quantity was also measured using the reaction ${}_{}{}^4{}_{}{}^{}\mathrm{He}(e,{}_{}{}^3{}_{}{}^{}\mathrm{H})p{e}^{\prime }$. These asymmetry data were fitted with an expression which consisted of a term which varied slowly with energy plus a $2^{+}$ resonance having parameters of ${\Gamma }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=3.5\mathrm{}$ MeV and $E_x\left(\mathrm{res}\right)=40.2\mathrm{}$ MeV.