Resonant and direct components in the ${}^3\mathrm{He}\left(d,p\right){}^4\mathrm{He}$ reaction at low energies

New experimental results for the cross section and $A_{yy}$ tensor analyzing power observables of the ${}^3\mathrm{He}\left(d,p\right){}^4\mathrm{He}$ reaction at a scattering angle of $\theta =0°$ are presented for $E_d=0.52,0.89,$ and $1.49\text{MeV}$, and all linearly independent scattering amplitudes at this angle are calculated. A hybrid $R\text{−}\text{matrix}+\text{potential}$ model is used to fit these results and other ${}^3\mathrm{He}\left(d,p\right){}^4\mathrm{He}$ reaction data for $E_d<1\text{MeV}$. This analysis indicates significant direct process contributions to the reaction mechanism.

Figure 1

Experimental setup used in the $A_{yy}$ measurement.

Figure 2

Experimental setup used in the cross section measurement.

Figure 3

Hybrid model angular distributions for $i{T}_{11}$ and $T_{2q}$ measurements of Geist et al. [1] at two deuteron energies, 0.424 and $0.641\text{MeV}$.

Figure 4

Hybrid model results for the energy dependence of $A_{yy}(0°)$, $\sigma (0°)$, and $K_y^{y^{\prime }}(0°)$.