Calculation of Multichannel Reactions in the Four-Nucleon System above Breakup Threshold

The exact four-body equations of Alt, Grassberger, and Sandhas are solved for neutron-${}^3\mathrm{He}$ and proton-${}^3\mathrm{H}$ scattering in the energy regime above the four-nucleon breakup threshold. Cross sections and spin observables for elastic, transfer, charge-exchange, and breakup reactions are calculated using realistic nucleon-nucleon interaction models, including the one with effective many-nucleon forces due to explicit $\mathrm{\Delta }$-isobar excitation. The experimental data are described reasonably well with only few exceptions such as vector analyzing powers.

Figure 1

$n\text{−}{}^3\mathrm{He}$ total and partial cross sections as functions of the neutron beam energy calculated using INOY04 potential. The data are from Refs. [26, 27, 28, 29, 30].

Figure 2

Differential cross section and neutron analyzing power of elastic $n\text{−}{}^3\mathrm{He}$ scattering at 12 and 22 MeV neutron energy. Results obtained with potentials INOY04 (solid curves) and CD $\text{Bonn}+\mathrm{\Delta }$ (dashed-dotted curves) are compared with data from Refs. [28, 31, 32, 33].

Figure 3

Differential cross section and proton analyzing power of elastic $p\text{−}{}^3\mathrm{H}$ scattering at 13.6 and 19.5 MeV proton energy. Curves as in Fig. 2. The data are from Refs. [34, 35].

Figure 4

Differential cross section of ${}^3\mathrm{H}(p,n){}^3\mathrm{He}$ reaction at 7, 9, 13.6, and 18 MeV proton energy. Curves as in Fig. 2. The data are from Refs. [36, 37, 38, 39].

Figure 5

Proton analyzing power and proton to neutron polarization transfer coefficients of ${}^3\mathrm{H}(p,n){}^3\mathrm{He}$ reaction at 13.6 MeV proton energy. Curves as in Fig. 2. The data are from Refs. [40, 41].

Figure 6

Differential cross section of ${}^3\mathrm{H}(p,d){}^2\mathrm{H}$ reaction at 13.6 MeV proton lab energy. Curves as in Fig. 2. The data are from Refs. [34, 42].