The $ddto ^3He n$ reaction is considered at the energies between 200 MeV and 520 MeV. The Alt-Grassberger-Sandhas equations are iterated up to the lowest order terms over the nucleon-nucleon t-matrix. The parameterized ${^3He}$ wave function including five components is used. The angular dependence of the differential cross section and energy dependence of tensor analyzing power $T_{20}$ at the zero scattering angle are presented in comparison with the experimental data.
Antiproton scattering off $^3He$ and $^4He$ targets is considered at beam energies below 300 MeV within the Glauber-Sitenko approach, utilizing the $bar N N$ amplitudes of the Julich model as input. A good agreement with available data on differential $bar p ^4He$ cross sections and on $bar p ^3He$ and $pbar ^4He$ reaction cross sections is obtained. Predictions for polarized total $bar p ^3$He cross sections are presented, calculated within the single-scattering approximation and including Coulomb-nuclear interference effects. The kinetics of the polarization buildup is discussed.
Mechanism of nuclear reactions on 197Au induced by 11B ions at energies above Coulomb barrier was studied by induced-activity method and gamma-spectroscopy. The cross sections of the reaction fragments from 197Au induced by 11B ions were measured at bombarding energies 137.5 and 255.5 MeV. The fission process was investigated by using multimodal fission approach at the energy 137.5 MeV, and pure symmetric distribution at 255.5 MeV. It was observed that the transferred linear momentum provides the information on the initial projectile-target information. The fissility for both fission reactions under study was deduced from measured fission cross section using the total inelastic cross section. Comparison with proton-induced fission shown, that the linear momentum transferred to the fissile system depends on the probe.
We present new accurate measurements of the differential cross section $sigma(theta)$ and the proton analyzing power $A_{y}$ for proton-$^{3}$He elastic scattering at various energies. A supersonic gas jet target has been employed to obtain these low energy cross section measurements. The $sigma(theta)$ distributions have been measured at $E_{p}$ = 0.99, 1.59, 2.24, 3.11, and 4.02 MeV. Full angular distributions of $A_{y}$ have been measured at $E_{p}$ = 1.60, 2.25, 3.13, and 4.05 MeV. This set of high-precision data is compared to four-body variational calculations employing realistic nucleon-nucleon (NN) and three-nucleon (3N) interactions. For the unpolarized cross section the agreement between the theoretical calculation and data is good when a $3N$ potential is used. The comparison between the calculated and measured proton analyzing powers reveals discrepancies of approximately 50% at the maximum of each distribution. This is analogous to the existing ``$A_{y}$ Puzzle known for the past 20 years in nucleon-deuteron elastic scattering.
We provide systematic analysis of the differential cross section of the proton-$^3{rm He}$ elastic scattering at $theta_{rm cm}=180^{circ}$ and at $T_p<700$ MeV. Three mechanisms are discussed: 2N pair exchange in the triplet and singlet spin states, pion exchange and direct mechanism. It is shown that t Tp>150 MeV tree-body structure, including triplet and singlet states of the 2N pair, becomes of great importance for understanding energy dependence of the reaction observables. Prediction for the differential cross section and the polarization correlation $C_{00nn} which can be studied now in experiment are given. PACS number(s): 21.30.Cb, 21.30.-x, 25.40.Cm, 25.55.Ci
We use realistic two- and three-nucleon interactions in a hybrid chiral-perturbation-theory calculation of the charge-symmetry-breaking reaction $ddtoalphapi^0$ to show that a cross section of the experimentally measured size can be obtained using LO and NNLO pion-production operators. This result supports the validity of our power counting scheme and demonstrates the necessity of using an accurate treatment of ISI and FSI.