Effects of the phase variation and high-order momentum transfer components of NN amplitude on p- $$^{\bf 4}$$ 4 He elastic scattering

Abstract

Elastic scattering differential cross sections for a p- $$^4$$ He system are calculated within the framework of optical limit approximation of the Glauber multiple scattering model. Three different ranges for proton energy ( $$E_{\text {lab}}$$ ), $$19<E_{\text {lab}} < 50$$ MeV, $$100 \le E_{\text {lab}} \le 1730$$ MeV, and $$45 \le E_{\text {lab}} \le 393$$ GeV are considered. It is shown that the Pauli blocking fails to describe the data up to the proton energy, $$E_{\text {lab}} < 100$$ MeV. For higher proton energies, a qualitative agreement is obtained. The observed elastic scattering differential cross section is nicely reproduced in the whole range of scattering angles in the center of mass system up to $$\Theta _{\text {c.m.}} < {200}^{\circ }$$ for $$19 <E_{\text {lab}} \le 100$$ MeV when the effect of both the nucleon–nucleon (NN) phase variation parameter $$\gamma _{\text {NN}}$$ and higher-order momentum transfer components ( $$\lambda _n, n=1$$ and 2) of (NN) elastic scattering amplitude is included. In the range of $$200 \le E_{\text {lab}} \le 1730$$ MeV, introducing $$\lambda _n$$ plays a significant role in describing the data up to the momentum transfer, $$q^2 \le 1.2$$ (GeV/c) $$^2$$ . Moreover, it is found that considering only the effect of phase variation parameter, $$\gamma _{\text {NN}}$$ , improved the agreement in the region of minima for elastic scattering differential cross section for $$45 \le E_{\text {lab}} \le 393$$ GeV. The values of $$\gamma _{\text {NN}}$$ and $$\lambda _n$$ as a function of incident proton energies are presented.