Estimation of Admixture of Twelve Quark Bag State in He4 Nucleus

Abstract

The $p{}^4He$ elastic scattering at the energy range from 0.695 to 393 GeV is analyzed in the framework of the Glauber theory. The Glauber amplitudes were evaluated using isospin-averaged nucleon-nucleon amplitudes and the ${}^4He$ wave function as a superposition of the Gaussian functions. The values of the calculated differential cross sections usually exceed the experimental ones. In order to overcome the discrepancy, it is assumed following to the paper by L.G. Dakno and N.N. Nikolaev (Nucl. Phys. {\bf A436} (1985) 653) that the ground state wave function of ${}^4He$ has an admixture of a twelve quark bag. Neglecting all transition amplitudes, the proton - 12q bag scattering amplitude was chosen in a simple gaussian form. The inclusion of the 12q bag leads to decreasing the $p{}^4He$ differential cross section and to a shift of the dip position to a large values of $t$ what is needed for a successful description of the experimental data. While fitting the data it is found that the weight of the 12q bag state in the ground state of the ${}^4He$ nucleus is $\sim 10.5$%, $\sigma ^{tot}_{p-12q}\sim 34$ mb, and the slope parameter of the $p-12q$ bag elastic scattering is $\sim$ 23 (GeV/c)$^{-2}$. Inelastic shadowing is not taken into account at the calculations.