Spin effects in backward deuteron scattering and baryonic degrees of freedom in the deuteron

The effect of the baryon-resonance admixture to the deuteron wave function on the momentum dependences of the differential cross section, the tensor analyzing power T20, and the polarization-transfer coefficient κ0 for backward elastic deuteron-proton scattering at high energies is investigated. The reaction in question is assumed to proceed predominantly through nucleon and nucleon-resonance exchanges. The formalism used in this study is based on light-front dynamics. The effect of various parameters of the problem on the results of the calculations is analyzed, and it is shown that, even at a 1% level of the total admixture of nucleon resonances to the deuteron wave function, a description of experimental data that is superior to that within the one-nucleon-exchange approximation can be achieved by appropriately choosing the contributions of various resonances. For qualitative agreement between the results of the calculations and experimental data to be attained, it is sufficient to take into account the contributions of the lightest negative-parity baryon resonances. Upon taking into account baryon exchanges, results computed for observables with different deuteron wave functions show a smaller scatter than analogous results obtained within the one-nucleon-exchange approximation