DYNAMICAL RESPONSE OF A SINGLE STAR POLYMER-CHAIN

The initial decay rate Omega((k) over bar) of the dynamical scattering factor of a single regular star polymer is investigated with the chai n conformational renormalization group method up to first order in eps ilon. The reduced relaxation rate Omega((k) over bar)/k(3) is expresse d as the ratio of the mobility to the static structure factor, and we have analyzed the two contributions separately. At the Gaussian fixed point we have found a qualitatively different result to that of the st andard calculation in three dimensions, and the difference comes from the effect of the epsilon-expansion on the mobility. The renormalizati on group result at the self-avoiding fixed point describes qualitative ly well the behavior of Omega((k) over bar)/k(3) observed in neutron s cattering experiments for 12-arm-stars in a good solvent.