Production of spin-3 mesons in diffractive DIS

We calculate the amplitudes of J = 3−− meson production in diffractive DIS within the kt-factorization approach, with a particular attention paid to the ρ3(1690) meson. We find that at all Q2 the ρ3(1690) production cross section is 2–5 times smaller than the ρ(1700) production cross section, which is assumed to be a pure D-wave state. Studying σL and σT separately, we observe domination of ρ3 in σL and domination of ρ(1700) in σT and offer an explanation of this behavior in simple terms. We also find very strong contributions — sometimes even domination — of the s-channel helicity violating amplitudes. The typical color dipole sizes probed in ρ3 production are shown to be larger than those in the ground state ρ production, and the energy dependence of ρ3 cross section turns out to be much flatter than the ρ production cross section. All the conclusions about the relative behavior of ρ3(1690) and ρ(1700) mesons are numerically stable against variations of input parameters.