Exclusive diffractive production of π+π− continuum and resonances within tensor pomeron approach

We discuss exclusive central diffractive dipion production in proton-(anti)proton collisions at high energies. The calculation is based on a tensor pomeron model and the amplitudes for the processes are formulated in an effective field-theoretic approach. We include the purely diffractive dipion continuum, and the scalar and tensor resonances decaying into the pi^+pi^- pairs as well as the photoproduction contributions (rho^0, Drell-So<ding). We discuss how two pomerons couple to tensor meson f_2(1270) and the interference effects of resonance and dipion continuum. The theoretical results are compared with CDF and CMS experimental data. We show the influence of the experimental cuts on the integrated cross section and on various differential distributions for outgoing particles. We find that the relative contribution of resonant f_2(1270) and dipion continuum strongly depends on the cut on proton transverse momenta (or four-momentum transfer squared t_1,2) which may explain some controversial observations made by different ISR experiments in the past. The cuts may play then the role of a pipi resonance filter. We suggest some experimental analyses to fix model parameters related to the pomeron-pomeron-meson coupling.