Meson transition form factors at KLOE/KLOE-2

In this work we present a study of the Dalitz decay phi -> eta e(+)e(-), with eta -> pi(0)pi(0)pi(0), performed using 1.7 fb(-1) of e(+)e(-) collisions collected at KLOE in the 2004-2005 data taking period. The resulting branching fraction is: BR(phi -> e(+)e(-)) = (1.059 +/- 0.007(stat.) +/- 0.038(norm.)) x 10(-4). We have also studied the invariant mass of the dilepton system, extracting the slope of the transition form factor: b(phi eta) = (1.17 +/- 0.10) GeV-2. The phi -> pi(0)e(+)e(-) rare decay is also being studied using the same data sample. The branching ratio will be measured, with a consistent reduction of the actual total uncertainty. The double off shell pi(0) Transition Form Factor will also be measured for the first time in the time-like region, with the momentum transfer given by the e(+)e(-) invariant mass.