π0π0 Production in proton-proton collisions at Tp=1.4 GeV

The reaction pp→ppπ0π0 has been investigated at a beam energy of 1.4 GeV using the WASA-at-COSY facility. The total cross section is found to be (324±21systematic±58normalization)μb. In order to study the production mechanism, differential kinematic distributions have been evaluated. The differential distributions indicate that both initial state protons are excited into intermediate Δ(1232) resonances, each decaying into a proton and a single pion, thereby producing the pion pair in the final state. No significant contribution of the Roper resonance N⁎(1440) via its decay into a proton and two pions is found.