6533b85bfe1ef96bd12ba9d7
RESEARCH PRODUCT
Two neutral pion photoproduction off the proton between threshold and 800 MeV
R. BeckF. HärterV. MetagB. KruscheM. WolfM. SchmitzTh. WalcherJ. AhrensH. Ströhersubject
PhysicsNuclear physicsNuclear and High Energy PhysicsPionPhotonProtonIntermediate stateDalitz plotInvariant massDecay chainAtomic physicsMicrotrondescription
Abstract The photoproduction of two neutral pions off the proton has been studied for incident photon energies between E γ = 309 MeV (threshold) and 792 MeV with the TAPS photon spectrometer at the Mainz Microtron MAMI. Both 3γ- and 4γ-events have been analysed in order to deduce the total p ( γ , 2 π 0 ) p cross section. The total cross section is less than 300 nb between threshold and ⋍ 460 MeV, beyond which it starts to rise to a maximum value of about 11 μb at around 750 MeV. For the highest energies it starts to decrease again. The 4γ-sample has been used to reconstruct 2 neutral pions from the above reaction channel by an invariant mass and a missing mass analysis. After reconstruction of the unobserved proton, a Dalitz-plot of m π 0 π 0 2 vs. m pπ 0 2 has been obtained, which indicates that the decay chain includes the Δ(1232)-resonance as an intermediate state.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1997-05-01 | Physics Letters B |