6533b825fe1ef96bd12826e1
RESEARCH PRODUCT
Intermediate resonance excitation in the γp→pπ0π0 reaction
J. HarmsenA ThomasR. Van De VyverL. Van HoorebekeD Von HarrachA. PanzeriP. JenneweinKurt HansenI. PreobrajenskiI. PreobrajenskiB SchochE. RadtkeT MichelR. LeukelF. WissmannA BraghieriF. ZapadtkaM. LangT. HasegawaH HolvoetB SeitzJ. NaumannHj ArendsN. TakabayashiT PinelliW. MeyerM. SauerS GoertzC BradtkeE. ReichertD RyckboschW. WeihofenS HasegawaF. KleinJ AhrensO. JahnG. ZeitlerV LisinA. WakaiS AltieriE. HeidT. KageyaN. DegrandeD. MenzeTakahiro IwataG. TamasJrm AnnandB LannoyP. GrabmayrB KielH DutzA. MeierT. SpecknerT. RostomyanR KondratievG ReicherzN. D'hoseP PedroniJc McgeorgeCh. RohlofK. AulenbacherT. MatsudaR BeckK. KossertG RosnerK. HelbingJ. KrimmerM SchumacherGisela AntonN Horikawasubject
PhysicsNuclear and High Energy PhysicsPhotonProton010308 nuclear & particles physicsResonance01 natural sciencesHelicityCross section (geometry)Nuclear physicsExcited state0103 physical sciencesPhysics::Accelerator PhysicsAtomic physicsNuclear Experiment010306 general physicsNucleonSpin (physics)description
The helicity dependence of the total cross section for the (gamma) over right arrow(p) over right arrow -> p pi(0)pi(0) reaction has been measured for the first time at incident photon energies from 400 to 800 MeV. The measurement, performed at the tagged photon beam facility of the MAMI accelerator in Mainz, used the large acceptance detector DAPHNE and a longitudinally polarized frozen-spin target. This channel is found to be excited predominantly when the photon and proton have a parallel spin orientation, most likely due to the intermediate production of the D-13(1520) resonance. However, the contribution of the antiparallel spin configuration, arising from other reaction mechanisms, is also not negligible. This result gives important new information to resolve the existing model discrepancies in the identification of the nucleon resonances contributing to this channel.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2005-09-01 | Physics Letters B |