6533b854fe1ef96bd12af33d

RESEARCH PRODUCT

First measurement of the helicity-dependent γ p↦pη differential cross-section

S GoertzJ. HarmsenR. Van De VyverR BeckK. KossertG RosnerD RyckboschE. ReichertC BradtkeV LisinR KondratievR. LeukelJ. NaumannJc McgeorgeB KielT. HasegawaT. MatsudaH DutzA. MeierW. WeihofenA. PanzeriHj ArendsE. RadtkeO. JahnT. KageyaM SchumacherL. Van HoorebekeF. KleinN. D'hoseJrm AnnandB LannoyJ AhrensP PedroniG ReicherzP. JenneweinAnton12 GiselaN HorikawaA. WakaiA BraghieriTakahiro IwataS AltieriKurt HansenB SchochW. MeyerB SeitzD. MenzeE. HeidDieter DrechselT. SpecknerF. WissmannP. GrabmayrJ. KrimmerS HasegawaG. ZeitlerG. TamasD Von HarrachT MichelH HolvoetT PinelliA ThomasI. PreobrajenskiF. ZapadtkaM. LangN. TakabayashiM. SauerK. HelbingCh. RohlofK. Aulenbacher

subject

PhysicsScattering cross-sectionNuclear and High Energy PhysicsParticle physics010308 nuclear & particles physicsHadronPhoton energy01 natural sciencesHelicityNuclear physics0103 physical sciencesPhysics::Accelerator PhysicsNuclear fusionPhoton beamNuclear Experiment010306 general physicsMicrotron

description

The helicity dependence of the (γ) over right arrow(p) over right arrow -+ peta reaction has been measured for the first time at a center-of-mass angle theta(eta)*= 70degrees in the photon energy range from 780 MeV to 790 MeV. The experiment, performed at the Mainz microtron MAMI, used a 4pi-detector system, a circularly polarized, tagged photon beam. and a longitudinally polarized frozen-spin target. The helicity 3/2 cross-section is found to be small and the results for helicity 1/2 agree with predictions from the MAID analysis.

https://doi.org/10.1140/epja/i2002-10153-2