Single π 0 production off neutrons bound in deuteron with linearly polarized photons.
C MullenS GardnerD I GlazierS J D KayK LivingstonI I StrakovskyR L WorkmanS AbtP AchenbachF AfzalZ AhmedC S AkondiJ R M AnnandM BashkanovR BeckM BirothN S BorisovA BraghieriW J BriscoeF CividiniC CollicottS CostanzaA DenigM DieterleE J DownieP DrexlerS FeganM I Ferretti-BondyD GhosalI GorodnovW GradlM GüntherG GurevicL HeijkenskjöldD HornidgeG M HuberN JermannA KaeserM KorolijaV L KashevarovB KruscheV V KulikovA LazarevS LuttererI J D MacGregorD M ManleyP P MartelM A MartemianovC MeierR MiskimenM MocanuE MornacchiA NeganovM OberleM OstrickP OtteD PaudyalP PedroniA PowellS N PrakhovG ReicherzG RonT RostomyanC SfientiV SokhoyanK SpiekerO SteffenTh StrubI SupekA ThielM ThielA ThomasM UnverzagtYu A UsovS WagnerN K WalfordD P WattsD WerthmüllerJ WettigL WitthauerM WolfesN Zachariounull nullPublished in: The European physical journal. A, Hadrons and nuclei (2021)
The quasifree γ → d → π 0 n ( p ) photon beam asymmetry, Σ , has been measured at photon energies, E γ , from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time. The data were collected in the A2 hall of the MAMI electron beam facility with the Crystal Ball and TAPS calorimeters covering pion center-of-mass angles from 49 ∘ to 148 ∘ . In this kinematic region, polarization observables are sensitive to contributions from the Δ ( 1232 ) and N(1440) resonances. The extracted values of Σ have been compared to predictions based on partial-wave analyses (PWAs) of the existing pion photoproduction database. Our comparison includes the SAID, MAID and Bonn-Gatchina analyses; while a revised SAID fit, including the new Σ measurements, has also been performed. In addition, isospin symmetry is examined as a way to predict π 0 n photoproduction observables, based on fits to published data in the channels π 0 p , π + n and π - p .