Single 0 production off neutrons bound in deuteron with linearly polarized photons

Abstract

The quasifree γ→ d→ πn(p) photon beam asymmetry, Σ, has been measured at photon energies, Eγ, 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 πn photoproduction observables, based on fits to published data in the channels πp, π+n and π-p.

Metadata

Funding Information: This work was supported in part by the UK Science and Technology Facilities Council (STFC Grants No. ST/L005719/1, ST/P004458/1, ST/T002077/1,ST/P004385/2, ST/V002570/1, ST/P004008/1 and ST/L00478X/2), the U. S. Department of Energy, Office of Science, Office of Nuclear Physics, under Awards no. DE-FG02-01ER41194, no. DE-SC0016583, no. DE-SC0016582, and no. DE-SC0014323. This work was supported by Schweizerischer Nationalfonds (Grants no. 200020-132799, no. 121781, no. 117601, and no. 113511), Deutsche Forschungsgemeinschaft (SFB Grant no. 443, No. SFB/TR 16, no. SFB 1044), DFG-RFBR (Grant no. 05-02-04014), European Community Research Infrastructure Activity (FP6), the U. S. DOE, U. S. NSF, and NSERC (Grant no. SAPPJ-2018-00020) Canada. This publication is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement STRONG-2020-No 824093. We would like to thank all the technical and nontechnical staff of MAMI for their support. Funding Information: This work was supported in part by the UK Science and Technology Facilities Council (STFC Grants No. ST/L005719/1, ST/P004458/1, ST/T002077/1,ST/P004385/2, ST/V002570/1, ST/P004008/1 and ST/L00478X/2), the U.?S.?Department of Energy, Office of Science, Office of Nuclear Physics, under Awards no. DE-FG02-01ER41194, no. DE-SC0016583, no. DE-SC0016582, and no. DE-SC0014323. This work was supported by Schweizerischer Nationalfonds (Grants no. 200020-132799, no.?121781, no.?117601, and no.?113511), Deutsche Forschungsgemeinschaft (SFB Grant no.?443, No. SFB/TR?16, no. SFB?1044), DFG-RFBR (Grant no. 05-02-04014), European Community Research Infrastructure Activity (FP6), the U.?S.?DOE, U.?S.?NSF, and NSERC (Grant no. SAPPJ-2018-00020) Canada. This publication is part of a project that has received funding from the European Union?s Horizon 2020 research and innovation programme under grant agreement STRONG-2020-No 824093. We would like to thank all the technical and nontechnical staff of MAMI for their support. Publisher Copyright: © 2021, The Author(s).

Keywords:

nucl-ex, hep-ex, hep-ph, nucl-th

Dates: