Abstract
The beam-helicity asymmetry was measured, for the first time, in photoproduction of π0η pairs on carbon, aluminum, and lead, with the A2 experimental setup at MAMI. The results are compared to an earlier measurement on a free proton and to the corresponding theoretical calculations. The Mainz model is used to predict the beam-helicity asymmetry for the nuclear targets. The present results indicate that the photoproduction mechanism for π0η pairs on nuclei is similar to photoproduction on a free nucleon. This process is dominated by the D33 partial wave with the ηΔ(1232) intermediate state.
Original language | American English |
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Article number | 135243 |
Journal | Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics |
Volume | 802 |
DOIs | |
State | Published - 10 Mar 2020 |
Bibliographical note
Funding Information:The authors wish to acknowledge the excellent support of the accelerator group and operators of MAMI. We also thank A. Sarantsev and V. Nikonov on behalf of the BnGa PWA group. This work was supported by the Deutsche Forschungsgemeinschaft ( SFB443 , SFB/TR16 , and SFB1044 ), DFG-RFBR (Grant No. 09-02-91330 ), the European Community-Research Infrastructure Activity under the FP6 “Structuring the European Research Area” program (Hadron Physics, Contract No. RII3-CT-2004-506078 ), Schweizerischer Nationalfonds (Contract Nos. 200020-156983 , 132799 , 121781 , 117601 , 113511 ), the U.K. Science and Technology Facilities Council (STFC 57071/1 , 50727/1 ), the U.S. Department of Energy (Offices of Science and Nuclear Physics, Award Nos. DE-FG02-99-ER41110 , DE-FG02-88ER40415 , DE-SC0014323 ) and National Science Foundation (Grant Nos. PHY-1039130 , IIA-1358175 ), INFN (Italy), and NSERC (Canada). We also acknowledge the support of the Carl-Zeiss-Stiftung . A. Fix acknowledges additional support from the Tomsk Polytechnic University competitiveness enhancement program. We thank the undergraduate students of Mount Allison University and The George Washington University for their assistance.
Funding Information:
The authors wish to acknowledge the excellent support of the accelerator group and operators of MAMI. We also thank A. Sarantsev and V. Nikonov on behalf of the BnGa PWA group. This work was supported by the Deutsche Forschungsgemeinschaft (SFB443, SFB/TR16, and SFB1044), DFG-RFBR (Grant No. 09-02-91330), the European Community-Research Infrastructure Activity under the FP6 “Structuring the European Research Area” program (Hadron Physics, Contract No. RII3-CT-2004-506078), Schweizerischer Nationalfonds (Contract Nos. 200020-156983, 132799, 121781, 117601, 113511), the U.K. Science and Technology Facilities Council (STFC 57071/1, 50727/1), the U.S. Department of Energy (Offices of Science and Nuclear Physics, Award Nos. DE-FG02-99-ER41110, DE-FG02-88ER40415, DE-SC0014323) and National Science Foundation (Grant Nos. PHY-1039130, IIA-1358175), INFN (Italy), and NSERC (Canada). We also acknowledge the support of the Carl-Zeiss-Stiftung. A. Fix acknowledges additional support from the Tomsk Polytechnic University competitiveness enhancement program. We thank the undergraduate students of Mount Allison University and The George Washington University for their assistance.
Publisher Copyright:
© 2020 The Author(s)