Polarization observables in double neutral pion photoproduction

IF 2.8 3区物理与天体物理 Q2 PHYSICS, NUCLEAR

The European Physical Journal A Pub Date : 2025-07-23 DOI:10.1140/epja/s10050-025-01612-7

The CBELSA/TAPS Collaboration

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引用次数: 0

Abstract

Measurements of target asymmetries and double-polarization observables for the reaction are reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility (Bonn University) using the Bonn frozen-spin butanol (\(\hbox {C}_4\hbox {H}_9\)OH) target, which provided transversely polarized protons. Linearly polarized photons were produced via bremsstrahlung off a diamond crystal. The data cover the photon energy range from to and nearly the complete angular range. The results have been included in the BnGa partial wave analysis. Experimental results and the fit agree very well. Observed systematic differences in the branching ratios for decays of and \({\varDelta ^*}\) resonances are attributed to the internal structure of these excited nucleon states. Resonances which can be assigned to SU(6)\(\times \)O(3) two-oscillator configurations show larger branching ratios to intermediate states with non-zero intrinsic orbital angular momenta than resonances assigned to one-oscillator configurations.

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双中性介子光生产中的偏振观测。

报道了该反应的靶不对称和双极化观测值的测量结果。数据是在ELSA设施（波恩大学）的CBELSA/TAPS实验中使用波恩冷冻自旋丁醇（c4h9oh）靶进行的，该靶提供横向极化质子。线性偏振光子是通过金刚石晶体的轫致辐射产生的。数据涵盖了光子能量范围从到和几乎完整的角度范围。结果已纳入bga分波分析。实验结果与拟合吻合较好。观察到的和Δ *共振衰变的分支比的系统差异归因于这些激发态的内部结构。SU(6) × O(3)双振结构的共振比单振结构的共振具有更大的分支比到具有非零本征轨道角动量的中间态。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

The European Physical Journal A 物理-物理：核物理

CiteScore

5.00

自引率

18.50%

发文量

216

审稿时长

3-8 weeks

期刊介绍： Hadron Physics Hadron Structure Hadron Spectroscopy Hadronic and Electroweak Interactions of Hadrons Nonperturbative Approaches to QCD Phenomenological Approaches to Hadron Physics Nuclear and Quark Matter Heavy-Ion Collisions Phase Diagram of the Strong Interaction Hard Probes Quark-Gluon Plasma and Hadronic Matter Relativistic Transport and Hydrodynamics Compact Stars Nuclear Physics Nuclear Structure and Reactions Few-Body Systems Radioactive Beams Electroweak Interactions Nuclear Astrophysics Article Categories Letters (Open Access) Regular Articles New Tools and Techniques Reviews.