Determination of two-photon exchange via $$e^+p/e^-p$$ scattering with CLAS12
Determination of two-photon exchange via $$e^+p/e^-p$$ scattering with CLAS12
复制标题
通过 CLAS12 的 $$e^ p/e^-p$$ 散射确定双光子交换
DOI：
10.1140/epja/s10050-021-00462-3
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Sharabian, Youri
中科院分区：
文献类型：
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作者：
Bernauer, Jan C.;Burkert, Volker D.;Cline, Ethan;Schmidt, Axel;Sharabian, Youri
质子的弹性形状因子比显示使用Rosenbluth技术在非偏振束和目标实验和使用偏振自由度的测量之间的差异。对这种差异的解释是未校正的硬双光子交换（TPE），这是一种通常被忽略的辐射校正。最近已经通过三个实验测试了效应大小和与理论预测的一致性。虽然结果支持存在小的双光子交换效应，但它们不能确定理论处理是有效的。在更大的动量转移，理论仍然未经检验。该建议旨在使用CLAS12实验以高精度测量扩展且迄今为止基本上未测试的范围内的双光子交换。这些数据对于明确确认或排除TPE作为差异驱动因素以及测试几种理论方法至关重要，这些方法被认为在测试范围的不同部分有效。
The proton elastic form factor ratio shows a discrepancy between measurements using the Rosenbluth technique in unpolarized beam and target experiments and measurements using polarization degrees of freedom. The proposed explanation of this discrepancy is uncorrected hard two-photon exchange (TPE), a type of radiative correction that is conventionally neglected. The effect size and agreement with theoretical predictions has been tested recently by three experiments. While the results support the existence of a small two-photon exchange effect, they cannot establish that theoretical treatments are valid. At larger momentum transfers, theory remains untested. This proposal aims to measure two-photon exchange over an extended and so far largely untestedandrange with high precision using the CLAS12 experiment. Such data are crucial to clearly confirm or rule out TPE as the driver for the discrepancy as well as test several theoretical approaches, believed valid in different parts of the testedrange.