Measurement of beam asymmetry for π−Δ++ photoproduction on the proton at Eγ=8.5GeV
Measurement of beam asymmetry for π−Δ++ photoproduction on the proton at Eγ=8.5GeV
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Eγ=8.5GeV 质子光生产中光束不对称性的测量
DOI：
10.1103/physrevc.103.l022201
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发表时间：
2021
影响因子：
3.1
通讯作者：
Barriga, E.
中科院分区：
文献类型：
--
作者：
Adhikari, S.;Akondi, C. S.;Ali, A.;Amaryan, M.;Asaturyan, A.;Austregesilo, A.;Baldwin, Z.;Barbosa, F.;Barlow, J.;Barriga, E.
我们报告了在光子束能量范围8.2-8.8 GeV的gluex实验数据中对反应的光产生光束不对称性的测量。与现象学模型相比，不对称是作为四动量传递到物体的函数来测量的。我们发现它作为一个函数变化：在较小的值为负，在较大的值为正。从理论上讲，该反应可以通过通道粒子交换来描述，通道粒子交换需要赝标量、矢量和张量中介。特别是，该反应需要电荷交换，这使我们能够探索介子交换和低动量转移下对一介子交换的高阶修正的意义。限制常规介子的产生机制有助于寻找和研究非常规介子。这是第一次测量这个能量下的过程。
We report a measurement of thephotoproduction beam asymmetry for the reactionusing data from theGlueXexperiment in the photon beam energy range 8.2–8.8 GeV. The asymmetryis measured as a function of four-momentum transferto theand compared to phenomenological models. We find thatvaries as a function of: negative at smaller values and positive at higher values of. The reaction can be described theoretically by-channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy.