Large logarithms in the beam normal spin asymmetry of elastic electron-proton scattering
Large logarithms in the beam normal spin asymmetry of elastic electron-proton scattering
复制标题
弹性电子-质子散射束法向自旋不对称性的大对数
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
N. Merenkov
中科院分区：
文献类型：
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作者：
A. Afanasev;N. Merenkov
我们研究了由双光子交换振幅的吸收部分引起的弹性电子-质子散射的奇偶守恒单自旋束不对称性。结果表明，由于硬共线准实光子的贡献，两个光子连续交换激发非弹性强子中间态导致对数和双对数增强。小电子散射角的不对称性用质子的总光生产截面表示，并预测达到20-30百万分之一的量级。在这些条件和固定的4动量转移下，不对称性随着电子束能量的增加呈对数增长，遵循质子的总光生产截面的高能衍射行为。
We study a parity-conserving single-spin beam asymmetry of elastic electron-proton scattering induced by an absorptive part of the two-photon exchange amplitude. It is demonstrated that excitation of inelastic hadronic intermediate states by the consecutive exchange of two photons leads to logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. The asymmetry at small electron scattering angles is expressed in terms of the total photoproduction cross section on the proton, and is predicted to reach the magnitude of 20-30 parts per million. At these conditions and fixed 4-momentum transfers, the asymmetry is rising logarithmically with increasing electron beam energy, following the high-energy diffractive behavior of total photoproduction cross section on the proton.