Measurement of e+e- Momentum and Angular Distributions from Linearly Polarized Photon Collisions
Measurement of e+e- Momentum and Angular Distributions from Linearly Polarized Photon Collisions
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线性偏振光子碰撞的 e( )e(-) 动量和角分布的测量
DOI：
10.1103/physrevlett.127.052302
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发表时间：
2021-07-27
影响因子：
8.6
通讯作者：
Zyzak, M.
中科院分区：
文献类型：
--
作者：
Adam, J.;Adamczyk, L.;Zyzak, M.
通过在s（NN）= 200 GeV的超周边Au + Au碰撞中观测到6085个排他电子对，对光子碰撞产生物质和反物质的Breit-Wheeler过程进行了实验研究.测量结果表明，在实验极限= 38.1 +/- 0.9 MeV时，cos 4 Delta phi =（16.8 +/- 2.5）%的四阶角调制和不含矢量介子（phi，omega和rho）的平滑不变质量分布，并显示出显着的中心依赖性。这些特点是一致的QED计算的碰撞线偏振光子量子化的极强的电磁场产生的高度带电的Au核在超相对论速度。实验结果对真空双折射和映射磁场具有重要意义，这对出现QCD现象很重要。
The Breit-Wheeler process which produces matter and antimatter from photon collisions is experimentally investigated through the observation of 6085 exclusive electron-positron pairs in ultraperipheral Au + Au collisions at root s(NN) = 200 GeV. The measurements reveal a large fourth-order angular modulation of cos4 Delta phi = (16.8 +/- 2.5)% and smooth invariant mass distribution absent of vector mesons (phi, omega, and rho) at the experimental limit of = 38.1 +/- 0.9 MeV and displays a significant centrality dependence. These features are consistent with QED calculations for the collision of linearly polarized photons quantized from the extremely strong electromagnetic fields generated by the highly charged Au nuclei at ultrarelativistic speed. The experimental results have implications for vacuum birefringence and for mapping the magnetic field which is important for emergent QCD phenomena.