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arXiv 2008.05355hep-exnucl-ex
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用ATLAS探测器测量Pb+Pb的2.2 nb $^{-1}$的光-光散射和寻找类轴子粒子

Measurement of light-by-light scattering and search for axion-like particles with 2.2 nb$^{-1}$ of Pb+Pb data with the ATLAS detector

ATLAS Collaboration

摘要:

本文介绍了一种基于ATLAS实验在LHC运行2期间记录的Pb+Pb碰撞数据的光-光散射测量。该研究使用了2015年和2018年在$\sqrt{s_\mathrm{NN}}=5.02$ TeV收集的积分亮度的$2.2$ nb $^{-1}$。光-光散射的候选者被选择在事件中与两个光子产生排他性,每个具有横向能量$E_{\mathrm{T}}^γ > 2.5$ GeV,赝快度$|η_γ| < 2.37$,双光子不变质量$m_{γγ} > 5$ GeV,并与小双光子横向动量和双光子共面性。积分和差分基准截面的测量和理论预测进行比较。双光子不变质量分布被用来限制轴子类粒子的产生。这一结果提供了迄今为止最严格的限制类轴子粒子生产的质量范围在6-100 GeV。在该质量区间的95% CL下,排除了2 - 70 nb以上的截面。

英文摘要:

This paper describes a measurement of light-by-light scattering based on Pb+Pb collision data recorded by the ATLAS experiment during Run 2 of the LHC. The study uses $2.2$ nb$^{-1}$ of integrated luminosity collected in 2015 and 2018 at $\sqrt{s_\mathrm{NN}}=5.02$ TeV. Light-by-light scattering candidates are selected in events with two photons produced exclusively, each with transverse energy $E_{\mathrm{T}}^γ > 2.5$ GeV, pseudorapidity $|η_γ| < 2.37$, diphoton invariant mass $m_{γγ} > 5$ GeV, and with small diphoton transverse momentum and diphoton acoplanarity. The integrated and differential fiducial cross sections are measured and compared with theoretical predictions. The diphoton invariant mass distribution is used to set limits on the production of axion-like particles. This result provides the most stringent limits to date on axion-like particle production for masses in the range 6-100 GeV. Cross sections above 2 to 70 nb are excluded at the 95% CL in that mass interval.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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