论文标题
使用$ llqq $最终状态在PB-PB超级外围碰撞中搜索低质量的leptoquarks
Search for Low-Mass Leptoquarks using the $llqq$ final states in Pb-Pb Ultra-Peripheral Collisions
论文作者
论文摘要
经过对过去实验和低能风味物理学的理论要求的审查后，我们认为由于测量中的假设，低质量leptoquarks（LQ）的可能性无法完全排除。因此，我们建议在PB-PB Ultra-feripher碰撞中搜索具有最小模型依赖性的PB-PB超级碰撞碰撞（假设一个小耦合常数$ \ lyssim0.1 $）。有几个优点：1）高光子通量为低质量LQ提供高生产率； 2）背景污染远低于$ p $ - $ p $碰撞中的污染。分析策略允许Leptokark衰减到所有可能的Lepton-Plus-Quark模式。采用标量LQ，$ s_3 $，带有电荷$ | q | = \ frac {4} {3} e $，例如，使用4〜pb $^{ - 1} $ pb-pb pb pb pb pb ultra-periprips $ sq y $ sq quistion cont = 5 \ sq的质量可以在95〜 \％置信度下排除。在运行〜2中的地图集检测器的性能。该方法还适用于在$ p $ - $ p $碰撞中搜索高质量LQ，只要LQ对生产机制占主导地位。
After a review over past experiments and theoretical requirements from low-energy flavour physics, we argue that the possibility of low-mass leptoquarks (LQ) cannot be fully excluded due to the assumptions made in the measurements. Therefore we propose to search for the pair production of low-mass leptoquarks in Pb-Pb ultra-peripheral collisions with the least model dependence (assuming a small coupling constant $\lesssim0.1$). There are a couple of advantages: 1) high photon flux provides high production rate for low mass LQs; 2) the background contamination is much lower than that in $p$-$p$ collisions. The analysis strategy permits a leptoquark to decay to all possible lepton-plus-quark modes. Taking the scalar LQ, $S_3$, with an electric charge $|q|=\frac{4}{3}e$, as example, the mass point of 100 GeV can be excluded at the 95~\% confidence level using a dataset of 4~pb$^{-1}$ Pb-Pb ultra-peripheral collisions at $\sqrt{s}=5.02$ TeV and the performance of the ATLAS detector in Run~2. The proposed method also applies to searching for high-mass LQs in $p$-$p$ collisions as long as the LQ pair production mechanism dominates.
