利用ATLAS探测器在LHC Run 2的139 fb⁻¹数据中搜索第三代轻子夸克对产生并衰变为b夸克和τ轻子，未发现超出标准模型的信号，对标量和矢量轻子夸克分别给出了1460 GeV和1650 GeV（1910 GeV）的质量排除下限。
摘要：
本文利用ATLAS探测器在质心能量为√s = 13 TeV的质子-质子碰撞中收集的完整LHC Run 2（2015-2018年）数据样本，总积分亮度为139 fb⁻¹，对成对产生的标量或矢量轻子夸克衰变为b夸克和τ轻子的过程进行了搜索。研究中考虑了至少一个τ轻子发生强子衰变的事件，并使用多变量判别器来提取信号。未观察到与标准模型预期有显著偏差，并给出了轻子夸克质量和衰变到τ轻子与b夸克的分支比B的函数形式的95%置信水平产生截面上限。对于标量轻子夸克，假设B=100%时，质量低于1460 GeV被排除；对于矢量轻子夸克，在最小耦合（Yang-Mills）情形下，相应的限制为1650 GeV（1910 GeV）。
英文摘要：
A search for pair-produced scalar or vector leptoquarks decaying into a $b$-quark and a $τ$-lepton is presented using the full LHC Run 2 (2015-2018) data sample of 139 fb$^{-1}$ collected with the ATLAS detector in proton-proton collisions at a centre-of-mass energy of $\sqrt{s} =13$ TeV. Events in which at least one $τ$-lepton decays hadronically are considered, and multivariate discriminants are used to extract the signals. No significant deviations from the Standard Model expectation are observed and 95% confidence-level upper limits on the production cross-section are derived as a function of leptoquark mass and branching ratio $B$ into a $τ$-lepton and $b$-quark. For scalar leptoquarks, masses below 1460 GeV are excluded assuming $B=100$%, while for vector leptoquarks the corresponding limit is 1650 GeV (1910 GeV) in the minimal-coupling (Yang-Mills) scenario.
Search for 1st-Generation Leptoquarks Using the ATLAS Detector
本文报道了在LHC记录的7 TeV ATLAS数据的1/fb中寻找标量细夸克对产生的结果。轻夸克是一种假设的三重色玻色子，它同时带有夸克和轻子的味道，因此衰变为夸克和轻子，与任何标准模型粒子不同。轻夸克产生于许多超越标准模型的理论。在这个分析中检查的通道需要至少一个轻夸克衰变到电子，其中包括最终状态eejj和evjj。没有多余的事件被观察到，从而限制允许leptoquark质量被确定。我们在95%的置信水平上排除了质量m < 660（607）GeV的第一代标量细夸克的产生，假设细夸克衰变到电子的分支分数为1.0（0.5）。
ATLAS Sensitivity to Leptoquarks, W_R and Heavy Majorana Neutrinos in Final States with High-pt Dileptons and Jets with Early LHC Data at 14 TeV proton-proton collisions
Search for a singly produced third-generation scalar leptoquark decaying to a $τ$ lepton and a bottom quark in proton-proton collisions at $\sqrt{s} =$ 13 TeV
Searches for third-generation scalar leptoquarks in $\sqrt{s}$ = 13 TeV pp collisions with the ATLAS detector
对标量轻夸克的对产生进行了限制，考虑了轻夸克衰变为第三代夸克（$t$，$b$）和轻子（$τ$，$ν$）的所有可能.对于上型（$\mathrm{LQ}_{3}^{u}$ $\rightarrow t ν/ b τ$）和下型（$\mathrm{LQ}_{3}^{d}$ $\rightarrow b ν/ t τ$）细夸克，极限是细夸克质量和带电轻子分支比的函数。许多结果是对以前发表的ATLAS检索的重新解释。在所有情况下，使用ATLAS探测器在2015年和2016年记录的质量中心能量为$\sqrt{s}$ = 13 TeV的LHC质子-质子碰撞数据，对应于36.1 fb $^{-1}$的积分光度。对于$\mathrm{LQ}_{3}^{u}$和$\mathrm{LQ}_{3}^{d}$两者，与分支比无关地排除低于800 GeV的质量，对于分支比等于零或1的极限情况，排除低于约1 TeV的质量。
Search for pair production of scalar leptoquarks decaying into first- or second-generation leptons and top quarks in proton-proton collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
Search for a leptoquark in events with a hadronically decaying $τ$-lepton and missing transverse momentum using $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
EUROPEAN ORGANISATION FOR NUCLEAR RESEARCH (CERN)（欧洲核子研究中心（CERN））
Search for pair-produced scalar and vector leptoquarks decaying into third-generation quarks and first- or second-generation leptons in pp collisions with the ATLAS detector
本研究利用LHC Run 2的139 fb⁻¹质子-质子碰撞数据，通过ATLAS探测器搜寻成对产生的多类轻夸克，未发现偏离标准模型的信号，给出了截面上限与质量下限，为解释B物理反常的两类模型设定了质量约束。
Search for pair production of third-generation scalar leptoquarks decaying into a top quark and a $τ$-lepton in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
Searches for scalar leptoquarks and differential cross-section measurements in dilepton-dijet events in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV with the ATLAS experiment
Search for heavy neutrinos or third-generation leptoquarks in final states with two hadronically decaying tau leptons and two jets in proton-proton collisions at sqrt(s) = 13 TeV
Search for excited $τ$-leptons and leptoquarks in the final state with $τ$-leptons and jets in pp collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector
Search for leptoquark pair production decaying into $te^- \bar{t}e^+$ or $tμ^- \bar{t}μ^+$ in multi-lepton final states in $pp$ collisions at 13 TeV with the ATLAS detector
Search for resonant leptoquark production via lepton-jet signatures in $pp$ collisions at $\sqrt{s} = 13$ TeV and $\sqrt{s} = 13.6$ TeV with the ATLAS detector
EUROPEAN ORGANISATION FOR NUCLEAR RESEARCH (CERN)（欧洲核子研究中心（CERN））
本文利用 ATLAS 装置在 13 和 13.6 TeV 激撞数据中，通过轻子-喷注信号搜索共振轻子淬克产生，排除了标量轻子淬克的高质量范围。
Search for a scalar partner of the top quark in the all-hadronic $t\bar{t}$ plus missing transverse momentum final state at $\sqrt{s}=13$ TeV with the ATLAS detector
Search for pair-production of vector-like quarks in final states with at least one $Z$ boson decaying into a pair of electrons or muons in $pp$ collision data collected with the ATLAS detector at $\sqrt{s}$ = 13 TeV
Search for heavy resonances decaying into a photon and a hadronically decaying Higgs boson in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
Search for heavy resonances decaying to a photon and a hadronically decaying $Z/W/H$ boson in $pp$ collisions at $\sqrt{s}=13$ $\mathrm{TeV}$ with the ATLAS detector
Search for down-type fourth generation quarks with the ATLAS detector in events with one lepton and hadronically decaying W bosons
这封信介绍了在轻子+喷流通道中通过b '->Wt衰变的重下型夸克的成对产生的研究，如b' b '->WtWt->bbWWWW->lvbbqqqqqq。除了需要恰好一个轻子、大的缺失横向动量和至少六个喷注之外，附近喷注对的不变质量被用来识别高横向动量的W玻色子。在ATLAS探测器记录的sqrt（s）= 7 TeV pp碰撞的积分亮度为1.04 fb^-1的数据中，在95%的置信水平下排除了质量小于480 GeV的重降型夸克。
Search for dark matter in events with missing transverse momentum and a Higgs boson decaying into two photons in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector
