"Table 92" of "Search for supersymmetry at sqrt(s)=8 TeV in final states with jets and two same-sign leptons or three leptons with the ATLAS detector"

CERN-LHC. A search for strongly produced supersymmetric particles is conducted using signatures involving multiple energetic jets and either two isolated leptons (e or mu) with the same electric charge, or at least three isolated leptons. The search also utilises jets originating from b-quarks, missing transverse momentum and other observables to extend its sensitivity. The analysis uses a data sample corresponding to a total integrated luminosity of 20.3 fb^-1 of sqrt(s) = 8 TeV proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider in 2012. No deviation from the Standard Model expectation is observed. New or significantly improved exclusion limits are set on a wide variety of supersymmetric models in which the lightest squark can be of the first, second or third generations, and in which R-parity can be conserved or violated. In the tables below, the efficiency is defined as the number of reconstructed events divided by the number of generated events. These numbers are calculated for events passing the selection requirements of each signal region. Please note that b-tagging efficiency, the requirement on the number of b-quark-initiated jets, is fully efficient for the generated events. The inefficiency of identifying b-jets using observed, reconstructed, data leads to significant migrations between the signal regions and, therefore, the efficiency can be greater than one. Acceptances are calculated using stable particles from MC event generators. For the acceptance calculation, final state electrons and muons from decays of massive W, Z, H bosons and SUSY particles are considered. The same kinematic requirements are applied as at reconstruction level, with the exception of the lepton-jet overlap requirements. Jets within a distance of Delta(R) = 0.2 of an electron are rejected, but leptons close to remaining jets are retained.

CERN-LHC实验。本研究针对强产生超对称粒子开展搜寻，其信号特征包含多个高能喷注，且满足两类条件之一：要么存在两个电荷相同的孤立轻子（电子e或μ子μ），要么至少存在三个孤立轻子。本搜寻还利用b夸克起源喷注、横向缺失动量及其他可观测量以提升探测灵敏度。本分析采用2012年大型强子对撞机（Large Hadron Collider, LHC）上ATLAS探测器采集的质心系能量√s=8 TeV的质子-质子对撞数据，总积分亮度为20.3 fb⁻¹。研究未观测到与标准模型（Standard Model, SM）预期不符的信号。本工作针对多种超对称模型设置了新的或显著优化的排除极限，这类模型中最轻的标量夸克可属于第一代、第二代或第三代，且R宇称（R-parity）可守恒或破缺。如下表所示，效率被定义为重建事件数与生成事件数的比值，该数值针对通过各信号区域选择要求的事件计算得到。请注意，b标记效率（即对b夸克起源喷注数量的要求）对于生成事件而言是完全有效的。利用观测到的重建数据识别b喷注时的效率损失会导致信号区域间出现显著的事件迁移，因此效率值可能大于1。接受度通过蒙特卡洛（Monte Carlo, MC）事件生成器产生的稳定粒子计算得到，计算过程中需考虑来自大质量W、Z、H玻色子以及超对称（SUSY）粒子衰变产生的末态电子和μ子。除轻子-喷注重叠要求外，其余运动学要求均与重建阶段一致：与电子的空间距离ΔR=0.2以内的喷注将被剔除，但靠近剩余喷注的轻子则予以保留。