Fakultät für Mathematik und Physik, Albert-Ludwigs-Universität, Freiburg iBr, Germany.
Phys Rev Lett. 2011 Jun 24;106(25):251801. doi: 10.1103/PhysRevLett.106.251801. Epub 2011 Jun 22.
This Letter presents the first search for a heavy particle decaying into an e ± μ(-/+) final state in sqrt[s] = 7 TeV pp collisions at the LHC. The data were recorded by the ATLAS detector during 2010 and correspond to a total integrated luminosity of 35 pb(-1). No excess above the standard model background expectation is observed. Exclusions at 95% confidence level are placed on two representative models. In an R-parity violating supersymmetric model, tau sneutrinos with a mass below 0.75 TeV are excluded, assuming all R-parity violating couplings are zero except λ(311)' = 0.11 and λ312 = 0.07. In a lepton flavor violating model, a Z'-like vector boson with masses of 0.70-1.00 TeV and corresponding cross sections times branching ratios of 0.175-0.183 pb is excluded. These results extend to higher mass R-parity violating sneutrinos and lepton flavor violating Z's than previous constraints from the Tevatron.
这封信件介绍了在 LHC 的 sqrt[s] = 7 TeV pp 碰撞中首次搜索重粒子衰变为 e ± μ(-/+)末态的情况。该数据由 ATLAS 探测器在 2010 年记录，总积分亮度为 35 pb(-1)。未观察到超出标准模型背景预期的多余信号。在 95%置信水平下，对两个代表性模型进行了排除。在违反 R 宇称的超对称模型中，假设所有 R 宇称破坏耦合都为零，除了 λ(311)' = 0.11 和 λ312 = 0.07，质量低于 0.75 TeV 的 tau 中微子被排除在外。在违反轻子味的模型中，排除了质量为 0.70-1.00 TeV 的类似 Z'的矢量玻色子以及相应的截面乘以分支比为 0.175-0.183 pb。这些结果扩展到了更高质量的违反 R 宇称的中微子和违反轻子味的 Z'，比之前来自 Tevatron 的约束更为严格。
