分类: 物理学 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: Motivated by the recent progress of direct search for the productions of stop pair and sbottom pair at the LHC, we examine the constraints of the search results on the stop (t ̃ ) mass in natural SUSY. We first scan the parameter space of natural SUSY in the framework of MSSM, considering the constraints from the Higgs mass, B-physics and electroweak precision measurements. Then in the allowed parameter space we perform a Monte Carlo simulation for stop pair production followed by t ̃ → tχ ̃0 or t ̃ → bχ ̃+ and sbottom pair production followed by ̃b → bχ ̃0 or ̃b → tχ ̃−. 1111 1111 Using the combined results of ATLAS with 20.1 fb−1 from the search of l + jets + E/ T , hadronic tt ̄+E/T and 2b+E/T, we find that a stop lighter than 600 GeV can be excluded at 95% CL in this scenario.
分类: 物理学 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: Taking into account the mixing effects between left- and right-handed top-squarks, we calculate the genuine supersymmetric eletroweak correction to top quark pro- duction at the Tevatron in the minimal supersymmetric model. The analytic ex- pressions of the corrections to both the parton level cross section and the total hadronic cross section are presented. Some numerical examples are also given to show the size of the corrections.
分类: 物理学 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We attempt to explain the recent ATLAS 3σ excess of dilepton events with an invariant mass near Z peak through the gluino-mediated sbottom production in a simplified scenario inspired by the minimal supersymmetric Standard Model. The additional Z bosons c