The Standard Model (SM) of particle physics, comprised of the unified electro-weak (EW) and Quantum Chromodynamic (QCD) theories, accurately explains almost all experimental results related to the micro-world, and has made a number of predictions for previously unseen particles, most notably the Higgs scalar boson, that were subsequently discovered. As a result, the SM is currently universally accepted as the theory of the fundamental particles and their interactions. However, in spite of its numerous successes, the SM has a number of apparent shortcomings including: many free parameters that must be supplied by experimental measurements; no mechanism to produce the dominance of matter over antimatter in the universe; and no explanations for gravity, the dark matter in the universe, neutrino masses, the number of particle generations, etc. Because of these shortcomings, there is considerable incentive to search for evidence for new, non-SM physics phenomena that might provide important clues about what a new, beyond the SM theory (BSM) might look like. Although the center-of-mass energies that BESIII can access are far below the energy frontier, searches for new, BSM physics are an important component of its research program. Here we describe ways that BESIII looks for signs of BSM physics by measuring rates for processes that the SM predicts to be forbidden or very rare, searching for non-SM particles such as dark photons, making precision tests of SM predictions, and looking for violations of the discrete symmetries $C$ and $CP$ in processes for which the SM-expectations are immeasurably small.
Searches for new physics beyond the Standard Model in hyperon sector
University of Chinese Academy of Sciences（中国科学院大学）；National Centre for Nuclear Research（国家核研究中心）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）
Comment on "Controlling the dynamical evolution of quantum coherence and quantum correlations in $e^{+} e^{-} \rightarrow Λ\barΛ$ processes at BESIII''
School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM)（粒子与加速器学院，基础科学研究所（IPM））
Exploring Nucleon Structure through Sub- and Near-threshold $ϕ$-Meson Photoproduction
Shanghai Jiao Tong University（上海交通大学）；Lanzhou University（兰州大学）；Shandong University of Technology（山东理工大学）；Zhengzhou University（郑州大学）；Tianjin University（天津大学）
Impact of Rare Decays $t \to \ell' νb \ell\ell$ and $t \to q q' b \ell\ell$ on Searches for Top-Associated Physics
对于顶夸克相关物理，如$t\bar t W$或$t\bar t H$，由于缺乏可重建的共振，需要仔细考虑预期的背景。我们证明，罕见的顶夸克衰变$t \to \ell' νb \ell\ell$和$t \to q q' b \ell\ell$，当一个软轻子没有被检测到，可以贡献一个不可忽略的背景，这样的搜索。LHC实验中的模拟通常不考虑这种衰变，因此这种搜索的背景可能被低估。
Colloquium: Hadron Production in Open-charm Meson Pair at $e^+e^-$ Collider
School of Physical Science and Technology, Lanzhou University（兰州大学物理科学与技术学院）；Lanzhou Center for Theoretical Physics, Key Laboratory of Theoretical Physics of Gansu Province, and Key Laboratory for Quantum Theory and Applications of MoE, Gansu Provincial Research Center for Basic Disciplines of Quantum Physics, Lanzhou University（兰州大学理论物理研究中心、甘肃省理论物理重点实验室、教育部量子理论与应用重点实验室、甘肃省量子物理基础学科省级研究中心）；School of Physics and Center of High Energy Physics, Peking University（北京大学物理学院高能物理中心）
Dalitz decays of vector heavy quarkonia into $χ_{QJ}(1P)$ in the Bethe-Salpeter approach
Hebei University（河北大学）；Hebei Vocational University of Industry and Technology（河北工业职业技术大学）；Harbin Institute of Technology（哈尔滨工业大学）；Northwestern Polytechnical University（西北工业大学）
