Long-Lived Particles at the Energy Frontier: The MATHUSLA Physics Case
David Curtin, Marco Drewes, Matthew McCullough, Patrick Meade, Rabindra N. Mohapatra, Jessie Shelton, Brian Shuve, Elena Accomando, Cristiano Alpigiani, Stefan … 展开作者
David Curtin, Marco Drewes, Matthew McCullough, Patrick Meade, Rabindra N. Mohapatra, Jessie Shelton, Brian Shuve, Elena Accomando, Cristiano Alpigiani, Stefan Antusch, Juan Carlos Arteaga-Velázquez, Brian Batell, Martin Bauer, Nikita Blinov, Karen Salomé Caballero-Mora, Jae Hyeok Chang, Eung Jin Chun, Raymond T. Co, Timothy Cohen, Peter Cox, Nathaniel Craig, Csaba Csáki, Yanou Cui, Francesco D'Eramo, Luigi Delle Rose, P. S. Bhupal Dev, Keith R. Dienes, Jeff A. Dror, Rouven Essig, Jared A. Evans, Jason L. Evans, Arturo Fernández Tellez, Oliver Fischer, Thomas Flacke, Anthony Fradette, Claudia Frugiuele, Elina Fuchs, Tony Gherghetta, Gian F. Giudice, Dmitry Gorbunov, Rick S. Gupta, Claudia Hagedorn, Lawrence J. Hall, Philip Harris, Juan Carlos Helo, Martin Hirsch, Yonit Hochberg, Anson Hook, Alejandro Ibarra, Seyda Ipek, Sunghoon Jung, Simon Knapen, Eric Kuflik, Zhen Liu, Salvator Lombardo, H. J. Lubatti, David McKeen, Emiliano Molinaro, Stefano Moretti, Natsumi Nagata, Matthias Neubert, Jose Miguel No, Emmanuel Olaiya, Gilad Perez, Michael E. Peskin, David Pinner, Maxim Pospelov, Matthew Reece, Dean J. Robinson, Mario Rodríguez Cahuantzi, Rinaldo Santonico, Matthias Schlaffer, Claire H. Shepherd-Themistocleous, Andrew Spray, Daniel Stolarski, Martin A. Subieta Vasquez, Raman Sundrum, Andrea Thamm, Brooks Thomas, Yuhsin Tsai, Brock Tweedie, Stephen M. West, Charles Young, Felix Yu, Bryan Zaldivar, Yongchao Zhang, Kathryn Zurek, José Zurita
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213 pages, 73 figures. Extended Section 2 to add more detailed discussion of LLP reconstruction and analysis, and background rejection. Updated comparison of MATHUSLA RH neutrino sensitivity to other experiments. Updated analysis of long-lived ALPs produced in weak-scale processes and decaying to jets. Various clarifications, fixed typos, and added references. Results and conclusions unchanged
We examine the theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of Standard Model (SM) extensions. LLPs are a common prediction of a wide range of theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). In most cases the LLP lifetime can be treated as a free parameter from the $μ$m scale up to the Big Bang Nucleosynthesis limit of $\sim 10^7$m. Neutral LLPs with lifetimes above $\sim$ 100m are particularly difficult to probe, as the sensitivity of the LHC main detectors is limited by challenging backgrounds, triggers, and small acceptances. MATHUSLA is a proposal for a minimally instrumented, large-volume surface detector near ATLAS or CMS. It would search for neutral LLPs produced in HL-LHC collisions by reconstructing displaced vertices (DVs) in a low-background environment, extending the sensitivity of the main detectors by orders of magnitude in the long-lifetime regime. In this white paper we study the LLP physics opportunities afforded by a MATHUSLA-like detector at the HL-LHC. We develop a model-independent approach to describe the sensitivity of MATHUSLA to BSM LLP signals, and compare it to DV and missing energy searches at ATLAS or CMS. We then explore the BSM motivations for LLPs in considerable detail, presenting a large number of new sensitivity studies. While our discussion is especially oriented towards the long-lifetime regime at MATHUSLA, this survey underlines the importance of a varied LLP search program at the LHC in general. By synthesizing these results into a general discussion of the top-down and bottom-up motivations for LLP searches, it is our aim to demonstrate the exceptional strength and breadth of the physics case for the construction of the MATHUSLA detector.
An Update to the Letter of Intent for MATHUSLA: Search for Long-Lived Particles at the HL-LHC
我们报告了HL-LHC拟议的MATHUSLA长寿命粒子（LLP）探测器设计的最新进展，更新了原始意向书（LoI）中的信息，见CDS：LHCC-I-031，arXiv：1811.00927。在LHC第5点确定了一个合适的位置，该位置比LoI中假设的更接近CMS相互作用点（IP）。衰变体积的高度从20 m增加到25 m。工程研究已经进行，以定位地下的大部分衰变体积，使探测器更接近IP。通过这些变化，100 m x 100 m探测器对于大c $τ$具有与LOI和其他研究中描述的200 m x 200 m探测器相同的物理范围。小c $τ$的性能由于接近IP而得到改善。探测器技术也在不断发展，同时保留了LOI中所述的电阻板室（RPC）中的条形传感器几何结构。本设计使用挤压闪烁体棒，使用波长偏移光纤和硅光电倍增器（SiPM）读出。操作将更简单，更强大，操作电压低得多，不使用温室气体。制造是简单的，应该会节省成本。由于2018年在ATLAS之上运行的MATHUSLA测试台进行了新的模拟研究和测量，对背景的理解也有了显著的进步。我们讨论了Mathusla合作的下一步，并确定了新成员可以做出特别重要贡献的领域。
Long-Lived Light Mediators from Higgs boson Decay at HL-LHC, FCC-hh and a Proposal of Dedicated LLP Detectors for FCC-hh
我们研究了SM希格斯玻色子玻色子衰变到标准模型粒子过程中长寿命介质粒子对的产生。我们计算预计的灵敏度，无论是模型独立和极小模型，使用μ介子光谱仪的CMS检测器在HL-LHC实验的ggF，VBF，和Vh生产模式的希格斯玻色子和各种衰变模式的介质粒子，随着专用探测器LLP搜索像CODEX-b和MATHUSLA。随后，我们研究了在100\，TeV对撞机实验中使用FCC-hh探测器对长寿命介质的改进，再次关注μ子光谱仪。我们提出了100\，TeV对撞机实验DELIGHT（\textbf{De} tector for \textbf{l} ong-1 \textbf{i} ved particles at high \textbf{gh} energy of 100\，\textbf{T} eV）专用LLP探测器的设计，并研究了它们的灵敏度.
