Ponten A, Sieber H, Oberhauser B Banto, Crivelli P, Kirpichnikov D, Gninenko S N, Hösgen M, Bueno L Molina, Mongillo M, Zhevlakov A
Department of Physics and Astronomy, High Energy Physics, Uppsala University, Ångströmlaboratoriet, Lägerhyddsvägen 1, 752 37 Uppsala, Sweden.
Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zurich, Switzerland.
Eur Phys J C Part Fields. 2024;84(10):1035. doi: 10.1140/epjc/s10052-024-13421-1. Epub 2024 Oct 9.
In this study, we demonstrate the potential of the NA64 experiment at CERN SPS to search for New Physics processes involving transitions after the collision of 100 GeV electrons with target nuclei. A new Dark Sector leptonic portal in which a scalar boson could be produced in the lepton-flavor-changing bremsstrahlung-like reaction, , is used as benchmark process. In this work, we develop a realistic Monte Carlo simulation of the NA64 experimental setup implementing the differential and total production cross-section computed at exact tree-level and applying the Weiszäcker-Williams phase space approximation. Using this framework, we investigate the main background sources and calculate the expected sensitivity of the experiment. The results indicate that with minor setup optimization, NA64 can probe a large fraction of the available parameter space compatible with the muon anomaly and the Dark Matter relic predictions in the context of a new Dark Sector leptonic portal with EOT. This result paves the way to the exploration of lepton-flavour-changing transitions in NA64.
在本研究中，我们展示了欧洲核子研究组织（CERN）超级质子同步加速器（SPS）上的NA64实验在寻找涉及100 GeV电子与靶核碰撞后跃迁的新物理过程方面的潜力。一个新的暗物质区轻子门户，其中标量玻色子可以在类似轻子味改变轫致辐射的反应中产生， ，被用作基准过程。在这项工作中，我们针对NA64实验装置开展了一个实际的蒙特卡罗模拟，实现了在精确树图水平计算的微分和总产生截面，并应用了魏茨泽克 - 威廉姆斯相空间近似。利用这个框架，我们研究了主要的背景源，并计算了该实验的预期灵敏度。结果表明，通过进行微小的装置优化，在具有EOT的新暗物质区轻子门户背景下，NA64能够探测与μ子反常和暗物质遗迹预测兼容的很大一部分可用参数空间。这一结果为在NA64中探索轻子味改变跃迁铺平了道路。
