Andreev Yu M, Banerjee D, Banto Oberhauser B, Bernhard J, Bisio P, Charitonidis N, Crivelli P, Depero E, Dermenev A V, Donskov S V, Dusaev R R, Enik T, Frolov V N, Gardikiotis A, Gertsenberger S V, Girod S, Gninenko S N, Hösgen M, Joosten R, Kachanov V A, Kambar Y, Karneyeu A E, Kasianova E A, Kekelidze G, Ketzer B, Kirpichnikov D V, Kirsanov M M, Kolosov V N, Kramarenko V A, Kravchuk L V, Krasnikov N V, Kuleshov S V, Lyubovitskij V E, Lysan V, Matveev V A, Mena Fredes R, Mena Yanssen R G, Molina Bueno L, Mongillo M, Peshekhonov D V, Polyakov V A, Radics B, Salamatin K M, Samoylenko V D, Shchukin D A, Soto O, Sieber H, Tikhomirov V O, Tlisova I V, Toropin A N, Tuzi M, Veit M B, Volkov P V, Volkov V Yu, Voronchikhin I V, Zamora-Saá J, Zhevlakov A S
Authors affiliated with an institute covered by a cooperation agreement with CERN.
CERN, European Organization for Nuclear Research, CH-1211 Geneva, Switzerland.
Phys Rev Lett. 2024 May 24;132(21):211803. doi: 10.1103/PhysRevLett.132.211803.
We report the first search for dark sectors performed at the NA64 experiment employing a high energy muon beam and a missing energy-momentum technique. Muons from the M2 beamline at the CERN Super Proton Synchrotron with a momentum of 160 GeV/c are directed to an active target. The signal signature consists of a single scattered muon with momentum <80 GeV/c in the final state, accompanied by missing energy, i.e., no detectable activity in the downstream calorimeters. For a total dataset of (1.98±0.02)×10^{10} muons on target, no event is observed in the expected signal region. This allows us to set new limits on the remaining (m_{Z^{'}},g_{Z^{'}}) parameter space of a new Z^{'} (L_{μ}-L_{τ}) vector boson which could explain the muon (g-2)_{μ} anomaly. Additionally, our study excludes part of the parameter space suggested by the thermal dark matter relic abundance. Our results pave the way to explore dark sectors and light dark matter with muon beams in a unique and complementary way to other experiments.
我们报告了在NA64实验中首次利用高能μ子束和缺失能量-动量技术对暗物质领域进行的搜索。来自欧洲核子研究组织（CERN）超级质子同步加速器M2束线、动量为160 GeV/c的μ子被导向一个有源靶。信号特征包括末态中一个动量<80 GeV/c的单个散射μ子，伴有缺失能量，即下游量能器中无可探测的活动。对于靶上总数据集为(1.98±0.02)×10^{10}个μ子的情况，在预期信号区域未观察到任何事件。这使我们能够对新的Z'（L_{μ}-L_{τ}）矢量玻色子的剩余（m_{Z^{'}},g_{Z^{'}}）参数空间设定新的限制，该矢量玻色子可能解释μ子的（g-2）_{μ}反常现象。此外，我们的研究排除了热暗物质遗迹丰度所暗示的部分参数空间。我们的结果为以独特且与其他实验互补的方式利用μ子束探索暗物质领域和轻暗物质铺平了道路。
