Probing and knocking with muons and new physics exploration

The PKMu (Probing and Knocking with Muons) project is an advanced and comprehensive research initiative aimed at exploring potential physics phenomena beyond the standard model through precision studies of muon scattering. The project utilizes high-resolution muon tracking detectors, including resistive plate chambers (RPCs) and other state-of-the-art instrumentation, to establish a dedicated experimental platform for investigating cosmic-ray muon interactions with various materials. Over a sustained 63-day direct detection campaign, extensive measurements were conducted, which were systematically compared with detailed cosmic-ray scattering simulations. This comparison allowed the project team to identify and quantify contributions from multiple cosmic-ray components to the observed scattering signals and to derive experimental constraints on the scattering cross sections between muons and low-velocity dark matter. These results provide the first direct experimental limits in this regime and significantly advance our understanding of possible interactions between cosmic-ray muons and hypothetical dark matter particles in the sub-GeV mass range.Beyond the direct search for dark matter, PKMu also investigates muon scattering processes relevant to hypothetical dark bosons and charged lepton flavor violation. By employing high-atomic-number target materials and carefully optimized muon–electron scattering configurations, extensive simulation studies demonstrate that the experimental setups possess unique sensitivity for probing previously inaccessible regions of parameter space. These studies indicate that the project can explore the sub-GeV mass region with unprecedented precision, offering potential insights into rare processes that are otherwise difficult to access in traditional high-energy physics experiments. In addition to particle searches, PKMu addresses fundamental quantum mechanical phenomena, including the investigation of entanglement and tests of Bell inequalities in muon–electron scattering. Simulation results suggest that these quantum effects could be observed under realistic experimental conditions at GeV-scale energies, providing a promising platform for precision tests of foundational principles of quantum mechanics in the context of particle physics experiments.Looking forward, PKMu plans to expand its studies to include both domestic and international high-intensity muon sources, enabling more comprehensive measurements and higher-statistics data collection. Such efforts are expected to improve sensitivity to rare scattering processes, facilitate detailed exploration of new physics scenarios, and allow systematic validation of simulation models against experimental observations. Overall, the PKMu research initiative integrates innovative experimental design, rigorous simulation studies, and direct measurement validation to construct a robust framework for studying novel muon interactions. By combining methodological innovation with thorough feasibility analysis, the project opens new possibilities for probing dark matter interactions, searching for dark-sector particles, investigating charged lepton flavor violation, and performing high-precision studies of quantum entanglement phenomena. The results achieved to date demonstrate the versatility and scientific potential of muon scattering as a tool for investigating physics beyond the standard model, while also laying a solid foundation for future high-precision experiments. In summary, PKMu not only proposes a new class of muon scattering experiments but also establishes a systematic, multi-faceted approach to advancing high-energy and fundamental particle physics, contributing to a deeper understanding of the interactions and underlying structure of matter and the universe.