发表机构
Washington University; Johannes Gutenberg-Universität Mainz; Texas A&M University; University of Michigan; University of Pittsburgh（华盛顿大学; 美因茨约翰内斯古腾堡大学; 德克萨斯农工大学; 密歇根大学; 匹兹堡大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究表明μ子轫致辐射为加速器中微子实验的轻新物理提供新机制，以与重中性轻子耦合的亲μ子标量为基准，发现短基线实验可借此探测特定参数空间的HNLs，扩展了加速器中微子实验对暗物质领域粒子的发现潜力。
AI 中文摘要
我们表明，μ子轫致辐射为加速器中微子实验中的轻新物理提供了一种新的产生机制。介子衰变中与中微子束一起产生的强烈、高度准直的μ子束，在撞击这些设施的束流卸料器时，为新物理的轫致辐射产生提供了强大来源。作为一个基准场景我们考虑一个与重中性轻子（HNLs）耦合的亲μ子标量，并表明μ子轫致辐射能够产生质量超出介子衰变运动学范围的HNLs。利用这种新的产生机制并专注于HNL与τ中微子的混合，我们发现正在进行的（即将进行的）短基线实验，如SBND（DUNE近探测器），可以通过它们在探测器中衰变成π介子、μ⁺μ⁻和e⁺e⁻末态，探测以前未探索的HNL质量高达\(\mathcal{O}(1) GeV\)的参数空间。产生的信号表现出独特的运动学，允许有效地与中微子诱导的标准模型背景区分开来。我们的结果表明，μ子轫致辐射机制大大扩展了加速器中微子实验对HNLs和其他暗物质领域粒子的发现潜力。
英文摘要
We show that muon bremsstrahlung provides a new production mechanism for light new physics at accelerator neutrino experiments beyond the meson kinematic limit. The intense, highly collimated muon beam produced alongside the neutrino beam in meson decays provides a powerful source for the bremsstrahlung production of new physics when it impinges on the beam dump at these facilities. As a benchmark scenario, we consider a muonphilic scalar coupled to Heavy Neutral Leptons (HNLs) and show that muon bremsstrahlung enables the production of HNLs with masses beyond the kinematic reach of meson decays. Using this new production mechanism and focusing on HNL mixing with tau neutrinos, we find that the upcoming neutrino experiments, such as the DUNE Near Detector, can probe previously unexplored parameter space for HNL masses up to $\mathcal{O}(1)~\mathrm{GeV}$ through their decay into pions, $μ^+μ^-$, and $e^+e^-$ final states at the detector. The resulting signals exhibit distinctive kinematics, allowing efficient discrimination from neutrino-induced Standard Model backgrounds. Our results demonstrate that the muon bremsstrahlung mechanism substantially extends the discovery potential of accelerator neutrino experiments for HNLs and other dark sector particles.
Comments10 pages, 6 figures
