AI 中文总结
研究重中性轻子介导的t通道过程，以LHC的矢量玻色子散射通道为例，强调轻中微子作用，其纳入改变搜索现象学，转而探索轻子数守恒但味违反的末态，详细分析$pp\to e\mu jj$通道，扩展LHC对TeV尺度HNL的探测灵敏度。
AI 中文摘要
重中性轻子（HNL）介导的t通道过程为探索超出高能对撞机直接产生运动学范围的质量尺度提供了独特机会。我们以大型强子对撞机（LHC）的矢量玻色子散射通道$WW\to\ell\ell$为例重新审视这些过程，强调轻中微子在恢复散射振幅正确的高能幺正行为中的关键作用。之前一些研究忽略了轻中微子，其纳入会导致相消干涉，强烈抑制轻子数违反信号。这表明对跷跷板全谱的一致处理会定性改变t通道HNL搜索的现象学。因此我们转而探索轻子数守恒但轻子味违反的末态。我们对$pp\to e\mu jj$通道进行详细分析，表明它在低尺度跷跷板情形下对TeV尺度HNL是有前景的探测手段，扩展了LHC超出现有直接搜索的灵敏度。
英文摘要
Heavy Neutral Lepton (HNL)-mediated t-channel processes provide a unique opportunity to probe mass scales beyond the kinematic reach of direct production at high-energy colliders. We revisit these processes using the vector boson scattering channel $WW\to\ell\ell$ at the LHC as a case study, highlighting the essential role of the light neutrinos in restoring the proper high-energy unitary behavior of the scattering amplitude. Their inclusion, overlooked in some previous studies, leads to destructive interference that strongly suppresses lepton number violating signatures, demonstrating that a consistent treatment of the full seesaw spectrum qualitatively alters the phenomenology of t-channel HNL searches. This motivates the exploration of lepton number conserving but lepton flavor violating final states instead. We present a detailed analysis of the $pp\to eμjj$ channel and show that it provides a promising probe of TeV-scale HNLs in low-scale seesaw scenarios with sizable active-sterile mixing, extending the LHC sensitivity beyond existing direct searches.
Comments17 pages + bibliography, 6 figures
