论文标题
Belle II
Right-handed Dirac and Majorana neutrinos at Belle II
论文作者
论文摘要
我们评估了Belle II实验探测MEV至GEV质量范围的大量右中微子（RHN）$ n $的狄拉克或主要性质的能力。我们认为RHN的产生和衰减是通过用右手中微子场（SMNEFT）扩展的标准模型有效田间理论（SMEFT）所描述的新相互作用进行的，而不是通过与主动中微子混合的质量混合。我们发现，如果可以访问运动学，Belle II有可能发现$ n $。我们对Lepton对的角度分布进行了详细的模拟。我们表明，对于$ m_n $以上的100 meV，Belle II可以以大多数运营商的5 $σ$ Cl的多数区分Dirac和Majoraana Neutrinos，并且可以从随后的重型中微子的衰减中识别出生产和衰减运营商的组合。此外，如果$ b \ to d \ ell n $和$ b \ d^*\ ell n $事件可以很好地分开，则可以使用三体$ b $ meson衰减来识别生产运营商。
We assess the ability of the Belle II experiment to probe the Dirac or Majorana nature of a massive right-handed neutrino (RHN) $N$ in the MeV to GeV mass range. We consider the production and decay of RHNs to proceed via new interactions described by the standard model effective field theory (SMEFT) extended with right-handed neutrino fields (SMNEFT), and not via mass mixing with active neutrinos. We find that Belle II has the potential to discover $N$ if kinematically accessible. We perform detailed simulations of the angular distributions of lepton pairs from the decay of $N$ produced in two-body and three-body decays of $B$ mesons. We show that for $m_N$ above 100 MeV, Belle II can distinguish between Dirac and Majorana neutrinos at more than the 5$σ$ CL for most operators, and the combination of the production and decay operators can be identified from the subsequent decay of the heavy neutrino. Also, the production operators can be identified using three-body $B$ meson decay for any $m_N$ if the $B\to D\ell N$ and $B\to D^*\ell N$ events can be well separated.
