论文标题
打破王子中的grossman-nir束缚
Breaking the Grossman-Nir Bound in Kaon Decays
论文作者
论文摘要
Kaon分支的分支分数的比率$ \ MATHCAL {b}（k_l \toπ^0ν\barν）/\ Mathcal {b}（k^+\toπ^+bbarν）$基础相互作用将等音变化为$ΔI= 1/2 $。这被称为Grossman-Nir（GN）结合，它受标准模型（SM）以及除其以外的许多情况所尊重的。 Koto和NA62合作搜索这些KAON模式的最新初步结果似乎意味着违反了这一约束。 Koto的发现还表明，$ \ Mathcal {B}（K_l \TOπ^0ν\barν）$可能要比SM中预测的要大得多，将近两个数量级。在这项工作中，我们研究了仅使用SM字段违反有效的现场理论方法中的GN的可能性。我们表明，除了原始的GN场景外，界限还具有限制，无论Kaon是否腐烂节省了Lepton的数字。我们证明，$ΔI= 3/2 $运算符的包含可以导致违反GN结合的行为，并以一个新的物理量表的量表来违反GN结合，并说明了如何达到Koto数字的示例。
The ratio $\mathcal{B}(K_L\toπ^0ν\barν)/\mathcal{B}(K^+\toπ^+ν\barν)$ of the branching fractions of kaon decays $K_L\toπ^0ν\barν$ and $K^+\toπ^+ν\barν$ has a maximum of about 4.3 under the assumption that the underlying interactions change isospin by $ΔI=1/2$. This is referred to as the Grossman-Nir (GN) bound, which is respected by the standard model (SM) and by many scenarios beyond it. Recent preliminary results of the KOTO and NA62 Collaborations searching for these kaon modes seem to imply a violation of this bound. The KOTO findings also suggest that $\mathcal{B}(K_L\toπ^0ν\barν)$ could be much larger, by nearly two orders of magnitude, than that predicted in the SM. In this work we study the possibility of violating the GN bound in an effective field theory approach with only SM fields. We show that the bound holds, in addition to the original GN scenarios, whether or not the kaon decays conserve lepton number. We demonstrate that the inclusion of $ΔI=3/2$ operators can lead to a violation of the GN bound and illustrate with an example of how the KOTO numbers may be reached with a new physics scale of order tens of GeV.
