论文标题
逃避grossman-nir限制$ΔI= 3/2 $新物理
Evading the Grossman-Nir bound with $ΔI=3/2$ new physics
论文作者
论文摘要
稀有的kaon因缺少能量而腐烂，$ k \toπ$+$ e _ {\ rm siss} $，因为可以在标准模型（SM）中准确地计算出它们的速率，其中未发现的中微子 - 抗抗乙酸抗抗乙酸抗抗酸对将缺失的能量带走。除了SM之外，还可以对这些过程做出干净的理论预测。一个这样的预测是所谓的grossman-nir（GN）绑定，它指出，$ k_l $和$ k^+$模式的分支分数必须满足关系$ \ mathcal {b}（k_l \toπ^0 $+$ e _ { MISS}）\ LISSSIM4.3 \，\ MATHCAL {B}（k^+\toπ^+$+$ e _ {\ rm miss}）$，只要HADRONIC TRANSITIONS将ISOSPIN变化Isospin by $δi= 1/2 $。在本文中，我们将这些模式的研究扩展到包括新的物理场景，其中缺失的能量是由于未观察到的Lepton-number-violation中微子对，看不见的新标量表或这类标量对。假定新的相互作用出现在电子量表之上，并通过有效的田间理论描述。我们探讨了通过$ΔI违反GN的可能性= 3/2 $在这些情况下对$ k \toπ$转换的贡献，并发现只有在缺失的能量是由于隐形的轻型新标量引起的情况下，才有可能进行大违规。
Rare kaon decays with missing energy, $K\toπ$+$E_{\rm miss}$, have received considerable attention because their rates can be calculated quite precisely within the standard model (SM), where the missing energy is carried away by an undetected neutrino-antineutrino pair. Beyond the SM, clean theoretical predictions can also be made regarding these processes. One such prediction is the so-called Grossman-Nir (GN) bound, which states that the branching fractions of the $K_L$ and $K^+$ modes must satisfy the relation $\mathcal{B}(K_L\toπ^0$+$E_{\rm miss})\lesssim4.3\,\mathcal{B}(K^+\toπ^+$+$E_{\rm miss})$ and applies within and beyond the SM, as long as the hadronic transitions change isospin by $ΔI=1/2$. In this paper we extend the study of these modes to include new-physics scenarios where the missing energy is due to unobserved lepton-number-violating neutrino pairs, invisible light new scalars, or pairs of such scalars. The new interactions are assumed to arise above the electroweak scale and described by an effective field theory. We explore the possibility of violating the GN bound through $ΔI=3/2$ contributions to the $K\toπ$ transitions within these scenarios and find that large violations are only possible in the case where the missing energy is due to an invisible light new scalar.
