B-decay discrepancies after Moriond 2019
B-decay discrepancies after Moriond 2019
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DOI：
10.1140/epjc/s10052-020-7817-x
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发表时间：
2020-03-19
影响因子：
4.4
通讯作者：
Straub, David M.
中科院分区：
文献类型：
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作者：
Aebischer, Jason;Altmannshofer, Wolfgang;Straub, David M.
在对B中的轻子味普适性（LFU）比RK进行更新测量之后。K衰变的LHCb，以及一些进一步的测量，例如RK* 由贝儿和Bs。利用ATLAS软件，分析了新物理学在B的地位。s跃迁在弱有效理论在b夸克尺度，在标准模型有效理论以上的电弱尺度，并在简化模型的新物理。我们发现，数据继续强烈倾向于新的物理在半轻子威尔逊系数的解决方案。一个纯粹的μ子贡献的组合C9 = -C10，非常适合紫外线完全的解释，现在有利于相对于μ子贡献的C9只。通过允许C9中的额外LFU移位来获得甚至更好的拟合。这样的转变可以从电弱标度以上的四费米子算子，特别是从半Tauonic算子，能够解释B的潜在差异引起的重整化群。C转换。这种情况在简化的U1轻夸克模型中很自然地实现了。我们还分析了简化模型中的LFU效应在B。s的辐射诱导从四夸克运营商，并表明，这样的设置是在排斥的边缘，由大型强子对撞机双喷共振搜索。
Following the updated measurement of the lepton flavour universality (LFU) ratio RK in B. K decays by LHCb, as well as a number of further measurements, e.g. RK* by Belle and Bs. mu mu by ATLAS, we analyse the global status of new physics in b. s transitions in the weak effective theory at the b-quark scale, in the Standard Model effective theory above the electroweak scale, and in simplified models of new physics. We find that the data continues to strongly prefer a solution with new physics in semileptonic Wilson coefficients. A purely muonic contribution to the combination C9 = -C10, well suited to UV-complete interpretations, is now favoured with respect to a muonic contribution to C9 only. An even better fit is obtained by allowing an additional LFU shift in C9. Such a shift can be renormalization-group induced from four-fermion operators above the electroweak scale, in particular from semi-tauonic operators, able to account for the potential discrepancies in b. c transitions. This scenario is naturally realized in the simplified U1 leptoquark model. We also analyse simplified modelswhere a LFU effect in b. s is induced radiatively from four-quark operators and show that such a setup is on the brink of exclusion by LHC di-jet resonance searches.