Lepton Universality Violation by Kaluza-Klein Neutrinos in $b\to s l l$ transition

Janus Aban^1*, Chuan-Ren Chen¹, Chrisna Setyo Nugroho¹

¹Physics, National Taiwan Normal University, Taipei, Taiwan

* Presenter:Janus Aban, email:janus.aban@gmail.com

LHCb at CERN has further strengthened the deviation of the latest measurement of $R_K$ involving $b\to s l^+ l^-$ transition from the Standard Model prediction. According to the updated global analysis, the best fit indicates that the muon specific Wilson coefficients $C^{bs\mu \mu}_9=-C^{bs\mu \mu}_{10}$ should be about $-0.41$. In this study, we demonstrate how the anomaly can be explained by the cumulative effects of the KK modes of a singlet Dirac neutrino propagating in the large extra-dimensional space. If there are two additional spatial dimensions and the muon Yukawa coupling is assumed to be around $5$, the fundamental scale in the extra-dimensional framework should be reduced to $20$ TeV.

Keywords: B-anomaly, extra dimensions, Kaluza-Klein neutrinos