• DOI:10.1103/PhysRevLett.115.181801
• Corpus ID: 119273141

Effective field theory approach to $b\to s\ell\ell^{(\prime)}$, $B\to K^{(*)}\nu\bar{\nu}$ and $B\to D^{(*)}\tau\nu$ with third generation couplings

@article{Calibbi2015EffectiveFT,
  title={Effective field theory approach to \$b\to s\ell\ell^\{(\prime)\}\$, \$B\to K^\{(*)\}\nu\bar\{\nu\}\$ and \$B\to D^\{(*)\}\tau\nu\$ with third generation couplings},
  author={Lorenzo Calibbi and Andreas Crivellin and Toshihiko Ota},
  journal={Physical Review Letters},
  year={2015},
  volume={115},
  pages={181801}
}

• L. Calibbi, A. Crivellin, T. Ota
• Published 8 June 2015
• Physics
• Physical Review Letters

LHCb reported anomalies in $B\to K^* \mu^+\mu^-$, $B_s\to\phi\mu^+\mu^-$ and $R(K)=B\to K \mu^+\mu^-/B\to K e^+e^-$. Furthermore, BaBar, BELLE and LHCb found hints for the violation of lepton flavour universality violation in $R(D^{(*)})=B\to D^{(*)}\tau\nu/B\to D^{(*)}\ell\nu$. In this note we reexamine these decays and their correlations to $B\to K^{(*)}\nu\bar{\nu}$ using gauge invariant dim-6 operators. For the numerical analysis we focus on scenarios in which new physics couples, in the interaction eigenbasis, to third generation quarks and lepton only. We conclude that such a setup can explain the $b\to s\mu^+\mu^-$ data simultaneously with $R(D^{(*)})$ for small mixing angles in the lepton sector (of the order of $\pi/16$) and very small mixing angles in the quark sector (smaller than $V_{cb}$). In these region of parameter space $B\to K^{(*)}\tau\mu$ and $B_s\to \tau\mu$ can be order $10^{-6}$. Possible UV completions are briefly discussed.