Interplay of \(\mathbf {R_{D^{(*)}}}\) and \(\mathbf {Z\ell \ell }\) in the Scalar Leptoquark Scenario

  • Monika Blanke
  • Marta MoscatiEmail author
  • Ulrich Nierste
Conference paper
Part of the Springer Proceedings in Physics book series (SPPHY, volume 234)


The deviations of the experimental values of \(R_{D^{(*)}}\) from the Standard Model predictions hint at the presence of new physics in the B sector, and the existence of a scalar SU(2)-singlet leptoquark with hypercharge \(-1/3\) has often been considered as explanation of this tension. The particle modifies the coupling of the charged leptons to the Z boson, and comparison with data from electroweak precision experiments severely constrains its parameter space. We evaluate the contribution of such a leptoquark to the charged leptons Z couplings including corrections of order \(\mathscr {O}(M_Z^2/m_t^2)\) and electroweak renormalisation effects.



M.M. acknowledges the support by the DFG-funded Doctoral School KSETA.


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Authors and Affiliations

  1. 1.Institut für KernphysikKarlsruhe Institute of TechnologyEggenstein-LeopoldshafenGermany
  2. 2.Institut für Theoretische TeilchenphysikKarlsruhe Institute of TechnologyKarlsruheGermany

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