Leptoquark manoeuvres in the dark: a simultaneous solution of the dark matter problem and the $R_{D^{(*)}}$ anomalies

Understand

The measured branching fractions of $B$-mesons into leptonic final states derived by the LHCb collaboration hint towards the breakdown of lepton flavour universality.

• In this work we take at face value the so-called $R_{D^{(*)}}$ observables that are defined as the ratios of neutral $B$-meson charged-current decays into a charged $D$-meson, a charged lepton and a neutrino final state in the tau and muon channels.
• A well-studied and simple solution to this charged current anomaly is to introduce a scalar leptoquark $S_1$ that couples to the second and third generation of fermions.
• We investigate how $S_1$ can also serve as a mediator between the Standard Model and a dark sector.