R_D^(*) and survival of the fittest scalar leptoquark

Motivated by the long-standing discrepancy in lepton flavor universality ratios R_D and R_D^∗ we assess the status of scalar leptoquark states R_2, R_2 and S_1 which can in principle provide a desired enhancement of ℬ(B→ D^(∗ )τν) in a minimal setup with two Yukawa couplings only. We consider unavoidable low-energy constraints, Z-pole measurements as well as high-p_T constraints. After setting mass of each leptoquark to 1.5 TeV we find that of all considered states only S_1 leptoquark, coupled to both chiralities of leptons and quarks, is still a completely viable solution while the scenario with R_2 is in growing tension with Γ(Z →ττ) and with the LHC constraints on the di-tau tails at high-p_T. We comment on the future experimental tests of S_1 scenario.