@Article{Celis_etal2017, author="Celis, A. and Jung, M. and Li, X. Q. and Pich, A.", title="Scalar contributions to b -> c(u) tau nu transitions", journal="Physics Letters B", year="2017", publisher="Elsevier Science Bv", volume="771", pages="168--179", abstract="We perform a comprehensive analysis of scalar contributions in b -> c tau nu transitions including the latest measurements of R(D-(*)), the q(2) differential distributions in B -> D-(*) tau nu the tau polarization asymmetry for B -> D*tau nu, and the bound derived from the total width of the B-c meson. We find that scalar contributions with the simultaneous presence of both left- and right-handed couplings to quarks can explain the available data, specifically R(D-(*)) together with the measured differential distributions. However, the constraints from the total B-c width present a slight tension with the current data on B -> D*tau nu in this scenario, preferring smaller values for R(D*). We discuss possibilities to disentangle scalar new physics from other new-physics scenarios like the presence of only a left-handed vector current, via additional observables in B -> D(*)tau nu decays or additional decay modes like the baryonic Lambda(b) -> Lambda(c)tau nu and the inclusive B -> X-c tau nu decays. We also analyze scalar contributions in b -> u tau nu transitions, including the latest measurements of B -> tau nu providing predictions for Lambda(b) -> p tau nu and B -> pi tau nu decays. The potential complementarity between the b -> u and b -> c sectors is finally investigated once assumptions about the flavour structure of the underlying theory are made.", optnote="WOS:000406183300024", optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=3260), last updated on Mon, 11 Sep 2017 12:48:30 +0000", issn="0370-2693", doi="10.1016/j.physletb.2017.05.037", opturl="http://arxiv.org/abs/1612.07757", opturl="https://doi.org/10.1016/j.physletb.2017.05.037", archivePrefix="arXiv", eprint="1612.07757", language="English" }