Scalar contributions to b -> c(u) tau nu transitions

Celis, Alejandro; Jung, Martin; Li, Xin-Qiang und Pich, Antonio (2017): Scalar contributions to b -> c(u) tau nu transitions. In: Physics Letters B, Bd. 771: S. 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. (C) 2017 The Author(s). Published by Elsevier B.V.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0370-2693
• Sprache: Englisch