%0 Journal Article
%T Study of new physics effects in (B)over-bars → Ds(*) τ-(ν)over-bar τ semileptonic decays using lattice QCD form factors and heavy quark effective theory
%A Penalva, N.
%A Flynn, J. M.
%A Hernandez, E.
%A Nieves, J.
%J Journal of High Energy Physics
%D 2024
%V 01
%N 1
%I Springer
%@ 1029-8479
%G English
%F Penalva_etal2024
%O WOS:001152794800001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5922), last updated on Sun, 11 Feb 2024 18:11:42 +0000
%X We benefit from the lattice QCD determination by the HPQCD of the Standard Model (SM) form factors for the (B) over bar (s) -> D-s [Phys. Rev. D101(2020) 074513] and the SM and tensor ones for the (B) over bar (s) -> D-s* (arXiv:2304.03137[hep-lat]) semileptonic decays, and the heavy quark effective theory (HQET) relations for the analogous B -> D-(*()) decays obtained by F.U. Bernlochner et al. in Phys. Rev. D95(2017) 115008, to extract the leading and sub-leading Isgur-Wise functions for the (B) over bar (s) -> D-s(()*()) decays. Further use of the HQET relations allows us to evaluate the corresponding scalar, pseudoscalar and tensor form factors needed for a phenomenological study of new physics (NP) effects on the (B) over bar (s) -> D-s(()*()) semileptonic decay. At present, the experimental values for the ratios R-D(*) = Gamma[ (B) over bar -> D-(*())(tau- (nu) over bar tau)]/Gamma[(B) over bar -> D-(*())e(-)(mu(-)) (nu) over bar (e(mu))]are the best signal in favor of lepton flavor universality violation (LFUV) seen in charged current (CC) b -> c decays. In this work we conduct a study of NP effects on the (B) over bar (s) -> D-s(()*()) tau(-)(tau) semileptonic decays by comparing tau spin, angular and spin-angular asymmetry distributions obtained within the SM and three different NP scenarios. As expected from SU(3) light-flavor symmetry, we get results close to the ones found in a similar analysis of the (B) over bar -> D-(*()) case. The measurement of the (B) over bar (s) -> D-s(()*())(l (nu) over bar tau) semileptonic decays, which is within reach of present experiments, could then be of relevance in helping to establish or rule out LFUV in CC b -> c transitions.
%K Effective Field Theories of QCD
%K Flavour Symmetries
%K Semi-Leptonic Decays
%K SMEFT
%R 10.1007/JHEP01(2024)163
%U https://arxiv.org/abs/2304.00250
%U https://doi.org/10.1007/JHEP01(2024)163
%P 163-33pp