2023/04/01 by Neus Penalva, J. M. Flynn, Penalva, Neus +5
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2304.00250
openalex publication_date 2023/04/01 · openalex created_date 2023/04/06 · openalex updated_date 2026/07/28
We benefit from the lattice QCD determination by the HPQCD of the Standard Model (SM) form factors for the Bs→ Ds [Phys. Rev. D 101, 074513 (2020)] and the SM and tensor ones for the Bs→ Ds* (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. D 95, 115008 (2017), to extract the leading and sub-leading Isgur-Wise functions for the Bs→ Ds(*) 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 Bs→ Ds(*) semileptonic decay. At present, the experimental values for the ratios \cal RD(*)=Γ[ B→ D(*)τ-ντ]/Γ[ B→ D(*)e-(μ-)νe(μ)] 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 Bs→ Ds(*)τ-ντ 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→ D(*) case. The measurement of the Bs→ Ds(*)ℓν_ℓ 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.