Updates on the determination of $\vert V_{cb} \vert$, $R(D^{*})$ and $\vert V_{ub} \vert/\vert V_{cb} \vert$ - Archive ouverte HAL
Article Dans Une Revue European Physical Journal C: Particles and Fields Année : 2024

Updates on the determination of $\vert V_{cb} \vert$, $R(D^{*})$ and $\vert V_{ub} \vert/\vert V_{cb} \vert$

G Martinelli
  • Fonction : Auteur
S Simula
  • Fonction : Auteur

Résumé

We present an updated determination of the values of $\vert V_{cb} \vert$, $R(D^*)$ and $\vert V_{ub} \vert/\vert V_{cb} \vert$ based on the new data on semileptonic $B \to D^* \ell\nu_\ell$ decays by the Belle Collaboration and on the recent theoretical progress in the calculation of the form factors relevant for semileptonic $B \to D^* \ell \nu_\ell$ and $B_s \to K \ell \nu_\ell$ decays. In particular we present results derived by applying either the Dispersive Matrix (DM) method of Refs. [1-6] or the more standard Boyd-Grinstein-Lebed (BGL) [7] approach to the most recent values of the form factors determined in lattice QCD. Using all the available lattice results for the form factors from the DM method we get the theoretical value $R^{\rm th}(D^*) = 0.266 \pm 0.009$ and we extract from a bin-per-bin analysis of the experimental data the value $\vert V_{cb} \vert = (40.56 \pm 0.50) \cdot10^{-3}$. Our result for $R(D^*)$ is compatible with the latest experimental world average $R^{\rm exp}(D^*) = 0.284 \pm 0.012$ [8] at the $\simeq 1.2\,\sigma$ level. Our value for $\vert V_{cb} \vert$ is consistent with the latest inclusive determinations $\vert V_{cb} \vert^{\rm incl} = (42.16\pm 0.50) \cdot 10^{-3}$ [9] and $\vert V_{cb} \vert^{\rm incl} = (41.69\pm 0.63) \cdot 10^{-3}$ [10] within $\simeq 2.3$ and $\simeq1.4$ standard deviations, respectively. From a reappraisal of the calculations of $\vert V_{ub} \vert / \vert V_{cb} \vert$, we also obtain $\vert V_{ub} \vert / \vert V_{cb} \vert = 0.087\pm 0.009$ in good agreement with the result $\vert V_{ub} \vert / \vert V_{cb} \vert = 0.0844\pm 0.0056$ from the latest FLAG review [11].

Dates et versions

hal-04239646 , version 1 (12-10-2023)

Identifiants

Citer

G Martinelli, S Simula, L Vittorio. Updates on the determination of $\vert V_{cb} \vert$, $R(D^{*})$ and $\vert V_{ub} \vert/\vert V_{cb} \vert$. European Physical Journal C: Particles and Fields, 2024, 84 (4), pp.400. ⟨10.1140/epjc/s10052-024-12742-5⟩. ⟨hal-04239646⟩
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