Approaches to inclusive semileptonic $B_{(s)}$-meson decays from Lattice QCD

Abstract

We address the nonperturbative calculation of the inclusive decay rate of semileptonic $B_{(s)}$-meson decays from lattice QCD. Precise Standard-Model predictions are key ingredients in searches for new physics, and this type of computation may eventually provide new insight into the long-standing tension between the inclusive and exclusive determinations of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements $|V_{cb}|$ and $|V_{ub}|$. We present results from a pilot lattice computation for $B_s\to X_{c}l{\nu }_l$, where the initial $b$ quark described by the relativistic-heavy-quark (RHQ) formalism on the lattice and the other valence quarks discretised with domain-wall fermions are simulated approximately at their physical quark masses. We compare two different methods for computing the decay rate from lattice data of Euclidean $n$-point functions, namely Chebyshev and Backus-Gilbert approaches. We further study how much the ground-state meson dominates the inclusive decay rate and indicate our strategy towards a computation with a more comprehensive systematic error budget.

43 pages, 18 figures. Add missing references, fix typos

References in corpus (9)

• The Kernel Polynomial Method
• FLAG Review 2021
• $B\to \pi \ell \nu$ and $B_s\to K\ell \nu$ form factors and $|V_{ub}|$ from 2+1-flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks
• From deep inelastic scattering to heavy-flavor semi-leptonic decays: Total rates into multi-hadron final states from lattice QCD
• On the extraction of spectral densities from lattice correlators
• Relativistic Heavy Quark Effective Action
• Inclusive semi-leptonic decays from lattice QCD
• Non-perturbatively Determined Relativistic Heavy Quark Action
• Improved lattice fermion action for heavy quarks

Cited by in corpus (6)

• FLAG Review 2024
• $B\to D^{\ast }\ell {\nu }_{\ell }$ semileptonic form factors from lattice QCD with Möbius domain-wall quarks
• Long distance contributions to neutral $D$-meson mixing from lattice QCD
• Inclusive semileptonic $B_s^0$ meson decays at the LHC via a sum-of-exclusive modes technique: possibilities and prospects
• Nevanlinna-Pick interpolation from uncertain data
• On magnitudes of some CKM matrix elements