$V_{cb}$ determination from inclusive $b\to c$ decays: an alternative method

Abstract

The determination of $V_{cb}$ relies on the Heavy-Quark Expansion and the extraction of the non-perturbative matrix elements from inclusive $b\to c$ decays. The proliferation of these matrix elements complicates their extraction at $1/m_b^4$ and higher, thereby limiting the $V_{cb}$ extraction. Reparametrization invariance links different operators in the Heavy-Quark expansion thus reducing the number of independent operators at $1/m_b^4$ to eight for the total rate. We show that this reduction also holds for spectral moments as long as they are defined by reparametrization invariant weight-functions. This is valid in particular for the leptonic invariant mass spectrum ($q^2$), i.e. the differential rate and its moments. Currently, $V_{cb}$ is determined by fitting the energy and hadronic mass moments, which do not manifest this parameter reduction and depend on the full set of 13 matrix elements up to $1/m_b^4$. In light of this, we propose an experimental analysis of the $q^2$ moments to open the possibility of a model-independent $V_{cb}$ extraction from semileptonic decays including the $1/m_b^4$ terms in a fully data-driven way.

arXiv comment16 pages, 2 figures. v2: version published in JHEP, references added plus minor changes

References in corpus (21)

• Reparameterisation Invariance Constraints on Heavy Particle Effective Field Theories
• Precision determination of the CKM element Vcb
• Taming the higher power corrections in semileptonic B decays
• Imprecated, yet Impeccable: On the Theoretical Evaluation of Gamma(B -> X_c \ell ν)
• Inclusive semileptonic fits, heavy quark masses, and V_cb
• Moments of semileptonic B decay distributions in the 1/m_b expansion
• Perturbative corrections to semileptonic b decay distributions
• Higher Order Power Corrections in Inclusive B Decays
• Poincare' invariance constraints on NRQCD and potential NRQCD
• Heavy-to-heavy quark decays at NNLO
• Determination of heavy quark non-perturbative parameters from spectral moments in semileptonic B decays
• Inclusive Semi-leptonic B Decays to order 1/m_b^4
• Lorentz invariance in heavy particle effective theories
• Perturbative corrections to power suppressed effects in semileptonic B decays
• Kinetic corrections to B -> X_c l nu at one loop
• B semileptonic moments at NNLO
• Reparametrization Invariance and Partial Re-Summations of the Heavy Quark Expansion
• Inclusive semileptonic B decays from QCD with NLO accuracy for power suppressed terms
• Improved Estimates for the Parameters of the Heavy Quark Expansion
• On HQET and NRQCD Operators of Dimension 8 and Above
• Reparametrization Invariance Constraints on Inclusive Decay Spectra and Masses

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• Lifetimes of singly charmed hadrons
• QCD corrections to inclusive heavy hadron weak decays at ${\Lambda }_{\mathrm{QCD}}^3/m_Q^3$
• NLO QCD Corrections to Inclusive $b\to c\ell \bar{\nu }$ Decay Spectra up to $1/m_Q^3$
• The Heavy Quark Expansion for Inclusive Semileptonic Charm Decays Revisited
• Determination of $|V_{cb}|$ using ${\overline{B}}^0\to D^{\ast +}{\ell }^{-}{\bar{\nu }}_{\ell }$ decays with Belle II
• NLO QCD corrections to inclusive semitauonic weak decays of heavy hadrons up to $1/m_b^3$
• Fingerprinting CP-violating New Physics with $B\to K{\mu }^{+}{\mu }^{-}$
• Perturbative corrections to power suppressed effects in $\bar{B}\to X_u\ell \nu$
• Inclusive Semileptonic $b\to c\ell \bar{\nu }$ Decays to Order $1/m_b^5$
• Impact of background effects on the inclusive $V_{cb}$ determination
• New physics contributions to moments of inclusive $b\to c$ semileptonic decays
• The forward-backward asymmetry and differences of partial moments in inclusive semileptonic B decays
• Master Integrals for Inclusive Weak Decays of Heavy Flavours at Next-to-Leading Order
• Charming Darwin: the evolution of QCD parameters across different species
• Inclusive semileptonic $B_s^0$ meson decays at the LHC via a sum-of-exclusive modes technique: possibilities and prospects
• Recent progress in decays of $b$ and $c$ hadrons
• Determination of the Strong Coupling Constant ${\alpha }_s$ from Inclusive Semi-leptonic $B$ Meson Decays
• Standard Model predictions for Lepton Flavour Universality ratios of inclusive semileptonic $B$ decays