Unknown size of higher-order HQE terms

Ascertain the size of the currently uncalculated higher-order terms in the heavy-quark expansion for inclusive semileptonic B→X_cℓν decays to enable disentangling potential quark–hadron duality–violating contributions from genuine higher-order HQE effects in global analyses.

Background

The authors propose incorporating their duality-violation model into global fits of kinematic moments. However, they emphasize that the lack of knowledge of higher-order HQE terms obstructs a clean separation of duality-violating effects from standard power corrections.

This uncertainty motivates constructing observables specifically designed to suppress lower-order HQE terms, thereby isolating sensitivity to higher orders and possible duality violations.

References

However, since we do not know the size of the higher-order terms of the HQE series, it may be hard to disentangle a small duality-violating effects from the unknown higher orders in $1/m_b$.

— Quark-Hadron Duality Violations and Higher-Order $1/m_b$ Corrections in Inclusive Semileptonic $B$ Decays  (2407.01473 - Mannel et al., 2024) in Section 6 (Quantifying Duality Violations from Data)

In addition, our analysis would benefit from including several higher-order corrections that are currently unknown:

— Inclusive $B$ decays, lifetimes, and $|V_{cb}|$: a unified heavy-quark expansion analysis  (2609.28752 - Fael et al., 23 Sep 2026) in Conclusion, final section

In addition, our analysis would benefit from including several higher-order corrections that are currently unknown:

— Inclusive $B$ decays, lifetimes, and $|V_{cb}|$: a unified heavy-quark expansion analysis  (2609.28752 - Fael et al., 23 Sep 2026) in Conclusion, final section

Perturbative corrections to these relations are not known.

— Inclusive $B$ decays, lifetimes, and $|V_{cb}|$: a unified heavy-quark expansion analysis  (2609.28752 - Fael et al., 23 Sep 2026) in Section 2, subsection “Semileptonic decay”