Resolve discrepancies among experimental determinations of the Ds+ decay constant

Resolve the discrepancy among different experimental determinations of the $D_s^+$-meson decay constant $f_{D_s^+}$ by achieving mutually consistent and more precise measurements.

Background

The paper identifies inconsistent experimental values of the Ds+D_s^+-meson decay constant, including earlier Belle and CLEO-c determinations and the more precise BESIII result. Because fDs+f_{D_s^+} is required for extracting the CKM matrix element ∣Vcs∣|V_{cs}| from leptonic decays, resolving this discrepancy is important for precision tests of the Standard Model and for comparisons with theoretical predictions.

References

These results indicate that the discrepancy among different experimental determinations of $f_{D_s+}$ remains unresolved, underscoring the need for further improvements in both experimental techniques and theoretical calculations.

— Characterize the properties of $D_s^+$-meson decay constant and leptonic decays by using QCD sum rules within background field theory framework  (2608.17483 - Chen et al., 18 Aug 2026) in Introduction