• Accepted Paper

First measurement of the Ds+→K*(892)0μ+νμ decay, study of dynamics and test of lepton universality with Ds+→K*(892)0ℓ+νℓ decays

M. Ablikim et al.

Phys. Rev. Lett. - Accepted 4 November, 2026

DOI: https://doi.org/10.1103/flqh-zxzr

Abstract

We report the first measurement of the semileptonic decay Ds+→K*(892)0μ+νμ and an improved measurement of the decay Ds+→K*(892)0e+νe using a sample of 7.33fb−1 of e+e− annihilation data collected at center-of-mass energies between 4.128 to 4.226~GeV with the BESIII detector at the BEPCII collider. We measure the branching fractions to be $\mathcal B({D^+_s\rightarrow K^*(892)^0 \mu^+\nu_{\mu}})=(2.07\pm0.22_{\rm stat}\pm0.10_{\rm syst})\times10^{-3}$ and $\mathcal B({D^+_s\rightarrow K^*(892)^0 e^+\nu_{e}})=(2.14\pm0.18_{\rm stat}\pm0.10_{\rm syst})\times10^{-3}$. Based on a simultaneous study of the dynamics in two semileptonic decays, the hadronic form factor parameters in the Ds+→K*(892)0 transition are determined to be $r_{V} = V(0)/A_1(0) = 1.63 \pm 0.14_{\rm stat} \pm 0.08_{\rm syst}$, $r_{2} = A_2(0)/A_1(0) = 0.60 \pm 0.13_{\rm stat} \pm 0.06_{\rm syst}$, and $A_1(0)=0.56 \pm 0.02_{\rm stat} \pm 0.01_{\rm syst}$, where V(0) is the vector form factor and A1,2(0) are the axial-vector form factors evaluated at q2=0. The precision of rV and r2 is improved by twofold and A1(0) is measured for the first time. We also report the first model-independent measurements of the differential decay rates and the lepton forward-backward asymmetries for Ds+→K*(892)0ℓ+νℓ decays. Based on these measurements, we perform a test of lepton flavor universality in full and separate q2 intervals with Ds+→K*(892)0ℓ+νℓ decays. No violation is found within uncertainties. Our results present for the first time a complete study of the dynamics in the Ds+→K*(892)0 transition, and provide stringent tests of various non-perturbative theoretical calculations.

Export citation

Export citation

Choose format for download:

Download Citation

If the author has provided any supplemental materials with this article they will be available upon publication of the version of record.

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation