Measurements of the branching fractions of semileptonic Ds+ decays via e+e- → Ds∗+ Ds∗-

We measure the absolute branching fractions of semileptonic Ds+ decays via the e+e-→Ds∗+Ds∗- process using e+e- collision data corresponding to an integrated luminosity of 10.64 fb-1 collected by the BESIII detector at center-of-mass energies between 4.237 and 4.699 GeV. The branching fractions are B(Ds+→ηe+νe)=(2.35±0.11stat±0.10syst)%, B(Ds+→η′e+νe)=(0.82±0.09stat±0.04syst)%, B(Ds+→φe+νe)=(2.21±0.16stat±0.11syst)%, B(Ds+→f0(980)e+νe,f0(980)→π+π-)=(0.15±0.02stat±0.01syst)%, B(Ds+→K0e+νe)=(0.24±0.04stat±0.01syst)%, and B(Ds+→K∗0e+νe)=(0.19±0.03stat±0.01syst)%. These results are consistent with those measured via the e+e-→Ds∗±Ds process by BESIII and CLEO. Using two-parameter series expansion, the hadronic transition form factors of Ds+→ηe+νe, Ds+→η′e+νe, and Ds+→K0e+νe are determined to be f+η(0)=0.442±0.022stat±0.017syst, f+η′(0)=0.557±0.062stat±0.024syst, and f+K0(0)=0.677±0.098stat±0.023syst.