Using the data samples collected in the energy range from 3.773 to 4.600 GeV with the BESIII detector at the BEPCII collider, we measure the dressed cross sections as a function of center-of-mass ...energy for e(+)e(-) -> K+K- pi(+)pi(-) (pi(0)), K+K-K+K- (pi(0)), pi(+)pi(-) pi(+)pi(-) (pi(0)), and p (p) over bar pi(+)pi(-)(pi(0)). The cross sections for e(+)e(-) -> K+K-K+K- pi(0), p (p) over bar pi(+)pi(-)(pi(0)) are the first measurements. Cross sections for the other five channels are much more precise than previous results in this energy region. We also search for charmonium and charmonium-like resonances, such as the Y(4230), decaying into the same final states. We find evidence of the psi(4040) decaying to pi(+)pi(-) pi(+)pi(-) pi(0) with a statistical significance of 3.6 sigma. Upper limits are provided for other decays since no clear signals are observed.
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Using a dataset of 6.32 fb −1 of e + e − annihilation data collected with the BESIII detector at center-of-mass energies between 4178 and 4226 MeV, we have measured the absolute branching fraction ...of the leptonic decay D + s →τ + ν τ via τ + →e + ν e ¯ν τ , and find BD + s→τ + ν τ = (5.27±0.10±0.12)×10 −2 , where the first uncertainty is statistical and the second is systematic. The precision is improved by a factor of 2 compared to the previous best measurement. Combining with fD + s from lattice quantum chromodynamics calculations or the |Vcs| from the CKMfitter group, we extract |V cs |=0.978±0.009±0.012 and fD + s = (251.1±2.4±3.0) MeV, respectively. Combining our result with the world averages of BD + s →τ + ν τ and BD + s →μ+νμ, we obtain the ratio of the branching fractions BD + s →τ+ν τ /BD + s →μ+νμ = 9.72±0.37, which is consistent with the standard model prediction of lepton flavor universality.
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