Plasma kinetic waves and alpha−proton differential flow are two important subjects on the topic of evolution of the solar wind. Based on the Wind data during 2005−2015, this paper reports that the occurrence of electromagnetic cyclotron waves (ECWs) near the proton cyclotron frequency significantly depends on the direction of alpha−proton differential flow V d . As V d rotates from anti-Sunward direction to Sunward direction, the occurrence rate of ECWs as well as the percentage of left-handed (LH) polarized ECWs decreases considerably. In particular, it is shown that the dominant polarization changes from LH polarization to right-handed polarization during the rotation. The investigation on proton and alpha particle parameters ordered by the direction of V d further illustrates that large kinetic energies of alpha−proton differential flow correspond to high occurrence rates of ECWs. These results are well consistent with theoretical predictions for effects of alpha−proton differential flow on proton temperature anisotropy instabilities.

Using 10.1 × 109J/ψ events produced by the Beijing Electron Positron Collider (BEPCII) at a center-of-mass energy $$ \sqrt{s} $$ s = 3.097 GeV and collected with the BESIII detector, we present a search for the rare semi-leptonic decay J/ψ → D−e+νe + c.c. No excess of signal above background is observed, and an upper limit on the branching fraction ℬ(J/ψ → D−e+νe + c. c.) < 7.1 × 10−8 is obtained at 90% confidence level. This is an improvement of more than two orders of magnitude over the previous best limit.

Using a data set corresponding to an integrated luminosity of 6.32 fb−1 recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, an amplitude analysis of the decay $$ {D}_s^{+} $$ D s + → π+π0π0 is performed, and the relative fractions and phases of different intermediate processes are determined. The absolute branching fraction of the decay $$ {D}_s^{+} $$ D s + → π+π0π0 is measured to be (0.50 ± 0.04stat ± 0.02syst)%. The absolute branching fraction of the intermediate process $$ {D}_s^{+} $$ D s + → f0(980)π+, f0(980) → π0π0 is determined to be (0.28 ± 0.04stat ± 0.04syst)%.