Narrow Results

This contribution summarizes recent results from the RHIC spin program and the measurement of light quark fragmentation functions at Belle.

The clean environment of the e⁺e^- collisions provided by the B-factory PEP-II and the high performances of the BABAR detector allow for precise measurements of the properties of inclusive hadron production. We present recent results obtained using the full data sample of nearly 500 fb^-1 on measurements of the inclusive light hadrons momentum spectra, and on anti-deuteron production from decays of bottomonium states, and from continuum e⁺e^- annihilation. We also present a measurement of the azimuthal asymmetries induced by the Collins effect in inclusive production of pion pairs in e⁺e^- → ππX annihilation, where the two pions are produced in opposite hemispheres.

We present the preliminary results of the measurement of the azimuthal asymmetries of two charged pions in the inclusive process $e^{+}{e}^{-}\to \pi \pi X$ in the BESIII experiment. These asymmetries are attributed to the so-called Collins fragmentation function, which depict the behavior of a hadron produced from a transversely polarized quark. This spin-dependent function is an important input for the global analysis of extracting the transversity inside the nucleon. In addition, by comparison with the measured asymmetries at Belle, this measurement provides the first data to explore the $Q^2$ evolution of the spin-dependent fragmentation function. This work is performed based on about 62${\mathrm{\text{pb}}}^{-1}$ data collected with the BESIII detector at BEPCII at $\sqrt{s}$=3.65GeV.