Journal of High Energy Physics
We study the production of polarized A-hyperons in electron-positron annihilation. We are particularly interested in the transverse-spin dependence of the cross section for unpolarized incident electron-positron pairs. At high energies this process may be described in the collinear twist-3 framework, where the hadronization transition of partons into a transversely polarized -hyperon can be written in terms of collinear twist-3 fragmentation matrix elements. We calculate the hard partonic cross sections and interference terms in perturbative QCD to next-to-leading order accuracy. We find that the QCD equation of motion plays a crucial role in our analysis. As a byproduct, assuming the validity of QCD factorization for twist-3 observables at next-to-leading order, we derive the evolution equation for the relevant twist-3 fragmentation matrix element.
Original Publication Citation
Gamberg, L., Kang, Z. B., Pitonyak, D., Schlegel, M., & Yoshida, S. (2019). Polarized hyperon production in single-inclusive electron-positron annihilation at next-to-leading order. Journal of High Energy Physics, 2019(1), 111. doi:10.1007/jhep01(2019)111
Gamberg, Leonard; Kang, Zhong-Bo; Pitonyak, Daniel; Schlegel, Marc; and Yoshida, Shinsuke, "Polarized Hyperon Production in Single-Inclusive Electron Positron Annihilation at Next-To-Leading Order" (2019). Physics Faculty Publications. 350.