Determination of pion and kaon fragmentation functions including spin asymmetries data in a global analysis

Abstract

We present a new functional form of pion and kaon fragmentation functions up to next-to-leading order obtained through a global fit to single-inclusive electron-positron annihilation data, and also employ the semi-inclusive deep inelastic scattering asymmetry data from HERMES and COMPASS to determine fragmentation functions. We also apply very recent electron-positron annihilation data from BABAR and Belle at $\sqrt{s}=10.54\text{ }\text{ }\mathrm{GeV}$ and $\sqrt{s}=10.52\text{ }\text{ }\mathrm{GeV}$, respectively. In this analysis we consider the impression of semi-inclusive deep inelastic scattering asymmetry data on the fragmentation functions, where the produced hadrons of different electric charge are identified. We break the symmetry assumption between the quark and antiquark fragmentation functions for favored partons by using the asymmetry data. The results of our analysis are in good agreement with electron-positron annihilation data and also with all the semi-inclusive deep inelastic scattering asymmetry data. We also apply the obtained fragmentation functions to predict the scaled-energy distribution of ${\ensuremath{\pi}}^{+}/{K}^{+}$ inclusively produced in top-quark decays at next-to-leading order using the zero-mass variable-flavor-number scheme, exploiting the universality and scaling violations of fragmentation functions.