Inclusive cross sections for pairs of identified light charged hadrons and for single protons in $e^{+}{e}^{-}$ at $\sqrt{s}=$ 10.58 GeV

Abstract

We report the first double differential cross sections of two charged pions and kaons ($e^{+}{e}^{-}\to hhX$) in electron-positron annihilation as a function of the fractional energies of the two hadrons for any charge and hadron combination. The dependence of these di-hadron cross sections on the topology (same, opposite-hemisphere or anywhere) is also studied with the help of the event shape variable thrust and its axis. The ratios of these di-hadron cross sections for different charges and hadron combinations directly shed light on the contributing fragmentation functions. For example, we find that the ratio of same-sign pion pairs over opposite-sign pion pairs drops toward higher fractional energies where disfavored fragmentation is expected to be suppressed. These di-hadron results are obtained from a $655{\mathrm{fb}}^{-1}$ data sample collected near the $\hat{I}\yen (4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. Extending the previously published single-pion and single-kaon cross sections, single-proton ($e^{+}{e}^{-}\to pX$) cross sections are extracted from a $159{\mathrm{fb}}^{-1}$ data sub-sample.

submitted to PRD