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

We report the first double differential cross sections of two charged pions and kaons (e+e−→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 655fb−1 data sample collected near the Υ(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−→pX) cross sections are extracted from a 159fb−1 data sub-sample.