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

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We report the first double differential cross sections of two charged pions and kaons ($e^+e^- \rightarrow hhX$) 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.