Invariant-mass and fractional-energy dependence of inclusive production of dihadrons in e+e− annihilation at sqrt(s)=10.58 GeV

The inclusive cross sections for dihadrons of charged pions and kaons (e(+)e(-) -> hhX) in electron-positron annihilation are reported. They are obtained as a function of the total fractional energy and invariant mass for any di-hadron combination in the same hemisphere as defined by the thrust event-shape variable and its axis. Since same-hemisphere dihadrons can be assumed to originate predominantly from the same initial parton, di-hadron fragmentation functions are probed. These di-hadron fragmentation functions are needed as an unpolarized baseline in order to quantitatively understand related spindependent measurements in other processes and to apply them to the extraction of quark transversity distribution functions in the nucleon. The di-hadron cross sections are obtained from a 655 fb(-1) data sample collected at or near the Y (4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.