Invariant-mass and fractional-energy dependence of inclusive production of dihadrons in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation at $\sqrt{s}=10.58\text{ }\text{ }\mathrm{GeV}$

Invariant-mass and fractional-energy dependence of inclusive production of dihadrons in $e^{+} e^{-}$ annihilation at $\sqrt{s} = 10.58 GeV$

R. Seidl et al. (Belle Collaboration)

Phys. Rev. D 96, 032005 – Published 31 August 2017

Abstract

The inclusive cross sections for dihadrons of charged pions and kaons ( $e^{+} e^{-} \to h h X$ ) 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 spin-dependent 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 $ϒ (4 S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+} e^{-}$ collider.