Unpolarized Dihadron Fragmentation Functions in Nonlocal Chiral Quark   Model
  We have calculated the unpolarized dihadron fragmentation functions (uDiFFs) of pions and kaons using the nonlocal chiral-quark model (NLChQM) and evolved our results to the transferred momentum scale Q$^2$=4$\mathrm{GeV}^2$ by the QCD evolution equations. These uDiFFs have also been computed in the Nambu--Jona-Lasinio-jet (NJL-jet) model for the sake of comparison. We find that there is substantial difference between the results of these two models. Furthermore, the DiFFs of $u\to \pi^{+}\pi^{-}$ and $g\to \pi^{+}\pi^{-}$ at $Q^2=109\,\mathrm{GeV}^2$ in these two models are presented in comparison with the parametrizations fitted by the Monte Carlo event generator JETSET. 
Dong-Jing Yang, Fu-Jiun Jiang, Chian-De Li, Chung-Wen Kao and Seung-il   Nam
hep-ph