Calculating Dihadron Fragmentation Functions in the NJL-jet model

Abstract

The NJL-jet model provides a framework for calculating fragmentation functions without the introduction of ad hoc parameters. We develop the NJL-jet model to investigate dihadron fragmentation functions (DFFs) of the form $D_q^{h_1{h}_2}(z_1,z_2)$. Here we studied DFFs for $q\to \{\ddot{I}{€}^{+}\ddot{I}{€}^{-}\}$, $\{\ddot{I}{€}^{+}{K}^{-}\}$, and $\{K^{+}{K}^{-}\}$,with $q=u,d,s$. The driving terms, which represent the probability of one of the hadrons being emitted in the first emission step of the quark-jet hadronization picture, dominate the solutions of the DFFs where either $z_1$ or $z_2$ is large, and $z_1$ ($z_2$) is the light-cone momentum fraction of the emitted hadron, $h_1$ ($h_2$). The higher order terms, which represent the probability of neither of the hadrons being emitted in the first emission step of the quark-jet, become more significant as $z_1$ ($z_2$) is lowered. Finally, we present a sample result for QCD evolution of DFFs, that significantly modify the model solutions when evolved to typical hadronic scale of $4{\mathrm{GeV}}^2$.

11 pages, 9 figures, v2: updated to correspond to published version in Phys.Rev.D