  We propose the formulation of a dihadron fragmentation function in terms of
parton matrix elements. Under the collinear factorization approximation and
facilitated by the cut-vertex technique, the two hadron inclusive cross section
at leading order (LO) in e+ e- annihilation is shown to factorize into a short
distance parton cross section and the long distance dihadron fragmentation
function. We also derive the DGLAP evolution equation of this function at
leading log. The evolution equation for the non-singlet and singlet quark
fragmentation function and the gluon fragmentation function are solved
numerically with the initial condition taken from event generators.
Modifications to the dihadron fragmentation function from higher twist
corrections in DIS off nuclei are computed. Results are presented for cases of
physical interest.
