  We present calculation on the azimuthal spin asymmetries for pion pair
production in semi-inclusive deep inelastic scattering (SIDIS) process at both
HERMES and COMPASS kinematics, with transversely polarized proton, deuteron and
neutron targets. We calculate the asymmetry by adopting a set of
parametrization of the interference fragmentation functions and two different
models for the transversity. We find that the result for the proton target is
insensitive to the approaches of the transversity but more helpful to
understand the interference fragmentation functions. However, for the neutron
target, which can be obtained through using deuteron and {$^3$He} targets, we
find different predictions for different approaches to the transversity. Thus
probing the two pion interference fragmentation from the neutron can provide us
more interesting information on the transversity.

High Energy Physics - Phenomenology;High Energy Physics - Experiment