D^+ → K_s^0 π^+ η reaction and a_0(980)^+

We study the D^+ →K̅^0 π^+ η reaction where the a_0(980) excitation plays a dominant role. We consider mechanisms of external and internal emission at the quark level, hadronize the q q̅ components into two mesons and allow these mesons to undergo final state interaction where the a_0(980) state is generated. While the a_0(980) production is the dominant term, we also find other terms in the reaction that interfere with this production mode and, through interference with it, lead to a shape of the a_0(980) significantly different from the one observed in other experiments, with an apparently much larger width.