  We predict the occurrence of Fano lineshapes in a semiconductor quantum wire
with local spin-orbit (Rashba) coupling. We show that the Rashba interaction
acts in a strictly one dimensional channel as an attractive impurity, leading
to the formation of purely bound states. In a quasi-one dimensional system
these bound states couple to the conduction ones through the Rashba
intersubband mixing, giving rise to pronounced dips in the linear conductance
plateaus. We give exact numerical results and propose an approximate model
capturing the main ingredients of the effect.
