Absorption of particles in extended relativity

It is shown that if an emitter A can emit both tachyons and antitachyons, then a receiver A' moving at suitable subluminal speed with respect to A receives two identical tachyon beams from opposite directions. This result, coupled with a recent achievement of tachyon physics concerning a kinematical restriction on the absorption of superluminal particles by a reveiver, leads to an asymmetry in the interaction between tachyons and matter. Several implications of this result are discussed