Orbital momentum effects due to a liquid nature of transient state

It is argued that directed flow $v_1$, the observable introduced for description of nucleus collisions, can be used for the detection of the nature of state of the matter in the transient state of hadron and nuclei collisions. We consider a possible origin of the directed flow in hadronic reactions as a result of rotation of the transient matter and trace analogy with nucleus collisions. Our proposal it that the presence of directed flow can serve as a signal that transient matter is in a liquid state.