Directed flow as a signal of a liquid state of transient matter

Abstract

Directed flow $v_1$, observable introduced for description of nucleus collisions is discussed. We consider a possible origin of the flow in hadronic reactions as a result of rotation of the transient matter and trace analogy with nucleus collisions. It is argued that the presence of directed flow can serve as a signal that transient matter is in a liquid state.

Comments: 15 pages, 6 figures, contribution to the NICA White Paper