Event characterization in (very) asymmetric collisions
  Event-by-event reconstruction of the collision geometry using some incarnation of the Glauber-model is a widely accepted method in studying heavy ion collisions. While there is no known problem with the procedure when applied to the collision of two large ions, we will argue that in very asymmetric collisions, like $p(d)$+A with at least one hard scattering process occuring the event geometry deduced with the simple Glauber-model may be biased. 
G. David
nucl-ex