Event characterization in (very) asymmetric collisions

TL;DR

This paper discusses potential biases in event geometry reconstruction in very asymmetric collisions, such as proton or deuteron plus nucleus, when using the Glauber-model, especially in the presence of hard scattering processes.

Contribution

It highlights limitations of the Glauber-model in asymmetric collisions and emphasizes the need for improved methods in event geometry reconstruction.

Findings

Glauber-model may be biased in asymmetric collisions with hard processes

Event geometry reconstruction accuracy decreases in p(d)+A collisions

Standard methods may not account for all asymmetries and hard scatterings

Abstract

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.