Ridge and Transverse Correlation without Long-Range Longitudinal Correlation

Abstract

A simple phenomenological relationship between the ridge distribution in Δ and the single-particle distribution in can be established from the PHOBOS data on both distributions. The implication points to the possibility that it is not necessary to have long-range longitudinal correlation to explain the data. An interpretation of the relationship is then developed, based on the recognition that longitudinal uncertainty of the initial configuration allows for non-Hubble-like expansion at early time. It is shown that the main features of the ridge structure can be explained in a model where transverse correlation stimulated by semihard partons is the principal mechanism. This work is related to the azimuthal anisotropy generated by minijets in Au-Au collisions at 0.2 TeV on the one hand and to the ridge structure seen in collisions at 7 TeV on the other hand.

What Can We Learn from (Pseudo)Rapidity Distribution in High Energy Collisions?

“…A lot of models were introduced in the past several decades. Different phenomenological mechanisms including initial interactions, intermediate processes, and final-state statistical laws have been proposed [14][15][16][17][18][19]. In a workshop held a few years ago at the CERN Theory Institute [20], many models reported their predictions for the heavy ion program at the LHC based on the explanations of the experimental results at the RHIC.…”