Energy Loss Approximations and Small Systems [Hybrid RBRC Seminar]

by William A. Horowitz (University of Cape Town)

Thursday 20 Jun 2024, 12:30 → 13:30 US/Eastern

2-160 ( https://bnl.zoomgov.com/j/1619458475?pwd=Z1VDdXVXcWF1eUhsRDZObVJnME4rUT09)

Abstract:

We make quantitative nuclear modification factor predictions for small and large systems at RHIC and the LHC from an energy loss model which receives small system size corrections to both the radiative and elastic energy loss. We find nontrivial predicted suppression for light-flavor hadrons in central d + Au collisions both light and heavy-flavor hadrons in central p + Pb collisions. The suppression predicted in central d + Au collisions is consistent with data from RHIC, while the suppression predicted at lower momenta in central p + Pb collisions is in tension with the lack of suppression measured at the LHC.

We systematically check the consistency of the assumptions used in the radiative energy loss derivation - such as collinearity, softness, and large formation time - with the final numerical model. While collinearity and softness are self-consistently satisfied in the final numerics, we find that the large formation time approximation breaks down at modest to high momenta pT≳30 GeV. We find that both the size of the small pathlength correction to RAA(pT) and the pT at which the large formation time assumption breaks down are acutely sensitive to the chosen distribution of scattering centers in the plasma.