Quark Matter 2018

First Unambiguous Measurements of Partonic Energy Loss in Cold Nuclear Matter at E906/SeaQuest

May 15, 2018, 5:00 PM

2h 40m

First floor and third floor (Palazzo del Casinò)

Poster Initial state physics and approach to equilibrium Poster Session

Speaker

Alexander Bernard Wickes (Los Alamos National Laboratory (US))

Description

Initial state partonic energy loss is an important benchmark of the nuclear medium properties in fixed target and heavy ion collision experiments, yet remains imprecisely determined up to now. The E906/SeaQuest experiment at Fermilab primarily measures Drell-Yan and J/psi production for p+A collisions with fixed targets H, D, C, Fe, and W. The experiment provides an ideal configuration for making unambiguous energy loss measurements based on the nuclear modification $R_{pA}$. The low energy 120 GeV proton beam from the Fermilab Main Injector amplifies the suppression, while the spectrometer's acceptance of high-$x_2$ (target $x > 0.1$) Drell-Yan events minimizes shadowing and final state effects, resulting in enhanced precision for the determination of radiation length $X_0$ and stopping power $-dE/dx$. We will present results from the Drell-Yan energy loss analysis and compare with previous experiments.