Study of Drell-Yan pair production on nuclear targets

Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions 2016

Krelina, Michal^1 ; Goncalves, Victor P.^2,3 ; Nemchik, Jan^1,4 ; Pasechnik, Roman^3

Czech Technical University in Prague, FNSPE, Brehova 7, Prague

11519, Czech Republic^1

High and Medium Energy Group, Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Pelotas, RS

96010-900, Brazil^2

Department of Astronomy and Theoretical Physics, Lund University, Lund

SE-223 62, Sweden^3

Institute of Experimental Physics, SAS, Watsonova 47, Kosice

04001, Slovakia^4

关键词: Coherence effects;    Color transparency;    Feynman variables;    Initial state interaction;    Nuclear modification factors;    Nuclear shadowing;    Nuclear targets;    Quantum coherence effects;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/832/1/012017/pdf
DOI  :  10.1088/1742-6596/832/1/012017

来源: IOP

【 摘 要 】

Drell-Yan pair production off nuclei is an ideal tool to test the cold nuclear effects occurring before a hard collision since no interaction in the final state is expected, neither energy loss or absorption. We present for the first time a comprehensive study of the nucleus-to-nucleon production ratio (the nuclear modification factor) within the color dipole approach using the Green function formalism which naturally incorporates for the color transparency and quantum coherence effects. We study a different onset of nuclear shadowing in various kinematical regions. At large values of the Feynman variable xFand dilepton invariant mass M we include also a suppression factor due to restrictions caused by the energy conservation induced by multiple initial state interactions (ISI effects). We present a variety of predictions for the nuclear suppression as a function of xFand M that can be verified by experiments at RHIC and LHC. The mixing of coherence effects with ISI effects can be eliminated going to large values of the dilepton invariant mass. Then predictions for the nuclear suppression is a direct manifestation for the onset of net ISI effects that can be verified by the future measurements.