Nuclear suppression of dileptons at forward rapidities

TL;DR

This paper analyzes nuclear suppression of dileptons at forward rapidities, proposing an effective energy loss model that aligns with experimental data and predicting effects at various kinematic regions for future experiments.

Contribution

It introduces an alternative interpretation of nuclear suppression as energy loss, distinct from coherence or Color Glass Condensate effects, with predictions for different kinematic regimes.

Findings

Good agreement with existing data on nuclear suppression.

Predictions for large-pT suppression at RHIC energies.

Forecasts for large-xF suppression in upcoming FNAL experiments.

Abstract

Data from E772 and E866 experiments on the Drell-Yan process exhibit a significant nuclear suppression at large Feynman xF. We show that a corresponding kinematic region does not allow to interpret this as a manifestation of coherence or a Color Glass Condensate. We demonstrate, however, that this suppression can be treated alternatively as an effective energy loss proportional to initial energy. To eliminate suppression coming from the coherence, we perform predictions for nuclear effects also at large dilepton masses. Our calculations are in a good agreement with available data. Since the kinematic limit can be also approached in transverse momenta pT, we present in the RHIC energy range corresponding predictions for expected large-pT suppression as well. Since a new experiment E906 planned at FNAL will provide us with more precise data soon, we present also predictions for expected large-xF nuclear suppression in this kinematic region.