Forward Lambda Production and Nuclear Stopping Power in d + Au Collisions at sqrt(s_NN) = 200 GeV

TL;DR

This paper measures Lambda and Anti-Lambda particle yields in d + Au collisions at 200 GeV, analyzing baryon transport and nuclear stopping power at forward and backward rapidities, and compares results with various theoretical models.

Contribution

It provides new measurements of baryon production at forward and backward rapidities in d + Au collisions and evaluates different models' ability to describe baryon transport and particle yields.

Findings

Baryon transport on the deuteron side aligns with multiple collisions of deuteron nucleons.

Models with initial state nuclear effects better describe the data on the gold side.

The multichain model effectively reproduces net baryon density at RHIC energies.

Abstract

We report the measurement of Lamda and Anti-Lamda yields and inverse slope parameters in d + Au collisions at sqrt(s_NN) = 200 GeV at forward and backward rapidities (y = +- 2.75), using data from the STAR forward time projection chambers. The contributions of different processes to baryon transport and particle production are probed exploiting the inherent asymmetry of the d + Au system. Comparisons to model calculations show that the baryon transport on the deuteron side is consistent with multiple collisions of the deuteron nucleons with gold participants. On the gold side HIJING based models do not describe the measured particle yields while models with initial state nuclear effects and/or hadronic rescattering do. The multichain model can provide a good description of the net baryon density in d + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider, and the derived parameters of the model agree with those from nuclear collisions at lower energies.