Optimization of Techniques for Λ Hyperon Measurement at MPD/NICA

Abstract

Obtaining quality physics results requires high-statistics data with low background contamination. The task of maximizing the signal as well as accurate estimation of combinatorial background is especially important at the start-up of the experiment when the amount of data is rather limited. The Multi-Purpose Detector (MPD) experiment at the NICA collider will have to deal with such issues in its first run. In this article, the task of reconstructing lambda hyperons with their weak decay into a proton and a negative pion using Monte Carlo simulated event samples of heavy-ion collisions is considered. Two approaches for evaluating the combinatorial background in the invariant mass spectra of decay products are studied: like-sign pair combinations and event mixing. Background-subtracted and efficiency-corrected hyperon distributions are presented, demonstrating performance of the MPD experiment in the future collider run.