Machine-learning-based particle identification with missing data
Miłosz Kasak Kamil Deja Maja Karwowska Monika Jakubowska Łukasz Graczykowski Małgorzata Janik
In this work, we introduce a novel method for Particle Identification (PID)
within the scope of the ALICE experiment at the Large Hadron Collider at CERN.
Identifying products of ultrarelativisitc collisions delivered by the LHC is
one of the crucial objectives of ALICE. Typically employed PID methods rely on
hand-crafted selections, which compare experimental data to theoretical
simulations. To improve the performance of the baseline methods, novel
approaches use machine learning models that learn the proper assignment in a
classification task. However, because of the various detection techniques used
by different subdetectors, as well as the limited detector efficiency and
acceptance, produced particles do not always yield signals in all of the ALICE
components. This results in data with missing values. Machine learning
techniques cannot be trained with such examples, so a significant part of the
data is skipped during training. In this work, we propose the first method for
PID that can be trained with all of the available data examples, including
incomplete ones. Our approach improves the PID purity and efficiency of the
selected sample for all investigated particle species.