Properties of robust vertex fitting algorithms at high luminosity HEP experiments

Robust vertex fitting algorithms are expected to improve the knowledge of the vertex position and of its uncertainty, in the presence of mis-measured or mis-associated tracks. Such contaminations are likely to happen in high luminosity HEP experiments. We have performed a simulation study of the sensitivity of two types of robust algorithms : a trimmed least-squares estimator and an adaptive estimator. Their statistical properties are studied as a function of the source and the level of contamination, and compared to the results obtained with classical least-squares estimators.