Selection of the D+ −→ K−K+K+ candidates at the LHCb experiment

The selection of D+ −→ K−K+K+ candidates is performed using a multivariate analysis. The study is based on a sample of pp-collision data, collected at a centre-of-mass energy of 13 TeV with the LHCb detector in 2016. Different multivariate classifiers are considered and their signal-background discrimination performance is evaluated. The signal significance is investigated and its optimization is examined for each classifier. The result is a final selection of D+ −→ K−K+K+ candidates useful for a further analysis, e.g, CP violation and amplitude analysis studies.