The performances on data of the silicon standalone track finder based on the Sector Map concept developed for the Belle II vertex detector (VXD) will be presented.
The Belle II VXD is a combined tracking system composed by two layers of DEPFET pixel detectors married with four layers of double sided silicon strip sensors (SVD).
The VXD is recording e+ e- collisions occurring at the interaction points of SuperKEKB, the asymmetric e+ e- collider operating at Y(4S) mass peak. The track finder algorithm must operate in a very harsh environment characterized by very high occupancy stemming from beam background and it must be very efficient in finding very soft charged tracks (total momentum around 50 MeV/c) that are in the lowest range of the momentum spectrum of the B mesons decay products. To achieve this demanding goal a set of novel algorithms that are fully exploiting the excellent time and spatial resolution of the SVD had been developed and tuned. The experience gained so far on a sample of half an inverse femtobarn collected on 2018 with a section of the full VXD will be presented together with the very first results from the phase 3 run that will start on March 2019.