Non-linear centre of gravity on LHCb Vertex Locator test beam data

Cluster position reconstruction for the LHCb Vertex Locator test beam software currently uses a linear centre of gravity algorithm. To investigate possible improvements of this approach, a study was performed that made use of a non-linear centre-of-gravity algorithm. All of the sensors in this study were Timepix chips with a 300 μ m layer of p-on-n silicon. The position resolutions obtained with the linear centre-of-gravity ranged between 5.5 μ m and 6.1 μ m. Applying the tuned non-linear algorithm reduces these by at least 0.6 μ m.