Impact of pixel size and shape on physics analyses

The choice of the pixel shape and size in the r - ϕ and z-directions results in different position resolutions, that in turn, influence the impact parameter resolution. A study based on a Monte Carlo simulation is presented to quantify the effect of the impact parameter resolution on the search for new physics using the rare decay B s 0 → μ + μ − . The presented study illustrates the performance of this search for different resolution scenarios. For an optimal result, it is found that the transversal and longitudinal impact parameter resolution must be balanced.