The overall experimental position resolution provided by the SVT should be < 25 m for both transverse directions.
The fundamental requirement for a vertex detector is excellent position resolution. Silicon drift detectors have been developed with intrinsic position resolution of 10 m for both transverse directions. Position resolution determines the ultimate accuracy of secondary vertex finding, two-track resolution, momentum resolution, and efficiencies. Simulations have shown that a position resolution of 25 m is adequate for the SVT.
STAR has a large SDD Research and Development program that is producing prototype SDDs with such position resolution.