  Influence of Vertex Detector (VTX) geometry on jet flavour tagging
performance was studied in presence of e+e- pair background from beamstrahlung
in the International Linear Collider (ILC). Five layer "long-barrel" VTX
geometry with varying layer thickness, space resolution and radius of the first
layer was tested with fast simulation tools. Influence of VTX geometry and e+e-
pair background on measurement of SM and MSSM Higgs boson branching ratios was
also studied.
