News from ITS GPU seeding vertexer (Gabriele)

• Found that ATLAS uses a Gaussian Seeding vertexer with a grid approach to find the maximum of the vertex function
• --> Motivates to continue into this direction
• Implemented CPU version
• Algorithm uses tracks made from the first three layers
• Uses Taylor expansion on innermost cluster to generalize to a line
• Creates a grid around the beampipe to look for the maximum of the vertex function
• Need to adjust resolution
• Need to test with MC data accuracy of vertex function
• If quality for PVs reconstruction is good, need to think a way to select the positions
• Also if evaluate all the grid or only around the pairs