Dear Colleagues,

 

As a follow-up to my analysis of FEE events which I presented at this morning’s analysis/recon meeting (https://confluence.slac.stanford.edu/pages/viewpage.action?pageId=341254335&preview=/341254335/341256282/20220322_CalibrationReconstruction_Graf_HPS_DAWG_Meeting.pdf) I have reconstructed the data that was taken using the SVT positioning wires as targets. The positions of these wires are known to much higher precision than that of the tungsten target, and using both positron and electron tracks in the data should reduce the systematics and improve the precision of the vertex measurement. I have posted a new set of slides summarizing the current state of this analysis to https://confluence.slac.stanford.edu/pages/viewpage.action?pageId=341254335&preview=/341254335/341257564/20220323_SVTWireTargetVertexAnalysis_Graf_HPS_Weekly_Meeting.pdf . There are a number of interesting features in the data but the most interesting feature for me is that the latest SVT geometry encapsulated in the HPS_Run2021Pass2FEE detector reconstructs the wire positions almost a centimeter downstream of their measured locations. I invite you to look at the slides and let me know if you have any questions or suggestions on how to improve this analysis.

 

Sincerely,

Norman