BELLE II

z-Vertex Track Trigger for Belle II

Project goals

The Belle II experiment in Tsukuba, Japan offers unique opportunities to study rare τ-decays, certain forms of dark photons, and physics beyond the standard model. For this purpose, electrons and their protons are accelerated to near-light velocities in the asymmetric SuperKEKB and collided around them in the Belle II detector. The resulting decay products are measured and recorded for later analysis. It is important to distinguish interesting new data from already known decays. To ensure this, a two-stage trigger system is installed to analyze all decays. The first stage consists of a pipelined dead-time FPGA system. The second stage is software based on mainframe computers.

ITIV participation

ITIV develops together with the Max Planck Institute for Physics FPGA based track triggers for the first trigger stage (L1). Neural networks are used to estimate the origin of the collision on the z-axis. The developed z-Vertex track trigger is the first neural network based trigger in L1 in a high energy physics experiment worldwide.