Speaker
Description
Reliable track reconstruction is vital for Belle II, especially as detector conditions evolve. The full tracking chain in the Belle II Analysis Software Framework (basf2) combines CDC-seeded and SVD-seeded tracking stages, which are merged and cleaned to produce final tracks. We focus on optimising the SVD-seeded CKF extension into the CDC, where SVD-only tracks are extrapolated to attach CDC hits. This step is sensitive to CDC inefficiencies caused by ageing electronics and inactive wires. A grid search is used to tune key CKF hyperparameters—such as allowed layer skips—using an F1 score built from hit efficiency and hit purity as the optimisation objective. The resulting parameter set, which yields the highest F1 score, is integrated into the full tracking chain, thereby improving tracking robustness and performance under degraded detector conditions.
