Reduce IFT sprucing bandwidth for 2025
A bandwidth test was performed using SMOG2 pp+pAr data filtered with an HLT1 configuration used towards the end of 2024 data-taking (to simulate 2025 conditions). The SMOG2 bandwidth was found to have increased substantially, so several measures were introduced to reduce the bandwidth for 2025, while also accommodating a few requested changes for physics analyses.
The following changes were made:
- Charm builders now only use particles associated to SMOG2 vertex (pvinsmog=True). Since the pion/kaon/proton containers are persisted in the SMOG2 charm sprucing lines for femtoscopy/B-hadron studies, the size of the containers (and therefore the bandwidth) is reduced by only saving particles originating from SMOG2 collisions.
- Persisted protons in the charm lines are required to pass the "tight" PID selection instead of "loose".
- The BPVIPCHI2 cut is removed in the persisted p/K/pi containers for femtoscopy studies
- The PID cut is tightened in the DY lines from -5 to -3. The DY SS line is also prescaled 0.5 (previously it was not prescaled at all).
- Persistreco is removed from the SMOG2 Xi and Omega lines. Instead only VeloTracks and LongTracks are persisted.
Current bandwidth = 0.04 GB/s. Note that this is only for pp+pAr, so when we inject any lighter gases (H, He, Ne) the bandwidth will be lower.
Edited by Kara Mattioli