1. Timm M. Steinbeck - Kirchhoff Institute of Physics - University Heidelberg 1 Tag Database for HLT Micro-ESDs

2. Timm M. Steinbeck - Kirchhoff Institute of Physics - University Heidelberg 2 HLT Micro-ESDs ● At beginning of operation HLT should store summary Micro-ESDs of input events processed – Check operation of HLT selection algorithms ● HLT Micro-ESDs can include – Trigger data & Interaction point – Track parameters of each particle ● 5 helix parameters ● First & last space point ● Impact parameter ● Particle ID information – Secondary vertices – Optional debugging: Packed spacepoint residuals

3. Timm M. Steinbeck - Kirchhoff Institute of Physics - University Heidelberg 3 HLT Micro-ESDs Data Volume Maximum data rate produced by HLT Micro-ESDs ● (Estimates from HLT tracking) ● Maximum HLT output: 1.2 GB/s ● Output rate of 200 Hz (= HLT input rate) ● Production (w/o. spacepoint residuals): ● ≈ 2 % of input data stream ● ≈ 300 MB/s @ 200 Hz full central ● ≈ 25 % of output data stream ● Debug (w. spacepoint residuals): ● ≈ 7 % of input data stream ● ≈ 1100 MB/s @ 200 Hz full central ● ≈ 90 % of output data stream

4. Timm M. Steinbeck - Kirchhoff Institute of Physics - University Heidelberg 4 Uses of HLT Micro-ESDs ● Check/Debug HLT selection algorithms/rejection rate/compression modes ● Pre-analysed events – High statistics ● Full HLT Input Rate – Probably lower resolution ● Compared to full offline analysis ● Determined by HLT analysis algorithms – Immediately available ● Analysis can already start during operation ● Event tags usable for quick offline event selection for specific/priority analysis

5. Timm M. Steinbeck - Kirchhoff Institute of Physics - University Heidelberg 5 Storage of HLT Micro-ESDs Suggestion from Offline: ● Hand Micro-ESDs to AliRoot for storage – Integration w. Offline Data Analysis – Tags for full event data ● Questions: – Will this work over DDL? – DDL bypass required? ● Ethernet link to ???

6. Timm M. Steinbeck - Kirchhoff Institute of Physics - University Heidelberg 6 Room for Discussion Points/Remarks/Results: