000000494 001__ 494
000000494 005__ 20170313121555.0
000000494 037__ $$aBELLE2-CONF-PROC-2017-004
000000494 041__ $$aeng
000000494 100__ $$aSoohyung Lee
000000494 245__ $$aDevelopment of High Level Trigger Software for Belle II at SuperKEKB
000000494 260__ $$a$$c2010-10-18
000000494 300__ $$a7
000000494 500__ $$aDate of Documetn is uncertain
000000494 520__ $$aThe Belle collaboration has been trying for 10 years to reveal the mystery of the current matter-dominated universe. However, much more statistics is required to search for New Physics through quantum loops in decays of B mesons. In order to increase the experimental sensitivity, the next generation B-factory, SuperKEKB, is planned. The design luminosity of SuperKEKB is 8 × 1035cm−2s−1 a factor 40 above KEKB’s peak luminosity. At this high luminosity, the level 1 trigger of the Belle II experiment will stream events of 300 kB size at a 30 kHz rate. To reduce the data flow to a manageable level, a high-level trigger (HLT) is needed, which will be implemented using the full offline reconstruction on a large scale PC farm. There, physics level event selection is performed, reducing the event rate by ∼ 10 to a few kHz. To execute the reconstruction the HLT uses the offline event processing framework basf2, which has parallel processing capabilities used for multi-core processing and PC clusters. The event data handling in the HLT is totally object oriented utilizing ROOT I/O with a new method of object passing over the UNIX socket connection. Also under consideration is the use of the HLT output as well to reduce the pixel detector event size by only saving hits associated with a track, resulting in an additional data reduction of ∼ 100 for the pixel detector. In this contribution, the design and implementation of the Belle II HLT are presented together with a report of preliminary testing results.
000000494 6531_ $$aTrigger
000000494 8560_ $$fkooktae.kim@desy.de
000000494 8564_ $$uhttps://docs.belle2.org/record/494/files/BELLE2-CONF-PROC-2017-004.pdf