# Minutes: Taskforce Meeting on CERN Testbeam Data (Mar. 1st, 2023)
## Time: 14:00 → 15:30 (GMT+8)
## [indico page](https://indico.ihep.ac.cn/event/19044/)
## Participants (18)
* IHEP: (Baohua), Hengyu, Yuzhi, Xin, Yong
* SJTU: Francois, Siyuan, Zhen, Zixun, Jiyuan, Zhiyu
* USTC: Hongbin, Jianbei, Jiaxuan, Yukun
* Tokyo: Ryonosuke, Tatsuki
* Shinshu: Tohru
(Chair and minutes by Yong)
## Talks and discussions
### Talk: Pedestal Correction, by Jiaxuan Wang
* Existing issue in pedestal data
* Small peak
* Multiple peaks
* Method
* Correction of pedetals using the Event Time information (a coarse counter in raw data)
* Pedestal shift to a higher value, due to a long acquisition time window without real events <- spill structure at SPS
* Results
* Small pedestal peaks can be removed by rejecting first events with HitTag==0
* Multiple peaks
* ADC-TDC: no correlation
* ADC_HG vs. ADC_LG : correlated
* To be further investigated
* Status
* Pedestal and HG-LG calibrations done
* Action items
* MIP calibration
* Pedestal correction and stability studies
### Discussion: AHCAL data processing, by Francois
* Status
* During data decoding, generated lists (.txt) for bad channel ID (>9) for all runs -> Those files were already shared to Zhongtao and Yunlong
* Will create an updated data structure to store the channel ID: two digits, instead of 1 digit
* Action item
* Will reprocess all the data samples to investigate the channel ID issues
### Slides: comparison between MC and Data, prepared by Baohua, presented by Yong
* Data samples
* Latest pion data decoded and calibrated by Yukun
* MIP and HG-LG calibrations done for each channel
* Simulation
* Assuming the same MIP response for each channel
* Digitisations implemented
* Photon statstics, SiPM non-linearity, ADC saturation
* Results
* Energy sum for all hits above threshold (0.3 MIP in MC)
* Discrepancies in low energy region (10 - 50 GeV)
* Showed different MC/data tendencies
* Previous pion data samples (10 GeV only) by Yukun: showed generally lower energy sum than MC
* Latest pion data samples (10-90 GeV) by Yukun: showed higher energy sum than MC
* MC: unchanged
* Discussions
* Possibly pion data contaminated with positrons? -> To be verified
* Action items
* Need to compare muon data/MC for the MIP calibration
* Compare raw ADC distributions
* Need to implement mappings from data of pedestal, MIP and HG-LG calibration for each channel into MC
* -> Calibration files from Zhen Wang, Peng Hu and Zixun -> input to MC