CMS Bulletin

ELECTROMAGNETIC CALORIMETER (ECAL)

ECAL has been stably running with an up-time efficiency of 99.4% during Run 2012D, with about half of the inefficiency due to a single downtime episode. More than 99% of the collected data are certified good by ECAL for offline analysis. The monitoring system and calibration chain have also been working smoothly, with an excellent stability of the new laser source, after final tuning during the technical stop in September. Some drifts in the response upon monitoring corrections and some degradation in the resolution throughout Run 2012C and 2012D have been observed and will be corrected in the next reprocessing. Calibration constants for the full 2012 dataset –– derived with well-established procedures –– are going to be delivered by the end of the pp run. In parallel to this, studies of the performance evolution have been carried out to predict the longevity of ECAL towards HL-LHC. Radiation damage effects are studied from P5 data, particularly in the endcaps, and in dedicated test beams.

As in all human activities, some players are stepping down at the end of the year, and new players are going to replace them. Albeit thankful to the former for what they did, and to the latter for the promise to do, we do not list their names. Individuals are doomed to die, and must accept their fate. The ECAL of the braves and the visionaries stands!