On November 4th at 22:10 the last 2025 proton-proton run of the LHC came to a close. As can be seen on the picture below, the LHC in the first third of the data taking fell a little behind the expectations but in a furious effort in early Fall crossed the expected line and never looked back ending a year significantly beyond what was planned and with another record year for proton-proton in the books. The LHC delivered an integrated luminosity of up to 125.4 fb⁻¹ for ATLAS and CMS.
For CMS the run was quite successful, but the age of the detector is showing, in particular the pixel vertex detector and even more specifically the innermost layer which is starting to show its age. Radiation has started to lower its efficiency, which can be mitigated with new thresholds and other massaging but lowers data taking efficiency, requires lot of attention, and cannot entirely fix the issue.
For the remainder of the active LHC year the PPC is bracing for the year-end Lead-Ion run (Nov 15 – Dec 6), where traditionally the highest recording rates are seen. The tests with the Storage Manager and File Transfer System show that we are in good shape, the Lustre file system showing excellent read/write performance and minimal fragmentation, while the SSD alternative data path has been further expanded to allow for record high data taking rates.