The first CMS week of 2025 took place during the first part of February, Monday 10th to Friday 14th. It was a rather busy week with a full agenda including a large number of plenary and parallel sessions. CMS is preparing the 2025 incoming data taking, but it is also analyzing both the large Run 2 data samples and the on-going Run 3. It was emphasized during the plenary sessions the need of increasing the number of people working on Run 3 analyses, which will be our larger data set for many years to come. In addition, as usual, a full afternoon was dedicated to the status of the Phase-II upgrade activities.
On Monday afternoon, during the opening plenary session, there was a talk about the CMS inputs to be provided to the European strategy for particle physics planning. Our projections on the measurements of longitudinally polarized W bosons were shown as one of the high-priority analyses to be performed with the large high-luminosity LHC data set.
On Thursday afternoon, during the plenary session on run coordination and TSG, there was a talk about DAQ activities during 2024 and towards 2025 data taking. There were a few slides dedicated to our storage manager work.
On Friday morning, during the second physics plenary session, our student Luca Lavezzo gave an excellent talk summarizing the status of the ongoing SUEP analyses we are working on.
There was a rather important discussion during the plenary offline, computing, and PPD session about the lack of tape space in CMS. We are producing a lot of different parallel data and simulation campaigns, and more importantly we have several data formats. Possible ideas were discussed, and the two main short-term solutions will be to make a new cleanup dataset campaign and more importantly to stop writing files in AODSIM format by default. Most physics analyses do not need AOD(SIM) format at this point, and therefore it makes sense to produce it upon request only.