The high-granularity calorimeter (HGCAL) is a major upgrade of CMS, and is necessary to maintain excellent calorimetric performance in the endcaps during HL-LHC operations. HGCAL is one of the most ambitious detector projects undertaken, due to the…

The CMS Gas Electron Multiplier (GEM) subsystem will form an extra layer of detectors, along with the Cathode Strip Chambers (CSC) layers, closest to the beam. The GEM's ability to cope with a very high particle rate will greatly improve muon…

Managing the amount of data from the Large Hadron Collider (LHC) collisions is a major challenge for CMS physicists. The detector produces more than 500 terabytes of data per second. Even after sophisticated real-time processing and filtering of the…

After the LHC was shut down in December 2018 following the successful completion of RUN 2 operation, CMS is undergoing an intensive upgrade and maintenance program during the current two-year break (“Long Shutdown 2” or LS2) in order to ensure an…

During LS2, CMS will install 144 additional muon detector modules specially designed to detect particles produced in the very forward region.    For the CMS experiment, Long Shutdown 2 (LS2) is like very prolonged open heart surgery. The main goal…

In February, the CMS and MoEDAL collaborations at CERN signed an agreement to hand over to MoEDAL a section of the LHC beam pipe that was located inside CMS between 2008 and 2013. The delicate object, 6 metres long and made of beryllium, will now be…

Suppose that you need to see what is inside a small room that is difficult to access. Thick walls between you and the object of your investigation; you cannot dig, and the closest that you can get to the target is inside a narrow tunnel, with no…

The CMS detector is built from several different layers, surrounding the beam pipe in which the LHC beams collide. The subdetector that is closest to the collisions is the pixel detector. It has a functionality similar to a digital camera taking 40…

After the LHC was shut down at the end of 2018, one might think that physicists working in the large experiments can sit back and relax. On the contrary, CMS will undergo an intensive upgrade and maintenance program during the two-year long break in…

A successful four years of CMS detector operation came to an end last week and now we are beginning a new chapter. The next two-years of Long Shutdown (LS2) will mark an important transition for CMS. Against a background of the intensive 5-yearly…

We are nearing the end of the year and LHC started colliding another species of particles than protons: the nuclei of heavy atoms. These so-called “heavy-ion” collisions are used to study the properties of a particle soup known as the “quark-gluon…

When the Large Hadron Collider is in operation, the cavern containing the CMS detector is an extremely inhospitable place, due to the high-energy radiation produced by the collisions. Even after a LHC fill finishes, some residual radioactivity can…