Cern’s Large Hadron Collider (LHC) has reopened following a three-year technical shutdown. The famous research facility’s expert scientists ran the powerful accelerator at the end of April, and Run 3 physics began in early July. The entire process was carried out at the highest level of energy ever achieved in an accelerator.
LHC experiments are designed to collect so much data about nature at the smallest level that it is measured in petabytes. While thousands of collaborators work on the Standard Model of particle physics and are always looking for new physics – things like supersymmetry, dark matter or even new undiscovered particles – CERN researchers prepare the next iteration of the LHC.
Preparing for even more energy
The LHC will operate as the High-Luminosity LHC in the late 2020s, an upgraded version of the original accelerator. The upgraded accelerator will collide more protons than ever before with greater luminosity (the magnifying of a particle beam’s energy, similar to using a magnifying glass to focus the sun’s rays and start a fire). Scientists anticipate five to seven times more collisions than before the upgrades. The equipment used to detect luminosity is also being improved. Scientists are working to improve detectors so that they can handle the increased luminosity. The detectors are operational now and will reach a data factor 20 times greater than it is today by the end of 2030.
The Compact Muon Solenoid (CMS) is the LHC’s general-purpose detector. Several systems are being upgraded as part of the CMS and Atlas experiments. A massive effort is being made by laboratories all over the world, including universities and even the US Department of Energy. To update the detectors, everyone is involved. With all of this information, CMS researchers will be able to more accurately measure & reconstruct how particles interact with detector. More knowledge of the interactions between particles and detectors may lead to new insights and even discoveries about how universe works.
The detector upgrades
CMS tracking is the graphical rendering process that tracks how a particle moves through a magnetic field. The internal pixel detector and an external stripe detector are completely replaced. The tracker is the part of the CMS detector closest to where the LHC’s proton particles collide, at the heart of the detector. The main reason updates are needed in this innermost area is that the HL-LHC will collide with the protons much more quickly and the protons’ paths will quickly run into each-other and pile up.
The pixel detector is one of the detector’s most recent additions. The granularity of the pixel detector is finer. As a result, the rates and granularity must be higher. This is due to faster particle paths, and the increased granularity and rates will aid in the detection of individual particles. Otherwise, the particles pass through the detector so quickly that the resulting particle images are just smears.
There are several additional detector layers. Timing detectors are designed to provide precise times for particle motion along particle paths. CMS trigger and data acquisition selects the most potentially interesting collision events and records the corresponding data. To keep the massive amounts of imagery information manageable, it discards the more benign events.
There are calorimeters in the CMS. The endcap and barrel calorimeters are used to detect & measure the energy signatures of particles. The calorimeter enables accurate reproduction of the enormous quantities of produced particles thanks to its exceptional spatial & time resolution.
Information about muons is gathered, which is a crucial part of the CMS. The muons from the particle collision can travel a long distance, hence the name Compact Muon Solenoid, and this part of the detector sits out the calorimeters. Enhancements include improved timing & resolution to detect muons coming off the beam from a wider range of angles.
Collaborators have been researching all of these upgrades and enhancements for years. The process of adding them is now being carried out in stages, with the goal of completing it by late 2029.
