Purdue-Built Detector Completes Its Mission at CERN

Purdue University built key parts of the 124-million-pixel detector that has tracked particles at the heart of CERN’s Compact Muon Solenoid (CMS) experiment since its installation in 2017. Purdue assembled close to 1000 silicon sensor modules in the Physics and Astronomy’s clean room facilities for the forward tracking systems, alongside the University of Nebraska-Lincoln, with final assembly at Fermilab. Now, after nearly a decade of service at the Large Hadron Collider (LHC), Purdue researchers are helping retire the detector and build its newly designed successor. The removal of the pixel detector marks an early milestone of Long Shutdown 3, when CERN’s accelerator and experiments are being upgraded for the High-Luminosity LHC (HL-LHC). The HL-LHC operations are set to restart in 2030, aiming to collect approximately 10x more data than collected so far.

Across its first three running periods, the LHC has delivered more than 500 inverse femtobarns (fb⁻¹) of proton-proton collisions to each of CMS and ATLAS. The resulting datasets will sustain years of physics analyses during LS3, while the detectors are upgraded for the 2030 restart.

This dataset allows the Purdue HEP group to study details of the Higgs bosons, electroweak interactions and searches for new particles. The capabilities of the silicon tracking devices are crucial for identifying bottom quarks, reconstructing top-quark decays, measuring Higgs-boson processes, and performing precision electroweak measurements. In other words, the detector hardware deep inside CMS ultimately underpins physics analyses spanning much of Purdue’s particle physics program.

In the next decade, the High-Luminosity LHC will deliver far larger datasets, allowing physicists to search even more precisely for extremely rare signals that may still be hiding beyond today’s reach.

Here is a link to the Purdue news article.