CMS experiment

The CMS experiment is one of two general-purpose detectors located on the Large Hadron Collider. It records the types, trajectories and momenta of particles produced during the high-energy collisions inside the LHC.

With more than 1,000 participants from 49 institutions across the country, US CMS is the largest national group in the 3,600-member international CMS collaboration. Supported by the US Department of Energy’s Office of Science and the National Science Foundation, the US CMS collaboration consists of more than 430 physicists, nearly 200 graduate students and more than 300 engineers, technicians and computer scientists.

The US CMS collaboration plays a vital role in the operation of the CMS detector and analysis of data from LHC collisions. US groups made significant contributions to the construction and installation of nearly every aspect of the CMS detector, including the construction and operation of the experiment’s global network of computing facilities (eight CMS computing centers are based in the US.) US scientists also continue to improve the highly sophisticated computing tools that enable physicists to operate the CMS detector, reconstruct the data, and make discoveries.



CMS stats

Total weight: 13,800 tons
 (approx. 1.3 times the mass of the Eiffel Tower in Paris)

Overall diameter: 52 feet

Overall length: 70 feet

Detection elements: 100 million

Collaborating scientists:

  • 3,600 worldwide
  • 1,000 from the United States


  • 38 countries
  • 23 US states and Puerto Rico
  • 49 US universities and 2 national laboratories

US Ph.D. physicists: More than 430

US graduate students: Nearly 200

Cost of US construction project: $167 million

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