What is TOTEM?

Part of the TOTEM detector. Image © CERN

The TOTEM (Total Cross Section, Elastic Scattering and Diffraction Dissociation) experiment measures the effective size of the proton—its so-called "cross-section"—to an unprecedented precision.

Modest in size, TOTEM has been installed near the point where protons collide in the center of the CMS detector. It uses silicon sensors installed in the LHC tunnel approximately 650 feet away from CMS.

The TOTEM collaboration comprises some 100 members from 10 universities and laboratories in seven countries, including US physicists from Case Western Reserve University.

Read more about the Science of TOTEM to learn about what this experiment studies.