Since 2000 he has been a member of the CMS (Compact Muon Solenoid) experimental collaboration at CERN's LHC (Large Hadron Collider), one of the two experiments responsible for the discovery of the Higgs Boson in 2012. Jesús participated in the design, construction, installation and commissioning of the CMS central muon detector between 2000 and 2008. Since then he has been part of the research team responsible for the operation and scientific exploitation of CMS. He is also a member since 2008 of the CALICE collaboration dedicated to the design of calorimeters for future collider experiments.

Parallel to his scientific activity, Jesús is an expert in communication, outreach and scientific training. He is the outreach manager of the CIEMAT-FP Unit, outreach coordinator of the CMS muon group, director of the Phy6cool summer school, co-organizer of the Spanish teacher training program at CERN and promoter of many other outreach activities, both at local and national level, collaborating on a regular basis with the National Center for Particle Physics (CPAN). He is also a regular contributor, among others, to the program A Hombros de Gigantes, on Radio Nacional de España, where he is responsible for the specialized section on particle physics.