The ATLAS experiment at CERN releases 65 TB of open data for research

The ATLAS experiment at CERN has made two years of scientific data available to the public for research purposes. The data include records of proton-proton collisions from the Large Hadron Collider (LHC) at a collision energy of 13 TeV.

This is the first time ATLAS has published data on this scale and represents a major milestone in terms of public access and use of LHC data.

“Open access is a core value of CERN and the ATLAS collaboration,” says Andreas Hoecker, ATLAS spokesperson. “Since its inception, ATLAS has strived to make its results fully accessible and reusable through open access archives such as arXiv and HepData. ATLAS routinely releases open data for educational purposes. Now we’re taking it a step further – inviting everyone to explore the data that led to our discoveries.”

Released under Creative Commons CC0, ATLAS has released all the data collected by the experiment during the LHC’s proton-proton operation in 2015 and 2016. That’s about 65 TB of data, representing more than 7 billion LHC collisions.

In addition, ATLAS has published 2 billion events of simulated “Monte Carlo” data, which are necessary to perform the physical analysis.

In particular, external researchers are encouraged to explore ATLAS open data. “Along with the data, we’ve provided comprehensive documentation on several of our analyzes to guide users through our process step-by-step,” says Zach Marshall, coordinator of ATLAS Computing.

“These guides provide first-hand experience of working on a real ATLAS result and allow anyone to test our instruments and evaluate the systematic uncertainties associated with the result.”

ATLAS has traditionally collaborated with non-ATLAS scientists through short-term fellowships, providing them with full access to ATLAS data, internal tools and information. Through open data, ATLAS scientists hope to further this dialogue and collaboration.

“In particular,” Zach adds, “we’d like to encourage phenomenologists as well as computer scientists to explore our datasets instead of relying on mockups.”

Today’s release follows on from previous releases of open data for educational purposes (in 2016 and 2020). “All of our open data releases are now available through the ATLAS Open Data website,” says Dilia Portillo, ATLAS Outreach and Education Coordinator.

“The website contains multi-level documentation, video tutorials, and online tools aimed at the entire spectrum of users, from high school students to senior particle physics researchers. In addition, the software used to create open data for educational use has been released.” .

“This provides a seamless transition from research open data to all the education and outreach tutorials, including the newly updated Higgs boson discovery documentation. With a little time and dedication, you can go from being a relative novice to an analysis expert.”

The ATLAS open data website also serves as a hub for a community that includes teachers, students, enthusiasts and, more recently, scientists. Anyone diving into open data can also connect directly with ATLAS physicists, who are ready to respond to user feedback and accept suggestions.

This release marks the beginning of more to come, with the first release of lead-lead-nuclear collision data from ATLAS. The ATLAS Collaboration, along with other major collaborations on the LHC experiments, has committed to making all of its data publicly available over a period of time. Openness is deeply rooted in the culture of high energy physics and enables greater accessibility, reproducibility and better science.