From Jan. 9-13, 2023, the LHC Physics Center at Fermilab hosted the first CMS Data Analysis School in person at Wilson Hall since 2020. CMS DAS brought new CMS members, primarily new graduate students and postdoctoral researchers, to the LPC for an intense week of lectures, hands-on exercises and a group competition to learn about the CMS detector, physics, software and analysis.
This year, more than 100 people took part in the DAS (46 students, 46 facilitators and eight speakers) with 11 facilitators and six students traveling from outside the U.S. The 2023 event was a welcome return to in person after two straight years of holding the event virtually over Zoom due to the pandemic.
This year’s DAS featured 12 short exercises focusing on specific aspects of the CMS experiment, such as particle identification and reconstruction, as well as five longer exercises covering a variety of analysis including both measurements and searches for new particles and processes.
Students used a range of software and computing tools, including python, C++, command line and jupyter notebook workflows. CMS DAS students, such as UW-Madison graduate student Anagha Aravind, took part in several short exercises and one long exercise each.
“CMSDAS was an amazing boot camp-like experience and I really enjoyed meeting and interacting with the other participants and facilitators,” said Aravind.
Students were guided in their short and long exercises by facilitators, mostly experienced postdocs and graduate students, who are topical experts. Lederman Fellow Grace Cummings, a first-time CMS DAS facilitator, also found the experience instructive for her own work. She said, “I got to see the tools used by different analyses, and update my own knowledge about the latest recommendations and reconstruction techniques.”

Fermilab Director Lia Merminga welcomes the CMSDAS participants to the lab. Photo: Marguerite Tonjes
As per DAS tradition, each of the five student groups presented their analysis on the final day of the school, with students in each group taking turns speaking. These talks were judged by a panel of senior CMS collaborators on the quality of the analysis, teamwork and presentation.
Guest speakers included Fermilab Director Lia Merminga, Isobel Ojalvo of Princeton University, Indara Suarez of Boston University, Emilo Nanni of SLAC, and Fermilab Scientists Kevin Pedro, Kaori Maeshima and Chris Quigg. The speakers covered a wide range of topics from the underlying theory and big questions of particle physics through the details of the accelerator, detector and physics analysis of CMS.
In addition, the school covered the important topics of how the publication process works, how to present results to a scientifically literate audience and handle tough questions about the details.
Traditionally, the school banquet included a trivia session, and the school concluded with a wine-and-cheese talk given by Fermilab scientist and DAS lecturer Kevin Pedro on searching for new physics with CMS.
There were times of both levity and learning. For instance, Thursday after the school dinner, there was a rubix cube-solving competition, and one of the long exercise groups had facilitators work on a collaborative digital art image, while students worked on finalizing their analyses.

CMS DAS students work as a team on their long exercise project with facilitators assisting in understanding the analysis. Photo: Marguerite Tonjes
This year’s CMS DAS was well received by the students with nearly unanimous agreement that the school provided a great experience and educational value to the students.
The school would not be possible without the tireless efforts of CMS LPC support staff: Gabriele Benelli from Brown University and Marguerite Tonjes from University of Illinois, Chicago.

LPC graduate scholar Ryan Kim provides assistance in understanding a short exercise. Photo: Marguerite Tonjes
The students attending CMS DAS are the future of CMS and the field of high-energy physics. Their creativity and drive were a constant inspiration to the facilitators and organizers.
“The students reminded me of what it was like when everything was new and exciting,” said Cummings, “and the novelty and cleverness of some of the things we do in analysis that we as experienced analyzers take for granted!”
Kevin Black is a professor of physics at the University of Wisconsin-Madison, and a co-coordinator of the LHC Physics Center at Fermilab, along with Fermilab scientist Bo Jayatilaka.