Dr. Juliette Alimena

About Me

I’m a staff scientist at DESY in Hamburg, Germany, working in high energy particle physics. I primarily work on the CMS experiment at the LHC, but I also work on CODEX-b and the FCC. I’m really interested in searching for new particles, such as those with long lifetimes, which could be a candidate for dark matter.

My Passion

Long-lived particles (LLPs) are an important possibility in the search for new phenomena, and they often appear in theories beyond the standard model of particle physics. However, most conventional searches at the LHC target promptly decaying particles. Thus, searches for new LLPs have a great potential for discovery. When produced at the LHC, LLPs have a distinct, unconventional experimental signature: they can decay far from the primary proton-proton interaction but within the detector, or even completely pass through the detector before decaying. Standard triggers, object reconstruction, and background estimation are usually inadequate for LLP searches because they are designed for promptly decaying particles, and custom techniques are often needed to analyze LLPs.

Brief Vita

• Staff scientist, DESY (Nov. 2022 – present)
• Senior research fellow, CERN (Oct. 2020 – Oct. 2022)
• Postdoctoral researcher, The Ohio State University (Dec. 2015 – Sept. 2020)

• PhD in Physics, Brown University (2015)
• BA in Physics with Honors, Math and English minors, University of Pennsylvania (2008)

Articles and videos for the general public

• Mapping Uncharted Territory: CMS Review Searches for Dark Matter
• Ever wonder what CMS knows about Dark Matter?
• Leptons Popping Out of Thin Air

Key publications

As member of the CMS Collaboration, I am an author of more than 1100 publications. A complete list of all my publications can be found through INSPIRE.

The following is a list of some of my recent and significant papers:

• CMS Collaboration, Dark sector searches with the CMS experiment, Accepted by Phys Rept.. One of three main editors, organized a team of 50 analysts, and major contributor to the text.
• Rygaard, L., Alimena, J. et al, Top Secrets: Long-Lived ALPs in Top Production, JHEP 10 (2023) 138. Supervised main analyzers.
• Verhaaren, C. B., Alimena, J., et al, Searches for long-lived particles at the future FCC-ee, Front. Phys. 10 (2022) 967881. Snowmass white paper. Primary author.
• CMS Collaboration, Search for long-lived particles decaying to leptons with large impact parameter in proton-proton collisions at sqrt(s) = 13 TeV, EPJC 82 (2022) 153. Primary author.
• Alimena, J. et al, Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider, J. Phys. G 47 (2020) 090501. Contributor, editor for 3 chapters. Received the 2023 Top Cited Paper Award for being in the top 1% of the most-cited articles recently published in IOP Publishing journals over the full breadth of scientific research, with corresponding authors based in North America.
• Alimena, J., Iiyama, Y., and Kieseler, J., Fast convolutional neural networks for identifying long-lived particles in a high-granularity calorimeter, JINST 15 (2020) P12006. Primary author.
• CMS Collaboration, Search for decays of stopped exotic long-lived particles produced in proton-proton collisions at sqrt(s) = 13 TeV, JHEP 05 (2018) 127. Primary author.
• D0 Collaboration, Search for charged massive long-lived particles, PRL 108 (2012) 121802. Primary author.

Contact me

The best way to contact me is by email