Muon Collider Workshop

Coordinators: Nathaniel Craig, Sergo Jindariani, Federico Meloni, Isobel Ojalvo, and Andrea Wulzer

High-energy muon colliders have recently emerged as compelling candidates for the next phase of exploration in fundamental physics. Blurring the dichotomy between energy and precision, they are poised to address many of the questions stemming from the discovery of the Higgs boson and meaningfully continue the pursuit of physics at shorter distances. The unparalleled efficiency and compact footprint of high-energy muon colliders offer considerable advantages, while their development would necessarily advance particle physics at both the intensity and energy frontiers.

This rapid response program will bring together theorists, experimentalists, and accelerator physicists with the ultimate goal of charting a collaborative international path for a muon collider. Focal points of the program include coordinating efforts among international collaborations; developing the physics case for a demonstrator facility; assessing the central needs and opportunities for theory, experiment, and accelerator physics; and building bridges to the broader particle physics community. 

The program will culminate on Friday, 3/10 with the Muon Accelerator Panel featuring Sergey Belomestnykh (FNAL), Young-Kee Kim (U Chicago), Michiko Minty (BNL), Mark Palmer (BNL), Tor Raubenheimer (SLAC), Chris Rogers (STFC), Daniel Schulte (CERN), and Vladimir Shiltsev (FNAL). The panelists are charged with presenting and discussing both critical and supporting views regarding the feasibility and technical challenges facing the realization of a muon collider. Panelists will also address questions from the audience.

Talks and discussions will take place primarily in-person. For those unable to attend in person, the KITP can provide a personalized Zoom link valid for all talks and discussions in the program, including the Muon Accelerator Panel. To request a Zoom link, please contact the organizers directly or via kitpmuoncollider [at]

Program Schedule

Week 1 (2/27-3/3)

Monday, 2/27: Introduction & Overview of Muon Collider Efforts

[14:00-16:00] Tao Han (University of Pittsburgh), “Muon colliders at Snowmass and beyond”

Tuesday, 2/28: Precision Physics Case

[9:15-10:30] Dario Buttazzo (INFN), “Precision Physics at a Muon Collider”

[11:15-12:30] Markus Luty (UC Davis), Da Liu (UC Davis), “Primary Observables for Indirect Searches”

[14:00-16:00] Nathaniel Craig (UCSB), Markus Luty (UC Davis), Da Liu (UC Davis), Ian Low (Argonne/Northwestern University), Brian Henning (EPFL), Discussion: Electroweak symmetry at high energies

Wednesday, 3/1: New Physics Benchmarks & Signals

[9:15-10:30] Ian Low (Argonne/Northwestern University), “Physics Benchmarks for Muon Colliders”

[11:15-12:30] Rodolfo Capdevilla (Fermilab), “Signal Benchmarks for Muon Colliders”

[14:00-16:00] Cari Cesarotti (MIT), “Beam Dumps and Other Synergistic Detectors”;

Maximilian Ruhdorfer (Cornell), “Very Forward Muon Detectors”;

Discussion: Coordinating US Input to P5

Thursday, 3/2: Neutrino Synergies

[9:15-10:30] Marcos Dracos (IPHC-IN2P3/CNRS Strasbourg), “The European Spallation Source neutrino Super Beam and muon synergies”

[11:15-12:30] Zahra Tabrizi (Northwestern University), “Neutrino Opportunities at a Muon Collider”

[14:00-16:00] Scott Berg (BNL), Katsuya Yonehara (Fermilab), “The State of Ionization Cooling”

Friday, 3/3: Muon Collider Theory Needs

[9:15-10:30] Andrea Wulzer (IFAE), “Electroweak Radiation Challenges & Opportunities”

[11:15-12:30] Keping Xie (University of Pittsburgh), Yang Ma (INFN-BO), “Electroweak Factorization at High-Energy Muon Colliders”

Week 2 (3/6-3/10)

Monday, 3/6: Accelerator

[14:00-16:00] Mark Palmer (BNL), “Accelerator Overview”;

Discussion: Staging possibilities

Tuesday, 3/7: Detectors

[9:15-10:30] Zhen Liu (Minnesota), “Physics requirements for the detector”

[11:15-12:30] Daniele Calzolari (CERN), “MDI and BIB mitigation”

[14:00-16:00] Roberto Franceschini (Roma Tre), Patrick Meade (Stony Brook), Michael Peskin (SLAC), Liantao Wang (U. Chicago), Theory Panel: Opportunities & Open Questions

Wednesday, 3/8: Detector++

[9:15-10:30] Lawrence Lee (Tennessee), “How to Build a Detector at a Muon Collider”

[11:15-12:30] Discussion: Unique R&D Directions

[14:00-16:00] Discussion: Coordinating US Input to P5

Thursday, 3/9: Accelerator Technology

[9:15-10:30] Chris Rogers (STFC), “Demonstrators overview”

[11:00-12:30] Sam Posen (Fermilab), “US accelerator technology capabilities for MuC”

[14:00-16:00] Patrick Meade (Stony Brook), “Sustainability Study”

Friday, 3/10: Muon Accelerator Panel & Closeout

[9:00-11:00] Sergey Belomestnykh (Fermilab), Young-Kee Kim (U. Chicago), Michiko Minty (BNL), Mark Palmer (BNL), Tor Raubenheimer (SLAC), Chris Rogers (STFC), Daniel Schulte (CERN), Vladimir Shiltsev (Fermilab), Muon Accelerator Panel

[11:30-12:30] Discussion: The Path Forward

[16:00-17:00] Nima Arkani-Hamed (IAS), KITP Blackboard Talk