Now more than ever, particle physics is an international, even global, endeavor. The experiments needed to address the most profound questions of our field often require resources and cooperation at a global scale and can take more than a decade to design and build. We found the scope of our charge and the responsibility it represents humbling. Throughout our deliberations, we were aware that the impact of our recommendations would be felt past the end of the next decade and beyond the borders of the US particle physics program. The recommended program reflects the consensus of the panel.

The 2014 P5 report laid the foundations for the current particle physics program. Embracing its recommendations positioned the US as a leader and strong international partner in efforts that encompass neutrino and flavor physics, the study of dark matter and cosmic evolution, and collider experiments. The community stands on the threshold of realizing the enormous scientific potential of the 2014 P5 program.

At the same time, the community-driven planning process organized by the Division of Particles and Fields of the American Physical Society produced a spectrum of exciting new ideas for the future. We thank the particle physics community members in the US and abroad for their dedication and thoughtful input, not only through the community planning process, but in numerous town halls, talks, and private communications.

The enthusiasm and engagement of early career participants, both in the planning process and in recent town halls, has been truly inspiring. They are the future leaders who will bring to life the goals and aspirations outlined in this report.

We strove to craft a balanced program in terms of scientific focus, project timescales, and the interplay between ongoing initiatives and the innovation essential for the future. Adhering to fiscal constraints means that not every ambitious endeavor can be immediately realized. Agile, adaptable, and forward-looking projects are essential to the balance. Sustained progress over the next decade requires enhanced investment in research, theoretical frameworks, critical infrastructure, and emerging technologies. Also crucial is the commitment to build a respectful and inclusive community. We hope the resulting program enables early career researchers to spearhead progress and shape the future.

We are excited to present our vision for US particle physics, one that builds on recent investments and successes, while opening pathways to innovation and discovery in the quest to explore the quantum universe.

Respectfully submitted,
2023 Particle Physics Project Prioritization Panel

Shoji Asai

University of Tokyo

Patrick Huber

Virginia Tech

Richard Schnee

South Dakota School of Mines & Technology

Amalia Ballarino


Kendall Mahn

Michigan State University

Sally Seidel, Interim HEPAP chair, ex officio since June 2023

University of New Mexico

Tulika Bose

University of Wisconsin-Madison

Rachel Mandelbaum

Carnegie Mellon University

Seon-Hee Seo

IBS Center for Underground Physics, Fermi National Accelerator Laboratory

Kyle Cranmer

University of Wisconsin-Madison

Jelena Maricic

University of Hawaii at Manoa

Jesse Thaler

Massachusetts Institute of Technology

Francis-Yan Cyr-Racine

University of New Mexico

Petra Merkel

Fermi National Accelerator Laboratory

Christos Touramanis

University of Liverpool

Sarah Demers

Yale University

Christopher Monahan

William & Mary

Abigail Vieregg

University of Chicago

Cameron Geddes

Lawrence Berkeley National Laboratory

Hitoshi Murayama, Chair

Univeristy of California, Berkeley

Amanda Weinstein

Iowa State University

Yuri Gershtein

Rutgers University

Peter Onyisi

University of Texas at Austin

Lindley Winslow

Massachusetts Institute of Technology

Karsten Heeger, Deputy Chair

Yale University

Mark Palmer

Brookhaven National Laboratory

Tien-Tien Yu

University of Oregon

Beate Heinemann


Tor Raubenheimer

SLAC National Accelerator Laboratory/Stanford University

Robert Zwaska

Fermi National Accelerator Laboratory

JoAnne Hewett, HEPAP chair, ex officio until May 2023

SLAC National Accelerator Laboratory

Mayly Sanchez

Florida State University

2023 Particle Physics Project Prioritization Panel in Denver, August 2023. Photo: Rowena Smith