Subatomic physics aims to understand the nature of the most basic building blocks of the universe and the laws that explain the behaviour of these fundamental constituents. Remarkable progress has been made in this field in recent years, notably with the discovery of the Higgs boson and the elucidation of the properties of neutrinos. Despite these achievements, many deep questions remain which continue to stimulate new research directions.

Canadian subatomic physicists have played an outsized role on the global stage, thanks to the support of government, funding agencies, universities, the Canadian community, and a history of effective self-organization in tackling the major science questions. Research in subatomic physics involves a synergy between advanced theoretical work and computational analysis with some of the most technologically advanced experiments ever devised and constructed. This research field is global, and often involves large international teams of skilled researchers and technicians. This in turn provides unique training opportunities for students and junior research personnel, many of whom move into a variety of areas in the growing knowledge-based economy.

This report, the Canadian Subatomic Physics Long-Range Plan 2022–2026 (LRP 2022), is the latest in a quinquennial series of plans developed to guide the progress of subatomic physics research in Canada. The present planning process was co-commissioned by NSERC, the Canadian Institute for Nuclear Physics (CINP) and the Institute for Particle Physics (IPP). The CINP and IPP community institutes represent the professional nuclear and particle physicists in Canada. The goals of this planning process are articulated in the mandate (see Planning Process section), and include the identification of the critical science questions driving the field with a fifteen year outlook, the associated opportunities for Canada, and the high priority projects that the community can pursue to address the science goals. The Canadian subatomic physics planning process is community-driven and characterized by extensive consultation and community engagement. The aim of the report is to present a realistic and community-supported vision for Canadian subatomic physics over the coming years. The report seeks to also articulate the funding and other technical support needs required to achieve the stated goals and to present opportunities for the community to enhance its processes, inclusivity, training and outreach.

The primary audience for LRP 2022 comprises the funding organizations and Canadian facilities that support subatomic physics research in Canada. This includes the federal department, Innovation, Science and Economic Development Canada (ISED), and associated agencies such as NSERC and CFI, along with provincial organizations and the research centres and universities that support subatomic physics researchers and their students. The report aims to highlight and articulate the subatomic physics community’s success, recent achievements, and opportunities and, as such, is also targeted more broadly at government policy makers. In addition, the subatomic physics community itself is an important audience for this report. Finally, high-level components of the report aim to share, with the broader Canadian public, the excitement, knowledge and other societal benefits gained by public support and investment of tax dollars in this field.

The Long-Range Plan Report is structured to provide a status update on the research field in Canada, a description of the research plan and necessary funding and infrastructure supports needed to implement the plan, and a presentation of broader benefits of investment in this field for Canadian society. A reading guide for subsequent sections follows below:

Section 1 —
Science Drivers and the Impact of Canadian Work

This section summarizes the global context for subatomic physics research, the drivers for specific sub-fields, and elaborates on Canadian achievements and broader scientific impact since the previous Long-Range Plan.

Section 2 —
Canadian Subatomic Physics Research Plan

Based on the scientific landscape presented in Section 1, Section 2 outlines the science opportunities for Canada, and the enabling technology and infrastructure. The research plan is then presented in the form of a multi-dimensional portfolio of high priority projects aiming to tackle the science drivers.

Section 3 —
Realizing the Research Plan

This section discusses the various forms of support required to realize the research plan. These are categorized into the broad areas of community actions, funding, technical and infrastructure support, and the broader policy framework.

Section 4 —
Benefits to Society

This concluding section takes a broader perspective of the return on investment in subatomic physics research, including the unique training opportunities, the development of new technological applications, commercial spin-offs, environmental impact and opportunities, and the broader cultural benefits of pursuing this most fundamental science.

Appendices provide a glossary of acronyms used throughout the report, the governing documents for the planning exercise, and a description of the process followed and extensive community input received by the planning committee. A number of concrete examples of the impact of subatomic physics research, and sample case studies, are distributed throughout the report.