is a fundamental science that seeks to understand the basic building blocks of the universe and the laws that explain the behaviour of those constituents.
Over the past century, the global subatomic physics community has developed an increasingly detailed understanding of this realm, culminating in the development of the Standard Model of particle physics. This theoretical framework unifies electromagnetism, the strong force that binds protons and neutrons, and the weak forces that control neutrinos and nuclear decay. The ongoing development of this theoretical framework most recently led to the discovery of the Higgs boson in 2012. While remarkable progress has been made in this field, many deep questions remain. Future goals include identifying the nature of dark matter and the origin of neutrino mass, explaining how nuclear structure emerges from the theory of quarks and gluons, and improving our understanding of quantum mechanics and relativity to uncover the basic structures underlying matter and the fundamental forces.
The development of our collective knowledge in subatomic physics is a collaborative global endeavour, involving a synergy between advanced theoretical work, cutting edge computational analysis, and experiments which utilize some of the most sophisticated machines ever devised, such as the Large Hadron Collider at CERN. Within this global community, Canadian subatomic physics has an enviable reputation, with leadership and impact on many of the major projects that have advanced our understanding in recent decades. In particular, Canadian researchers have played leading roles on experimental projects connected with recent Nobel Prize awards for the discovery of the Higgs boson and the discovery of neutrino flavour change.
Over the past five years, Canadians have taken on significant roles in national and international experiments, ranging from substantial involvement in the ATLAS experiment at the LHC, to a variety of strategic efforts on projects at world-class Canadian and international facilities. The focus of these projects has been to test neutrino properties and search for dark matter, test the structure of protons, neutrons and increasingly complex nuclei, and to perform a variety of precision tests of fundamental symmetries and foundational properties of the Standard Model. Canada is also uniquely positioned to play a major role in the future development of this international field, hosting the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, and two world-class experimental facilities, the SNOLAB deep underground laboratory in Sudbury, Ontario, and TRIUMF, Canada’s particle accelerator centre in Vancouver, BC. The Canadian community has pursued projects at these domestic facilities, and has also strategically invested in international laboratories that provide world-leading and complementary infrastructure.
Investment in subatomic physics research leads to returns that are multi-faceted. In addition to expanding our collective understanding of nature, the field provides inspiration and a rich and unique training ground for students and research personnel. In addition to the core skills in problem solving that are typical of physics education, the highly collaborative nature of subatomic physics research also provides trainees with valuable “soft skills”, and the strong synergies between subatomic physics and other fields, including astronomy and cosmology, materials science, quantum technologies, and high-performance computing, provide many opportunities for cross-disciplinary research. Subatomic physics research also drives the development of technology, with spin-off developments now important in many areas such as health care, energy, and computing.
The impact of the Canadian subatomic physics community in recent years has been bolstered by collective organization, and cohesive effort on carefully identified projects with significant science outcomes. The Subatomic Physics Long-Range Plan Committee, in consultation with the Canadian subatomic physics community, has developed a roadmap for continued success over the period 2022–2026, with an outlook to 2036. The research plan follows from the same guiding principles that have supported past success:
- tackle the most important research problems in the field;
- maximize impact by concentrating effort and taking on leadership responsibilities in select major projects, while strategically engaging in a range of smaller-scale projects with the potential for high reward;
- maintain flexibility to adjust to new scientific advances; and
- fully engage an increasingly diverse population of students and postdocs in all aspects of research, and support their career development.
The scientific drivers for subatomic physics research, and the associated opportunities, can be structured around three broad science directions:
Broad Science direction —
From quarks and gluons to nuclei.
Canada’s TRIUMF Laboratory, with its Advanced Rare Isotope Laboratory (ARIEL) upgrade and associated suite of targets and experiments utilising rare isotope beams, presents an opportunity for Canada to continue its leading role in mapping out nuclear structure and properties. In addition, strategic investment in new and complementary offshore facilities in US and Europe will broaden research capacity.
Broad Science direction —
Matter in the weakly coupled universe.
Seeking the identity of dark matter in the universe, and the underlying properties of neutrinos is a growing area of focus worldwide. Canada is very well-positioned to continue its central role in this international effort, with the SNOLAB underground facility in Sudbury currently hosting a variety of world-leading experiments and being well-placed to take a leading role in next generation searches. Canada is also actively involved in major international neutrino experiments.
Broad Science direction —
Beyond the electroweak energy scale.
The Canadian community is well-positioned to explore the high energy frontier through its long-standing involvement in international particle collider projects in Europe and Japan, and strategic involvement in smaller-scale precision experiments. In addition, Canada’s TRIUMF Laboratory has the opportunity to position itself as a world-leading facility for future high-precision tests of physics at the energy frontier using rare isotopes. Canada is also poised to take a significant role in the development of the next generation of particle colliders.
Theoretical work by Canadian subatomic physicists on all of these themes is critical to future progress. This includes work that is closely tied to analysis and interpretation of experiments, and also fundamental theory that seeks the new ideas that will explain existing puzzles and shape our understanding of subatomic physics in the future.
A number of external and internal sources of support will be required for the subatomic physics community to take full advantage of these opportunities for Canada. Moderate but critical increases to operational funding via the NSERC subatomic physics envelope, and continued access to capital funding at current levels for new experimental projects via CFI, are required.
Substantial and stable funding is also necessary to maximize the impact of Canada’s unique world-class facilities: SNOLAB, TRIUMF, and the Perimeter Institute. Computing and network infrastructure is critical to this field, and Canada’s new Digital Research Alliance (formerly NDRIO) and CANARIE are vital components of the subatomic physics research ecosystem. Funding opportunities to develop enabling and emerging technologies are also critical in support for future research projects. Maintaining support for Canada’s Institute of Particle Physics (IPP) Research Scientist Program is a high-priority for the community. In addition, initiatives developed and run by the Arthur B McDonald Institute have added considerable value to the subatomic physics ecosystem in Canada. At the governmental level, future scientific developments would be greatly facilitated by the existence of high-level national structures to coordinate costs for large-scale science endeavours, and to aid international engagement in multi-national projects. Finally, achieving a more equitable, diverse and inclusive Canadian subatomic physics community is vital to ensure research excellence and that the societal benefits stemming from subatomic physics research are equitably distributed. Sustained efforts by individuals and organizations to improve equity, diversity and inclusion need to encompass training, career development and outreach.
The subatomic physics community in Canada has achieved great success, and is well-positioned to take on future challenges in unlocking the secrets of fundamental physics at the subatomic scale. The Long-Range Plan for 2022–2026 is described in detail in this report, with the key action items, some of which were highlighted above, expressed in a series of recommendations on Science, Funding, Policy, and Community.
We recommend fully capitalizing upon the unique science opportunities provided by the SNOLAB and TRIUMF infrastructure, and by the Perimeter Institute, in pursuit of the science drivers.
Critical mass and research breadth are vital for the theory community in Canada, to maximize the future impact of subatomic physics research. We recommend strong support for theoretical subatomic physics research over the next decade, both to explore new purely theoretical directions and to support the synergistic interaction between subatomic theory and experiment.
A broad experimental program is required to address the scientific drivers of subatomic physics research. We recommend pursuit of the following high-priority scientific directions.
- From quarks and gluons to nuclei — The future program should explore the structure of hadrons and nuclei using rare isotope and accelerator-based facilities. It should include the full exploitation of TRIUMF, offshore electron beam and rare isotope beam (RIB) facilities, and a future electron-ion collider.
- Matter in the weakly coupled universe — The future program should incorporate the search for dark matter using complementary direct and indirect techniques, including via multi-ton scale direct detection. The future program should include the further exploration of neutrino properties via neutrinoless double-beta decay experiments, long baseline experiments and neutrino observatories.
- Beyond the electroweak energy scale — The future program should study matter and its interactions at increasingly higher energy scales, including the exploitation of a future Higgs factory and energy frontier collider, as well as high-precision indirect techniques.
This scientific program is currently implemented through Canadian leadership in a set of flagship projects identified based on their potential scientific payoff, Canadian core expertise, the level of community engagement, opportunities for the scientific and technological training of the next generation, and Canadian investments to date:
|Flagship projects with broad physics outcomes||Flagship projects with strategic physics outcomes|
|From quarks and gluons to nuclei||TRIUMF ARIEL-ISAC experiments, EIC||JLab 12 GeV program, Offshore RIB experiments|
|Matter in the weakly coupled universe||T2K/HK, IceCube, SNO+||DEAP, PICO-500, SuperCDMS|
|Beyond the electroweak energy scale||ATLAS(LHC/HL-LHC), Belle II||ALPHA/HAICU, MOLLER, TUCAN|
We recommend the support of these projects and also those initiatives within the scientific program, with the potential for high impact, that are under development or may be developed in the coming years. Potential future projects with ongoing development activities and their timelines are listed in the research portfolio presented in Figure 4.
We recommend the support of R&D activities for the future development of particle accelerators and detector technology, and the development and use of emerging technologies including novel computational and analysis tools.
Equity, Diversity & Inclusion
The Canadian subatomic physics community lacks diversity, as do some other science and technology fields. This lack of representation has many causes, and spans the full career range from graduate students to senior faculty. It is widely recognized that diversity is valuable for the research enterprise, and that a lack of diversity in itself creates a barrier to entry into the field.
- We recommend the pursuit of further sustained actions aligned with the Tri-Council Dimensions Charter, including regular data-gathering and analysis, targeted initiatives to enhance equity, diversity and inclusion within community activities, and community use of formal committees through the Institutes to support these efforts and/or coordinate with partners.
- We recommend that the subatomic physics community promote balanced representation in high visibility leadership roles, as individuals in these positions are important role models, while recognizing that achieving adequate representation can increase the workload for members from under-represented groups.
- We recommend that the subatomic physics community promotes inclusion through acknowledgement of the legacy of colonization in Canada, e.g. with the use of land acknowledgements at events held in Canada, consistent with the spirit of the Calls to Action of the Truth and Reconciliation Commission of Canada and of the United Nations Declaration on the Rights of Indigenous Peoples.
Training & career development
To enable highly qualified personnel to receive training that makes use of the national collaborative structure of subatomic physics research, we recommend the coordination and sharing of training opportunities across Canadian centres, institutes, and universities.
To support early career development, we recommend that Early Career Researchers be supported to quickly gain knowledge of the Canadian subatomic physics research support and funding ecosystem, and be given opportunities to interact broadly with the community.
Communication & Engagement with Agencies & Government
We recommend the formalization (e.g. by CINP and IPP) of a subatomic physics consultation committee for engagement and advocacy to funding agencies and government.
Support for the development of capital infrastructure through CFI has been instrumental for the development of subatomic physics research in Canada. We recommend continuation of this investment at current annualized levels, which will be critical for the success of the Canadian subatomic physics research plan including many of the proposed future initiatives.
NSERC Subatomic Physics Envelope
To maximize the impact of current and future investments, and to take advantage of future science opportunities, growth of the NSERC subatomic physics envelope is required for operational support.
- We recommend retention of the NSERC subatomic physics envelope structure, and its programs, which have been instrumental for the operational funding of subatomic physics research.
- We recommend growth of the NSERC subatomic physics envelope by $6.2M in 2021 dollars over the next five years to ensure that the Canadian program remains globally competitive. This growth is required for several reasons: to accommodate the transition of McDonald Institute faculty requiring NSERC support; to utilize the full community capacity for training of highly qualified personnel and maximize the return on capital investment; and to ensure sufficient availability of funds for small infrastructure projects and the development of future science opportunities.
- We recommend continued support for all the program categories available within the NSERC subatomic physics envelope; this includes the Major Resources Support (MRS) program, which critically supports the efficient collaborative use of unique technical resources in the development and construction of new instruments, and the Research Tools and Instruments (RTI) program which provides important support for detector and accelerator development.
- We recommend the monitoring and protection of the NSERC subatomic physics envelope fraction allocated to fund theory investigators. In addition, the minimum award threshold should not be below the level of funding required to support graduate training, as is the case in other Physics Evaluation Sections.
Support for Canada’s World-leading Centres
Canada’s large-scale centres for subatomic physics research have global stature, and provide competitive advantages in pursuing high-priority scientific programs.
We recommend maintaining strong support for Canadian centres (TRIUMF, SNOLAB, Perimeter Institute) so that they remain at the forefront of research worldwide.
IPP Research Scientist Program
The IPP Research Scientist program has had a major impact on Canada’s leadership and contributions to international projects.
We recommend maintaining full support for the IPP Research Scientist program.
Arthur B McDonald Institute
The existence of the Arthur B McDonald Institute and its research support and outreach programs has added considerable value to the community. However, its CFREF funding is coming to an end.
We recommend that in addition to growth of the NSERC subatomic physics envelope to support operational costs, new mechanisms be identified to fund and maintain continuity of the research and technical support programs provided by the Institute.
Canada’s Digital Research Infrastructure
All components of digital research infrastructure (e.g. Compute Canada, CANARIE) are critical to the success of subatomic physics research.
We recommend that CANARIE continues to be funded by the Canadian federal government for operation of the national research network and key links to our international partners. Further, we recommend that critical computing infrastructure provided by national computing organizations (Compute Canada and the Digital Research Alliance (formerly NDRIO)) continue to be strongly supported by federal and provincial governments, at a level appropriate to address the needs of the subatomic physics research community.
Funding for R&D Activities
New research opportunities are enabled by the development of novel instruments and technologies. This development relies upon the ability to explore technological frontiers that are beyond the scope of individual subatomic physics experiments.
We recommend that appropriate mechanisms be identified to efficiently fund modest and timely investments in generic R&D activities that have the potential to address the scientific goals of subatomic physics research.
Support for Large-scale Science Endeavours
Coordination of the capital costs and operational funding over the life-cycle of large-scale (≳ $50M) science endeavours and infrastructure projects is difficult within the current ecosystem.
We recommend the formation of a new administrative structure to provide this coordination (as articulated in Recommendation 4.7 of Canada’s Fundamental Science Review 2017: Investing in Canada’s Future, http://sciencereview.ca).
Canadian Office for International Research Engagement
Subatomic physics research is intrinsically global, and increasingly requires complex multinational agreements.
We recommend the identification of an office in Canadian government responsible for engaging with the international community with the goal of advancing major new science initiatives.