[Paper Review] On the Future High Energy Colliders

Vladimir Shiltsev|arXiv (Cornell University)|Sep 28, 2015

Particle Detector Development and Performance1 references3 citations

TL;DR

This paper evaluates next-generation high-energy colliders—such as the FCC, ILC, and CLIC—using a unified framework that balances energy reach, performance potential, and cost. It provides a comparative analysis to guide future accelerator development, emphasizing feasibility and long-term physics impact beyond the LHC's high-luminosity upgrade.

ABSTRACT

High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

Motivation & Objective

• To assess the feasibility and scientific potential of next-generation high-energy colliders beyond the LHC.
• To establish a standardized framework for comparing diverse collider designs based on energy reach, performance, and cost.
• To support long-term planning in accelerator-based high-energy physics by evaluating medium- and far-future collider projects.
• To guide international and national strategies in particle physics toward optimal investment in future facilities.
• To provide a balanced assessment of the trade-offs between performance, technical challenges, and financial constraints in future collider projects.

Proposed method

• The author applies a uniform evaluation metric that integrates energy reach, luminosity performance, and cost estimates across different collider designs.
• The analysis draws on existing technical designs and conceptual studies for future colliders, including the FCC, ILC, and CLIC.
• Feasibility is assessed through a synthesis of current accelerator physics principles, technological readiness, and projected R&D challenges.
• Performance potential is evaluated using key accelerator parameters such as beam energy, luminosity, and operational lifetime.
• Cost ranges are estimated based on historical data, scale models, and extrapolations from existing projects like the LHC and ILC.
• The methodology enables side-by-side comparison of diverse collider types, including hadron and lepton colliders, under consistent criteria.

Experimental results

Research questions

• RQ1 What are the key technical and financial trade-offs between different next-generation collider designs?
• RQ2 How does the energy reach of future colliders compare to the LHC and its high-luminosity upgrade?
• RQ3 What performance metrics (e.g., luminosity, beam stability) are essential for future colliders to achieve their physics goals?
• RQ4 How can a standardized evaluation framework be applied to compare vastly different collider technologies?
• RQ5 What are the most promising pathways for achieving high-energy physics goals beyond the HL-LHC within realistic cost and technical constraints?

Key findings

• The Future Circular Collider (FCC) concept offers the highest energy reach, with potential to reach 100 TeV center-of-mass energy.
• The International Linear Collider (ILC) and Compact Linear Collider (CLIC) are viable options for high-precision lepton collisions, with ILC targeting 250 GeV and CLIC up to 3 TeV.
• Cost estimates for the FCC range from $15 to $20 billion, depending on configuration and infrastructure reuse.
• The paper identifies a strong correlation between collider performance and cost, with higher energy and luminosity demanding significantly greater investment.
• The evaluation framework enables clear prioritization of projects based on physics return per unit cost, favoring those with high energy reach and moderate cost growth.
• The analysis supports continued development of the HL-LHC as a near-term priority, while advocating for long-term planning toward the FCC and other next-generation facilities.