From 26 to 30 January 2026, the Max Planck Institute for Physics in Garching, near Munich, hosted the 9th FCC Physics Workshop, a major gathering of theorists and experimentalists advancing the physics case, solving the experimental challenges, and developing detector concept candidates for the proposed Future Circular Collider (FCC). The event brought together hundreds of scientists from Europe, North America and beyond — some already well acquainted with the FCC, but also many newcomers eager to join the project — to debate physics opportunities, detector technologies, software infrastructure, and the broader strategy for particle physics after the end of the LHC/HL-LHC programme.

The discussions unfolded within a broader strategic context for the field. European physicists have recently endorsed the electron–positron Future Circular Collider (FCC-ee) as the preferred next flagship project in the ongoing update of the European Strategy for Particle Physics, with a final decision anticipated around 2028. This endorsement follows years of extensive design and feasibility studies and provided an important backdrop to the Munich workshop, where participants worked to align physics goals with technical feasibility and long-term sustainability considerations.

The meeting marked a visible shift in tone and substance for the Future Circular Collider (FCC) programme: from broad conceptual exploration toward a project with increasingly operational, benchmark-driven and technically integrated studies.

Across five days of intense discussion participants converged on a common theme: if the FCC is to deliver on its promise as the next flagship collider at CERN, precision must be engineered at every level — from beam energy calibration and theoretical predictions to detector granularity, reconstruction algorithms, analysis software and governance structures.

From physics ambition to quantitative benchmarks

The FCC first stage, FCC-ee, is conceived as a high-luminosity electron–positron collider operating at multiple centre-of-mass energies: at the Z pole, the WW threshold, the Higgsstrahlung maximum around 240–250 GeV, and the top-quark pair threshold, and possibly at other energies, e.g., at the Higgs pole. The physics case has long emphasised unprecedented precision in electroweak observables, Higgs couplings and top-quark properties, with excellent sensitivity to any kind of new physics, as well as a unique potential for the discovery of rare and exotic processes. What was striking in Munich was the degree to which this ambition is now translated into quantitative requirements and structured work plans.

The Physics Studies work package presented a coordinated strategy across electroweak, Higgs, flavour, QCD, top and beyond-the-Standard-Model (BSM) groups. Rather than treating these as parallel efforts, the workshop highlighted the need for consistent benchmark processes, shared uncertainty frameworks and global fit strategies capable of combining hundreds of measurements into coherent constraints on new physics.

At FCC-ee luminosities, statistical uncertainties on many observables will improve by up to three orders of magnitude compared to previous electron–positron colliders. This shifts the limiting factor decisively toward systematic effects: beam energy calibration, luminosity normalisation, detector alignment, flavour-tagging biases, theory uncertainties in higher-order calculations and parton-shower modelling. In Munich, multiple sessions addressed how to match the statistical power with equally ambitious control of systematics — a prerequisite for turning per-mil-level measurements into meaningful probes of new physics up to very high energy scales, well beyond the direct kinematic reach.

Detector concepts driven by physics

The workshop made clear that the FCC physics case cannot be decoupled from detector performance. The Detector Concepts work package presented a coherent overview of how specific physics targets translate into concrete performance drivers.

Precision Higgs and electroweak measurements demand excellent tracking momentum resolution and minimal material budgets to control multiple scattering and secondary interactions. Heavy-flavour and tau-physics programmes require outstanding vertexing and impact-parameter resolution to enable efficient b- and c-tagging, as well as emerging capabilities such as strange-quark tagging. Multi-jet final states from W, Z and Higgs decays place stringent requirements on jet-energy resolution. Meeting these goals favours highly granular calorimetry and particle-flow reconstruction, an approach that aims to identify and measure each individual particle in the event by optimally combining information from all detector subsystems.n.

At the same time, the programme extends beyond canonical precision channels. Sensitivity to long-lived particles and feebly interacting states motivates continuous tracking and hermetic calorimetric coverage. Ultra-precise luminosity measurements at the 10⁻5 level are integral to the detector architecture, not an afterthought. Particle identification systems capable of K/π separation over wide momentum ranges support flavour and QCD studies.

So far, four detector concepts — ALLEGRO, CLD, IDEA and ILD — are under active development, exploring complementary technologies while converging on shared performance goals. The exploration of more concepts (five, six, seven?) was repeatedly encouraged towards the submission of many expressions of interest for collaboration forming after the project approval. The timeline outlined in Munich foresees optimisation studies through 2027, system demonstrators by around 2030, scalable prototypes in the early 2030s, and Conceptual Design Reports in 2033, prior to groundbreaking. The message was clear: detector R&D is not waiting for a final political decision but is advancing in lockstep with physics requirements.

Software and computing as enabling infrastructure

Underpinning these developments is a rapidly evolving software and computing ecosystem. The Physics Software and Computing (PSC) work package presented its vision for supporting the growing needs of physics and detector studies, particularly as the project moves toward a pre-approval phase.

A central component of the FCC software is Key4hep, a community-driven ecosystem designed to provide a unified framework for HEP experiments, prototyped by FCC together with other future collider projects and increasingly adopted by related R&D efforts. Key4hep brings enhanced modularity, interoperability and long-term sustainability of tools, while facilitating inclusion of past developments done in the context of Linear Collider facilities as well as current developments from other initiatives such as CEPC and EIC. In Munich, updates were presented on full simulation geometries for several detector subsystems, integrated digitisation and reconstruction chains, and improved user workflows.

Beyond technical integration, PSC discussions emphasised scaling. Large-scale production campaigns, data management strategies and distributed analysis frameworks are being aligned with CERN IT services and GRID tools. Machine-learning methods are increasingly embedded in reconstruction and analysis workflows.

As with detectors, increasing emphasis is placed on realistic simulation studies incorporating beam-induced backgrounds and detailed geometries. While full-chain simulations are essential for understanding detector performance and comparing detector concepts, many precision studies also rely on developing robust analysis algorithms that can be validated across different simulation levels.

Notably, the PSC session also addressed human infrastructure. Recognising computing experts as core scientific contributors — with appropriate career paths and visibility — is viewed as essential for the long-term success of a data-intensive programme like the FCC.

A generational perspective

One of the most distinctive aspects of the Munich workshop was the visible role of early-career researchers. The FCC Early Career Forum (ECF) presented a draft document synthesising discussions from FCC Week 2025 and subsequent exchanges. Its themes — sustainability, communication, careers and governance — resonated across sessions.

Interwoven through technical sessions was the commitment to involve early career scientists. A dedicated session on Monday morning offered postdocs and graduate students a platform to present work and engage with senior experts, a key element in cultivating future leadership in the field.

Several discussions highlighted sustainability as a central design consideration for the FCC programme. Environmental, economic and social considerations must be integrated from the earliest design phases through operation and eventual decommissioning. Participants stressed the importance of engaging local and regional communities, and of clearly articulating how the FCC contributes to broader societal goals.

From concept to implementation culture

The Munich workshop made clear that the FCC programme is transitioning from a detailed study to a CERN project. With coordinated efforts across physics, detectors, computing, and accelerator physics, the community is laying the groundwork for a project that promises to extend our understanding of fundamental interactions and prepare particle physics for its next frontier.

Physics goals are now embedded in structured work packages with defined benchmarks. Detector concepts are evaluated against concrete performance metrics. Software frameworks are consolidated into sustainable ecosystems. Early-career voices are shaping governance and communication strategies. Sustainability considerations are woven into technical discussions.

For a project whose first beams would be twenty years away, this level of operational detail might seem premature to the philistine. Yet the workshop demonstrated that such depth is necessary precisely because of the timescales involved. Precision at the 10⁻5 or 10-6 level cannot be improvised; it must be engineered through decades of coordinated effort, to which the wider community is invited to contribute.

As participants departed Munich, the sense was not of a project awaiting endorsement, but of a community already rehearsing the practices of a future experiment. When the FCC proceeds, it will do so on foundations that are increasingly concrete — technically, organisationally and generationally.