Input to the European Strategy for Particle Physics - 2026 update

Submitted Input

273. 2026 EPPSU input from the ANUBIS Collaboration

It is imperative for us as a particle physics community to fully exploit the physics potential of the High-Luminosity LHC.
This calls for us not to leave any stone unturned in the search for Beyond the Standard Model (BSM) physics.
Many BSM models that address fundamental questions of physics like the particulate nature of dark matter, the matter-antimatter asymmetry in the Universe, small...

255. A Flexible Strategy for the Future of Particle Physics at CERN

This document outlines a strategy to ensure CERN remains at the forefront of particle physics by addressing the most pressing questions of our field in a timely and effective manner. The strategy balances ambition with feasibility—financially, logistically, and environmentally—while ensuring a robust path to exploring fundamental interactions at energies far beyond those of the LHC.

This...

133. A High-Precision, Fast, Robust, and Cost-Effective Muon Detector Concept for the FCC-ee

We propose a high-precision, fast, robust and cost-effective muon detector concept for an FCC-ee experiment. This design combines precision drift tubes with fast plastic scintillator strips to enable both spatial and timing measurements. The drift tubes deliver two-dimensional position measurements perpendicular to the tubes with a resolution around 100~$\mu$m. Meanwhile, the scintillator...

140. A Linear Collider Vision for the Future of Particle Physics

In this paper we review the physics opportunities at linear ee colliders with a special focus on high centre-of-mass energies and beam polarisation, take a fresh look at the various accelerator technologies available or under development and, for the first time, discuss how a facility first equipped with a technology that is mature today could be upgraded with technologies of tomorrow to reach...

165. A Possible Future Use of the LHC Tunnel

The FCC program at CERN provides an attractive all-in-one solution to address many of the key questions in particle physics. While we fully support the efforts towards this ambitious path, we believe that it is important to prepare a mitigation strategy in case the program faces unexpected obstacles for geopolitical or other reasons. This approach could be based on two components: I) a...

215. A roadmap for astroparticle theory in Europe

Important and challenging questions remain unanswered about the fundamental constituents of Nature, their interactions, and the evolution of the Universe and its extreme environments. Astroparticle physics, lying at the interface between particle physics, astrophysics and cosmology, aims to provide vital clues to answer them. A vibrant effort in theoretical astroparticle physics is needed to...

77. A Silicon-Tungsten ECAL for Higgs Factory Detectors

A highly granular electromagnetic calorimeter, based on silicon sensors associated with tungsten absorbers (SiW-ECAL), is proposed for the Higgs-Factory detectors, based on Particle Flow approach such as the ILD, the SiD, CEPC baseline, or the CLD. The concept has been developed considering all the technical, instrumental, and construction constraints for linear colliders, backed-up on tested...

271. A Spin-Based Pathway to Testing the Quantum Nature of Gravity

A key open problem in physics is the correct way to combine gravity (described by general relativity) with everything else (described by quantum mechanics). This problem suggests that one or both of these cherished theories may need fundamental corrections. Most
physicists expect that gravity should be quantum in character, but gravity is fundamentally different to the other forces because it...

142. A Straw Tracker for an FCC-ee experiment

We propose a straw tracker concept for an FCC-ee experiment. Combining excellent track reconstruction accuracy with a minimal material budget, the straw tracker enables precise momentum measurements with a resolution in the range of 0.1%. In addition, it provides excellent charged particle identification capabilities over a wide momentum range through dE/dX or dN/dX measurements.

88. A Survey of the Latin American High Energy Physics community on the future flagship project at CERN for the ESPP Update

This document collects input from Latin America as a contribution to the Update of the European Strategy for Particle Physics. It emerges from a survey of members of the Latin American Association for High Energy, Cosmology and Astroparticle Physics (LAA-HECAP) that collected data in February and a subsequent town-hall meeting, inspired by the ECFA guidelines for national communities. This...

65. Accelerator R&D proposals by INFN

The study of the next accelerator at CERN is fundamental to the future of European particle physics, as highlighted in the INFN National Input document. Within the current ESPP, INFN has already provided substantial support to the particle accelerator R&D program through various initiatives relating to the general design of the Future Circular Collider (FCC) and the muon collider, as well as...

168. Addressing Scientific Computing for HEP needs beyond Experimental Particle Physics

We propose the establishment of a specialized group at CERN focused on Advanced Scientific Computing. This group would address the increasing complexity of computing applications beyond experimental particle physics, such as Lattice QCD and event generator libraries for experiments at colliders. Building on advancements in heterogeneous computing, large-scale computation, and AI...

220. Advanced Accelerator and HEP Developments through Networking between the Large Particle Physics Laboratories and CERN

Together, the large particle physics laboratories of the CERN Member States and Associate Member States own significant resources. Their infrastructure and technical capabilities are necessary for the implementation of most large-scale projects in the field. The LDG provides a forum to synchronize the laboratories’ respective strategies, projects and priorities, with the aim of maximising...

216. Advancing Global Collaboration through the Electron-Ion Collider (EIC)

The Electron-Ion Collider (EIC) at Brookhaven National Laboratory represents a groundbreaking opportunity to explore the fundamental structure of matter by colliding polarized electron beams with polarized hadron beams. This facility is designed to address critical questions in Quantum Chromodynamics (QCD), particularly the role of gluons in binding quarks within nucleons and nuclei. With the...

167. AI-RDs: A EuCAIF proposal to structure AI research in Particle Physics

Accelerating the development and application of state-of-the-art artificial intelligence (AI) solutions for high-energy physics calls for a structured effort. The European Coalition for AI in Fundamental Physics (EuCAIF) provides a framework for coordinating AI research in fundamental physics. We propose AI Research and Development Groups (AI-RDs) to enable a long-term, fundamental AI research...

197. AMoRE Experiment

AMoRE searches for the signature of neutrinoless double beta decay
from the $^{100}$Mo with an experiment on the scale of 100 kg of the isotope $^{100}$Mo.
We developed scintillating molybdate crystals to run at millikelvin temperatures coupled with a metallic magnetic calorimeter and a SQUID sensor.
To demonstrate the full-scale AMoRE, we ran pre-experiments at the Yangyang Underground...

187. ATLAS Software and Computing for the Future

To achieve its physics program, the ATLAS collaboration operates large, internationally- distributed computing systems and maintains millions of lines of code. These systems and software are growing in complexity in preparation for the High Luminosity upgrade of the LHC. The planned development of the experiment software has been shaped by the integration, validation, and adoption of new...

203. Austrian input to the European Strategy of Particle Physics Update 2026

We present the current activities, future objectives and strategic needs of the Austrian particle physics research community. The present document will also outline our main recommendations and approach to future experiments and facilities at CERN and beyond. This document summarizes, among other consultation processes, three round table meetings which the Austrian community held in the last year.

172. AWAKE - Input to the European Strategy for Particle Physics Update on behalf of the AWAKE Collaboration

The Advanced Wakefield Experiment, AWAKE, is a well-established international collaboration and aims to develop the proton-driven plasma wakefield acceleration of electron bunches to energies and qualities suitable for first particle physics applications, such as strong-field QED and fixed target experiments (∼50–200 GeV). Numerical simulations show that these energies can be reached with an...

160. Beam monitoring through beamstrahlung

Beam monitoring is crucial for particle accelerators to achieve high luminosity. We describe our work to develop a reliable beam monitoring device utilizing observation of the beamstrahlung, radiation emitted by a beam of charged particles when it accelerates in the electromagnetic field of another beam of charged particles.

194. Brazilian input to the European Strategy for Particle Physics Update

TheBrazilianHigh-EnergyPhysics(HEP) community has expanded remarkably since its first involvement at CERN and Fermilab in the 1980s. Its recent organization under the Brazilian Network for High-Energy Physics (RENAFAE), since 2008, has further strengthened its scientific and technological goals, particularly in detector instrumentation, computing, and industry partnerships. In 2024, Brazil...

161. Call for a new approach to detector developments involving microelectronics

Microelectronics technologies form the basis of many innovative developments for HEP detectors and will continue to do so. However, the cost of access (both in terms of monetary resources and design manpower) has exploded over recent years. Even the largest experiments (ALTAS and CMS) have been obliged to pool design resources for their latest pixel detector upgrades. The Medipix...

248. Canadian pre-submission to the ESPP

This is the preliminary Canadian input to the ESPP. A full submission is anticipated for the May deadline.

71. CERN AD/ELENA Antimatter Program

The CERN AD/ELENA Antimatter program studies the fundamental charge, parity, time (CPT) reversal invariance through high-precision studies of antiprotons, antihydrogen, and antiprotonic atoms. Utilizing the world-unique Antiproton Decelerator (AD) and the Extra Low Energy Antiproton (ELENA) decelerator, the program supports multiple groundbreaking experiments aimed at testing fundamental...

18. CERN openlab: A Flagship Model for Industry-Science Computing R&D

CERN openlab is a unique public-private partnership initiative at CERN (European Organization for Nuclear Research), dedicated to addressing the ICT-related challenges of hosting the world's most advanced particle accelerator. Through strategic collaborations with leading technology companies, CERN openlab co-develops, tests, and integrates advanced computing solutions, ensuring timely access...

186. CERN-MEDICIS: A unique facility for the production of innovative biomedical research radionuclides

This document provides an input on behalf of the CERN-MEDICIS collaboration to the call for the European Strategy for Particle Physics Update (ESPPU) 2026 . While MEDICIS has been developping its programme for the past few years on the development of the production and supply of innovative medical radionuclides for translational research, 2025 acts as a corner stone for its translationnal...

74. Charged Lepton Flavour Violations searches with muons: present and future

Charged-lepton flavor violation (cLFV) is one of the most powerful probes for New Physics (NP). Since lepton flavor conservation is an accidental symmetry in the Standard Model (SM), it is naturally violated in many NP models, with contributions at the level of the current experimental sensitivities. Moreover, the negligible SM contributions would make the observation of cLFV unambiguous...

39. Clarifications for the Israeli Input for ESG

This document contains clarifications for the Israeli input for ESG. It is a summary of answers to specific questions, following the ECFA guides document.

107. CMS Offline Software and Computing input to the European Strategy for Particle Physics - 2026 update

This document outlines the CMS Offline Software and Computing strategy in preparation for the High-Luminosity LHC (HL-LHC) era and serves as input to the 2026 update of the European Strategy for Particle Physics. As CMS faces a significant increase in data volume, event complexity, and computing demands in Phase-2, this report details the necessary evolution of software, computing models,...

199. CODEX-b: Opening New Windows to the Long-Lived Particle Frontier at the LHC

This document is written as a contribution to the European Strategy of Particle Physics (ESPP) update. We offer a detailed overview of current developments and future directions for the CODEX-b detector, which aims to detect long-lived particles beyond the Standard Model. We summarize the scientific motivation for this detector, advances in our suite of simulation and detector optimization...

264. Coherent Neutrino-Nucleus Scattering Experiment (CONNIE)

Abstract

The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) employs low-noise, fully depleted charge-coupled devices (CCDs) to detect low-energy recoils from coherent elastic neutrino-nucleus scattering (CEνNS) of reactor antineutrinos in silicon, providing a window into physics beyond the Standard Model. The experiment operates approximately 30 meters from the core of the 3.8 GW...

218. COMET ---An Experiment to Search for Muon-to-Electron Conversion in Nuclear Field at J-PARC---

COMET is an experiment aiming to search for the muon to electron conversion in a nuclear field (µ-e conversion) with a sensitivity at a level of $10^{−17}$. The µ-e conversion is one of charged-Lepton Flavor Violation (cLFV) processes and not only strictly forbidden in the Standard Model of Particle Physics (SM), but also undetectable in a SM minimally extended via massive Dirac neutrinos....

144. Communicating for the future of particle physics

The European Particle Physics Communication Network (EPPCN) has its origins in the inaugural European Strategy for Particle Physics exercise in 2006. The need for greater coordination in communicating CERN’s large-scale scientific projects was a key recommendation and EPPCN was established at the request of the CERN Council.

EPPCN provides strategic communication guidance to CERN and its...

158. Community input to the European Strategy on particle physics: Searches for Permanent Electric Dipole Moments

Searches for electric dipole moments (EDMs) in fundamental particles and quantum
systems with spin are pivotal experiments at the intersection of low-energy and
high-precision particle physics. These investigations offer a complementary pathway to
uncovering new physics beyond the Standard Model, parallel to high-energy collider
searches. EDM experiments are among the most sensitive probes...

224. Community Support for Physics with high-luminosity proton-nucleus collisions at the LHC

This document promotes the physics case for the operation of high-luminosity proton-nucleus $p$A collisions during Run 3 and 4 at the LHC. The collection of $\mathcal{O}$(1--10 pb$^{-1}$) of proton-lead ($p$Pb) collisions at the LHC will provide broad and unique physics reach on multiple fronts including proton and nuclear Parton Distribution Functions (PDFs and nPDFs), Generalised Parton...

33. Computer Algebra for Precision Calculations in Particle Physics: the FORM project

Precision calculations in particle physics rely on computer algebra tools to manipulate and process the large-scale algebraic expressions that result from applying perturbation theory in the Standard Model. Commercial computer algebra packages are often insufficient to handle state-of-the-art problems. The FORM computer algebra system is a community-based effort overcoming these restrictions,...

127. Computing and software for LHCb Upgrade II

A second major upgrade of the LHCb experiment is necessary to allow full exploitation of the High Luminosity LHC for flavour physics. The new experiment will operate in Run 5 of the LHC at a maximum luminosity of $ 1.5 \times 10^{34}cm^{-2}s^{-1}$. The experiment will therefore experience extremely high particle fluences and data rates, posing a high challenge not only for the detector but...

7. Conclusions of the Town Meeting: Heavy Ion and QGP Physics at CERN

On Monday, February 17, 2025, a town meeting was held at CERN to gather input on heavy ion and quark gluon plasma (QGP) physics for the European Strategy for Particle Physics 2026. The meeting included brief presentations on current and upcoming heavy ion experiments at CERN's LHC and SPS, along with future projects at the FAIR facility in Darmstadt and Brookhaven RHIC. It also highlighted...

267. Constraining the real scalar singlet extension of the SM

The real scalar singlet extension of the Standard Model (SM) represents one of the simplest and most theoretically motivated scenarios beyond the SM, with potential implications for electroweak baryogenesis and vacuum stability. In this work, we present an up-to-date study of the model parameter space under current and projected constraints. We systematically combine indirect probes...

4. Contribution about Neutrino Physics to the European Strategy for Particle Physics

On behalf of the French community
structured by the Neutrino International Research Network

159. Contribution of ALEGRO to the Update of the European Strategy on Particle Physics

Advanced and novel accelerators (ANAs), driven a by laser pulse or a relativistic particle bunch, have made remarkable progress over the last decades. They accelerated electrons by 10 GeV in 30 cm (laser driven) and by 42 GeV in 85 cm (particle bunch driven). Rapid progress continues with lasers, plasma sources, computational methods, and more. In this document we highlight the main...

182. CONUS100: Precision neutrino physics with coherent elastic scattering of reactor neutrinos

Abstract:
Coherent Elastic Neutrino-Nucleus Scattering (CEvNS) was predicted in 1974, but it took until 2017 before it was first observed in the COHERENT experiment in pion decays at rest. Recently first indications were presented that solar neutrinos are detected in the direct dark matter experiments XENONnT and PandaX via CEνNS. Last but not least the reactor anti-neutrino experiment CONUS+...

252. Cosmic Microwave Background (CMB) as a window to particle physics.

Since the 1970s the Italian CMB community has played a leading role in several groundbreaking CMB experiments, including the very successful BOOMERanG and Planck projects, that have contributed significantly to the present-day era of precision cosmology, where models and theories can be tested and cross-checked with data from other fields, in particular high-energy physics. During the last ten...

25. Countering the biodiversity loss using particle physics research sites

Together with the climate changes and the finite amounts of resources, the loss of bio- diversity is one of the major global socio-ecological problems to tackle. Land use, degradation and destruction was identified as the major cause of biodiversity loss. The fact that all areas, even small or urban, are suitable places to work on countering this loss justifies that actions are conducted on...

106. Country input - Serbia

The Serbian research community strongly supports the Future Circular Collider (FCC) as CERN’s next major project, with FCC-hh as the preferred option due to its unparalleled energy reach and broad physics potential. While there is some backing for a Linear Collider (LC) and a Muon Collider, they are seen as secondary alternatives. Key considerations include physics potential, long-term...

59. Croatian national input to European Strategy for Particle Physics 2026 update

The Croatian high-energy physics community convened at the Faculty of Science of the University of Zagreb on February 18, 2025, to discuss its contributions to the third update of the European Strategy for Particle Physics. The meeting marked a critical step in shaping Croatia’s input to the update process, which is summarized in this document.

35. Cusp Spectroscopy, Hyperon-Nucleon Scattering, and Femtoscopy: Pioneering Tools for Next-Generation Hadron Interaction Studies

Cusp spectroscopy, hyperon-nucleon (YN) scattering, and femtoscopy are indispensable tools for unraveling the complexities of hadron interactions and hypernuclear physics. Cusp spectroscopy enables precise determination of scattering lengths and interaction strengths by analyzing threshold cusp structures. YN scattering experiments provide valuable information on hyperon-nucleon interactions,...

274. Dark Matter Complementarity: from the Snowmass process to the EPPSU

This submission consists of:

1. a main document (main.pdf), where we describe the dark matter complementarity whitepapers developed for the Snowmass process and the highlights that we would like to submit to the ESG
2. the extended version of the Snowmass dark matter complementarity whitepaper (dark_matter_complementarity_extended.pdf)
3. the summarised version of the same document...

268. Dark Matter Searches with Low-Radioactivity Argon

We present the case for the DarkSide-Argo program for direct dark matter searches
with low-radioactivity argon from underground sources.

The immediate objective is the DarkSide-20k two-phase liquid argon detector, currently under construction at the Gran Sasso laboratory (LNGS). DarkSide-20k will have ultra-low backgrounds, with the ability to measure its backgrounds in situ, and...

138. Data Preservation in High Energy Physics

Data preservation significantly increases the scientific output of high-energy physics experiments during and after data acquisition. For new and ongoing experiments, the careful consideration of long-term data preservation in the experimental design contributes to improving computational efficiency and strengthening the scientific activity in HEP through Open Science methodologies. This...

98. Design Initiative for a 10 TeV pCM Wakefield Collider

The community-driven Design Study for a 10 TeV pCM Wakefield Accelerator Collider introduced by this document is motivated by the 2020 ESPP Report emphasizing the need for advanced accelerator R&D for future colliders, and the 2023 P5 Report calling for the "delivery of an end-to-end design concept, including cost scales, with self-consistent parameters throughout" targeting the energy...

72. DESY’s role in Europe: A Contribution to the European Particle Physics Strategy Update Process

The Deutsches Elektronen-Synchrotron DESY is Germany’s largest acceler-
ator laboratory, with programmes in particle physics, astroparticle physics and
photon science, and with R&D activities in the areas of accelerators, detectors
and computing. In particle physics, DESY is a key contributor to experiments
at the LHC and at the SuperKEKB collider. The laboratory hosts the ALPS...

229. Development of Gaseous Detector Technologies: CERN-DRD1 Collaboration Model

This report summarizes CERN-DRD1 collaboration model and its main pillars

81. Discovery potential of LHCb Upgrade II

A second major upgrade of the LHCb detector is necessary to allow full exploitation of the HL-LHC for flavour physics. The new detector will be installed during long shutdown 4 (LS4), and will operate at instantaneous luminosity up to $1.5 \times 10^{34}\,{\rm cm}^{−2} {\rm s}^{−1}$. By upgrading all subsystems and adding new detection capability it will be possible to accumulate a sample...

108. DRD 6 Calorimetry - Input to European Strategy of Particle Physics Update (ESPPU)

This contribution outlines the status of plans of the DRD-on-Calorimetry (DRD 6).

121. DUNE Software and Computing Research and Development

The international collaboration designing and constructing the Deep Underground Neutrino Experiment (DUNE) at the Long-Baseline Neutrino Facility (LBNF) has developed a two-phase strategy toward the implementation of this leading-edge, large-scale science project. The ambitious physics program of Phase I and Phase II of DUNE is dependent upon deployment and utilization of significant computing...

42. Early Career Researcher Input to the European Strategy for Particle Physics Update — Fifty-five recommendations for the future of our field

This document, written by early career researchers (ECRs) in particle physics, aims to represent the perspectives of the European ECR community and serves as input for the 2025–2026 update of the European Strategy for Particle Physics. With input from a community-wide survey, it highlights key challenges faced by ECRs — career stability, funding access and long-term research opportunities —...

198. Einstein Telescope - The future European Gravitational Wave Observatory

The Einstein Telescope (ET) is a groundbreaking scientific initiative aiming to build a third-generation gravitational wave observatory with the ambitious goal of revolutionizing our understanding of the Universe.
ET will greatly exceed the sensitivity and range of current detectors, unlocking new horizons by detecting gravitational waves—spacetime ripples produced by events such as merging...

66. Empowering particle physics beyond discoveries: a unified European communication strategy for the next generation research infrastructures

Our society is experiencing a delicate historical moment, marked by critical issues and global challenges that are often interdependent. At the same time, the European particle physics community is facing decisive choices that will shape the future of research in the field and must ensure Europe's long-standing leadership in one of the most cutting-edge scientific sectors. In this complex...

17. Enabling future detector technology within ePIC at the EIC

The ePIC experiment at the EIC incorporates a wide variety of detector technologies. The different technological approaches are imposed by the broad EIC physics scope and by the nature of the collider, which is asymmetric in energy and beam particles, and by the wide variety of ion species that will collide with electrons. Major parts of the experiment use novel technologies, developed for...

112. Enhancing European Cooperation in the Search for Dark Matter

The search for dark matter is an exciting topic that is pursued in different communities over a wide range of masses and using a variety of experimental approaches.
The result is a strongly correlated matrix of activities across Europe and beyond, both on the experimental and the theoretical side.
We suggest to encourage and foster the collaboration of the involved institutions on...

234. Enhancing New Physics Searches with a Future Beam Dump Configuration at SBND

Accelerator-based neutrino experiments, especially those with high-intensity beams and highly capable detectors, offer a powerful and complementary method for probing new physics scenarios. The MiniBooNE experiment at Fermilab pioneered a special Booster Neutrino Beam (BNB) beam dump run and set new limits on sub-GeV dark matter. This white paper explores the physics opportunities enabled by...

79. Ensuring continued operation of INSPIRE as a cornerstone of the HEP information infrastructure

The INSPIRE platform — the most widely-used discovery service specifically tailored to
the needs of researchers in High Energy Physics (HEP) — has become a central component
of the information infrastructure for the discipline. Despite this, INSPIRE’s continued
sustainability is frequently endangered by resource constraints, recently made more acute
by the loss of support from historical...

259. Equity, Diversity and Inclusion: Strategic Elements of the European Particle Physics Programme

This document provides input concerning HEP programmes and activities in Equity, Diversity and Inclusion (EDI) for the open call for the European Strategy for Particle Physics Update (ESPPU) 2026. It briefly describes important development and growth of activity in EDI since ESPPU 2020, outlines current challenges, and provides specific recommendations for the High-Energy Physics (HEP)...

193. ESPP - 2026 update: input from the Romanian experimental particle physics community

RO-ESPP-2026-Update.pdf
RO-ESPP-2026-Update - Back-up document.pdf

254. ESPP Contribution - Gravitational Field of Proton Bunches

The Newtonian law describing the gravitational interaction of non-relativistic (slowly moving) gravitating matter, has been tested in many laboratory experiments with very high precision. In contrast, the post Minkowskian predictions for the gravitational field of ultra-relativistic matter, dominated by momentum instead of rest mass, have not been tested directly yet. The intense...

206. ESPPU contribution of Finland-2025

In the report current plans and some ideas for the future are reported for particle physics and related fields in Finland.

97. ESPPU INPUT: C3 within the "Linear Collider Vision"

The Linear Collider Vision calls for a Linear Collider Facility with a physics reach from a Higgs Factory to the TeV-scale with e$^+$e$^−$ collisions. One of the technologies under consideration for the accelerator is a cold-copper distributed-coupling linac capable of achieving high gradient. This technology is being pursued by the C$^3$ collaboration to understand its applicability to future...

151. ESSnuSB (European Spallation Source neutrino Super Beam)

ESSnuSB (the European Spallation Source neutrino Super Beam) is a design study for a Long Baseline (LBL) neutrino experiment to precisely measure the CP violation in the lepton sector, at the second neutrino oscillation maximum, using a beam driven by the uniquely powerful ESS proton linear accelerator in Lund, Sweden, a near detector suite and two large underground water Cherenkov detectors...

195. Estonian national input to the ESPP

The Estonian high-energy physics community, represented by the Estonian CERN Science Consortium, discussed potential candidates for CERN's next flagship experiment and reached the following conclusions.
Our first choice is the Future Circular Collider (FCC). The FCC offers the most compelling physics potential, with electron-electron (ee), electron-proton (ep), and proton-proton (pp)...

185. EuCAIF Recommendations for Scaling AI Capabilities in Particle Physics

Artificial intelligence (AI) is transforming scientific research, with deep learning methods playing a central role in data analysis, simulations, and signal detection across particle, nuclear, and astroparticle physics. Within the JENA communities—ECFA, NuPECC, and APPEC—and as part of the EuCAIF initiative, AI integration is advancing steadily. However, broader adoption remains constrained...

120. European Contributions to Fermilab Accelerator Upgrades and Facilities for the DUNE Experiment

The Proton Improvement Plan (PIP-II) to the FNAL accelerator chain and the Long-Baseline Neutrino Facility (LBNF) will provide the world's most intense neutrino beam to the Deep Underground Neutrino Experiment (DUNE) enabling a wide-ranging physics program. This document outlines the significant contributions made by European national laboratories and institutes towards realizing the first...

10. European Strategy for Particle Physics 2024-26 Israeli Input

This report constitutes Israel’s national contribution to the European Strategy for Particle Physics for 2024–2026. It provides an overview of the ongoing research activities and outlines future plans of the Israeli High Energy Physics community, covering experimental, theoretical (phenomenological), and formal theory research. The report also discusses key considerations and offers...

131. European Strategy for Particle Physics 2026: the NA60+/DiCE experiment at the SPS

The exploration of the phase diagram of Quantum ChromoDynamics (QCD) is carried out by studying ultrarelativistic heavy-ion collisions. The energy range covered by the CERN SPS ($\sqrt{s_{\rm \scriptscriptstyle{NN}}} \sim 6-17$ GeV) is ideal for the investigation of the region of the phase diagram corresponding to finite baryochemical potential ($\mu_{\rm B}$), and has been little explored up...

30. European training in instrumentation and particle accelerators

Training researchers in instrumentation and accelerator physics is crucial for the timely realization of the European Strategy for Particle Physics (ESPP). To achieve this, a coordinated and well-supported effort at the European level is necessary.
This document highlights the urgent need for a strategic plan to attract, train, and retain young talent in particle accelerator and detector...

236. Expanding the neutrino facility at the South Pole: IceCube-Upgrade and IceCube-Gen2

Since its completion in 2011, the IceCube Neutrino Observatory has opened a new window to the extreme Universe. Building on its success in multi-messenger astronomy and particle physics, the collaboration is pursuing two major extensions: the IceCube Upgrade, a low-energy addition under construction to enhance studies of neutrino properties and dark matter; and IceCube-Gen2, which is optimized...

155. Experimental Study of Rare Kaon Decays at J-PARC with KOTO and KOTO II

The rare kaon decay $K_L\to\pi^0\nu\bar{\nu}$ is extremely sensitive to new physics, because the contribution to this decay in the Standard Model (SM) is highly suppressed and known very accurately; the branching ratio is $3\times 10^{-11}$ in the SM with a theoretical uncertainty of just 2\%. The measurement of this branching ratio could provide essential new information about the flavor...

27. Exploring the Dark Universe: A European Strategy for Axions and other WISPs Discovery

Axions and other very weakly interacting slim (with $m <$ 1 GeV) particles (WISPs) are a common feature of several extensions of the Standard Model of Particle Physics. The search of WISPs was already recommended in the last update of the European strategy on particle physics (ESPP). After that, the physics case for WISPs has gained additional momentum. Indeed, WISPs may provide a new...

211. Expression of Interest for the ALLEGRO Full-Detector Concept for FCC-ee

The following document proposes ALLEGRO as a high-performance general-purpose detector concept for FCC-ee, that is being designed to fulfil all the requirements of its ambitious physics program. While the concept is centered around a noble-liquid based electromagnetic calorimeter, the technology choices concerning all other sub-detectors are open at this stage. We document interests and ideas...

262. Expression of Interest Toward MCMOS Time of Flight Tracking Layers for a detector at FCC-ee

We express interest to prepare a Time of Flight system to enhance the physics reach
of the FCC-ee detectors. The physics motivations are well established and we mostly
present here technical options considered and their possible implementations as ToF layers in the overall foreseen detector concepts. The performance target is to achieve a 30 ps MIP ToF precision with Monolithic CMOS sensor...

95. Expressions of Interest for the Development of Detector Concepts and Sub-detector Systems for the Future Circular Collider FCC

Contact persons: M. Dam, M.-A. Pleier, F. Sefkow

This document accompanies a compilation of submissions of Expressions of Interest
(EoIs) for the development of detector concepts and sub-detector systems for the
Future Circular Collider (FCC). The actual EoIs can be found in a back-up document
submitted in parallel; they are also collected in an indico repository and individually
linked...

233. FCC Integrated Programme Stage 1: The FCC-ee

The Future Circular Collider (FCC) ‘integrated programme’ consists of an initial electron-positron collider FCC-ee, which is followed by a proton-proton collider, FCC-hh. This integrated programme is well matched to the current scientific landscape after 15 years of LHC operation. The proposed staging takes into account: (1) the physics priorities as developed and stated by EPPSU 2013 and...

247. FCC Integrated Programme Stage 2: The FCC-hh

The Future Circular Collider (FCC) 'integrated programme' consists of an initial electron-positron collider FCC-ee, which is later followed by a proton-proton collider, FCC-hh. This comprehensive programme is well matched to the current scientific landscape after 15 years of LHC operation. The proposed staging takes into account: (1) the physics priorities as developed and stated by EPPSU 2013...

209. FCC: QCD physics

he Future Circular Collider (FCC) will deliver unprecedented precision in the measurement of the properties and parameters of the Standard Model (SM), directly and indirectly probing new physics up to the 100-TeV scale. Its broad and diverse programme, including very high-luminosity $\rm e^+e^-$ collisions (FCC-ee) and hadronic collisions at the energy frontier (FCC-hh), will offer exceptional...

11. Fermilab Interest in a Higgs Factory at CERN

The 2023 Particle Physics Project Prioritization Panel (P5) in the US, in putting forth a strategic plan for the US in the context of a 20 year vision for global particle physics, has recommended the construction of an off-shore Higgs Factory and that the US engage in the feasibility studies and contribute and collaborate if the project is approved for construction.

Fermilab teams have made...

15. French HEP community input to the European Strategy for Particle Physics

In view of the European Strategy for Particle Physics process, the French HEP community has organized a national process of collecting written contributions and has pursued a series of workshops culminating with a national symposium held in Paris on January 20-21, 2025 that involved over 280 scientists. The present document summarises the main conclusions of this bottom-up approach centred on...

70. Frontier sensor R&D for the ALICE 3 apparatus

The ALICE Collaboration plans to build a new experimental setup, ALICE3, which will be installed during Long Shutdown 4. This apparatus will maximize the potential of the HL-LHC as a heavy-ion collider by giving access to new and unexplored experimental observables, thereby enabling the investigation of open fundamental questions regarding the quark-gluon plasma and other aspects of the strong...

20. Future of CERN

Focal point: It is too early to decide the future of CERN from now all the way until the end of this century.

69. Future Opportunities with Lepton-Hadron Collisions

Deep Inelastic lepton-hadron Scattering (DIS) is a cornerstone of particle physics discovery and the precision measurement of the structure of matter. This document surveys the international DIS landscape, exploring current and future opportunities to continue this rich heritage, leading to new understandings and enabling discoveries. Of immediate relevance to the future of the field in...

75. Future perspectives for $\mu \to e \gamma$ searches

Searches for charged lepton flavor violation in the muon sector stand out among the most sensitive and clean probes for physics beyond the Standard Model. Currently, $\mu^+ \to e^+ \gamma$ experiments provide the best constraints in this field and, in the coming years, new experiments investigating the processes of $\mu^+ \to e^+e^+e^-$ and $\mu \to e$ conversion in the nuclear field are...

54. Grenoble Axion Haloscopes: From BabyGrAHal to GrAHal for axion dark matter search in the 1-150 micro-eV mass range

Particle physics is not only confined to the high energy frontier. There are unexplored territories at ultra-low energies, i.e. sub-eV, which are also promising for major discoveries. The emblematic particle for this physics is the axion, a pseudo-scalar particle predicted to solve the fundamental problem of the apparent non-violation of the CP symmetry by the strong interaction. This...

57. HALHF: a hybrid, asymmetric, linear Higgs factory using plasma- and RF-based acceleration

HALHF is a hybrid linear collider that uses electron-driven plasma-wakefield acceleration to accelerate electrons to high energy while using radio-frequency cavity technology to accelerate positrons. The most cost-effective solution collides low-energy positrons with high-energy electrons, producing a boost to the final state in the electron direction with $\gamma= 1.67$. The current HALHF...

82. Heavy ion physics with LHCb Upgrade I

A second major LHCb detector upgrade will be installed during long shutdown 4 (LS4) of the CERN Large Hadron Collider. The new detector will provide excellent performance for studies of Quantum Chromodynamics at high temperature and density, as achieved in collisions of heavy nuclei. The high granularity of the tracking system will allow lead-lead collisions to be reconstructed across the full...

26. HFLAV input to the 2026 update of the European Strategy for Particle Physics

Heavy-flavour physics is an essential component of the particle-physics programme, offering critical tests of the Standard Model and far-reaching sensitivity to physics beyond it. Experiments such as LHCb, Belle II, and BESIII drive progress in the field, along with contributions from ATLAS and CMS. The LHCb Upgrade II and upgraded Belle II experiments will provide unique and highly sensitive...

85. Higgs Criticality and the Metastability Bound: a target for future colliders

New physics at the TeV scale or lower may destabilise the electroweak vacuum. How low could the vacuum instability scale be? This fundamental question may be tied to a deeper understanding of the Higgs potential and its associated hierarchy problem. The scale of vacuum instability can be viewed as an upper bound on the Higgs mass-the so-called vacuum metastability bound-and criticality of the...

243. High Field Magnet Programme – European Strategy Input

In this submission, we describe research goals, implementation, and
timelines of the High Field Magnet Programme, hosted by CERN. The
programme pursues accelerator-magnet R&D with low-temperature-
and high-temperature superconductor technology with a main focus
on the FCC-hh. Following a long tradition of magnet R&D for high-
energy particle colliders, HFM R&D fosters important societal...

49. High Performance and Cost Effective Superconducting Accelerator Magnet R&D at IHEP

High-field superconducting accelerator magnets are pivotal components for next-generation high-energy accelerators such as the Super Proton-Proton Collider (SPPC) and the Future Circular Collider (FCC-hh). Enhancements in field strength are directly correlated with increases in center-of-mass energy, as well as reductions in size and cost of the accelerators. Initiated in 2014, the Institute...

170. Highlights of the HL-LHC physics projections by ATLAS and CMS

The ATLAS and CMS experiments are unique drivers of our fundamental understanding of nature at the energy frontier. In this contribution to the update of the European Strategy for Particle Physics, we update the physics reach of these experiments at the High-Luminosity LHC (HL-LHC) in a few key areas where they will dominate the state-of-the-art for decades to come. With a collected luminosity...

181. HOLMES+ Project

HOLMES+ is the natural evolution of the HOLMES project toward an ambitious experiment capable of directly measuring a neutrino mass lower than 100 meV. Since HOLMES, together with the competing ECHo experiment, has demonstrated both the feasibility of electron-capture calorimetry with $^{163}$Ho as a method for investigating neutrino mass and the availability of all the necessary technologies,...

104. HTS Potential and Needs for Future Accelerator Magnets

HTS has the potential of a game changer for many applications of superconductivity, not last in the field of particle accelerators and detectors. This paper explores the potential of HTS, with a focus on REBCO-coated conductors, in relation to the evolving demands of superconducting magnets for accelerators. HTS already have a spectacular current carrying ability at high field, demonstrated...

226. ICARUS contribution to the European Strategy Process 2026

We present the scientific and technical progress from the ICARUS experimental project at Fermilab. The ICARUS detector represents a major investment in accelerator neutrino science and liquid argon technology from Europe and particularly from INFN/Italy. This report is a summary from the ICARUS collaboration for the European Strategy for Particle Physics Update 2025-26. We will describe the...

80. INFN - Gran Sasso National Laboratory - Input for the European Particles Physics Strategy

In the panorama of Astroparticles Physics, Deep Underground Laboratories (DULs) play a key role in characterizing astronomical particles sources, elementary particles properties and stellar nuclear reactions. The main mission of DULs in particle physics is to enable world-class science that requires low-background environment. In that sense LNGS is considered as the leading laboratory in the...

73. INFN Input on the update of the European Strategy for Particle Physics: Computing

Computing plays a crucial role in High-Energy Physics experiments and, to deal with the large amount of data that will be collected in the HL-LHC era and beyond, substantial changes are needed both in the software and computing models of the experiments and in the computing infrastructure. The HEP community can't rely only on the current High-Throughput Computing infrastructure and has to take...

62. INFN National Committee for Particle Physics (CSN1): Input to the European Strategy for Particle Physics Update

This document represents the input of INFN CSN1 to the European Strategy for Particle Physics Update. CSN1 (Commissione Scientifica Nazionale 1) is the INFN scientific committee in charge of reviewing, monitoring, and supporting particle physics experiments and projects at accelerators. The projects supported on the mid-term, in construction or approved, are briefly described, followed by...

208. Initial INFN Input on the Update of the European Strategy for Particle Physics

Advancing particle physics through the development of a new accelerator at CERN represents a primary step in exploring the frontiers of fundamental science. Such an endeavour is crucial to addressing key unanswered questions in physics, including the nature of the electroweak symmetry breaking, the hierarchical pattern of fermion masses, the nature of dark matter, the unification of the...

277. Initial input from the Danish CERN Community to the European Strategy for Particle Physics update

This document presents the interests and priorities of the Danish high energy and nuclear physics community based on the town hall meeting held by the National Center for CERN research (NICE) in January 2025 in Nyborg, Denmark, and other dedicated meetings and consultations.

276. Input by the AstroParticle Physics European Consortium

This statement as input to ESPP 2026 summarises some recommendations on how the common goals of answering fundamental physics questions can be achieved synergistically by astroparticle physics and particle physics on a European basis in an efficient and sustainable way. The recommendations are then followed by the core statements of the European Strategy for Astroparticle Physics (Update...

6. Input for the EUROPEAN STRATEGY FOR PARTICLE PHYSICS UPDATE 2026 compiled by THE ISOLDE COLLABORATION COMMITTEE

The scientific opportunities using the ISOLDE Facility are presented as a series of themes that are expected to form the scientific programme for the facility in future running periods. The facility status, operations and competitiveness are discussed. The facility developments planned for the LS3 period and for future shutdowns are outlined. Ideas for the longer term are discussed within the...

68. Input from the ALICE Collaboration

The ALICE Collaboration is planning to build a new experimental apparatus, ALICE3, to be installed during Long Shutdown 4, that will ensure the full exploitation, before the end of the HL-LHCoperations, of the unique environment for the study of the quark-gluon plasma (QGP) offered by nuclear collisions at the multi-TeV scale. The very high QGP temperatures, the abundant production of heavy...

173. Input from the Netherlands to ESPP 2026

The process of shaping the input from the Netherlands for the European Strategy Update has been led by the Dutch National Institute for Subatomic Physics Nikhef. It has been a structured, open and iterative effort, starting early-2024 by broadly informing our community, followed by multiple days of in-depth presentations and discussions. We concluded the process with an open session to refine...

63. Input from the SND@LHC collaboration to the 2026 Update to the European Strategy for Particle Physics

By observing collider neutrino interactions of different flavours, the SND@LHC and Faser$\nu$ experiments have shown that the LHC can make interesting contributions to neutrino physics. This document summarizes why the SND@LHC Collaboration intends to continue taking data at the High Luminosity LHC (HL-LHC).

The upgraded detector will instrument the regions of both the neutrino vertex...

183. Input of the German Nuclear and Hadron Physics Community to the ESPPU 2026 Regarding the Programs at CERN, at FAIR, and Related Activities

This document summarizes the contributions of the German nuclear and hadron physics community, represented by the elected KHuK committee, to the ESPPU 2026 and complements the input from the German particle physics community submitted by KET\footnote{https://www.ketweb.de/stellungnahmen/}. Our statements and recommendations are based on both our established priorities and those outlined in the...

47. Input of Ukraine to the 3rd Update of the European Strategy for Particle Physics

The discovery of the Higgs boson at the LHC confirmed the validity of the Standard Model (SM) across a broad range of energies. However, the SM remains incomplete as it does not incorporate gravity, explain neutrino masses, or address dark matter, highlighting the need for a more comprehensive theory that ongoing and future accelerator-based research aims to uncover. In this regard, a new...

76. Input on the update of the European Strategy for Particle Physics by the INFN Nuclear and Hadron Phyiscs Community

This document contains input from the INFN Nuclear and Hadron Physics Commission 3 (CSN3) to the ongoing development of INFN contributions to the update of the European Strategy for Particle Physics. The medium-term strategy for Nuclear and Hadron Physics at the Italian National Laboratories has been the subject of an extensive review in 2022, involving the whole Italian CSN3 scientific...

126. Input to ESPPU by the German Astroparticle Community

This document summarises, from a German perspective, the close relation of astroparticle physics and particle physics. It specifically identifies CERN activities complementing and supporting astroparticle physics, and concludes with recommendations on cooperation between both fields, on the projects mentioned, and on suggested astroparticle-related activities at CERN.

265. Input to European Strategy Update for Particle Physics: Sustainability

Human activity continues to have an enormous negative impact on the ability of the planet to sustain human and other forms of life. Six out of the nine planetary boundaries have been crossed, a seventh is close to threshold. Prominent manifestations of this development are climate change caused by greenhouse gas emissions, as well as loss of biodiversity. In recognition of the urgency of these...

41. Input to the European Strategy for Particle Physics - 2026 update by the Czech particle physics community

This document presents the strategic priorities of the Czech particle physics community in response to the European Strategy Group's key questions. It outlines the near-term commitment to the High-Luminosity Large Hadron Collider (HL-LHC) upgrade, evaluates the preferred path for the next-generation collider, and discusses broader research directions beyond the main collider program.

136. Input to the European Strategy for Particle Physics - 2026 update from the Greek Community

This report presents the views of the Greek particle physics community regarding the future of high-energy physics in Europe, particularly in relation to the European Strategy for Particle Physics (ESPP) update. The survey outlines the community’s academic and research profile, current challenges, and preferences for future projects. The dominant preference is for the Future Circular Collider...

253. Input to the European Strategy for Particle Physics - 2026 update: The COHERENT Experiment

The COHERENT experiment measures neutrino-induced recoils from coherent elastic neutrino-nucleus scattering (CEvNS) with multiple nuclear targets at the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL), USA.
Three successful CEvNs measurements have been achieved in the recent years with tens-of-kg detector masses, with a CsI scintillating crystal; a liquid...

14. Input to the European Strategy for Particle Physics 2024-2026 from the Hungarian high-energy physics community

The document summarizes the Hungarian national input to the European Strategy for Particle Physics 2024-2026, representing the high-energy physics community.

132. Input to the European Strategy for Particle Physics – KATRIN collaboration

Direct kinematic neutrino-mass measurement is essential for determining the absolute neutrino mass scale, a key unknown in particle physics with deep implications for cosmology and for theories beyond the Standard Model. Unlike neutrino oscillation experiments, which probe mass differences, kinematic methods directly measure absolute neutrino masses. Precision spectroscopy of weak decays, such...

191. Input to the European Strategy for Particle Physics: Strong-Field Quantum Electrodynamics

The attached document sets out the intention of the strong-field QED community to carry out, both experimentally and numerically, high-statistics parametric studies of quantum electrodynamics in the non-perturbative regime, at fields approaching and exceeding the critical or ‘Schwinger’ field of QED. In this regime, several exotic and fascinating phenomena are predicted to occur that have...

123. IUPAP Commission 11 (Particles and Fields) Support Letter on behalf of the High Energy Physics (HEP) Information Infrastructure

High Energy Physics (HEP) is a data-intensive and highly collaborative scientific field that produces, analyses, and distributes large amounts of information around the globe, including experimental results, theoretical models, and computational simulations. Efficient curation, analysis, and dissemination of the information produced by international experimental collaborations and theoretical...

99. Japan's Updated Strategy for High Energy Physics for the ESPP Update 2026

The Japanese High Energy physics community, JAHEP (Japan Association of High Energy Physicists) provides Japan's Updated Strategy for High Energy Physics for the ESPP Update 2026. High energy physics research in Japan encompasses a variety of groundbreaking experiments conducted at major facilities. These include the SuperKEKB accelerator and the Belle II experiment, which focus on search for...

124. JENA White Paper on European Federated Computing

The Joint ECFA-NuPECC-APPEC (JENA) Activities launched an initiative (JENA Computing) in 2023 to promote the increasing need for discussions on the strategy and implementation of European federated computing at future large-scale research facilities. In workshops and dedicated working groups on specific topics, expert groups from all relevant research areas were formed to compile an overview...

55. Kaon Physics: A Cornerstone for Future Discoveries

The kaon physics programme, long heralded as a cutting-edge frontier by the European Strategy for Particle Physics, continues to stand at the intersection of discovery and innovation in high-energy physics (HEP). With its unparalleled capacity to explore new physics at the multi-TeV scale, kaon research is poised to unveil phenomena that could reshape our understanding of the Universe.
This...

240. Key4hep: A Software Framework for Future Colliders

The Key4hep project provides a collaborative software ecosystem for the development and study of future collider detector concepts. Initiated in 2019 by multiple
international particle physics communities, it offers a comprehensive software
infrastructure for simulation, reconstruction, and analysis. By developing its
own event data model, EDM4hep, and integrating it with established tools...

249. KM3NeT contribution to the European Strategy for Particle Physics

The two KM3NeT neutrino detectors, currently under construction in the Mediterranean Sea, have been optimised to cover a broad neutrino energy range, spanning from a few GeV to tens of PeV. This document aims to highlight the expected key physics results. In particular the ORCA detector, designed to study neutrino oscillations in the atmospheric neutrino flux, will be able to determine the...

13. Laboratori Nazionali di Frascati of INFN

This document presents the status and plans of the INFN Frascati Laboratory, the largest Italian infrastructure in particle physics. Established in 1957 for the development of particle accelerators, it is the oldest national laboratory of the INFN and is renowned world-wide for its contributions to both theoretical and experimental physics.
At present, it offers infrastructure for accelerator...

270. LEGEND-1000

The observation of neutrinoless double-beta decay (0νββ) would show that lepton number is violated, reveal that neutrinos are Majorana particles, and provide information on the neutrino mass. The LEGEND collaboration, founded in 2016, is developing a phased, $^{76}$Ge based double-beta decay experimental program located at the Italian Underground Laboratori Nazionali del Gran Sasso (LNGS). The...

269. LEP Data@EDM4HEP: Mitigating Data Loss Risks and Strengthening FCC-ee Potential Studies

The LEP data represent the most precise sample of e+e- collision data collected to date. Numerous scientific articles have been published since the conclusion of the experiments, underscoring the ongoing relevance of this dataset. In the context of FCC-ee, these data could play a crucial new role, which would be significantly enhanced by making them available in a standardized event data...

188. LEP3: A High-Luminosity e+e− Higgs & Electroweak Factory in the LHC Tunnel

As stated in the 2019 European Strategy for Particle Physics (ESPP), it is of the utmost importance that the HL-LHC upgrade of the accelerator and the experiments be successfully completed in a timely manner. All necessary efforts should be devoted to achieving this goal.
We also recall two of the principal recommendations of the 2019 ESPP for future accelerator initiatives, namely that
•...

213. LHCspin: a Polarized Gas Target for LHC

The goal of the LHCspin project is to develop innovative solutions for measuring the 3D structure of nucleons in high-energy polarized fixed-target collisions, exploring new processes and new probes in a unique, poorly explored kinematic regime at LHC beam energies.
This ambitious task is being based on the recent experience with the successful installation and exploitation of the SMOG2...

2. Light Ion Collisions at the LHC

In the week of 11-15 November 2024, more than 150 theorists, experimentalists and accelerator physicists met at CERN to discuss newly emerging opportunities with light ion beams, [cern.ch/lightions][1]. This workshop responded to the growing realisation that light ion collisions open qualitatively novel possibilities for the study of QCD at extreme temperature or parton densities. In...

83. Lithuanian Particle Physics Community Input to the 2026 Update of European Strategy for Particle Physics

Current engagements of the Lithuanian particle physics community are outlined together with the opinion on the focus of near-term European strategy for particle physics.

37. Long-Baseline Atom Interferometry

Long-baseline atom interferometry is a promising technique for probing various aspects of fundamental physics, astrophysics and cosmology, including searches for ultralight dark matter (ULDM) and for gravitational waves (GWs) in the frequency range around 1~Hz that is not covered by present and planned detectors using laser interferometry. The MAGIS detector is under construction at Fermilab,...

122. LVK contribution on Gravitational Waves Physics

The first detection of GW in 2015 and the successful data recording campaigns of those last ten years have opened a new avenue for observing the Universe, studying general relativity and the fundamental interactions that govern it. GW detection constitutes a pillar of multimessenger astronomy in place today and for the 2030s.
The improved sensitivity of the LIGO-Virgo-KAGRA interferometers...

105. Magnet R&D for the Muon Collider

The Muon Collider, proposed under the International Muon Collider Collaboration (IMCC), represents a groundbreaking advancement in circular collider technology. By using muons instead of protons or electrons, this collider has the potential of unprecedented discovery reach, luminosity, and compact design, significantly increasing energy efficiency, reducing environmental impact and improving...

61. MATHUSLA: An External Long-Lived Particle Detector to Maximize the Discovery Potential of the HL-LHC

We present the current status of the MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) long-lived particle (LLP) detector at the HL-LHC, covering the design, fabrication and installation at CERN Point 5. MATHUSLA40 is a 40 m-scale detector with an air-filled decay volume that is instrumented with scintillator tracking detectors, to be located near CMS. Its large size,...

154. Midterm Review of the European Accelerator R&D Roadmap

The European Accelerator R&D Roadmap with five topical R&D panels was implemented in 2022, following a recommendation of the 2020 update of the European Strategy for Particle Physics Update (ESPPU) to intensify the accelerator R&D. This first phase of the accelerator roadmap is planned till 2026. In February 2025 a mid-term review of the roadmap activities has been conducted on behalf of LDG,...

149. MINERvA neutrino interaction experiment input to the ESPP

The MINERvA neutrino interaction experiment operated at Fermilab from 2009 to 2019. We achieved a set of measurements on nuclei from helium to lead that support current and future neutrino experiments. Among neutrino experiments, we have a world-leading number of scientific publications with about twenty more in the pipeline. In our experience, new measurements on elementary nucleons (hydrogen...

245. MUonE Contribution to the European Strategy: status of the project

The MUonE experiment aims at an independent and very precise determination of the leading hadronic contribution to the muon magnetic moment, based on an alternative method, complementary to the existing ones. This can be achieved by measuring with unprecedented precision the shape of the differential cross section of μe elastic scattering, using the intense muon beam available at CERN, with...

257. National input from Belgium to the 2026 Update to the European Strategy for Particle Physics

This document summarises the input of the Belgian scientists to the European Strategy Group (ESG) in the context of the upcoming European Strategy Update for Particle Physics (ESPP) research. The Belgian HEP community, together with related community representatives, met on several occasions to exchange views on future collider and non-collider based high energy physics experiments. Our...

110. National Input from the Swedish Community to the Update of the European Strategy for Particle Physics

This document presents Sweden's national input to the 2026 update of the European Strategy for Particle Physics (ESPP). The status and current involvements of the Swedish community working on both experiments and theory are first described in order to provide some context, however a more comprehensive overview of particle physics activities in Sweden was provided in the previous ESPP update in...

176. National input from the United Kingdom to the 2026 Update to the European Strategy for Particle Physics

This document has been prepared on behalf of the UK particle physics community to provide input to the 2026 Update to the European Strategy for Particle Physics (ESPPU). The UK process began with an initial workshop hosted by the IPPP in Durham in September 2024, aiming to bring together the experimental and theoretical communities to discuss the physics and technological opportunities and...

192. National Input to the European Strategy for Particle Physics 2026 - Slovenia

The document summarizes the Slovenian input to the ESPP 2026 update process.

272. Neutrino Astronomy in the Peruvian Andes with TAMBO

The detection of high-energy astrophysical neutrinos by IceCube has opened a new window on our Universe. While IceCube has measured the flux of these neutrinos at energies up to several PeV, much remains to be discovered regarding their origin and nature. Currently, measurements are limited by the small number of astrophysical neutrino sources discovered and by the difficulty of discriminating...

135. Neutrino Scattering: Connections Across Theory and Experiment

In this document drafted by the Neutrino Scattering Theory Experiment Collaboration (NuSTEC), we provide input on the synergies between theoretical and experimental efforts that can provide critical input to the prediction accuracy needed for the forthcoming high-precision neutrino measurements. These efforts involve a wide range of energies and
interaction processes, as well as target nuclei...

38. Neutrino Theory in the Precision Era

This document summarises discussions on future directions in theoretical neutrino physics, which are the outcome of a neutrino theory workshop held at CERN in February 2025. The starting point is the realisation that neutrino physics offers unique opportunities to address some of the most fundamental questions in physics. This motivates a vigorous experimental programme which the theory...

200. Neutrinos from Stored Muons (nuSTORM)

The Neutrinos from Stored Muons, nuSTORM, facility has been designed to deliver a definitive neutrino-nucleus scattering programme using beams of $\nu_e$ and $\nu_\mu$ from the decay of muons confined within a storage ring. The facility is unique, it will be capable of storing $\mu^\pm$ beams with a central momentum of between 1\,GeV/c and 6\,GeV/c and a momentum spread of 16\%. This...

139. Neutrinos@CERN: A Community-Driven Contribution to the Update of the European Strategy for Particle Physics

The Neutrinos@CERN workshop was held on January 23-24, 2025, at CERN. Organized by the CERN Neutrino Platform and Physics Beyond Colliders, this two-day event aimed to explore opportunities for neutrino physics experiments at CERN, leveraging existing, planned, and proposed facilities. The workshop brought together a significant portion of the neutrino physics community to discuss these...

177. Norwegian Input to the European Strategy for Particle Physics

Norwegian experimental and theoretical particle physics, heavy-ion physics, nuclear physics, astroparticle physics, and cosmology, present their research programme for the next period of the European Strategy for Particle Strategy Update. The Norwegian response to the ECFA questionnaire concerning the future of particle physics in Europe is detailed, including our preferred flagship project(s)...

266. Novel 3D-Projection Pixelated Detector for Next-Generation High-Energy Physics Experiments

We are proposing a single, homogeneous, and cost-effective calorimetry system capable of seamlessly achieving particle identification, tracking, and energy measurement. While 3D-projection readout, opaque liquid scintillators, and metal doping have each been investigated separately, this project for the first time combines all three into a fully homogeneous and active detector with...

103. Nuclear Physics and the European Particle Physics Strategy Update 2026

This document provides input to the update of the European Strategy for Particle Physics in fields that are related to Nuclear Physics as described in the NuPECC Long Range Plan 2024 https://arxiv.org/abs/2503.15575.

53. P-ONE: The Pacific Ocean Neutrino Experiment A Next-Generation Deep-Sea Neutrino Detector for Fundamental Physics

The Pacific Ocean Neutrino Experiment (P-ONE) is a next-generation neutrino observatory planned for deployment in the deep Pacific Ocean off the coast of Canada. By detecting high-energy (up to the PeV scale) and ultra-high-energy (above the PeV scale) cosmic neutrinos with unprecedented sensitivity and resolution, P-ONE will probe extreme cosmic environments—such as those powered by black...

169. Pakistan Input to the European Strategy for Particle Physics 2026

1. Introduction
2. Pakistan’s Contributions to the European Strategy for Particle Physics
3. Proposed Areas for Collaboration
4. Answers to ECFA questions
5. Executive Summary

48. Particle Data Group Input to European Strategy for Particle Physics Update

The Particle Data Group's (PDG) Review of Particle Physics is used pervasively throughout particle physics. This document summarizes the organization and funding of the international PDG collaboration with an emphasis on European contributions, provides usage statistics, and discusses the input received from the user community in a comprehensive survey carried out in 2022. In order to ensure...

190. Particle Physics at the European Spallation Source

In this paper we outline the opportunities for fundamental nuclear and particle physics at the European Spallation Source, which will eventually be the world’s most powerful pulsed neutron source and simultaneously the worlds brightest pulsed neutrino source. The ESS provides unprecedented and unique opportunities to address outstanding questions in the Standard Model of particle physics,...

32. Performance study of the MUSIC detector in $\sqrt{s}=10$ TeV muon collisions

This study investigates the performance of the MUSIC (MUon System for Interesting Collisions) detector concept in the context of sqrt{s} = 10 TeV muon-antimuon collisions. The detector is designed to mitigate machine-induced background effects while maintaining high efficiency and accuracy in reconstructing physics events, particularly in the Higgs boson sector and searches for new physics....

56. PERLE : an ERL facility for future sustainable colliders (LHeC, FCC)

Energy recovery linacs (ERLs) have been emphasized by the 2020 update of the European Strategy for Particle Physics as one of the most promising technologies for the accelerator base of future high-energy physics. Their unique combination of bright, linac-like beam quality with high average current and extremely flexible time structure, excellent operating efficiency, and compact footprint...

174. Phase-One LHeC

In White Paper on the Large Hadron electron Collider (LHeC), submitted to the ESPP Update, its commissioning is proposed several years after the completion of the HL-LHC programme in 2041. Here an alternative staged approach is considered in which a phase-one LHeC is using a 20 GeV single-pass Energy Recovery Linac (ERL), to be commissioned at P2 after LS4 allowing for unique studies of the...

251. Physics opportunities with high-brightness, high-intensity muon beams at CERN: a staged approach

This report presents new physics opportunities at CERN made possible by muon and neutrino beams of unprecedented intensity, achieved through a staged approach in the realization of the Muon Collider as proposed by the International Muon Collider Collaboration (IMCC).

Unlike other facilities, in a multi-TeV Muon Collider every advancement in energy and intensity opens new windows of...

239. Physics Prospects for a near-term Proton-Proton Collider

Hadron colliders at the energy frontier offer significant discovery potential through precise measurements of Standard Model processes and direct searches for new particles and interactions. A future hadron collider would enhance the exploration of particle physics at the electroweak scale and beyond, potentially uniting the community around a common project. The LHC has already demonstrated...

115. PIONEER: a next generation rare pion decay experiment

PIONEER: A next-generation rare pion decay experiment

PIONEER is a rapidly developing effort aimed to perform a pristine test of lepton flavour universality (LFU) and of the unitarity of the first row of the CKM matrix by significantly improving the measurements of rare decays of the charged pion. The experiment is approved at the Paul Scherrer Institute (PSI). In Phase I, PIONEER aims to...

16. Polish national input to the 2026 update of the European Strategy for Particle Physics

The Polish high energy physics (HEP) community fully recognizes the urgent need to host at CERN a flagship project implementing a broad, long-term, and comprehensive vision of particle physics research and pursuing technological advances. Thus, we give preference and declare willingness to actively engage and participate in every aspect of the FCC project (both FCC-ee and FCC-hh), particularly...

45. Portuguese HEP community input to the update of the European Strategy for Particle Physics

Following the European Strategy Group’s call for national contributions to update the European Strategy for Particle Physics, the Portuguese community of particle physicists collaborated with its national representatives at the CERN Council and ECFA to organise the process for preparing the Portuguese input. This document was prepared in a collaborative way and reflects the position of the...

89. Precision cross-sections for advancing cosmic-ray physics

The latest generation of cosmic-ray direct detection experiments is providing a wealth of high-precision data, stimulating a very rich and active debate in the community on the related strong discovery and constraining potentials on many topics, namely dark matter nature, and the sources, acceleration, and transport of Galactic cosmic rays. However, interpretation of these data is strongly...

100. Probing and Knocking with Muons

We propose here a set of new methods involving probing and knocking with
muons (PKMu). There is a wealth of rich physics to explore with GeV muon beams. Examples include but not limited to: muon scattering can occur at large angles, providing evidence of potential muon-philic dark matter or dark mediator candidates; muon-electron scattering can be used to detect new types of bosons associated...

223. Projections for Key Measurements in Heavy Flavour Physics

Precision studies of flavour-changing processes involving quarks and leptons provide a number of ways to improve knowledge of the Standard Model and search for physics beyond it. There are excellent short- and mid-term prospects for significantly improved measurements in heavy flavour physics (involving b and c hadrons and τ leptons), with upgrades in progress or planned for the ATLAS, CMS and...

44. Proposal for a shared transverse LLP detector for FCC-ee and FCC-hh and a forward LLP detector for FCC-hh

As the particle physics community has explored most of the conventional avenues for new physics, the more elusive areas are becoming increasingly appealing. One such potential region, where new physics might be hiding, involves light and weakly interacting long-lived particles (LLPs). To probe deeper into this region, where the possibility of highly displaced scenarios weakens the role of...

171. Proposal from the NA61/SHINE Collaboration for the update of the European Strategy for Particle Physics

Building on the current program’s success and driven by new physics challenges, the NA61/SHINE Collaboration proposes to continue measuring hadron production properties in reactions induced by hadron and ion beams after CERN Long Shutdown 3. These measurements are of significant interest to the heavy-ion, cosmic-ray, and neutrino physics communities and will focus on:

(i) Investigating...

5. Prospective report of the French QCD community to the ESPPU 2025 with respect to the program of the LHC Run 5 and beyond and future colliders at CERN

This document summarizes the prospective physics plans of the French QCD and Heavy-Ion community, including the experimental programs at the LHC Run 5 and beyond and future colliders at CERN, within the context of the French contribution to the update of the European Strategy in Particle Physics (ESPPU 2025), as discussed in the workshop on European Strategy for Particle Physics Update 2025...

23. Prospects and Opportunities with an upgraded FASER Neutrino Detector during the HL-LHC era: Input to the EPPSU

The FASER experiment at CERN has opened a new window in collider neutrino physics by detecting TeV-energy neutrinos produced in the forward direction at the LHC. Building on this success, this document outlines the scientific case and design considerations for an upgraded FASER neutrino detector to operate during LHC Run 4 and beyond. The proposed detector will significantly enhance the...

227. Prospects for physics at FCC-hh

This submission reviews and updates the extensive work done over the years to explore and quantify the physics potential of FCC-hh, the hadron collider component of the integrated Future Circular Collider facility. The document introduces the context of these studies, as it has developed over the years, and offers an update of key targets of FCC-hh such as the precision Higgs studies and the...

242. Prospects in BSM physics at FCC

The exceptional opportunities offered by the FCC programme in the search for physics beyond the Standard Model are reviewed. Uniquely to FCC, all frontiers on which the search for new physics must continue are significantly pushed back: Flavour, Intensity, Higgs, Dark, Electroweak and High Energy.

217. Prospects in Electroweak, Higgs and Top physics at FCC

The FCC integrated programme offers a unique opportunity to comprehensively explore the Higgs, electroweak and top sectors. The FCC-ee clean experimental conditions and well-defined initial state enable the exploitation of all produced Higgs, W, Z bosons and top quarks and allow, in a record time, for a precise characterisation of the Standard Model properties with unrivalled precision. The...

196. Prospects in flavour physics at the FCC

The sample of $6 \times 10^{12}$ $\rm Z$ decays that will be produced by FCC-ee offers immense opportunities for flavour physics. The low background environment, and high acceptance and reconstruction efficiencies of the detectors will allow this dataset to be fully exploited for a wide range of studies in the beauty, charm and tau sectors. In many cases, it is expected that these...

210. Proton-Driven Plasma Wakefield Acceleration for Future HEP Colliders

We discuss the main elements of a collider facility based on proton-driven plasma wakefield acceleration. We show that very competitive luminosities could be reached for high energy e+e- colliders. A first set of parameters was developed for a Higgs Factory indicating that such a scheme is indeed potentially feasible. There are clearly many challenges to the development of this scheme,...

134. PSI European Strategy Input

We emphasize the unique and peculiar opportunities that PSI provides in the field of particle physics. PSI is home
to a number of accelerator-based, low-energy precision experiments with unique reach, complementing particle physics
at the collider frontier. The document outlines both mid- and long-term projects, connected to international collabo-
rations. It highlights how particle physics...

113. Quantum Information meets High-Energy Physics: Input to the update of the European Strategy for Particle Physics

Some of the most astonishing and prominent properties of Quantum Mechanics, such as entanglement and Bell nonlocality, have only been studied extensively in dedicated low-energy laboratory setups. The feasibility of these studies in the high-energy regime explored by particle colliders was only recently shown, and has gathered the attention of the scientific community. For the range of...

260. Quantum Sensing for Dark Matter and Gravitational Waves

Searches for wave-like dark matter can benefit from efforts to develop experimental sensitivity beyond the Standard Quantum Limit. In particular, RF cavity experiments and spin magnetometers are promising technologies in this endeavour. In recent years, it has been shown that experiments of this kind can also be sensitive to high-frequency gravitational waves. As part of the community input to...

228. Quantum Technologies in High Energy Physics. The CERN Quantum Technology Initiative input to the European Strategy for Particle Physics

Quantum technology has the potential to revolutionize High Energy Physics (HEP), thanks to its disruptive nature. Quantum hardware could be employed to conceive novel detector technologies. Quantum software could speed up computing-demanding tasks in the next or next-to-next generation of particle physics experiments. Several national initiatives, across CERN Member States and beyond, are...

204. R&D on quantum sensors for particle physics: the DRD5 collaboration

The detector R&D roadmap initiated by ECFA in 2020 highlighted the large number of particle physics opportunities that can be enabled by targeted and collaborative R&D in the field of quantum sensors and related technologies. Task Force 5 (TF5) of that roadmap exercise, together with the involved communities, established a list of the most promising areas for investment, and defined the R&D...

43. REDTOP: Rare Eta Decays TO Explore New Physics

REDTOP will undertake an unprecedented experimental effort to search for Beyond Standard Model (BSM) physics by studying rare decays of the $\eta$ and $\eta^{\prime}$ mesons. Strong theoretical motivations exist to explore New Physics in the MeV to GeV range.
The $\eta$ and $\eta^{\prime}$ mesons are unique particles as they carry no standard model charges, a property shared only by the Higgs...

150. Reinterpretation and preservation of data and analyses in HEP

Data from particle physics experiments are unique and are often the result of a very large investment of resources. Given the potential scientific impact of these data, which goes far beyond the immediate priorities of the experimental collaborations that obtain them, it is imperative that the collaborations and the wider particle physics community publish and preserve sufficient information...

219. RF developments for future colliders

A Coordination Panel of European RF experts is following up the implementation of the Accelerator R&D roadmap prepared for the European Large National Laboratory Directors Group (LDG) of CERN in Jan 2022, on the topic of high-gradient RF structures and systems.
This paper is intended to summarise the main results achieved in 2022-25, those still expected during the current ESPP period (until...

250. Rich dark sectors

The Standard Model (SM) of particle physics provides a very successful description of fundamental particles and their interactions but it is incomplete, as neutrino masses, dark matter and the baryon asymmetry of the Universe indicate. In addition, the origin of masses and of the approximate fundamental symmetries call out for deeper explanations. The hunt for a New SM Theory, that extends the...

101. SBN@CERN: A short-baseline neutrino beam at CERN for high-precision cross-section measurements

A new generation of neutrino cross-section experiments at the GeV scale is crucial in the precision era of oscillation physics and lepton flavor studies. In this document, we present a novel neutrino beam design that leverages the experience and R&D achievements of the NP06/ENUBET and NuTag Collaborations and explore its potential implementation at CERN. This beam enables flux monitoring at...

164. Science of the LISA mission: A Summary for the European Strategy for Particle Physics

The LISA mission is an international collaboration between ESA, its member states, and NASA, for the detection of gravitational waves from space. It was adopted in January 2024 and is scheduled for launch in the mid-2030’s. It will be a constellation of three identical spacecraft forming a near-equilateral triangle in an heliocentric orbit, transferring laser beams over 2.5 million km long...

163. Science4Peace: A Plea for Continued Peaceful International Scientific Cooperation

The European Strategy for Particle Physics (ESPP) - 2026 update is taking place in a turbulent international climate. Many of the norms that have governed relations between states for decades are being broken or challenged. The future progress of science in general, and particle physics in particular, will depend on our ability to maintain peaceful international scientific collaboration in the...

46. Search for feebly interacting particles with the Lohengrin experiment at the ELSA accelerator

An interesting family of extensions to the Standard Model features new, light particles that interact only feebly with the SM sector. A prominent example are models that aim to explain dark matter with the existence of a dark sector. A feeble coupling between the dark sector and the SM is established by introducing a kinetic mixing term between the SM photon and a new massive vector portal,...

21. Search for the electric dipole moment of the neutron with the n2EDM experiment

This is the contribution of the nEDM collaboration for the European Strategy for Particle Physics - 2026. We point out the high relevance of the search for a permanent neutron electric dipole moment (nEDM). We sketch the theoretical challenges and worldwide experimental efforts, with the nEDM collaboration currently commissioning the n2EDM apparatus at the ultracold neutron source of the Paul...

50. Searching for Light Dark Matter and Dark Sectors with the NA64 experiment at the CERN SPS

Since its approval in 2016, NA64 has pioneered LDM searches with electron [1], positron [2], muon [3], and hadron [4] beams. The experiment has successfully met its primary objectives, as outlined in the EPPS input (2018), and even exceed them producing results that demonstrate its ability to operate in a near-background-free environment. The Physics Beyond Collider (PBC) initiative at CERN...

109. Searching for millicharged particles with the FORMOSA experiment at the CERN LHC

In this contribution, we evaluate the sensitivity for particles with charges much smaller than the electron charge with a dedicated scintillator-based detector in the far forward region at the CERN LHC, FORMOSA. This contribution will outline the scientific case for this detector, its design and potential locations, and the sensitivity that can be achieved. The ongoing efforts to prove the...

184. Sensitivity study on $H \to b \bar b$, $H \to W W^*$ and $H\!H\to b \bar b b \bar b$ cross sections and trilinear Higgs self-coupling with the MUSIC detector in $\sqrt{s}=10$ TeV muon collisions

This study investigates the physics reach in the Higgs sector of muon-antimuon collisions at a center-of-mass energy of 10 TeV. The statistical sensitivity of the production cross sections for $H\to b\bar{b}$, $H\to WW^{\ast}$, and $HH\to b\bar{b}b\bar{b}$, as well as the measurement of the Higgs boson trilinear self-coupling, is evaluated using a detailed detector simulation that includes the...

145. SHiP experiment at the SPS Beam Dump Facility

In 2024, the SHiP experiment, together with the associated Beam Dump Facility (BDF) under the auspices of the High Intensity ECN3 (HI-ECN3) project, was selected for the future physics exploitation of the ECN3 experimental facility at the SPS. The SHiP experiment is a general-purpose intensity-frontier setup designed to search for physics beyond the Standard Model in the domain of Feebly...

130. Simplified Models Expose the Interplay of Direct and Indirect Searches

We propose to use Simplified Models as a tool to investigate the new physics potential of both direct and indirect searches at the LHC and future colliders. This approach leads to more transparent interpretation and reframes questions of theoretical validity in terms of concrete models. A number of examples are given to illustrate the utility of this approach. By way of three characteristic...

31. Slovak Particle Physics Community Input to Update of the European Strategy for Particle Physics

This document contains the input collected in Slovak HEP community.

34. Some thoughts on the future of particle physics.

I present some considerations on the possible future of particle physics,
taking into account the challenge from climate change.
For a more thorough theoretical background some references are given.

58. Spanish astroparticle community input to the European Strategy Group

This document summarises the view of the Spanish astroparticle community for the 2026 update of the European Strategy for Particle Physics (ESPP).
The contribution was prepared by representatives of three national astroparticle networks: RENATA (National Network on Astroparticles), MultiDark (Multimessenger Approach for Dark Matter Detection), and RedONGRA (Spanish Network on Gravitational...

147. Spanish national input to the European Strategy for Particle Physics

The LHC will continue to be the world's leading project in particle physics for the next two decades. Therefore, completing its high-luminosity upgrade and fully exploiting its physics programme must remain the top medium-term priority. The FCC project, including the initial electron-positron and subsequent hadron-hadron phases, has broad support across the Spanish community as the preferred...

180. SPECTRUM Project: Input to the European Particle Physics Strategy Update 2026

The amount of data gathered, shared and processed in frontier research is set to increase steeply in the coming decade, leading to unprecedented data processing, simulation and analysis needs. In particular, High Energy Physics (HEP) and Radio Astronomy (RA) are gearing up for groundbreaking instruments, necessitating digital infrastructures many times larger than the current capabilities. In...

22. Statement by the German Particle Physics Community as Input to the Update of the European Strategy for Particle Physics

This is the national statement by the German particle physics community, which is based on the results of four open community workshops.

The German community agrees that Europe’s leading role in particle physics is to be secured by a flagship collider project at CERN after the LHC, which is essential to search for answers to the fundamental questions in particle physics. A Higgs factory...

201. Statement of the Pierre Auger Collaboration as input for the 2026 European Particle Physics Strategy

This document describes, on behalf of the Pierre Auger Collaboration, the close relation between the research interests of the particle and astroparticle physics communities. We underline the main areas in which synergies between the CERN and the astroparticle physics fields of reasearch can be developed, providing input to the 2026 European Particle Physics Strategy Update. We conclude with...

275. Status of the International Linear Collider

This paper is not a proposal for a CERN future project but provides information
on the International Linear Collider (ILC) considered for Japan to facilitate the
European Strategy discussion in a global context. It describes progress to date,
ongoing engineering studies, updated cost estimate for the machine at √s = 250 GeV
and the situation in Japan. The physics of the ILC is not...

90. Strategic Imperative: Investing in Accelerator R&D and Technologies for the Future of Particle Physics and Societal Impact – Comments in the framework of the European Strategy for Particle Physics (ESPP) update by the German Committee of Accelerator Physics (KfB)

Abstract: This document outlines recommendation for accelerator R&D in the context of the European Strategy for Particle Physics (ESPP) update and highlights the strategic importance of accelerator research and development (R&D). The German Committee of Accelerator Physics (KfB) emphasizes the importance of accelerator technology for both scientific research and industrial applications,...

12. Strategy for HPC Integration in WLCG/HEP

High-Energy Physics (HEP), and particularly the sector supported by the WLCG Collaboration at the LHC experiments, is entering a new era of data-intensive research. This shift is driven by the High-Luminosity LHC (HL-LHC) that will generate exabyte-scale datasets each year. Fully realizing the physics potential of this massive volume of data will require a significant increase of resources....

29. Strategy for the Future of Lattice QCD

This submission highlights the sustained importance and requirements, over the coming decades, of the Lattice Quantum Chromodynamics community. We provide predictions for an increasing set of Standard Model observables and parameters with nonperturbative-physics contributions, such as matrix elements for hadron-transitions, hadron structure, the QCD phase diagram, and even properties of...

93. Strengthening the Instrumentation Programme

Instrumentation Community Input to the European Strategy for Particle Physics 2026 Update

235. Summary Report of the Physics Beyond Colliders Study at CERN

The Physics Beyond Collider Study Group was initially mandated by the CERN Management to prepare the previous European Particle Physics Strategy Update for CERN projects other than the high-energy frontier colliders. The main findings were summarized in a report. Following the Update process, the Physics Beyond Collider Study Group was confirmed on a permanent basis with an updated mandate...

231. Super Tau Charm Facility

The Super Tau Charm Facility (STCF) is a third-generation high-luminosity electron-positron collider designed to operate at a center-of-mass energy ($\sqrt{s}$) ranging from 2 to 7${~\mathrm{GeV}}$, achieving a peak luminosity exceeding $5\times 10^{34}~{\rm cm^{-2}s^{-1}}$ at $\sqrt{s}=4~{\rm GeV}$. Compared to other experiments, STCF represents a substantial advancement for...

256. Superconductivity Global Alliance (ScGA) European Strategy Input

This document presents a rationale for CERN, and the broader High Energy Physics (HEP) community, to engage strategically with the Superconductivity Global Alliance (ScGA). Building on HEP's historical leadership in superconducting technologies and aligned with future needs, we outline three primary motivations for engagement:

1. Research and development efforts enhance collaboration with...

162. Sustainability Assessment of Future Accelerators

The Large Particle Physics Laboratory Directors Group (LDG) established the Working Group on the Sustainability Assessment of Future Accelerators in 2024 with the mandate to develop guidelines and a list of key parameters for the assessment of the sustainability of future accelerators in particle physics.
While focused on accelerator projects, much of the work will also be relevant to other...

64. Swiss inputs to the 2026 update of the European Strategy for Particle Physics (ESPP)

This document summarizes the Swiss inputs to the 2026 update of the European Strategy for Particle Physics (ESPP), compiled by CHIPP, the Swiss Institute for Particle Physics. Building on the “CHIPP Community Roadmap 2024,” which outlined national research infrastructure needs, a series of workshops were held to develop consensus on the strategy. The resulting responses were finalized and...

114. Synergies between a U.S.-based Electron-Ion Collider and European Research in Particle Physics

This document is submitted as input to the European Strategy for Particle Physics Update (ESPPU). The U.S.-based Electron-Ion Collider (EIC) aims at understanding how the complex dynamics of confined quarks and gluons makes up nucleons, nuclei and all visible matter, and determines their macroscopic properties. In April 2024, the EIC project received approval for critical-decision 3A (CD-3A)...

116. T2K Experiment: future plans and capabilities

The Tokai-to-Kamioka (T2K) experiment uses an intense (anti)neutrino source produced at J-PARC, which is sampled by detectors close to production (280m) and far from it (295km). T2K's physics program includes precision measurements of oscillation physics, neutrino interactions, and searches for exotic phenomena. T2K has made important contributions to the evolving landscape of oscillation...

148. Technology developments for LHCb Upgrade II

A major LHCb detector upgrade will be installed during Long Shutdown 4 (LS4) of the CERN Large Hadron Collider.The experiment will operate at a maximum luminosity of $1.5\times 10^{34}\textrm{cm}^{-2}\sec^{-1}$, with acceptance covering a pseudorapidity range close to the beamline. The detector will therefore experience extremely high particle fluences. In order to carry out the LHCb physics...

52. The Astro-particle Physics Commission 2

This document contains some initial input from INFN Commission 2 on Astro-particle Physics (CSN2) for the update of the European Strategy for Particle Physics. It is not intended to provide a comprehensive overview of CSN2 activities or to cover all possible relevant aspects of the Strategy: this will be defined with other stakeholders during the update process in February 2024. The goal is to...

189. The ATLAS Upgrade for the HL-LHC

The HL-LHC projects a leveled instantaneous proton–proton luminosity of up to 7×10−34 cm−2s with 200 simultaneous collisions within a bunch crossing (pileup) and an integrated luminosity
of 3000 fb−1. These conditions require unprecedented detector technologies in terms of radiation hardness, high detection granularity and resolution, precision track timing, and powerful triggers. To meet...

205. The Belle II Experiment at SuperKEKB

Belle II is an intensity-frontier experiment at the SuperKEKB collider in Tsukuba, Japan. Over the coming decades, it will record the decays of billions of bottom mesons, charm hadrons, and tau leptons produced in 10 GeV electron-positron collisions. The experiment's low-background environment and precisely known kinematics enable high-precision measurements of hundreds of Standard Model (SM)...

84. The CERN Festival Programme

The CERN Festival Programme offers a novel approach to science communication by embedding cutting-edge research and technology into mainstream cultural events across Europe. Since its inception in 2016, the programme has successfully engaged diverse and typically underserved audiences, effectively addressing contemporary societal challenges such as science skepticism, sustainability, and the...

129. The CERN n_TOF neutron-time-of-flight facility: present and future

The CERN n_TOF neutron-time-of-flight facility: present and future

Alberto Mengoni (*) on behalf of the n_TOF Collaboration

The neutron time-of-flight facility, n_TOF at CERN, will approach the 25th year of operation in 2026. Its long successful history can be ascribed to the unique features of the neutron beams...

153. The Circular Electron Positron Collider (CEPC)

The Higgs boson, discovered in 2012 by the ATLAS and CMS Collaborations at the Large Hadron Collider (LHC), plays a central role in the Standard Model. The arrival of the Higgs boson brings along great scientific opportunities for the human being. Measuring the Higgs properties precisely will advance our understandings of some of the most important questions in particle physics, such as the...

78. The Compact Linear e$^+$e$^-$ Collider (CLIC)

The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear e$^+$e$^-$ collider studied by the international CLIC and CLICdp collaborations hosted by CERN. CLIC uses a two-beam acceleration scheme, in which normal-conducting high-gradient 12 GHz accelerating structures are powered via a high-current drive beam. For an optimal exploitation of its physics potential, CLIC is foreseen...

67. The Critical Importance of Software for HEP

Particle physics has an ambitious and broad global experimental programme for the coming decades. Large investments in building new facilities are already underway or under consideration. Scaling the present processing power and data storage needs by the foreseen increase in data rates in the next decade for HL-LHC is not sustainable within the current budgets. As a result, a more efficient...

60. The Critical Role of Particle Physics Education and Outreach

This document provides input concerning Education and Outreach for the open call for the European Strategy for Particle Physics Update (ESPPU) 2026. It addresses new and increasing challenges since ESPPU 2020, and emphasises the need to expand and diversify global Outreach programmes. This necessity is driven not only by our community’s desire to develop critical new long-term, large-scale...

221. The DArk Messenger Searches at an Accelerator Experiment, A Case of a Table-Top Scale Experiment at a Beam Dump

DAMSA (DArk Messenger Searches at an Accelerator) is a table-top scale, extremely-short-baseline experiment designed to probe dark-sector particles (DSPs) that serve as portals between the visible sector and the hidden dark-matter sector. These particles, such as axion-like particles (ALPs), can decay into two photons or $e^{+}e^{-}$ pairs. DAMSA is specifically optimized to...

119. The DUNE Phase II Detectors

The international collaboration designing and constructing the Deep Underground Neutrino Experiment (DUNE) at the Long-Baseline Neutrino Facility (LBNF) has developed a two-phase strategy for the implementation of this leading-edge, large-scale science project. The 2023 report of the US Particle Physics Project Prioritization Panel (P5) reaffirmed this vision and strongly endorsed DUNE Phase I...

118. The DUNE Science Program

The international collaboration designing and constructing the Deep Underground Neutrino Experiment (DUNE) at the Long-Baseline Neutrino Facility (LBNF) has developed a two-phase strategy for the implementation of this leading-edge, large-scale science project. The 2023 report of the US Particle Physics Project Prioritization Panel (P5) reaffirmed this vision and strongly endorsed DUNE Phase I...

141. The ECFA Higgs/Electroweak/Top Factory Study

This is the executive summary of the ECFA Higgs/Electroweak/Top Factory Study report being submitted as input to the 2025 European Strategy for Particle Physics Update. A very brief overview of the Study's activities is given here, taking the Focus Topics developed in the course of the Study as a structure to highlight aspects that were explored. A broad effort across the experimental and...

237. The Elastic Analysis Facility’s (EAF’s) Contribution to the Future of Analysis at Multi-Experiment Institutions and Future Colliders

The Elastic Analysis Facility (EAF) hosted at Fermi National Accelerator Laboratory (Fermilab) is a platform being developed with the goal of providing a fast and efficient facility for physics analysis. As high-energy physics moves towards collecting larger datasets, such as those from the High-Luminosity LHC, the EAF strives to provide a powerful and adaptable framework for future colliders...

258. The Electron Capture in Ho-163 experiment – ECHo

The Electron Capture in Ho-163 Experiment has been conceived to determine the effective electron neutrino mass by the analysis of the end-point region of the calorimetrically measured Ho-163 electron capture spectrum. The key technology is based on metallic magnetic calorimeters (MMC) enclosing Ho-163 which are operated at millikelvin temperature and readout via microwave SQUID multiplexing....

241. The FCC integrated programme: a physics manifesto

The FCC integrated programme comprises an $\rm e^+e^-$ high-luminosity circular collider that will produce very large samples of data in an energy range $88 \le \sqrt{s} \le 365$\,GeV, followed by a high-energy $\rm pp$ machine that, with the current baseline plan, will operate at a collision energy of around 85\,TeV and deliver datasets an order of magnitude larger than those of the HL-LHC....

19. The Forward Physics Facility at the Large Hadron Collider

The Forward Physics Facility (FPF) is a proposal developed to exploit the unique scientific potential made possible by the intense hadron beams produced in the far-forward direction at the high luminosity LHC (HL-LHC). Housed in a well-shielded cavern 627 m from the LHC interactions, the facility will enable a broad and deep scientific programme which will greatly extend the physics capability...

179. The HIBEAM/NNBAR program

The European Spallation Source will open a new intensity frontier
in particle physics. The two-stage HIBEAM/NNBAR program can exploit
the potential of the ESS with a series of high-precision searches and
measurements. A key part of the program is the first search for over
thirty years for free neutrons converting to antineutrons, thereby testing
baryon number conservation. A discovery...

238. The Hyper-Kamiokande experiment: input to the update of the European Strategy for Particle Physics

This document summarises the input of the Hyper-Kamiokande collaboration to the
2026 Update to the European Strategy for Particle Physics, ESPPU.

Hyper-Kamiokande is a large infrastructure for particle and astroparticle physics being built in Japan and aiming to start operations by the end of 2027 whose objective is to address the most important questions in science today, for instance...

102. The ILD Detector: A Versatile Detector for an Electron-Positron Collider at Energies up to 1~TeV

The International Large Detector, ILD, is a detector concept for an experiment at a future high energy lepton collider. The detector has been optimised for precision physics in a range of energies from 90~GeV to about 1~TeV. ILD features a high precision, large volume combined silicon and gaseous tracking system, together with a high granularity calorimeter, all inside a central solenoidal...

244. The Importance of Test Beams for Particle Physics worldwide

The test beams provided by the major laboratories worldwide are a key infrastructure for developing detectors for high-energy physics, nuclear physics, and adjacent fields. They are also an ideal training ground for the next generation of instrumentation experts. Close to a thousand users make use of the worldwide test beam facilities, with CERN, DESY and Fermilab being the most heavily used...

117. The INFN National Scientific Committee for Theoretical Physics

This document summarizes the discussions within the INFN national scientific commission for theoretical physics (CSN4) on the future challenges in theoretical physics of interest for INFN, triggered by the national meeting on the INFN input for the update of the European Strategy for Particle Physics. Present and future challenges in theoretical physics are presented, with the vision of CSN4...

146. The International Axion Observatory (IAXO): case, status and plans.

The International Axion Observatory (IAXO) is a next-generation axion helioscope designed to search for solar axions with unprecedented sensitivity. IAXO holds a unique position in the global landscape of axion searches, as it will probe a region of the axion parameter space inaccessible to any other experiment. In particular, it will explore QCD axion models in the mass range from meV to eV,...

36. The JUNO Experiment

The Jiangmen Underground Neutrino Observatory (JUNO) is new-generation 20-kton multipurpose underground Liquid Scintillator detector designed to address fundamental questions in neutrino and astroparticle physics. Its primary scientific goal is to determine the neutrino mass hierarchy (MH) with a significance of 3-4 σ within approximately six years of data collection. JUNO's exceptional energy...

214. The Large Hadron electron Collider (LHeC) as a bridge project for CERN

The LHeC program elaborated in the CDR of 2021 included a first phase with concurrent operation of electron-hadron and hadron-hadron collisions at the HL-LHC, followed by a second phase of standalone electron-hadron collisions. In view of the current HL-LHC schedule, we propose an LHeC program extending the regular HL-LHC program with only a standalone electron-hadron operation phase. In this...

40. The Linear Collider Facility (LCF) at CERN

In this paper we outline a proposal for a Linear Collider Facility as the next flagship project for CERN.
This proposal offers the opportunity for a timely, cost-effective and staged construction of a new collider that will be able to comprehensively map the Higgs boson's properties, including the Higgs field potential, thanks to a large span in centre-of-mass energies and polarised...

92. The LUXE Experiment

This document presents an overview of LUXE (Laser Und XFEL Experiment), an experiment that will combine the high-quality and high-energy electron beam of the European XFEL with a high-intensity laser, to explore the uncharted terrain of strong-field quantum electrodynamics. The scientific case, facility, and detector setup are presented together with an overview of the foreseen timeline and...

207. The Muon Collider

Muons offer a unique opportunity to build a compact high-energy electroweak collider at the 10 TeV scale. A Muon Collider enables direct access to the underlying simplicity of the Standard Model and unparalleled reach beyond it.
It will be a paradigm-shifting tool for particle physics representing the first collider to combine the high-energy reach of a proton collider and the high...

87. The NEXT Search for Neutrinoless Double Beta Decay in Xe-136

The Neutrino Experiment with a Xenon TPC (NEXT) is an experimental program searching for neutrinoless double-beta decay (bbonu) in Xe-137 using high-pressure xenon time projection chambers (HPXe) with electroluminescent (EL) amplification of the ionization signal. This technology offers several advantages:
(a) Low intrinsic background—signals occur in the gas volume, away from surfaces where...

225. The Project 8 Neutrino Mass Experiment

Measurements of the $\beta^-$ spectrum of tritium give the most precise direct limits on neutrino mass. Project 8 will investigate neutrino mass using Cyclotron Radiation Emission Spectroscopy (CRES) with an atomic tritium source. CRES is a new experimental technique that has the potential to surmount the systematic and statistical limitations of current-generation direct measurement methods....

28. The PTOLEMY project

The PTOLEMY project aims at taking a snapshot of the first second of the Universe, when the Cosmic Neutrino Background (CνB) decoupled, which has been for a long time a dream in the field
of Cosmology. The PTOLEMY detection principle relies on CνB capture on a target of beta-unstable elements, since in this process mono-energetic electrons are emitted just above the beta-decay endpoint. The...

111. The Role of Particle Physics in Revolutionising Imaging Technologies: From Quantum Entanglement to Clinical Applications

Positron emission tomography (PET) has become an indispensable tool in clinical medicine over the past three decades, enabling high-resolution imaging with spatial resolution of 1–3 mm and temporal resolution on the order of seconds. However, a significant portion of signal information is currently discarded due to photon scattering. Harnessing this lost data—for instance, by exploiting the...

232. The Short-Baseline Near Detector at Fermilab

The Short-Baseline Near Detector (SBND) is a 112-ton liquid argon time projection chamber (LArTPC) neutrino detector located 110 meters from the Booster Neutrino Beam (BNB) target at Fermilab. Its main goals include searches for eV-scale sterile neutrinos as part of the Short-Baseline Neutrino (SBN) program, other searches for physics beyond the Standard Model, and precision studies of...

94. The SiD Detector concept Input to the European Strategy Process Update 2026

The SiD Detector is one of two detector designs validated in 2012 for the International Linear Collider (ILC). SiD features a compact, cost-constrained design for precision Higgs and other measurements, with sensitivity to a wide range of possible new phenomena. A robust silicon vertex and tracking system, combined with a five Tesla central solenoidal field, provides excellent momentum...

125. The SNO+ Science Programme: Input to the European Strategy for Particle Physics - 2026 Update

The search for neutrinoless double beta decay ($0\nu\beta\beta$) is considered by the community as one of the most important topics in neutrino physics and as a priority by successive updates of the European Strategy for Particle Physics. An understanding of the nature of neutrino mass is connected to the charge conjugation nature -- Dirac or Majorana -- of neutrinos. An observation of...

9. The Worldwide LHC Computing Grid input to the ESPP24-26

The Worldwide LHC Computing Grid (WLCG) is the global infrastructure, developed and operated over the last two decades, that provides the computing infrastructure for the processing and analysis of data from the LHC experiments. The WLCG Collaboration comprises the sites being part of the infrastructure and the LHC experiments, with a thin management layer. The notable achievement of WLCG has...

263. Theia: technology and summary of physics program

White paper submission to the European Strategy for Particle Physics on behalf of the Theia detector concept

222. To build or not to build: FCC

This is my individual contribution to the discussions ongoing on the update of the European Strategy for Particle Physics. After participating in many discussions and contributing to a number of documents being prepared for the ESPP submission, I came to the conclusion that these “official” documents do not give the whole picture. I wanted to express my concerns about the strategy update...

157. Towards instrumentation for future HEP experiments

This input provides a perspective on progress of the formation of Detector Research and
Development collaborations and where they stand on their way to execute the scientific
program outlined in the ECFA Detector Development Roadmap.

246. U.S. interest in high-energy nuclear physics at the LHC

The authors are experimental heavy-ion physicists from universities and a national laboratory across the U.S. We are writing to stress interest and support in a continued heavy-ion physics program at the LHC. The arguments in this document are intended to be synergistic with those organized by the broader U.S. community for the U.S. 2023 Long Plan for Nuclear Science, and international...

202. U.S.Higgs Factory Consortium input to ESG on CERN's future collider options.

This white paper responds to the request by the European Strategy Group (ESG) to submit national inputs as part of the European Strategy for Particle Physics Update (ESPPU). It focuses on CERN’s future collider options and provides strong support for FCC-ee as its preferred next major flagship project. The paper follows the ECFA guidelines, responding explicitly to item 3, and is supported by...

51. Ultra-relativistic Heavy-Ion Collisions: Inputs of the Italian community for the ESPP 2026

This document has been prepared by the community that is active in Italy, within INFN (Istituto Nazionale di Fisica Nucleare), in the field of ultra-relativistic heavy-ion collisions. The experimental study of the phase diagram of strongly-interacting matter and of the Quark–Gluon Plasma (QGP) deconfined state will proceed, in the next 15–20 years, along two directions: the high-energy regime...

91. United States Early Career Researchers in Collider Physics input to the European Strategy for Particle Physics Update

This document represents a contribution of the United States early career collider physics community to the 2025-2026 update to the European Strategy for Particle Physics. Preferences with regard to different future collider options and R&D priorities were assessed via a survey. The early career community was defined as anyone who is a graduate student, postdoctoral researcher, untenured...

152. United States Muon Collider Community White Paper for the European Strategy for Particle Physics Update

This document is being submitted to the 2024-2026 European Strategy for Particle Physics Update (ESPPU) process on behalf of the US Muon Collider community, with its preparation coordinated by the interim US Muon Collider Coordination Group. The US Muon Collider Community comprises a few hundred American scientists. The purpose of the document is to inform ESPPU about the US plans for Muon...

230. US National Input to the European Strategy Update for Particle Physics

In this document we summarize the output of the US community planning exercises for particle physics that were performed between 2020 and 2023 and comment upon progress made since then towards our common scientific goals. This document leans heavily on the formal report of the Particle Physics Project Prioritization Panel and other recent US planning documents, often quoting them verbatim to...

175. XLZD: The low-background observatory for astroparticle physics

The XLZD underground rare event observatory based on liquid xenon technology will address some of the most important open questions in fundamental physics and cosmology: the nature of dark matter, which drives the formation of structures in the universe such as galaxies and clusters, and the fundamental nature of neutrinos, which is closely tied to the puzzling matter-antimatter asymmetry in...