The Workshop “Future Research Infrastructures; Challenges and Opportunities”, hosted in Varenna (Italy) from 8th to 9th of July, 2015, was part of the series of the International School of Physics “Enrico Fermi” organized by the Italian Physical Society.

The purpose of the workshop was to bring together the communities of scientists working on and with Particle Accelerators in order to cast an eye on the current developments and on the perspectives of the future research infrastructures, discussing new ideas, technical challenges and scientific opportunities.

The interest and the expectation of the international scientific community in such infrastructures have not slowed down, and the major world research laboratories have planned or are envisaging the construction of new accelerators in order to foster the progress of science in many fields, from the High Energy Physics, to Nuclear Physics, Material Science, Biology, Medicine, Energy, Cultural Heritage and Environment.

The program of the workshop and the list of outstanding speakers was organized with the help of an International Scientific Advisory Committee. Talks on “science and applications with accelerators” were interleaved with talks on the “development of future accelerators”, with the scope of presenting the future horizon of the science and the need of new scientific instrumentation.

Thursday July 9th, was devoted to the perspectives in the high energy physics after the discovery of the Higgs Boson (M. Mangano, CERN). Three consecutive talks described the recent development of LHC High Luminosity (L. Rossi, CERN) and the International Linear Collider (S. Komamiya, Japan), and the ongoing studies about Future electron/proton Circular Colliders (F. Zimmermann, CERN). The Gamma Beam Source, ELI-NP-GBS project, in construction at Magurele, Romania, (C.A. Ur, ELI-NP, RO), and the future multifold perspectives of such radiation sources (L. Serafini, INFN) have shed some light on the use of high energy high intensity Gamma radiation beam in photo-nuclear physics and as exotic colliders. Of high interest was the talk about the European Spallation Source (R. Garoby, ESS) in construction at Lund (SE). In the last part of the day there was a dedicated session regarding the emerging science of coherent high energy X-rays (C. Jacobsen, Argonne, USA), followed by the scientific perspectives of X-FEL radiation (C. Bressler, X-FEL, Hamburg) and by FEL application in multicolour spectroscopy (C. Masciovecchio, Trieste).

Friday July 10th started with two talks presenting the status of the development of the European X-FEL source (G. Geloni, X-FEL, Hamburg), and the SwissFEL source (C. Milne, PSI, CH). Then, a sequence of three talks on Hadron Therapy (S. Rossi, CNAO), Bio-Medical Applications (A. Bravin, ESRF), Cultural Heritage (M. Cotte, ESRF) drew the attention on the relevant applications of Accelerators.

The future of the Synchrotron Radiation Sources was discussed by two talks on the Diffraction Limited storage ring frontier (M. Borland, Argonne, USA) and its implementation in the ESRF Ring upgrade (R. Pantaleo, ESRF). A particular interesting case of application at the Advanced X-ray techniques at SSRF in the Catalysis Research developed to contrast the serious environmental issues of CO2 emission in China (J. Wang, China). The session was concluded with the presentation of the future perspectives of the Swiss Light Source (A. Streun, PSI, CH), and the Elettra and Fermi sources at Trieste (A. Fabris).

Saturday July 11th, the first talk concerned the Laser Plasma waves acceleration technique with the latest promising experimental results (C. Schroeder, LBNL, USA), then the future scenarios in USA (J.B. Rosenzweig), China (Z. Zhao) and Korea (I.S. Ko) completed the workshop talks.

The workshop was concluded by a very interesting Panel on “The need of International World Infrastructures” moderated by Luisa Cifarelli (SIF). The contributions by Sergio Bertolucci (CERN), Fernando Ferroni (INFN), Amy Flatten (APS), Michael Lubell (APS), Z. Zhao (SINAP-China), S. Komamiya (Japan), W. Sandner (ELI-DC, EU), C. Spinella (CNR) were focussed on the future developments and international collaboration policies in the world scenario in USA, Europe, and Asia.

The talks and the final panel were well appreciated by more than 75 participants in the beautiful scenario of Villa Monastero on the Como lake.

We wish to thank the Italian Physical Society for the accurate and efficient organization, the Local Organizing Committee, the Villa Monastero support and hospitality, the International Advisory Committee, the speakers and the participants for contributing to make the workshop a success.

Finally our deepest thanks go to Maria Rita Ferrazza, Scientific Secretary of the Workshop, for her competent and dedicated work in the effective planning and smooth running of this workshop, and in the executive editing of these proceedings.

S. Bertolucci and L. Palumbo