Letter of Intent: The Forward Physics Facility
Abstract
The Forward Physics Facility (FPF) is a proposed extension of the HL-LHC program designed to exploit the unique scientific opportunities offered by the intense flux of high energy neutrinos, and possibly new particles, in the far-forward direction. Located in a well-shielded cavern 627 m downstream of one of the LHC interaction points, the facility will support a broad and ambitious physics program that significantly expands the discovery potential of the HL-LHC. Equipped with four complementary detectors -- FLArE, FASER2, FASER2, and FORMOSA -- the FPF will enable breakthrough measurements that will advance our understanding of neutrino physics, quantum chromodynamics, and astroparticle physics, and will search for dark matter and other new particles. With this Letter of Intent, we propose the construction of the FPF cavern and the construction, integration, and installation of its experiments. We summarize the physics case, the facility design, the layout and components of the detectors, as well as the envisioned collaboration structure, cost estimate, and implementation timeline.
Keywords
Cite
@article{arxiv.2510.26260,
title = {Letter of Intent: The Forward Physics Facility},
author = {Luis A. Anchordoqui and John K. Anders and Akitaka Ariga and Tomoko Ariga and David Asner and Jeremy Atkinson and Alan J. Barr and Larry Bartoszek and Brian Batell and Hans Peter Beck and Florian U. Bernlochner and Bipul Bhuyan and Jianming Bian and Aleksey Bolotnikov and Silas Bosco and Jamie Boyd and Nick Callaghan and Gabriella Carini and Michael Carrigan and Kohei Chinone and Matthew Citron and Isabella Coronado and Peter Denton and Albert De Roeck and Milind V. Diwan and Sergey Dmitrievsky and Radu Dobre and Monica D'Onofrio and Jonathan L. Feng and Max Fieg and Elena Firu and Reinaldo Francener and Haruhi Fujimori and Frank Golf and Yury Gornushkin and Kranti Gunthoti and Claire Gwenlan and Carl Gwilliam and Andrew Haas and Elie Hammou and Daiki Hayakawa and Christopher S. Hill and Dariush Imani and Tomohiro Inada and Sune Jakobsen and Yu Seon Jeong and Kevin J. Kelly and Samantha Kelly and Luke Kennedy and Felix Kling and Umut Kose and Peter Krack and Jinmian Li and Yichen Li and Steven Linden and Ming Liu and Kristin Lohwasser and Adam Lowe and Steven Lowette and Toni Mäkelä and Roshan Mammen Abraham and Christopher Mauger and Konstantinos Mavrokoridis and Josh McFayden and Hiroaki Menjo and Connor Miraval and Keiko Moriyama and Toshiyuki Nakano and Ken Ohashi and Toranosuke Okumura and Hidetoshi Otono and Vittorio Paolone and Saba Parsa and Junle Pei and Michaela Queitsch-Maitland and Mary Hall Reno and Sergio Rescia and Filippo Resnati and Adam Roberts and Juan Rojo and Hiroki Rokujo and Olivier Salin and Jack Sander and Sai Neha Santpur and Osamu Sato and Paola Scampoli and Ryan Schmitz and Matthias Schott and Anna Sfyrla and Dennis Soldin and Albert Sotnikov and Anna Stasto and George Stavrakis and Jacob Steenis and David Stuart and Juan Salvador Tafoya Vargas and Yosuke Takubo and Simon Thor and Sebastian Trojanowski and Yu Dai Tsai and Serhan Tufanli and Svetlana Vasina and Matteo Vicenzi and Iacopo Vivarelli and Nenad Vranjes and Marija Vranjes Milosavljevic and Kazuhiro Watanabe and Michele Weber and Benjamin Wilson and Wenjie Wu and Tiepolo Wybouw and Kin Yip and Jaehyeok Yoo and Jonghee Yoo},
journal= {arXiv preprint arXiv:2510.26260},
year = {2026}
}