The search for feebly interacting particles

Gaia Lanfranchi, Maxim Pospelov, Philip Schuster

Research output: Contribution to journalReview articlepeer-review

14 Scopus citations


At the dawn of a new decade, particle physics faces the challenge of explaining the mystery of dark matter, the origin of matter over antimatter in the Universe, the apparent fine-tuning of the electroweak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves New Physics at mass scales comparable to that of familiar matter—below the GeV scale but with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and existing data may even provide hints of this possibility. Emboldened by the lessons of the LHC, a vibrant experimental program to discover such physics is underway, guided by a systematic theoretical approach that is firmly grounded in the underlying principles of the Standard Model. We give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs, and we focus in particular on accelerator-based experiments.

Original languageEnglish (US)
Pages (from-to)279-313
Number of pages35
JournalAnnual Review of Nuclear and Particle Science
StatePublished - Sep 21 2021

Bibliographical note

Publisher Copyright:
Copyright © 2021 by Annual Reviews. This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See credit lines of images or other third-party material in this article for license information


  • Beyond the Standard Model
  • Dark matter
  • Dark sectors
  • Feebly interacting particles


Dive into the research topics of 'The search for feebly interacting particles'. Together they form a unique fingerprint.

Cite this