Intensity Frontier

Conveners: JoAnne Hewett (SLAC), Harry Weerts (Argonne)


The Intensity Frontier working group is charged with summarizing the current
state of knowledge and identifying the most promising future opportunities at
the intensity frontier. Topics are described under the working groups.

The Intensity Frontier manifesto

All frontiers of high energy physics aim to discover and understand the constituents of matter and their interactions at the highest energies, at the shortest distances, and at the earliest times in the Universe. The Standard Model fails to explain all observed phenomena: new interactions and yet unseen particles must exist. They may manifest themselves either directly, as new particles, or by causing Standard Model reactions to differ from often very precise predictions. The Intensity Frontier explores these fundamental questions by searching for new physics in processes extremely rare or those forbidden in the Standard Model. This requires the greatest possible beam intensities, as well as massive ultra-sensitive detectors. Many of these experiments are sensitive to new physics at higher mass scales, or weaker interaction strengths, than those directly accessible at the LHC or any foreseeable high-energy collider, thus providing opportunities for paradigm-changing new discoveries complementary to Energy and Cosmic Frontier experiments.

The range of experiments encompassing the Intensity Frontier is broad and diverse. Intense beams of neutrinos aimed over long distances at very large detectors will explore the neutrino mass hierarchy, search for CP violation and non-standard interactions, and increase sensitivity to proton decay. Multi-ton-scale detectors will determine whether neutrinos are their own antiparticles. Intense beams of electrons will enable searches for hidden-sector particles that may mediate dark matter interactions. Extremely rare muon and tau decay experiments will search for violation of charged lepton quantum numbers. Measurements of intrinsic lepton properties, such as electric and magnetic dipole moments are another promising thrust. Rare and CP-violating decays of bottom, charm, and strange particles, measured with unprecedented precision, will be important to unravel the new physics underlying discoveries at the LHC. In any new physics scenario, Intensity Frontier experiments with sensitivities to very high mass scales will be a primary tool for exploration.


The work of the Intensity Frontier is divided into 6 subgroups. Activities within the subgroups are described on their individual web pages.

Please send all comments and suggestions to intensity-frontier at anl.gov.
Also feel free to use the Forum, which is linked below, so that others can follow the discussion.


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