New Prospects in Fixed Target Searches for Dark Forces with the SeaQuest Experiment at Fermilab

TL;DR

This paper explores how the SeaQuest experiment at Fermilab can be extended to detect light, weakly interacting hidden-sector particles, potentially revealing new insights into dark matter and hidden gauge forces.

Contribution

It proposes an extension of the SeaQuest experiment to serve as an ultrasensitive probe for hidden vector gauge forces, both Abelian and non-Abelian.

Findings

Potential to detect hidden gauge bosons via decay signatures

Constraints on hidden-sector models based on experimental sensitivity

Feasibility of using existing infrastructure for dark matter searches

Abstract

An intense, 120 GeV proton beam incident on an extremely long, iron target generates enormous numbers of light-mass particles that also decay within that target. If one of these particles decays to a final state with a hidden gauge boson, or if such a particle is produced as a result of the initial collision, then that weakly interacting, hidden-sector particle may traverse the remainder of the target and be detected downstream through its possible decay to an $e^+e^-$, $\mu^+\mu^-$, or $\pi^+\pi^-$ final state. These conditions can be realized through an extension of the SeaQuest experiment at Fermilab, and in this initial investigation we consider how it can serve as an ultrasensitive probe of hidden vector gauge forces, both Abelian and non-Abelian. A light, weakly coupled hidden sector may well explain the dark matter established through astrophysical observations, and the proposed search can provide tangible evidence for its existence --- or, alternatively, constrain a "sea" of possibilities.