Signatures of pseudo-Dirac dark matter at high-intensity neutrino experiments

Abstract

We (re)consider the sensitivity of past (LSND) and future (JSNS 2 ) beam dump neutrino experiments to two models of MeV-scale pseudo-Dirac dark matter. Both LSND and JSNS 2 are close (24-30 m) to intense sources of light neutral mesons which may decay to dark matter via interactions involving a light mediator or dipole operators. The dark matter can then scatter or decay inside of the nearby detector. We show that the higher beam energy of JSNS 2 and resulting η production can improve on the reach of LSND for light-mediator models with dark matter masses greater than mπ/2. Further, we find that both existing LSND and future JSNS 2 measurements can severely constrain the viable parameter space for a recently-proposed model of dipole dark matter which could explain the 3.5 keV excess reported in observations of stacked galaxy clusters and the Galactic Center.

Inelastic dark matter at the LHC lifetime frontier: ATLAS, CMS, LHCb, CODEX-b, FASER, and MATHUSLA

“…In addition to the various LHC searches discussed in Sec. VI, we also show the projected reach from low-energy accelerators as dot-dashed colored contours, such as Belle II (red) [33], SeaQuest (purple) [29], dedicated searches for displaced vertices at BaBar (magenta) [8], MiniBooNE (green) [24], JSNS 2 (red) [68], BDX (brown) [24], and LDMX (pink) [10,29,69]. Also shown is the future sensitivity from electroweak precision tests (EWPT) at the LHC (dark teal) [20].…”

Dark sector-photon interactions in proton-beam experiments

“…Nevertheless, these experiments are in general not expected to provide noticeably stronger (projected) bounds than those obtained above (see e.g. [86,107,[116][117][118]), and are thus not further studied in this work. 4 A unity efficiency was also used in [102,112].…”

The Short-Baseline Neutrino Program at Fermilab

“…Triggering on highly off-axis beams may help reduce backgrounds, as well as analyzing spectral information or running the experiment in beam dump mode (see the recent analysis performed by the MiniBooNE collaboration (127)). Variations of this model where the dark particle decays to a dark photon and a lighter dark matter species can be probed in SBN by looking at e + e − pairs with no hadronic activity (128).…”