Search by the SENSEI Experiment for Millicharged Particles Produced in the NuMI Beam.

Millicharged particles appear in several extensions of the standard model, but have not yet been detected. These hypothetical particles could be produced by an intense proton beam striking a fixed target. We use data collected in 2020 by the SENSEI experiment in the MINOS cavern at the Fermi National Accelerator Laboratory to search for ultrarelativistic millicharged particles produced in collisions of protons in the NuMI beam with a fixed graphite target.

Search for Dark Photons with Superconducting Radio Frequency Cavities.

We conduct the first "light-shining-through-wall" (LSW) search for dark photons using two state-of-the-art high-quality-factor superconducting radio frequency (SRF) cavities -Dark SRF-and report the results of its pathfinder run. Our new experimental setup enables improvements in sensitivity over previous searches and covers new dark photon parameter space. We design delicate calibration and measurement protocols to utilize the high-Q setup at Dark SRF.

First Constraints on Heavy QCD Axions with a Liquid Argon Time Projection Chamber Using the ArgoNeuT Experiment.

We present the results of a search for heavy QCD axions performed by the ArgoNeuT experiment at Fermilab. We search for heavy axions produced in the NuMI neutrino beam target and absorber decaying into dimuon pairs, which can be identified using the unique capabilities of ArgoNeuT and the MINOS near detector. This decay channel is motivated by a broad class of heavy QCD axion models that address the strong CP and axion quality problems with axion masses above the dimuon threshold.

One-Electron Quantum Cyclotron as a Milli-eV Dark-Photon Detector.

We propose using trapped electrons as high-Q resonators for detecting meV dark photon dark matter. When the rest energy of the dark photon matches the energy splitting of the two lowest cyclotron levels, the first excited state of the electron cyclotron will be resonantly excited. A proof-of-principle measurement, carried out with one electron, demonstrates that the method is background free over a 7.

Improved Limits on Millicharged Particles Using the ArgoNeuT Experiment at Fermilab.

A search for millicharged particles, a simple extension of the standard model, has been performed with the ArgoNeuT detector exposed to the Neutrinos at the Main Injector beam at Fermilab. The ArgoNeuT liquid argon time projection chamber detector enables a search for millicharged particles through the detection of visible electron recoils. We search for an event signature with two soft hits (MeV-scale energy depositions) aligned with the upstream target.