  The Diffuse Gamma-Ray Background (DGB) above 100 GeV at high-latitudes is
expected to be produced by unresolved extragalactic objects such as active
galactic nuclei, isotropic Galactic gamma-rays, and possible emission from dark
matter annihilations or decays in the Galactic dark matter halo. The DGB has
been observed up to nearly 1 TeV, but has yet to be detected at higher
energies. Detections or stringent limits on the DGB above this energy would
have strong multimessenger consequences, such as constraining the origin of
astrophysical neutrinos observed in IceCube. The High Altitude Water Cherenkov
(HAWC) observatory has its highest sensitivity to gamma rays above 1 TeV and
observes over 2/3 of the sky each day. With its high energy reach and large
areal coverage, HAWC can significantly improve searches of the DGB at TeV
energies. We will investigate parameter cuts to the HAWC dataset to better
isolate gamma-ray air showers from background hadronic showers. This, combined
with new background estimation techniques will improve the HAWC sensitivity to
the DGB. We will present a limit on the DGB with HAWC as well as its
implications for multimessenger and dark matter studies.
