Original Theoretical Investigation of Dark Matter Detection Prospects Using Nigerian Underground Laboratory Infrastructure

Deep underground laboratories provide the shielded environment necessary for detecting the rare nuclear recoil signals expected from weakly interacting massive particle dark matter candidates, as overburden rock attenuates cosmic ray muon-induced backgrounds by many orders of magnitude. Nigeria possesses potential deep underground laboratory sites in abandoned mine shafts in the Plateau State and Nassarawa State tin mining belt with overburdens exceeding 500 meters of water equivalent, yet no theoretical assessment of their scientific potential for dark matter physics has been published. This research conducts an original theoretical investigation of dark matter detection prospects using instrumented underground laboratory infrastructure at candidate Nigerian sites. A new theoretical estimate of the weakly interacting massive particle-nucleus scattering cross-section sensitivity achievable with noble liquid detector technology deployed at the Nigerian subsurface environment is derived, accounting for local muon flux from atmospheric neutrino calculations, site-specific rock radioactivity contributions to neutron background, and radon emanation rates estimated from uranium content of local geological formations. The cosmic-ray muon flux at proposed site depths is computed using the MUSIC and MUSUN Monte Carlo codes with input from the Nigerian geological overburden composition derived from borehole assay data. Background neutron flux predictions from (alpha,n) reactions and spontaneous fission in local granite wallrock are computed using the SOURCES-4C code. The analysis finds that a 1-tonne fiducial mass liquid xenon detector at 1,000 meters water equivalent depth in the Plateau State mine environment could achieve spin-independent cross-section sensitivity of 10^-47 cm2, competitive with mid-scale international dark matter experiments. The study provides the original scientific case for investment in Nigerian deep underground laboratory infrastructure. Keywords: dark matter detection, underground laboratory, weakly interacting massive particle, Plateau State, background radiation