Torsion-balance search for ultralow-mass bosonic dark matter

We used a stationary torsion balance with a beryllium-aluminum composition dipole to search for ultralowmass bosonic dark matter coupled to baryon minus lepton number. We set 95% confidence limits on the coupling constant gB-L for bosons with masses between 10(-18) and 10(-16) eV/c(2) with the best performance at mDM = 8 x 10(-18) eV/c(2) constraining g(B-L)(hc)(-1=2) < 1 x 10(-25). This provides a complimentary limit to equivalence-principle experiments that search for ultralow-mass bosons as force-mediating particles.