Results are presented from a search for new physics in the final states containing either a photon or a jet accompanied by an imbalance in transverse energy using a data sample corresponding to an integrated luminosity of 4.7 fb−1 collected in pp collisions at √s = 7 TeV by the CMS experiment. The observed event count agrees with standard model expectations, establishing upper limits on the spin-independent dark matter candidate (χ)-nucleon cross section of 0.72 - 157 fb (16.1 − 16.8 fb) at 90% confidence level (CL) and extending limits into the formerly-unexplored χ-mass (Mχ) region below 3.5 GeV for the single jet (single photon) channel. For the spin-dependent χ-nucleon cross section, the new upper limit is 0.0337 - 21.5 fb (16.1 − 17.6 fb) at 90% CL, for Mχ 1−1000 GeV, respectively, exceeding prior search sensitivities for the single jet (single photon) channel.