Search for new physics in monojet events in pp collisions at sqrt(s)= 8 TeV

A search has been made for events containing an energetic jet and an imbalance in transverse momentum using a data sample of pp collisions at a center-of-mass energy of 8 TeV. The data were collected by the CMS detector at the LHC and correspond to an integrated luminosity of 19.5 fb$^{-1}$. The number of observed events is consistent with the standard model expectation. Constraints on the dark matter-nucleon scattering cross sections are determined for both spin-independent and spin-dependent interaction models. Limits are also placed on the Arkani-Hamed, Dimopoulos, and Dvali model parameter $M_\mathrm{D}$ as a function of the number of extra dimensions and the production of Unparticles.