Dark matter pair associated with a $W$ boson production at the LHC in   next-to-leading order QCD
  We investigate the QCD next-to-leading order (NLO) corrections to the production of a pair of fermionic dark matter particles associated with a W boson production through a mediator which couples to standard model particles via either a vector or axial-vector coupling at the LHC. We find that the QCD NLO corrections reduce the dependence of the total cross sections on the factorization and renormalization scales, and the $K$-factors increase with the increment of the dark matter mass. We also provide the LO and QCD NLO corrected distributions of the transverse momenta $p_T^\mu$ of final muon and transverse mass $M_T$. We find that the LO cross section is significantly changed by the QCD NLO corrections. 
Song Mao, Li Gang, Ma Wen-Gan, Zhang Ren-You and Guo Jian-You
hep-ph