Constraints on nuclear parton distribution functions with dijets in pp, pPb collisions at $\sqrt {s_{NN}}=$ 5.02 TeV with the CMS detector

Dijet measurements in pPb collisions have been shown to be one of the most important tools for constraining the gluon nuclear parton distribution functions (nPDFs) at large Bjorken x. The dijet pseudorapidity distributions are measured as a function of dijet average transverse momentum in order to study the nuclear modifications of PDFs at various factorization scales. The final results from pp and pPb data samples are compared with next-to-leading-order perturbative QCD predictions obtained from both nucleon and nuclear PDFs. In this paper, we show the latest constraints on nPDFs from studies of dijet pseudorapidity distributions in pp and pPb with the CMS detector.