  We present the new CTEQ-TEA global analysis of quantum chromodynamics (QCD).
In this analysis, parton distribution functions (PDFs) of the nucleon are
determined within the Hessian method at the next-to-next-to-leading order
(NNLO) in perturbative QCD, based on the most recent measurements from the
Large Hadron Collider (LHC) and a variety of world collider data. Because of
difficulties in fitting both the ATLAS 7 and 8 TeV $W$ and $Z$ vector boson
production cross section data, we present four families of (N)NLO CTEQ-TEA
PDFs, named CT18, A, X and Z PDFs, respectively. We study the impact of the
CT18 family of PDFs on the theoretical predictions of standard candle cross
sections at the LHC.
