  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 two families of PDFs, named CT18 and
CT18$Z$ PDFs, respectively, without and with the ATLAS 7 TeV $W$ and $Z$
measurements. We study the impact of the CT18 family of PDFs on the theoretical
predictions of standard candle cross sections at the LHC.
