We discuss the impact of the charm quark mass in the CTEQ NNLO global analysis of parton distribution functions of the proton. The $bar{rm MS}$ mass $m_c(m_c)$ of the charm quark is extracted in the S-ACOT-$chi$ heavy-quark factorization scheme at ${cal O}(alpha_s^2)$ accuracy and found to be in agreement with the world-average value. Impact on $m_c(m_c)$ of combined HERA-1 data on semiinclusive charm production at HERA collider and contributing systematic uncertainties are reviewed.
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 QC
D, 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.
We overview progress in the development of general-purpose CTEQ PDFs. The preprint is based on four talks presented by H.-L. Lai and P. Nadolsky at the 17th International Workshop on Deep Inelastic Scattering and Related Subjects (DIS 2009).
I discuss advances in the determination of strange, charm, and bottom quark parton distribution functions obtained in the CTEQ6.5 and CTEQ6.6 global analyses. These results affect electroweak precision observables and certain new physics searches at
the Large Hadron Collider. I focus, in particular, on high-energy implications of the consistent treatment of heavy-quark threshold effects in DIS in the general-mass factorization scheme; an independent parametrization for the strangeness PDF; and the possible presence of nonperturbative (intrinsic) charm.
The CTEQ program for the determination of parton distributions through a global QCD analysis of data for various hard scattering processes is fully described. A new set of distributions, CTEQ3, incorporating several new types of data is reported and
compared to the two previous sets of CTEQ distributions. Comparison with current data is discussed in some detail. The remaining uncertainties in the parton distributions and methods to further reduce them are assessed. Comparisons with the results of other global analyses are also presented.
An overview is given of recent progress on a variety of fronts in the global QCD analysis of the parton structure of the nucleon and its implication for collider phenomenology, carried out by various subgroups of the CTEQ collaboration.