Speaker
Description
Achieving percent-level accuracy and precision in parton distribution functions (PDFs) requires a careful optimization of the theoretical and methodological ingredients entering their determination. In this talk, we present a multidimensional correlation study based on multiple CT25 PDF fits at NNLO in QCD, aimed at investigating and quantifying the correlations among the strong coupling $\alpha_s(M_z)$, the top-quark pole mass $m_t$, and the gluon PDF parameterization. We perform simultaneous fits using optimized combinations of recent high-precision differential cross-section measurements for top-quark pair production at the LHC, and illustrate the individual roles of the parameters contributing to the observed multidimensional correlations to understand their effect on the resulting PDFs. We then perform a simultaneous extraction of $\alpha_s(M_z)$ and $m_t$ and highlight their relation to the stability of the Higgs vacuum.