Experimental QCD summary (ICHEP 2020)

Abstract

This writeup summarizes the main experimental studies of the strong interaction, theoretically described by quantum chromodynamics (QCD), that were presented during the ICHEP-2020 conference. The latest results, measured mostly in p-p collisions at the LHC, are categorized in seven broad topics:(i) Extractions of the strong coupling constant α s (m Z );(ii) Comparison of data to fixed-order (N n LO) perturbative QCD calculations;(iii) Determinations of parton distribution functions (PDFs);(iv) Comparison of data to resummed (N n LL) pQCD calculations;(v) Parton showering and jet substructure analyses;(vi) Semihard (double parton interactions, multiparton interactions, hard diffraction), and soft (elastic and diffractive) QCD scatterings;(vii) Studies of parton hadronization in e + e − and p-p collisions.

How to discover QCD Instantons at the LHC

“…The study of Quantum Chromodynamics (QCD) in this perturbative regime has seen tremendous advancements in the last decades. Hard processes have been calculated up to the third order in the strong coupling [2,3], and perturbative QCD predictions have been verified to incredible precision over many order of magnitudes of momentum transfer at high energy colliders [4]. At the same time a fundamental understanding of Yang-Mills theories in the strongly coupled limit is still lacking, and remains one of the biggest challenges for particle physics to date.…”