Johannes Michel (Amsterdam): QCD Factorization and Resummation from Heavy Jets to Heavy Hadrons

Existing data from LEP, B factories, and the LHC, as well as the experimental programs at the upcoming EIC and other future colliders, contain the key to a new level of depth in our understanding of QCD. These advances can range from precision determinations of the strong coupling -- the main parameter of QCD -- to new ways of probing the still-mysterious physics of hadronization, but require equally precise and refined first-principle QCD predictions. In the first part of my talk, I will discuss the all-order resummation of perturbative logarithms near so-called Sudakov shoulders, specifically for the case of the heavy jet mass (HJM) event shape in electron-positron collisions. I present a unified formalism that describes the partonic HJM distribution from the dijet to the shoulder region, and discuss in particular how we cleared a roadblock on the way to higher perturbative precision by adapting techniques from transverse momentum-dependent (TMD) resummation. In the second part of my talk I turn to the physics of TMD fragmentation functions (FFs) for heavy quarks, which we recently proposed as a unique new probe of hadronization.
I show highlights of our results, including the phenomenology of these functions at colliders, their factorization in boosted Heavy-Quark Effective Theory, and complete one-loop results featuring a rich singularity and renormalization structure.