The spectrum of light hadrons encodes essential information about the non-perturbative dynamics of QCD. Most observed hadrons are resonances, rigorously defined as poles of scattering amplitudes in the complex energy plane. Their properties, such as masses, widths, and couplings, are therefore determined by the analytic structure of the amplitudes describing low-energy hadronic interactions....
Quarkonia are bound states formed by a heavy-quark pair. They are commonly described within the framework of non-relativistic QCD. Yet, this description is not sufficient to fully exploit data involving quarkonium production, which still hide precious information and call for theoretical improvements. In this talk, I will try to give a (biased) perspective on what quarkonium physics can teach...
We will discuss the recent developments in renormalization group improvements of the cold and dense QCD pressure (Phys. Rev. D 111, 034020 and Phys. Rev. Lett. 129, 212001) at next-to-next-to leading order (NNLO) through the renormalization group optimized perturbation theory (RGOPT) and at all-order resummation of the soft modes. RGOPT applied for the very first time at NNLO displayed a...
Very high energy electrons passing through ordinary matter initiate electromagnetic showers that are produced by bremsstrahlung and pair production. At extremely high energies, the quantum-mechanical duration of these processes becomes longer than the mean free time for elastic scattering in the medium, which leads to a significant suppression of bremsstrahlung (and pair production). This...