Puzzles and Challenges in Heavy-Quarkonium Theory

par Bernd Kniehl (Hamburg Universität)

vendredi 22 mars 2024, 11:00 → 13:00 Europe/Paris

100/2-A201 - Salle A201 (IJCLab)

The factorization formalism of nonrelativistic QCD (NRQCD) provides a rigorous theoretical framework for the description of heavy-quarkonium production and decay, and predicts the existence of color-octet processes in nature. This involves NRQCD long-distance matrix elements, being nonperturbative input parameters, which are predicted to be universal. The verification of NRQCD factorization by comparison of its predictions with the world data of heavy-quarkonium yield and polarization has turned out to be a long and winding road. The state of the art of this endeavor is reviewed and an outlook is presented.