Quantum 2025 – scientific programme

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MON: Monday Contributed Sessions

MON 10: Standard Model and Beyond

MON 10.1: Talk

Monday, September 8, 2025, 14:15–14:30, ZHG103

QCD chemistry and heavy-light diquarks — •Mikhail Shifman — William Fine Theoretical Physics Institute, University of Minnesota, MN 55455, USA

In connection with recent discoveries of heavy-quark containing exotic states publications discussing Qq diquarks (Q,q stand for a heavy and light quarks, respectively) proliferated in the literature. After a brief summary of the diquark concept I present various general reasons why the heavy-light diquark (with sufficiently heavy Q) does not exist. Then I argue (this is the focus of my talk) that the most direct way to confirm non-existence of the Qq diquarks is the study of pre-asymptotic corrections in the inclusive decays of Qqq baryons, e.g. Λb. Since the c quarks are much lighter than b, namely, the ratio (m_b)^2/(m_c^2) is of the order of 11, traces of the cq attraction in the color anti-triplet spin-0 state may or may not be present in the cqq baryons.

Keywords: Heavy quarks; Diquarks in Qqq baryons; Total decay widths of Qqq baryons