Heavy Baryon Mixing in Chiral Perturbation Theory
Abstract
We discuss the SU(3) and heavy quark spin-symmetry breaking mixing between the Xic and Xi'c charmed baryons. Chromomagnetic hyperfine interactions are the leading source of spin-symmetry breaking and together with the SU(3) breaking mass differences between the lightest pseudo-Goldstone bosons gives the leading contribution to the mixing. Such contributions are computed in chiral perturbation theory and compared to quark model expectations. We also compute the leading contribution to the semileptonic decay Xib -> Xi'c l nu at zero recoil, and find that it is an order of magnitude smaller than naive power counting would suggest. It appears that Xib -> Xi'c l nu is dominated by incalculable counterterms, and we discuss the implications for quark models based on the essential role of hyperfine interactions.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.