Isospin splittings of doubly heavy baryons

Abstract

The SELEX Collaboration has reported a very large isospin splitting of doubly charmed baryons. We show that this effect would imply that the doubly charmed baryons are very compact. One intriguing possibility is that such baryons have a linear geometry Q-q-Q where the light quark q oscillates between the two heavy quarks Q, analogous to a linear molecule such as carbon dioxide. However, using conventional arguments, the size of a heavy-light hadron is expected to be around 0.5 fm, much larger than the size needed to explain the observed large isospin splitting. Assuming the distance between two heavy quarks is much smaller than that between the light quark and a heavy one, the doubly heavy baryons are related to the heavy mesons via heavy quark-diquark symmetry. Based on this symmetry, we predict the isospin splittings for doubly heavy baryons including Xi_{cc}, Xi_{bb} and Xi_{bc}. The prediction for the Xi_{cc} is much smaller than the SELEX value. On the other hand, the Xi_{bb} baryons are predicted to have an isospin splitting as large as (6.3\pm1.7) MeV. An experimental study of doubly bottomed baryons is therefore very important to better understand the structure of baryons with heavy quarks.

11 pages

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Cited by in corpus (20)

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• Spectroscopy of doubly-charmed baryons from lattice QCD
• Implications of Heavy Quark-Diquark Symmetry for Excited Doubly Heavy Baryons and Tetraquarks
• Isospin splittings in baryons with two heavy quarks
• Deuteron-like states composed of two doubly charmed baryons
• The masses and axial currents of the doubly charmed baryons
• Puzzles in Hadronic Physics and Novel Quantum Chromodynamics Phenomenology
• Strong interaction of doubly heavy spin-3/2 baryons with light vector mesons
• Screening of quark charge and mixing effects on transition moments and M1 decay widths of baryons
• 70 Years of Hyperon Spectroscopy: A review of strange $\Xi$, $\Omega$ baryons, and the spectrum of charmed and bottom baryons
• Chiral effective Lagrangian for doubly charmed baryons up to $\mathcal{O}(q^4)$
• One-loop analysis of the interactions between doubly charmed baryons and Nambu-Goldstone bosons
• Static properties and Semileptonic transitions of lowest-lying double heavy baryons
• An introduction to the quark model
• Analysis of the bottom-charm baryon states with QCD sum rules
• Observation of the doubly charmed baryon ${\Xi }_{cc}^{+}$ with the LHCb Run 3 detector
• Novel Perspectives for Hadron Physics