nucl-th digest · May 7, 2026

[Submitted on 6 May 2026] (cross-list from hep-ph)

The $T_{b c}$ tetraquarks near the $B D ˉ$ threshold

We study the doubly heavy open-flavor tetraquarks $T_{b c}^{(0)}$ ( $J^{P} = 0^{+}$ ) and $T_{b c}^{(1)}$ ( $J^{P} = 1^{+}$ ) in the dynamical diquark model, describing the system as a heavy antidiquark--light diquark pair interacting through the lattice-QCD $Σ_{g}^{+} (1 S)$ Born--Oppenheimer potential. Solving the radial Schrödinger equation yields $M (T_{b c}^{(0)}) = 7.143$ -- $7.158$ GeV and $M (T_{b c}^{(1)}) = 7.217$ -- $7.222$ GeV, with hyperfine splittings of $Δ_{H F} ≃ 59$ -- $79$ MeV. The splitting is driven mainly by the mass difference between symmetric and antisymmetric heavy-antidiquark configurations, while the chromomagnetic interaction contributes linearly with $\partial Δ_{H F} / \partial κ_{b ˉ c ˉ} = 2$ , consistent with heavy-antidiquark spin algebra. The mean separation, $⟨ r ⟩ ≃ 0.45$ -- $0.46$ fm, and inverse radius, $⟨ 1/ r ⟩^{- 1} ≃ 0.33$ -- $0.34$ fm, exhibit weak parameter dependence and support a compact diquark--antidiquark interpretation. Relative to open-flavor thresholds, the scalar state lies essentially at the $B D ˉ$ threshold and may appear either as a weakly decaying bound tetraquark or as a narrow near-threshold resonance. In contrast, the axial-vector state is consistently predicted as an $S$ -wave resonance located $23$ -- $28$ MeV above $B^{*} D ˉ$ and about $70$ MeV below $B D ˉ^{*}$ , implying a line shape strongly influenced by the nearby $B^{*} D ˉ$ threshold.

Comments:: 13 pages, 1 figure
Subjects:: High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:: 2605.05150 [pdf]

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Thursday·May 7, 2026

Nonlocal Nonstabilizerness from Holographic Schwinger Pair Production

The $T_{b c}$ tetraquarks near the $B D ˉ$ threshold

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Nonlocal Nonstabilizerness from Holographic Schwinger Pair Production

The Tbc​ tetraquarks near the BDˉ threshold

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The $T_{b c}$ tetraquarks near the $B D ˉ$ threshold