82 research outputs found
Are there compact heavy four-quark bound states?
We present an exact method to study four-quark systems based on the
hyperspherical harmonics formalism. We apply it to several physical systems of
interest containing two heavy and two light quarks using different quark-quark
potentials. Our conclusions mark the boundaries for the possible existence of
compact, non-molecular, four-quark bound states. While states
may be stable in nature, the stability of states would imply
the existence of quark correlations not taken into account by simple quark
dynamical modelsComment: 10 pages, 1 figure. Accepted for publication in Phys. Rev.
Stable p-wave resonant two-dimensional Fermi-Bose dimers
We consider two-dimensional weakly-bound heterospecies molecules formed in a
Fermi-Bose mixture with attractive Fermi-Bose and repulsive Bose-Bose
interactions. Bosonic exchanges lead to an intermolecular attraction, which can
be controlled and tuned to a p-wave resonance. Such attractive fermionic
molecules can be realized in quasi-two-dimensional ultracold isotopic or
heteronuclear mixtures. We show that they are stable with respect to the
recombination to deeply-bound molecular states and with respect to the
formation of higher-order clusters (trimers, tetramers, etc.
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