arXiv subjects

Hyeongock Yun

Publications and source records attributed to Hyeongock Yun.

4 recordsLinked to original sources

arXiv2026

Three-body forces in the quark model

We review the connection between constituent-quark Hamiltonians and QCD and investigate the long-standing difficulty of describing meson and baryon spectra with one common two-body interaction. A Hamiltonian calibrated to ground-state mesons leaves systematic baryon mass residuals, largest in the light-quark sector and decreasing toward heavier flavors. We show that a short-range, color-spin-dependent connected three-quark interaction substantially reduces this incompatibility. Mass-scaled finite-range profiles yield high-accuracy baryon spectra, whereas flavor-independent common-range profiles do not remove the residual flavor pattern. The result is tested on additional ground-state baryons outside the calibration set and through meson--baryon compatibility analyses across several alternative quark-model Hamiltonians. We also benchmark radial and orbital excitations to identify the regime in which a static compact valence Hamiltonian remains reliable, and provide explicit color-spin matrix elements for two- and three-body operators in baryons and multiquark configurations. Within the tested valence-space representations, the results indicate that a mass-dependent short-range connected three-quark interaction provides the missing contribution required for a consistent simultaneous description of meson and baryon ground-state spectra.

hep-ph↗

arXiv2024

The Inevitable Quark Three-Body Force and its Implications for Exotic States

Three-body nuclear forces are essential for explaining the properties of light nuclei with a nucleon number greater than three. Building on insights from nuclear physics, we extract the form of quark three-body interactions and demonstrate that these terms are crucial for extending the quark model fit of the meson spectrum to include baryons using the same parameter set. We then discuss the implications of our findings for exotic configurations involving more than three quarks, such as the $T_{cc}$ and $χ_{c1}(3872)$. We find that the quark three-body interactions provide additional repulsion on the order of 10 MeV for the compact configurations of both the $T_{cc}$ and $χ_{c1}(3872)$. This result, combined with previous calculations, strongly suggests that these tetraquark states are molecular rather than compact states.

hep-ph↗

arXiv2024

Diquarks and the production of charmed baryons

Utilizing a quark model characterized by parameters that effectively replicate the masses of ground state hadrons, we illustrate that $(us)$ or $(ds)$ diquarks exhibit greater compactness in comparison to $(ud)$ diquarks. Concretely, the binding energy of the $(us)$ diquark - defined as the diquark's mass minus the combined masses of its individual quarks - is found to be stronger than that of the $(ud)$ diquark. This heightened attraction present in $(us)$ diquarks could lead to enhanced production of $Ξ_c/D$ particles in high-energy pp or ultrarelativistic heavy-ion collisions.

hep-ph↗

arXiv2022

$X(3872)$ and $T_{cc}$: structures and productions in heavy ion collisions

We argue why the recently observed $T_{cc}$ could either be a compact multiquark configuration or a loosely bound molecular configuration composed of charmed mesons, whereas the $X(3872)$ is most likely a molecular configuration. The argument is based on different short range interactions for these tetraquark states coming from the color-color and color-spin interaction in a quark model, and the presence of a common strong D-wave mixing at larger distance similar to the deuteron case, which for the molecular configurations lead to large sizes. Such an analogy at large distance allows us to calculate the transverse momentum dependence of the loosely bound molecular configuration of tetraquarks produced in heavy ion collisions using the coalescence model that successfully reproduces the deutron data using the proton spectra. The ratio of the integrated $X(3872)$ yield obtained from our method to the $ψ(2S)$ yield obtained from statistical hadronization model method is calculated to be $0.806 \pm 0.234$, which is a factor of 2.47 larger than that obtained by using statistical model predictions for both particles and in line with the data from the CMS experiment. As the previously calculated transverse momentum distribution of the $T_{cc}$ assuming the structure to be a compact multiquark configuration is markedly different, experimental measurements of the transverse distribution of the tetraquark states will discriminate between their two possible structures.

hep-ph↗