arXiv subjects

Aaron Park

Publications and source records attributed to Aaron Park.

At least 19 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↗

arXiv2026

Multiquark clustering in neutron-star matter from color-spin molecular dynamics

We study the equation of state of neutron-star matter with color-spin molecular dynamics. The calculation includes the internal color and spin degrees of freedom and their time evolution. The matter composition, including strangeness under $\beta$ equilibrium, is determined by energy minimization. We find two main trends. First, within the present color-spin molecular dynamics framework and under the adopted clustering criterion along the stable neutron-star branch, isolated quarklike configurations do not appear; instead, color-magnetic interactions favor the self-consistent formation of multiquark clusters. Within the same criterion, the cluster-size distribution is concentrated at quark numbers that are multiples of three, corresponding to integer baryon numbers. Second, relative to the conventional no-$K^*$ baseline, the interaction between strange and light quarks has a strong impact on neutron-star radii. This suggests that future radius measurements, together with phenomenological information on the strangeness-onset density, may help constrain flavor-sector interactions involving strangeness.

astro-ph.HE↗

arXiv2026

The structure of the $X(3915)$ meson and its production in heavy ion collisions

We study the structure of the $X(3915)$ meson in a quark model and explore how its production in heavy ion collisions depends on its internal structure. We first analyze the $X(3915)$ as a $c\bar{c}s\bar{s}$ state and solve the Hamiltonian with color-spin interactions within the quark model. We find that the ground state of the $c\bar{c}s\bar{s}$ with total spin 0 obtained from the quark model analysis favors a separated $D_s \bar{D}_s$ state. To probe its structure further, we study its production in relativistic heavy ion collisions for various proposed configurations. We calculate the transverse momentum distributions and yields for the $X(3915)$ assuming its structure to be either a charmonium, a tetraquark, or a hadronic molecular state. We argue that by measuring the transverse momentum distributions and yields of the $X(3915)$ produced in heavy ion collisions, one can identify the structure of the $X(3915)$.

hep-ph↗

arXiv2026

Exploring bound states and interactions of the nucleon-antinucleon system in a constituent quark model

In this work, we study the nucleon-antinucleon system in a constituent quark model. We first construct the nucleon-antinucleon wave function such that the multiquark and multiantiquark components each satisfy the Pauli exclusion principle, and then investigate the possibility of a bound state using a Hamiltonian that includes color-color, spin-dependent interactions and three-quark potentials. Our results indicate that, in specific channels, the nucleon-antinucleon interaction exhibits significant attraction, suggesting a strong possibility of a bound state.

nucl-th↗

arXiv2025

Octaquarks in a simple chromomagnetic model

In this work, we study the octaquark, which is composed of two baryons and one meson using a simple chromomagnetic model. First, we construct the wave function of the octaquark satisfying the Pauli exclusion principle in the flavor SU(3) breaking case. In order to calculate the binding energy, we consider the lowest threshold by taking into account the decay products. By calculating the color-spin interaction of octaquarks for all possible quantum numbers, we determine several candidates for compact octaquarks.

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 $\chi_{c1}(3872)$. 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 $\chi_{c1}(3872)$. This result, combined with previous calculations, strongly suggests that these tetraquark states are molecular rather than compact states.

hep-ph↗

arXiv2023

Multibaryon configurations in a simple chromomagnetic model

In this work, we study the multibaryon configurations in a simple chromomagnetic model. We first construct the wave function of the multibaryon states using the multiquark configuration. We consider all possible quantum numbers assuming the spatial part of the wave function to be totally symmetric. Then, we calculate the color-spin factors for tetrabaryons, pentabaryons and hexabaryons in the flavor SU(3) breaking case.

hep-ph↗

arXiv2023

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 $\Xi_c/D$ particles in high-energy pp or ultrarelativistic heavy-ion collisions.

hep-ph↗

arXiv2022

Diquarkyonic matter: quarks, diquarks and baryons

In this work, we investigate the color-spin interaction of a quark, a diquark and a baryon with their surrounding baryons and/or quark matter. We extend our previous work by increasing the maximum number of surrounding baryons to 5 and additionally consider all possible diquark probes that are immersed in such surroundings. This is accomplished by classifying all possible flavor and spin states of the resulting multiquark configuration in both the flavor SU(2) and SU(3) symmetric cases. We also discuss the three-body confinement potential and show that this does not contribute to the outcome. Furthermore, we find that a quark becomes more stable than a baryon when the number of surrounding baryons is three or more. Finally, when we consider the internal color-spin factor of a probe, our results show that the effects of the color-spin interaction of a multiquark configuration is consistent with the so-called diquarkyonic configuration.

nucl-th↗

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 $\psi(2S)$ 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↗

arXiv2022

Algebraic approach to quarkyoniclike configuration and stable diquarks in dense matter

We study the color-spin interaction energy of a quark, a diquark and a baryon with their surrounding baryons and/or quark matter. This is accomplished by classifying all possible flavor and spin states of the resulting multiquark configuration in both the flavor SU(2) and SU(3) symmetric cases. We find that while the baryon has the lowest interaction energy when there is only a single surrounding baryon, the quark has the lowest interaction energy when the surrounding has more than three baryons or becomes a quark gas. As the short range nucleon-nucleon interactions are dominated by the color-spin interactions, our finding suggests that the baryon modes near other baryons are suppressed due to larger repulsive energy compared to that of a quark and thus provides a quark model basis for the quarkyoniclike phase in dense matter. At the same time, when the internal interactions are taken into account, and the matter density is high so that the color-spin interaction becomes the dominant interaction, the diquark becomes the lowest energy configuration and will thus appear in both the dense baryonic and/or quark matter.

nucl-th↗

arXiv2021

Case for quarkyoniclike matter from a constituent quark model

Based on the fact that the constituent quark model reproduces the recent lattice result on baryon-baryon repulsion at short distance and that it includes the quark dynamics with confinement, we analyze to what extent the quarkyonic modes appear in the phase space of baryons as one increases the density before only quark dynamics and hence deconfinement occurs. We find that as one increases the baryon density, the initial quark mode that appears will involve the $d(u)$-quark from a neutron (proton), which will leave the most attractive ($ud$) diquark intact.

hep-ph↗

arXiv2020

Tribaryons in a constituent quark model

We calculate the matrix elements of the color-spin interaction for all possible multi-quark states of tribaryons in flavor SU(3) broken case. For that purpose, we construct the flavor$\otimes$color$\otimes$spin wave functions of the tribaryons, which are taken to be antisymmetric to satisfy the Pauli exclusion principle. Furthermore, we analyze the diquark structure of the tribaryon configurations using the symmetric and antisymmetric basis set of flavor, color and spin states.

hep-ph↗

arXiv2020

Signatures of the vortical quark-gluon plasma in hadron yields

We investigate the hadron production from the vortical quark-gluon plasma created in heavy-ion collisions. Based on the quark-coalescence and statistical hadronization models, we show that total hadron yields summed over the spin components are enhanced by the local vorticity with quadratic dependence. The enhancement factor amounts to be a few percent and may be detectable within current experimental sensitivities. We also show that the effect is stronger for hadrons with larger spin, and thus propose a new signature of the local vorticity, which may be detected by the yield ratio of distinct hadron species having different spins such as $ϕ$ and $η'$. The vorticity dependence of hadron yields seems robust, with consistent predictions in both of the hadron production mechanisms for reasonable values of the vorticity strength estimated for heavy-ion collisions.

nucl-th↗

arXiv2019

Intrinsic three-body nuclear interaction from a constituent quark model

We study the short distance part of the intrinsic three-nucleon interaction in a constituent quark model with color-spin interaction. For that purpose we first calculate the transformation coefficient between the tribaryon configuration and their corresponding three baryon basis. Using a formula for the intrinsic three-body interaction in terms of a tribaryon configuration, we find that after subtracting the corresponding two-baryon contributions, the intrinsic three-body interaction vanishes in flavor SU(3) symmetric limit for all quantum numbers for the three nucleon states. We further find that the intrinsic three-body interaction also vanishes for flavor-spin type of quark interaction.

hep-ph↗

arXiv2019

Baryon-baryon interactions at short distances -- constituent quark model meets lattice QCD

The interaction energies between two baryons at short distance in different flavor channels are calculated from the constituent quark model (CQM) and are compared with the recent lattice QCD (LQCD) results for baryon-baryon potentials at short distance. We consider the six-quark system with two strange quarks and focus on the quantum numbers, (Flavor,Spin)=(1,0),(8,1),(10,1),($\overline{10}$,1) and (27,0). The interaction energy is defined by subtracting out isolated baryon masses and relative kinetic energy of two baryons from the total energy of a compact six-quark state. We introduce interaction energy ratio between different flavors as a useful measure to test the prediction of CQM. We find that the ratios in CQM show good agreement with those in LQCD, which indicates that the short range part of the baryon-baryon interaction can be understood qualitatively in terms of the Pauli principle and spin-dependent color interaction among constituent quarks.

hep-ph↗

arXiv2018

QCD sum rules for the $Δ$ isobar in neutron matter

We study the properties of the $Δ$ isobar in the symmetric and asymmetric nuclear matter using the QCD sum rules approach based on the energy dispersion relation. Allowing for different continuum thresholds for the polarization tensors with different dimensions, we find stable masses for the $Δ$ in both the vacuum and the medium. Compared to the nucleon case, we find that the vector repulsion is smaller for the $Δ$ while the scalar attraction is similar (75 MeV vector repulsion and 150 MeV scalar attraction in the symmetric matter). The smaller vector repulsion can be understood using the Pauli principle and a constituent quark model. Also the isospin dependence of the quasiparticle energy, which mainly comes from the vector self energy, is quite weak. We also allow for an explicit $π-N$ continuum contribution to the polarization function, but find its effect to be minimal. Phenomenological consequences of our results are discussed.

nucl-th↗

arXiv2018

Tribaryon configurations and the inevitable three nucleon repulsions at short distance

We decompose the tribaryon configuration in terms of SU(3) flavor and spin state and analyse their color-spin-flavor wave function following Pauli principle. By comparing the color-color and color-spin interactions of compact tribaryon configuration against the lowest three nucleon threshold within a constituent quark model, we show that the three nucleon forces have to be repulsive at short distance for all possible quantum numbers and all values of the SU(3) symmetry breaking parameter. Our work identifies the origin of the repulsive nuclear three body forces including the hyperons at short distance that are called for from phenomenological considerations starting from nuclear matter to the maximum mass of a neutron star.

hep-ph↗