arXiv subjects

In Woo Park

Publications and source records attributed to In Woo Park.

7 recordsLinked to original sources

arXiv2026

$f_2(1270)\toπ+π$ as a probe of spin and vorticity in heavy-ion collisions

The correlation between vorticity and spin alignment in heavy-ion collisions can be probed through polarization measurements of hadrons, whose total spin originates from both constituent-quark spins and orbital angular momentum in the quark-model framework. To motivate such experimental studies, we calculate the general angular distribution of produced pion in $f_2(1270)\toπ+π$ using interaction Lagrangian and helicity formalism and check that both methods yield the same result. The distribution is given as a function of angle between pion and initial quantization axis of $f_2$ and the spin density matrix element of $f_2$. Its diagonal entries and $ρ_{20}$ component were computed assuming local thermal equilibrium and blast wave model for different centrality classes, hence given as a function of azimuthal angle with respect to the impact parameter.

nucl-th↗

arXiv2025

Long-Range $N-J/ψ$ Interaction from an Operator Product Expansion Perspective

A recent lattice QCD study has shown that the $N-J/ψ$ potential is attractive at all distances, and its long-range tail is well described by two-pion exchange. Here, we study to what extent the long-range part of the attraction can be reproduced from the perspective of the operator product expansion (OPE). This is accomplished by extracting the leading-order four-quark operator that couples to two pions and calculating its contribution to the $J/ψ$ mass in nuclear matter, to linear order in density, within the QCD sum rule framework. Using previous estimates of the four-quark operators for the chiral symmetric and breaking parts, we obtain a mass decrease that is smaller in magnitude but qualitatively consistent with the attraction obtained in the lattice QCD calculation. By expressing the interaction in terms of four-quark operators, we can analyze the effects of chiral symmetry restoration in dense matter on the masses of the $J/ψ$ and other mesons composed of heavy quarks.

nucl-th↗

arXiv2025

The Electron-Ion Collider as A Prospective Facility for Pentaquark Measurements

The Electron-Ion Collider provides a groundbreaking opportunity to study heavy pentaquarks with unprecedented precision, leveraging its high collision energy and beam spin polarization capabilities. As a representative case, we analyze electroproduction cross sections of Pc (4312) under different spin-parity hypotheses using the vector meson dominance model. To ensure a parameter-free approach and minimize ambiguity, we incorporate results from the LHCb and GlueX experiments. To characterize the spin and the parity of Pc (4312), we propose measuring the beam spin asymmetry and decay kinematic polarization, quantities that can be accurately determined by the ePIC detector. Our approach can be extended to investigate other heavy pentaquarks produced in electron-proton and electron-deuteron collisions, as well as to study their interactions with nuclear matter in electron-heavy ion collisions. We strongly encourage the EIC community to explore this potential and integrate pentaquark studies as a critical element of the scientific mission.

hep-ph↗

arXiv2024

Separating the transverse and longitudinal modes of $ϕ$, $ρ$, $K^*$ and $K_1$ mesons through their angular-dependent two-body decay modes

The mass shift a spin-1 particle moving in the nuclear medium will depend on its polarization direction. To study polarization-independent mass shifts in the medium, we explore methods to isolate each polarization direction of spin-1 mesons through the angular-dependent two-body decay modes. Specifically, we study $ϕ\to K^{+}K^{-}$, $ρ\toππ$, $K^{*}\to Kπ$, $ϕ\to e^{+}e^{-}$ and $K_{1}\toρK(K^{*}π)$ decays. While each polarization mode can be isolated through angular dependencies, accomplishing the decomposition for the $K_1$ meson further requires measuring the polarization of the $ρ(K^*)$ meson. Concerning $K^{*}$ and $K_1$ mesons, since both particles have vacuum widths smaller than 100 MeV, they are ideal candidates for experimentally measuring chiral partners. The simultaneous observation of mass shifts of these chiral partners would provide valuable insights into the contribution of chiral symmetry breaking to the generation of hadron masses.

hep-ph↗

arXiv2024

Identifying the transverse and longitudinal modes of the $K^*$ and $K_{1}$ mesons through their angular dependent decay modes

Observing the mass shifts of chiral partners will provide invaluable insight into the role of chiral symmetry breaking in the generation of hadron masses. Because both the $K^*$ and $K_1$ mesons have vacuum widths smaller than 100 MeV, they are ideal candidates for realizing mass shift measurements. On the other hand, the different momentum dependence of the longitudinal and transverse modes smear the peak positions. In this work, we analyze the angular dependence of the two-body decays of both the $K^*$ and $K_1$. It is found that the longitudinal and transverse modes of the $K^*$ can be isolated by observing the pseudoscalar decay in either the forward or perpendicular directions, respectively. For the $K_1$ decaying into a vector meson and a pseudoscalar meson, one can accomplish the same goal by further observing the polarization of the vector meson through its angular dependence on the two pseudoscalar meson decay.

hep-ph↗

arXiv2023

Disentangling longitudinal and transverse modes of the $ϕ$ meson through dilepton and kaon decays

Angular distributions of $ϕ$ meson decay amplitudes of $e^+e^-$ and $K^+K^-$ channels are computed using both specific interaction Lagrangians and simple arguments relying on angular momentum conservation. Based on the obtained results, we assess methods to experimentally disentangle the longitudinal and transverse polarization modes of the $ϕ$ meson and discuss advantages and disadvantages of employing either the leptonic or hadronic decay modes for this task.

hep-ph↗

arXiv2022

Production of $P_{c}$(4312) state in electron-proton collisions

We study the cross sections for the electro-production of $P_c(4312)$ particle, a recently discovered pentaquark state, in electron-proton collisions assuming possible quantum numbers to be $J^{P}=\frac{1}{2}^\pm, \frac{3}{2}^\pm$. $\sqrt{s}$ is set to the energy of the future Electron Ion Collider at Brookhaven National Laboratory, in order to asses the possibility of the measurement in this facility. One can discriminate the spin of $P_c(4312)$ by comparing the pseudorapidity distribution in two different polarization configurations for proton and electron beams. Furthermore, the parity of $P_c(4312)$ can be discerned by analyzing the decay angle in the $P_c \rightarrow p +J/ψ$ channel. As the multiplicity of $P_c$ production in our calculation is large, the EIC can be considered as a future facility for precision measurement of heavy pentaquarks.

hep-ph↗