arXiv subjects

Jin-Yu Hu

Publications and source records attributed to Jin-Yu Hu.

5 recordsLinked to original sources

arXiv2026

Nonlinear response of flow harmonics in Gubser flow with participant-reaction planes mismatch

We investigate the nonlinear response of flow harmonics $v_2,v_4$ to initial-state eccentricities $\epsilon_2,\epsilon_4$ within the Gubser-flow framework. By extending the perturbative solutions of Gubser flow, we derive analytic nonlinear response relations connecting the eccentricities $\epsilon_2,\epsilon_4$ to the flow harmonics $v_2,v_4$. Our results reproduce the well-known result $v_4/v_2^2 \to 1/2$ in large transverse momentum $p_T$ limit. Furthermore, we study the effects of a mismatch between the participant and reaction planes. We find that the conventional nonlinear response coefficients acquire an additional factor determined by the participant-plane angles, which is often approximated as statistical noise driven by event-by-event fluctuations. This factor can modify both the strength but even the sign of the effective nonlinear response coefficient, making it sensitive to the initial configuration of the colliding nuclei. Our study provides new analytical insight into the origin of collective phenomena in relativistic heavy-ion collisions.

nucl-th↗

arXiv2025

Probing the tetrahedral $\alpha$ clusters in relativistic $^{16}$O + $^{16}$O collisions

Relativistic $^{16}$O +$^{16}$O collisions probe the Quark-Gluon Plasma formed in small systems, while their collective phenomena illuminate the structure of $^{16}$O. Recently, various configurations of $^{16}$O from \textit{ab initio} calculations were implemented in heavy-ion models, such as the hydrodynamic model and a multiphase transport model (AMPT) to study cluster effects in relativistic $^{16}$O +$^{16}$O collisions. However, divergent predictions across configurations and models complicate interpretations. In this Letter, we isolate the impact of multi-nucleon correlations in relativistic $^{16}$O +$^{16}$O collisions while fixing the one-body density distribution of $^{16}$O. Our results show that the normalized ratios ${\rm Norm}(v_{2}\{2\}/v_{2}\{4\})$ and ${\rm Norm}(v_{2}\{2\}/v_{3}\{2\})$ effectively probe the effects of one-body density (e.g., tetrahedral symmetry) and multi-nucleon correlations (e.g., $\alpha$ clusters). These observables provide critical constraints for refining heavy-ion models, essential for investigating cluster configurations in light nuclei through relativistic heavy-ion collisions.

nucl-th↗

arXiv2024

Light nuclei photoproduction in relativistic heavy ion ultraperipheral collisions

We have investigated light nuclei pair photoproduction in relativistic heavy ion ultraperipheral collisions. As a first attempt, we employ our previously developed quantum electrodynamics model, which incorporates a wave-packet description of initial nuclei, to compute the cross section for proton-antiproton pair photoproduction. The effective vertex for the photon and proton interaction is chosen based on studies of two-photon exchange effects in hadron physics. We present the transverse momentum, invariant mass, and azimuthal angle distributions of proton-antiproton pairs at $\sqrt{s_{NN}}=200$ GeV in Au+Au ultraperipheral collisions. We observe a $\cos(2ϕ)$ modulation and an almost negligible $\cos(4ϕ)$ modulation in the azimuthal angle distribution. Our studies helps us better understand the matter generated by light.

hep-ph↗

arXiv2024

Nuclear deformation effects in photoproduction of $\rho$ mesons in ultraperipheral isobaric collisions

We have investigated the $\rho^{0}$ meson photoproduction in ultraperipheral isobaric collisions between $_{44}^{96}\textrm{Ru}+_{44}^{96}\textrm{Ru}$ and $_{40}^{96}\textrm{Zr}+_{40}^{96}\textrm{Zr}$ at $\sqrt{s_{NN}}=200$ GeV, employing the dipole model with the equivalent photon approximation. By implementing the Woods-Saxon distribution to represent the nuclear mass density, which is derived from density functional theory with an inclusion of nuclear deformation effects, we have calculated the transverse momentum $q_{T}$ spectra in isobaric collisions. We observe the characteristic dip behavior in these spectra, indicative of diffraction phenomena in high-energy physics. We notice that the deformation effects cause a nearly linear increase with $q_{T}^{2}$ for $q_{T}^{2}\lesssim0.015$ $\textrm{GeV}^{2}$, aligning with experimental observations. We offer a simple explanation for the observed behavior in these spectra by introducing the effective width of the nuclei in the thickness function. We also extend our discussion on the $\rho^{0}$ meson photoproduction with the targets $^{63}\textrm{Cu}$,$^{197}\textrm{Au}$, and $^{238}\textrm{U}$.

hep-ph↗

arXiv2023

Ophtha-LLaMA2: A Large Language Model for Ophthalmology

In recent years, pre-trained large language models (LLMs) have achieved tremendous success in the field of Natural Language Processing (NLP). Prior studies have primarily focused on general and generic domains, with relatively less research on specialized LLMs in the medical field. The specialization and high accuracy requirements for diagnosis in the medical field, as well as the challenges in collecting large-scale data, have constrained the application and development of LLMs in medical scenarios. In the field of ophthalmology, clinical diagnosis mainly relies on doctors' interpretation of reports and making diagnostic decisions. In order to take advantage of LLMs to provide decision support for doctors, we collected three modalities of ophthalmic report data and fine-tuned the LLaMA2 model, successfully constructing an LLM termed the "Ophtha-LLaMA2" specifically tailored for ophthalmic disease diagnosis. Inference test results show that even with a smaller fine-tuning dataset, Ophtha-LLaMA2 performs significantly better in ophthalmic diagnosis compared to other LLMs. It demonstrates that the Ophtha-LLaMA2 exhibits satisfying accuracy and efficiency in ophthalmic disease diagnosis, making it a valuable tool for ophthalmologists to provide improved diagnostic support for patients. This research provides a useful reference for the application of LLMs in the field of ophthalmology, while showcasing the immense potential and prospects in this domain.

cs.CL↗