arXiv subjects

Hongge Xu

Publications and source records attributed to Hongge Xu.

6 recordsLinked to original sources

arXiv2026

A comparative study of $T_{cc}$ versus $X(3872)$ production in $pp$ collisions at $\sqrt{s}=$ 7 TeV

The production of exotic hadrons $T_{cc}$ and $X(3872)$ in $pp$ collisions at $\sqrt{s}=7$ TeV is compared using the parton and hadron cascade model PACIAE together with the dynamically constrained phase-space coalescence model DCPC. In the simulation, the compact tetraquark state and the loose molecular state are formed in the partonic and hadronic levels, respectively. Our analysis of the transverse momentum spectra reveals a significant discrepancy between the compact state and the molecular states. Furthermore, the production asymmetry between $T_{cc}^+$ and $T_{cc}^-$ is investigated. Finally, the coalescence parameters are extracted from the calculated spectra to further characterize the emission source properties. These distributions are proposed as valuable criteria for distinguishing between these states and investigating their internal structures in experimental measurements.

hep-ph↗

arXiv2024

Three-Nucleon Correlations in Light Nuclei Yields Ratios from AMPT Model for QCD Critical Point Investigation

This research use the AMPT model in Au+Au collisions to study the influence of the three nucleons correlation $C_{n^2p}$ on the light nuclei yield ratios. It is found that neglecting $C_{n^2p}$ leads to an overestimated relative neutron density fluctuation extraction. Including $C_{n^2p}$ will enhances the agreement with experimental results with higher yield ratios, yet it does not change the energy dependence of the yield ratio. Since there is no first-order phase transition or critical physics in the AMPT model, our work fails to reproduce the experimental energy-dependent peak around $\sqrt{s_\text{NN}} = $20-30 GeV. Our work might offer a baseline for investigating critical physics phenomena using the light nuclei production as a probe.

nucl-th↗

arXiv2024

Effect of Light Nuclei on Chemical Freeze-out Parameters at RHIC Energies

In this study, the chemical freeze-out of hadrons, including light-and strange-flavor particles and light nuclei, produced in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC), was investigated. Using the thermal-FIST thermodynamic statistical model, we analyzed various particle sets: those inclusive of light nuclei, those exclusive to light nuclei, and those solely comprising light nuclei. We determined the chemical freeze-out parameters at $\sqrt{s_\text{NN}}=$ 7.7--200 GeV and four different centralities. A significant finding was the decrease in the chemical freeze-out temperature $T_{\textrm{ch}}$ with light nuclei inclusion, with an even more pronounced reduction when considering light nuclei yields exclusively. This suggests that light nuclei formation occurs at a later stage in the system's evolution at RHIC energies. We present parameterized formulas that describe the energy dependence of $T_{\textrm{ch}}$ and the baryon chemical potential $\mu_B$ for three distinct particle sets in central Au+Au collisions at RHIC energies. Our results reveal at least three distinct $T_{\textrm{ch}}$ at RHIC energies correspond to different freeze-out hypersurfaces: a light-flavor freeze-out temperature of $T_L$ = 150.2$\pm$6 MeV, a strange-flavor freeze-out temperature $T_s$ = 165.1$\pm$2.7 MeV, and a light-nuclei freeze-out temperature $T_{\textrm{ln}}$ = 141.7$\pm$1.4 MeV. Notably, at the Large Hadron Collider (LHC) Pb+Pb 2.76 TeV, the expected lower freeze-out temperature for light nuclei was not observed; instead, the $T_{\textrm{ch}}$ for light nuclei was found to be approximately 10 MeV higher than that for light-flavor hadrons.

nucl-th↗

arXiv2024

The general propagator for S-wave threshold states

We demonstrate that the propagator, derived from an Effective Field Theory (EFT) that incorporates Weinberger's compositeness theorem, provides a more general formula for describing S-wave near-threshold states. By fitting the lineshape using this propagator, we can extract the $Z$ factor for these states and elucidate their structures.

hep-ph↗

arXiv2023

Study the structure of X(3872) from its lineshape

We fit the invariant mass distribution of ${X(3872)}\rightarrow{J}/{\psi}\pi^+\pi^-$ from LHCb using the propagator for S-wave near-threshold states in effective field theory. In this way, we can directly determine the $Z$ which measures the projection of the bound state on the compact state in ${X(3872)}$. Consequently, the structure of ${X(3872)}$ can be elucidated. Moreover, the fitting result also can describe well the data for ${X(3872)}\rightarrow{D}^{0}\overline{D}^{0*}$ from Belle experiment, which demonstrate the reliability of our fitting. The fitting indicates that $Z$ is a non-vanishing value within error, which supports that $X(3872)$ has a compact short-distant core.

hep-ph↗

arXiv2022

Neutron density fluctuation and neutron-proton correlation from AMPT model

Using the multiphase transport (AMPT) model, we study the relative neutron density fluctuation and neutron-proton correlation in matter produced by Au+Au collisions at $\sqrt{s_\text{NN}} = $7.7-200 GeV. The rapidity, centrality, and energy dependence of these two observations are also discussed. The light nuclei yield ratio of proton, deuteron, and triton $N_tN_p/N_d^2$ calculated directly from the relative neutron density fluctuation and neutron-proton correlation, decreases with rapidity coverage and increases with collision centrality. Our study also found that the ratio does not exhibit any non-monotonic behavior in collision energy dependence. Since there is no first-order phase transition or critical physics in the AMPT model, our work provides a reference for extracting the relative neutron density fluctuation from light nuclei production in experiments.

nucl-th↗