arXiv subjects

Yu-Xin Xiao

Publications and source records attributed to Yu-Xin Xiao.

5 recordsLinked to original sources

arXiv2025

System-size dependence of $γ$-jet modifications in heavy-ion collisions

Medium modifications of the $γ$-triggered jets are investigated with the Linear Boltzmann Transport (LBT) model in heavy-ion collisions with varying system sizes, focusing on centrality dependence in Pb+Pb and Xe+Xe collisions at the LHC. Our numerical results reveal that jets produced in central collisions exhibit a wider transverse asymmetry ($A_N^y$) distribution, a broader jet shape, and a more pronounced $γ$-jet transverse momentum imbalance ($X_{Jγ}=p_T^{\rm jet}/p_T^γ$) compared to peripheral collisions. These effects arise from the longer path length and stronger jet-medium interactions in central collisions, leading to enhanced jet quenching and medium response. Our findings demonstrate that the magnitude of $γ$-jet modifications is sensitive to the size and centrality of the collision system, with larger systems inducing more significant alterations due to increased energy loss and medium feedback.

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arXiv2024

Non-extensive Hard Thermal Loop Resummation and Its Applications: Analysis in Zero and Finite Magnetic Fields

The impact of non-extensive statistics on the hard thermal loop (HTL) resummation technique is investigated, in the absence and presence of a magnetic field. By utilizing the non-extensive bare propagators in the real-time formalism of finite temperature field theory, we determine the non-extensive deformations of both HTL gluon self-energies and resummed gluon propagators at the one-loop order. We observe that the introduction of non-extensivity results in distinct shifts in the Debye masses for the retarded/advanced and symmetric gluon self-energies. Applying the non-extensive modified resummed gluon propagators to obtain the dielectric permittivity of a quark-gluon plasma (QGP), we thereby derive the static heavy quark potential, which incorporates both short-range Yukawa and long-range string-like interactions between heavy quarks and the QGP medium. The real part of the potential exhibits increased screening as the non-extensive parameter $q$ ($q \geq 1$) increases, reducing the binding energies of heavy quarkonia. Furthermore, including non-extensivity enhances the magnitude of the imaginary part of the potential, causing a broadening in the decay widths of heavy quarkonia. Based on these observations, we estimate the melting temperatures of heavy quarkonia. Our results indicate that non-extensivity lowers the melting temperatures of heavy quarkonia, thus facilitating their dissociation, whereas the presence of a magnetic field inhibits this dissociation.

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arXiv2024

Impact of (magneto-)thermoelectric effect on diffusion of conserved charges in hot and dense hadronic matter

We investigate the thermoelectric effect, which describes the generation of an electric field induced by temperature and conserved charge chemical potential gradients, in the hot and dense hadronic matter created in heavy-ion collisions. Utilizing the Boltzmann kinetic theory within the repulsive mean-field hadron resonance gas model, we evaluate both the diffusion thermopower matrix and diffusion coefficient matrix for the baryon number ($B$), electric charge ($Q$), and strangeness ($S$). The Landau-Lifshitz choice for the rest frame of the fluid is enforced in the derivation. We find that the thermoelectric effect hinders the diffusion processes of multiple conserved charges, particularly reducing the coupling between electric charge and baryon number (strangeness) in baryon (strangeness) diffusion. Given that the repulsive mean-field interactions between hadrons have a significant effect on the diffusion thermopower matrix and diffusion coefficient matrix in the baryon-rich region, we extend the investigation to include the impact of magnetic fields, analyzing the magneto-thermoelectric effect on both the diffusion coefficient matrix and the Hall-like diffusion coefficient matrix. The sensitivities of the magnetic field-dependent diffusion thermopower matrix and magneto-thermoelectric modified diffusion coefficient matrix to the choices of various transverse conditions are also studied.

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arXiv2024

Asymmetric jet shapes with 2D jet tomography

Two-dimensional (2D) jet tomography is a promising tool to study jet medium modification in high-energy heavy-ion collisions. It combines gradient (transverse) and longitudinal jet tomography for selection of events with localized initial jet production positions. It exploits the transverse asymmetry and energy loss that depend, respectively, on the transverse gradient and jet path length inside the quark-gluon plasma (QGP). In this study, we employ the 2D jet tomography to study medium modification of the jet shape of $γ$-triggered jets within the linear Boltzmann transport (LBT) model for jet propagation in heavy-ion collisions. Our results show that jets with small transverse asymmetry ($A_N^{\vec{n}}$) or small $γ$-jet asymmetry ($x_{Jγ}=p_T^{\rm jet}/p_T^γ$) exhibit a broader jet shape than those with larger $A_N^{\vec{n}}$ or $x_{Jγ}$, since the former are produced at the center and go through longer path lengths while the later are off-center and close to the surface of the QGP fireball. In events with finite values of $A_N^{\vec{n}}$, jet shapes are asymmetric with respect to the event plane. Hard partons at the core of the jet are deflected away from the denser region while soft partons from the medium response at large angles flow toward the denser part of QGP. Future experimental measurements of these asymmetric features of the jet shape can be used to study the transport properties of jets and medium responses.

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arXiv2022

Phenomenological study of the anisotropic quark matter in the 2-flavor Nambu-Jona-Lasinio model

With the two flavor Nambu-Jona-Lasinio (NJL) model we carry out a phenomenological study on the chiral phase structure, mesonic properties and transport properties in a momentum-space anisotropic quark matter. To calculate transport coefficients we have utilized the kinetic theory in the relaxation time approximation, where the momentum anisotropy is embedded in the estimation of both distribution function and the relaxation time. It is shown that an increase of the anisotropy parameter $ξ$ may results in a catalysis of chiral symmetry breaking. The critical endpoint (CEP) is shifted to smaller temperatures and larger quark chemical potentials as $ξ$ increases, the impact of momentum anisotropy on temperature of CEP is almost the same as that on the quark chemical potential of CEP. The meson masses and the associated decay widths also exhibit a significant $ξ$ dependence. It is observed that the temperature behavior of scaled shear viscosity $η/T^3$ and scaled electrical conductivity $σ_{el}/T$ exhibit a similar dip structure, with the minima of both $η/T^3$ and $σ_{el}/T$ shifting toward higher temperatures with increasing $ξ$. Furthermore, we demonstrate that the Seebeck coefficient $S$ decreases when temperature goes up and its sign is positive, indicating the dominant carriers for converting the temperature gradient to the electric field are up-quarks. The Seebeck coefficient $S$ is significantly enhanced with a large $ξ$ for the temperature below the critical temperature.

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