arXiv subjects

Hai-Cang Ren

Publications and source records attributed to Hai-Cang Ren.

9 recordsLinked to original sources

arXiv2026

Spectral Functions of $J/ψ$ Meson in Rotating Thermal Background from Holography

We investigate the spectral functions of the $J/ψ$ meson in a rotating thermal background within the soft-wall holographic model. The global rotation is implemented through a rotating AdS-like metric, while a local inertial frame is introduced in which the vector field can be decomposed into different spin states. We solve the equations of motion of the vector field in the bulk with incoming wave condition near the horizon and compute the retarded Green function, from which we extract the invariant-mass spectral functions for $J/ψ$. When the momentum is parallel to the rotation axis, the peak energies shift by $-ΩJ_z$, as expected by a coupling between rotation and angular momentum, while the widths are nearly independent to $Ω$. When the momentum is in perpendicular direction, the spectral functions for spin-$\pm1$ states deviate significantly from the single-peak behavior and the energy shifts depart from $-ΩJ_z$. The resulting triplet splittings of the spectral functions provides a holographic perspective on spin-dependent vector meson properties in rotating systems.

hep-th↗

arXiv2025

Strong Coupling Expansion of Gluodynamics on a Lattice under Rotation

The analytic strong coupling expansion of the gluodynamics under a rotation with an angular velocity $ω$ is reported. While the expansion is systematic, free from additional assumptions, the deconfinement temperature determined by the onset of the Polyakov loop expectation value decreases with the angular velocity up to $ω^2$, opposite to the tendency found in numerical simulations. As a by-product, a simple formula is obtained for the $ω^2$ coefficient of the deconfinement temperature shift in terms of the latent heat and the discontinuity of the moment of inertia at the transition without rotation. This formula is independent of the strong coupling and may benefit further investigation of the subject.

hep-ph↗

arXiv2025

String tension and Polyakov loop in a rotating background

We study the influence of a rotation on the string tension and the temperature of the confinement-deconfinement transition of gluodynamics by gauge/gravity duality. We explore two distinct approaches, global transformation and local transformation, to introduce rotation and compare the results. It is shown that the string tension extracted from the free energy in the presence of a heavy quarkonium decreases with the increasing angular velocity, while the transition temperature determined by the Polyakov loop increases with increasing angular velocity, which is in line with lattice simulations.

hep-ph↗

arXiv2024

Drag force and heavy quark potential in a rotating background

We explored the gravity dual of a rotating quark-gluon plasma by transforming the boundary coordinates of the large black hole limit of Schwarchild-$\text{AdS}_5$ metric. The Euler-Lagrange equation of the Nambu-Goto action and its solution become more complex than those without rotation. For small angular velocity, we obtained an analytical form of the drag force acting on a quark moving in the direction of the rotation axis and found it stronger than that without rotation. We also calculated the heavy quark potential under the same approximation. For the quarkonium symmetric with respect to the rotation axis, the depth of the potential is reduced by the rotation. For the quarkonium oriented in parallel to the rotation axis, the binding force is weakened and the force range becomes longer. We also compared our holographic formulation with others in the literature.

hep-ph↗

arXiv2023

De Haas - van Alphen Effect under Rotation

We explored the interplay between magnetic field and rotation in the de Hass - van Alphen oscillation. The effect is found to be reduced because of the re-weighting of different states within the same Landau level by rotation energy. The implications of our results on high energy physics and condensed matter physics are speculated.

hep-ph↗

arXiv2022

Axial Chiral Vortical Effect in a Sphere with finite size effect

We investigate the axial vortical effect in a uniformly rotating sphere subject to finite size. We use MIT boundary condition to limit the boundary of the sphere. For massless fermions inside the sphere, we obtain the exact axial vector current far from the boundary that matches the expression obtained in cylindrical coordinates in the literature. On the spherical boundary, we find both the longitudinal and transverse(with respect to the rotation axis) components with magnitude depending on the colatitude angle. For massive fermions, we derive an expansion of the axial conductivity far from the boundary to all orders of mass whose leading order term agrees with the mass correction reported in the literature. We also obtain the leading order mass correction on the boundary which is linear, and stronger than the quadratic dependence far from the boundary. The qualitative implications on the phenomenology of heavy ion collisions are speculated.

hep-th↗

arXiv2005

A Neutral Two Flavor Loff Color Superconductor

In this paper we construct analytically a LOFF color superconducting state that is both color and charge neutral using the weak coupling approximation. We demonstrate that this state is free from chromomagnetic instabilities. Its relevance to the realistic quark matter at moderately high baryon density is discussed.

hep-ph↗

arXiv2005

The Meissner Effect in a Two Flavor LOFF Color Superconductor

We calculate the magnetic polarization tensor of the photon and of the gluons in a two flavor color superconductor with a LOFF pairing that consists of a single plane wave. We show that at zero temperature and within the range of the values of the displacement of the Fermi sea that favors the LOFF state, all the eigenvalues of the magnetic polarization tensor are positive. Therefore the chromomagnetic instabilities pertaining to a gapless color superconductor disappear.

hep-th↗

arXiv2004

Chromomagnetic Instability and the LOFF state in a two flavor Color Superconductor

We explore the relation between the chromomagnetic instability of a homogeneous two flavor color superconductor and the LOFF state. We perturb the free energy of the 2SC by generating a small net momentum for the quark pair. We find that the imaginary Meissner mass of a particular gluon implies that the LOFF state is energetically favored.

hep-ph↗