nucl-th digest · Oct 6, 2023

Heavy-ion collisions, Gubser flow, and Carroll hydrodynamics

Gubser flow provides an analytic model for describing the spacetime dynamics of the quark-gluon plasma produced in heavy-ion collisions. Along with boost and rotation invariance along the beam axis, the model assumes invariance under a combination of translations and special conformal transformations in the transverse plane, leading to a flow profile which evolves not just along the beam axis, but also radially. We argue that Gubser flow and its associated symmetry assumptions arise naturally as a consequence of Carrollian symmetries for a conformal Carroll fluid, thereby providing a dual geometric picture for the flow. Given the inherent ultrarelativistic nature of the flow, this duality with Carroll hydrodynamics - which arises in the

c \to 0

limit of relativistic hydrodynamics, is natural. We provide a precise map between Gubser flow and the conformal Carroll fluid, appropriate to capture the duality between the two not just at the ideal level, but also with the inclusion of hydrodynamic derivative corrections.

Comments:: 11 pages, 1 figure, two-column format
Subjects:: High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:: 2310.03167 [pdf]

PRD(2024)·35 citations

[Submitted on 5 Oct 2023] (cross-list from hep-lat)

Localized Modes in the IR Phase of QCD

Andrei Alexandru🇺🇸 · Ivan Horváth🇺🇸 · Neel Bhattacharyya🇺🇸

Infrared (IR) dimension function $d_{IR} (λ)$ characterizes the space effectively utilized by QCD quarks at Dirac scale $λ$ , and indirectly the space occupied by glue fields. It was proposed that its non-analytic behavior in thermal infrared phase reflects the separation of QCD system into an IR component and an independent bulk. Here we study the ``plateau modes" in IR component, whose dimensional properties were puzzling. Indeeed, in the recent metal-to-critical scenario of transition to IR phase, this low-dimensional plateau connects the Anderson-like mobility edge $λ_{IR} = 0$ in Dirac spectrum with mobility edges $\pm λ_{A}$ . For this structure to be truly Anderson-like, plateau modes have to be exponentially localized, implying that both the effective distances $L_{eff} \propto L^{γ}$ and the effective volumes $V_{eff} \propto L^{d_{IR}}$ in these modes grow slower than any positive power of IR cutoff $L$ . Although $γ = 0$ was confirmed in the plateau, it was found that $d_{IR} \approx 1$ . Here we apply the recently proposed multidimension technique to the problem. We conclude that a plateau mode of pure-glue QCD at UV cutoff $a = 0.085$ fm occupies a subvolume of IR dimension zero with probability at least 0.9999, substantiating this aspect of metal-to-critical scenario to a respective degree.

Comments:: 5 pages, 7 figures; v2: minor improvements, published version
Subjects:: High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:: 2310.03621 [pdf]

PRD(2024)·12 citations

Friday·October 6, 2023

Heavy-ion collisions, Gubser flow, and Carroll hydrodynamics

Localized Modes in the IR Phase of QCD

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