HEIndividual fellowship2023–2025

RelSpinHydro · Relativistic Spin Hydrodynamics: Theory and Applications

Horizon Europe — Marie Skłodowska-Curie Actions

Duration
2023-10-01 → 2025-09-30
EU contribution
€210,789
Participants
1
Scheme
HORIZON-TMA-MSCA-PF-EF

Lines connect the coordinator with its partners.

Results in brief

Relativistic Spin Hydrodynamics: Theory and Applications

One of the main challenges in nuclear physics is understanding the emergent phenomena of strongly interacting matter governed by quantum chromodynamics (QCD). Heavy-ion collisions conducted at the Large Hadron Collider at CERN and the Relativistic Heavy Ion Collider at BNL create a unique and puzzling state of matter known as quark-gluon plasma (QGP), where quarks and gluons are deconfined. The QGP behaves like a nearly perfect liquid, which is modeled using relativistic hydrodynamics. Recent experiments have shown that the QGP exhibits spin-polarization phenomena, such as the global polarization of Lambda baryons and the spin alignment of vector mesons. While existing theoretical models, based on the assumption of local thermodynamic equilibrium of spin degrees of freedom, successfully describe the global polarization, they fail to explain other observables, such as the spin alignment. These discrepancies highlight the need to extend conventional hydrodynamic models to include spin effects. This has motivated the development of what is now called relativistic spin hydrodynamics. Developing relativistic spin hydrodynamics is essential for a deeper understanding of the QGP and hadron polarization in heavy-ion collisions. The main objectives of this proposal are (i) the formulation of causal and stable theories of relativistic spin hydrodynamics, (ii) their extensions to the far-from-equilibrium regime, and (iii) Applications of spin hydrodynamics to QGP physics.

Data: CORDIS, © European Union

Project objective

This proposal establishes connections between fluid dynamics, quantum field theory, and mathematical physics to develop new tools to better characterise out-of-equilibrium properties of relativistic quantum many-body systems. My work is instrumental to understand the emergence of novel fluid-like behaviours which are not apparent in the fundamental laws. The focus of my research is the quark-gluon plasma (QGP), an exotic phase of quantum chromodynamics (QCD) where quarks and gluons are not confined inside of nucleons. The QGP is formed in relativistic heavy-ion collisions performed at the Large Hadron Collider (LHC) and the Relativistic Heavy Ion Collider (RHIC). A huge surprise was the discovery that the QGP behaves as a relativistic liquid with very special properties, namely, it flows with the lowest specific viscosity of any known liquid, and it is by far the system with the largest vorticity ever observed. Such large vorticity triggers particle polarisation, which is a phenomenon resembling the magnetisation displayed by a ferromagnet that is spinning around an axis. This effect shows the interplay between a macroscopic quantity, the fluid rotation, and a microscopic quantity, which is inherently of quantum nature: the spin of the particles. The recent observation of polarisation phenomena of hadrons emitted from the rotating QGP in heavy-ion collisions calls for a new formulation of relativistic fluids where spin degrees of freedom are crucial to the dynamics -- this is called relativistic spin hydrodynamics. Despite fluid dynamics being an old subject, the formulation of the full causal and stable theory of relativistic spin hydrodynamics which can be used for theoretical predictions is yet to be developed.Expected outcomes from this proposal include:* the formulation of causal and stable theories of relativistic spin hydrodynamics,* their extensions to the far-from-equilibrium regime,* applications to QGP physics.

Original text from CORDIS.

Participants

  • ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE · GENEVE 23CoordinatorSwitzerland

Links

Data: CORDIS, © European Union