Physics

Thermalisation

Baryon

Transverse plane

Omega

Heavy ion

Hyperon

Structural engineering

Astronomy

Vortex

Engineering

Physical chemistry

Atomic physics

Angular momentum

Azimuth

Nuclear physics

Chemistry

Scattering

Vorticity

Polarization (electrochemistry)

Quark–gluon plasma

Glauber

Quantum mechanics

Quark

Thermodynamics

Physical Review Research

We revisit the azimuthal angle dependence of the local spin polarization of hyperons in heavy-ion collisions at 200 GeV in the framework of the (3+1)D viscous hydrodynamic model CLVisc. Two different initial conditions are considered in our simulation: the optical Glauber initial condition without initial orbital angular momentum and the AMPT initial condition with an initial orbital angular momentum. We find that the azimuthal angle dependence of the hyperon polarization strongly depends on the choice of the so-called "spin chemical potential" $\Omega_{\mu\nu}$. With $\Omega_{\mu\nu}$ chosen to be proportional to the temperature vorticity, our simulation shows qualitatively coincidental results with the recent measurements at RHIC for both the longitudinal and transverse polarization. We argue that such a coincidence may be related to the fact that the temperature vorticity is approximately conserved in the hot quark-gluon matter.

Local spin polarization in high energy heavy ion collisions