English

Meson spin alignment and baryon polarization from coalescence with spin-vorticity non-equilibrium

High Energy Physics - Phenomenology 2024-10-23 v1 Nuclear Theory

Abstract

We estimate both the polarization of spin 1/21/2 baryons and the spin density matrix coefficients of spin 11 mesons using a thermal model that incorporates vorticity and polarization to describe quarks, along with a coalescence formalism where spin and vorticity are not in equilibrium. We find that while our model is not predictive due to its considerable number of free parameters, it has the potential to explain several seemingly puzzling features of experimental spin measurements, such as the absence of baryon polarization alongside significant vector meson spin alignment. We suggest the measuring meson spin off-diagonal matrix elements, and examining the dependence of polarization observables on azimuthal angles, as methods to falsify this model and gain insights into the freezeout details of baryon and meson spin structure.

Keywords

Cite

@article{arxiv.2410.16448,
  title  = {Meson spin alignment and baryon polarization from coalescence with spin-vorticity non-equilibrium},
  author = {Kayman J. Gonçalves and Giorgio Torrieri and Radoslaw Ryblewski},
  journal= {arXiv preprint arXiv:2410.16448},
  year   = {2024}
}