What can we learn from the global spin alignment of ϕ\phi mesons in heavy-ion collisions?

Oct 30, 2019
8 pages
Published in:
  • Phys.Rev.D 101 (2020) 9, 096005,
  • Phys.Rev.D 105 (2022) 9, 099903 (erratum)
  • Published: May 13, 2020
    and
  • Published: May 1, 2022
e-Print:

Citations per year

20192021202320252025051015202530
Abstract: (APS)
We propose that a significant positive deviation from 1/3 for the spin density matrix element ρ00 of the ϕ meson may indicate the existence of a mean field of the ϕ meson generated in heavy-ion collisions. This explains why STAR preliminary data for the ϕ meson’s ρ00 are much larger than 1/3, while the data of Λ and Λ¯ polarization seem not to allow such a significant and positive deviation. The contribution is from the polarization of the strange quark and antiquark through the spin-orbit interaction in the ϕ field, a similar interaction that is responsible for nuclear shell structure at the nucleon level. We show that ρ00 for the ϕ meson is a good analyzer for fields even if they may strongly fluctuate in space-time.
Note:
  • ReVTex 4, 8 pages, 1 figure. A sign error in the polarization formula for the anti-quark is corrected, related discussions are changed accordingly. The results for the case with the quark polarization along all directions are added as an appendix
  • Phenomenological aspects of field theory, general methods
  • heavy ion: scattering
  • spin: density matrix
  • spin: alignment
  • Phi(1020)
  • polarization
  • coherence
  • STAR