Related papers: Spin Alignment of Vector Mesons Induced by Local S…
Global spin alignment of vector mesons is a sensitive probe of system vorticity and particle production mechanism in relativistic heavy ion collisions. The measurement of global spin alignment is gaining increasing interest and deserves…
Experimental data on transverse single-spin asymmetry, hyperon polarization and vector meson alignment in h+h, h+A and A+A-collisions have been analyzed. A new mechanism for the origin of single spin effects is proposed, which takes into…
We study the mass spectra and spin alignment of vector meson $J/\psi$ in a thermal magnetized background using a generalized theoretical framework based on gauge/gravity duality. Utilizing a soft wall model for the QGP background and a…
We derive expressions for the vector and tensor components of the spin polarization of massive vector bosons at local thermodynamic equilibrium up to second order in the space-time gradients of the thermodynamic fields pertaining to the…
We propose that a significant positive deviation from 1/3 for the spin density matrix element $\rho_{00}$ of the $\phi$ meson may indicate the existence of a mean field of the $\phi$ meson generated in heavy-ion collisions. This explains…
In these proceedings, we present new measurements from STAR of the global spin alignment($\rho_{00}$) of $\phi$ mesons in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 19.6, 14.6 GeV using BES-II data and of $J/\psi$ mesons in isobar…
The difference between the spin alignments of $K^\ast$ and those of $\phi$ at the low collision energies is a puzzle raised by the recent experiments. Unlike $\phi$ meson, $K^\ast$, carrying a unit strange charge, should react to strange…
The spin alignment of vector meson produced in high energy reactions is determined by the spin-dependent fragmentation function $D_{1LL} (z,\mu_f)$ that is shown to be independent of the polarization of the fragmenting quark. In this paper,…
We compute the $00$ element of the spin density matrix, denoted as $\rho_{00}$ and called the spin alignment, up to the second order of the gradient expansion in local equilibrium by Zubarev's approach. In the first order, we obtain…
We investigate the behaviour of vector mesons $\rho$, $\phi$, and $J/\Psi$ in both non-rotating and rotating thermal media using the soft-wall holographic QCD model with four flavours. By incorporating anisotropic backgrounds derived from…
Collective spin phenomena in the final states of heavy-ion collisions are typically understood to originate from vorticity and shear in the quark-gluon plasma. Here, we ask whether spin could already be present in the initial condition of…
As the spin alignment of a vector meson is predicted to be correlated with its spectral properties, we study the spectral properties of the $\phi$ meson using two microscopic Lagrangians based either on chiral effective field theory or the…
The dynamics of a spin in the presence of a deterministic and a fluctuating magnetic field is solved for analytically to obtain the averaged value of the spin as a function of time for various kinds of fluctuations (noise). Specifically,…
A dynamical valence and sea quark mixing model is shown to fit the baryon ground state properties as well as the spin content of the nucleon. The relativistic correction and the $q^3{\leftrightarrow} q^3q\bar{q}$ transition terms induced by…
We derive the quantum kinetic theory for massive fermions with collision terms and self-energy corrections based on quantum field theory. We adopt an effective power counting scheme with $\hbar$ expansion to obtain the leading-order…
Exclusive production of the isoscalar vector mesons $\omega$ and $\phi$ is measured with a 190 GeV$/c$ proton beam impinging on a liquid hydrogen target. Cross section ratios are determined in three intervals of the Feynman variable $x_{F}$…
We report the measurements of global spin polarization of hyperons ($P_{\Lambda}$) from FAIR, RHIC and LHC energies. The $P_{\Lambda}$ continue to follow an increasing trend at $\sqrt{s_{\mathrm NN}}$ < 7.7 GeV indicating that enormous…
We develop a quantum spin-density-matrix framework for heavy-quark spin dynamics in relativistic heavy-ion collisions. Starting from an initial polarization induced along the magnetic-field direction, we derive the evolution equation for…
A significant $\phi$-meson global spin alignment ($\rho_{00}$) signal was measured in Au+Au collisions at $\sqrt{s_{NN}}\le62$ GeV. Conventional physics mechanisms such as $s(\bar{s})$ spin polarization fail to accommodate this $\rho_{00}$…
The findings on the spin polarization of $\Lambda$, $\Xi$, and $\Omega$ hyperons and spin alignment of $K^{*0}$, $\phi$, and $D^{*+}$ mesons in relativistic heavy-ion collision experiments at the RHIC and LHC facilities propose the…