Related papers: Exploring the interplay of helicity and global-fra…
The helicity density matrix elements rho[00] of rho(770)+- and omega(782) mesons produced in Z decays have been measured using the OPAL detector at LEP. Over the measured meson energy range, the values are compatible with 1/3, corresponding…
Spin alignment of vector mesons in heavy-ion collisions provides a novel probe of quark polarization and hadronization mechanism in quark-gluon plasma. Hadronic rescattering may affect the measured spin alignment of vector mesons due to…
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…
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 report the transverse momentum ($p_{\mathrm{T}}$) and centrality dependence of global spin alignment ($\rho_{00}$) of $K^{*0}$ vector meson at midrapidity ($|y|<0.5$) in Au + Au collisions at $\sqrt{s_{NN}}$ = 54.4 and 200~GeV with the…
We estimate both the polarization of spin $1/2$ baryons and the spin density matrix coefficients of spin $1$ mesons using a thermal model that incorporates vorticity and polarization to describe quarks, along with a coalescence formalism…
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…
Notwithstanding decades of progress since Yukawa first developed a description of the force between nucleons in terms of meson exchange, a full understanding of the strong interaction remains a major challenge in modern science. One…
We study helicity polarization through the (3+1) dimensional relativistic viscous hydrodynamic models at $\sqrt{s_{NN}}=200$GeV Au+Au collisions. Similar to the local spin polarization, we consider the helicity polarization beyond global…
Spin Density Matrix Elements (SDMEs) describing the angular distribution of exclusive rho^0 electroproduction and decay are determined in the HERMES experiment with 27.6 GeV beam energy and unpolarized hydrogen and deuterium targets. Eight…
We propose an improved quark coalescence model for spin alignment of vector mesons and polarization of baryons by spin density matrix with phase space dependence. The spin density matrix is defined through Wigner functions. Within the model…
We report the measurements of spin alignment ($\rho_{00}$) for $K^{*0}$, $\overline{K^{*0}}$, $K^{*+}$, and $K^{*-}$ vector mesons in RHIC isobar collisions (Zr+Zr and Ru+Ru) at $\sqrt{s_{\mathrm {NN}}}$ = 200 GeV. We observe the first…
Final state interactions in quark fragmentation may give origin to non zero values of the off-diagonal element rho_(1,-1) of the helicity density matrix of vector mesons V produced in current jets, with a large energy fraction x_E; the…
Exclusive electroproduction of $\omega$ mesons on unpolarized hydrogen and deuterium targets is studied in the kinematic region of Q$^2$>1.0 GeV$^2$, 3.0 GeV < W < 6.3 GeV, and -t'< 0.2 GeV$^2$. Results on the angular distribution of the…
The correlation between vorticity and spin alignment in heavy-ion collisions can be probed through polarization measurements of hadrons, whose total spin originates from both constituent-quark spins and orbital angular momentum in the…
Based on the formalism presented in [1], we make a systematic study of spin polarizations of hadrons with different spins including vector mesons, spin-1/2 and spin-3/2 hyperons and spin correlations of hadron-hadron such as…
The LEPS/SPring-8 experiment made a comprehensive measurement of the spin-density matrix elements for $\gamma p \to \phi p$, $\gamma d \to \phi p n$ and $\gamma d \to \phi d$ at forward production angles. A linearly polarized photon beam at…
The recent measurements of the global polarization and vector meson spin alignment along the system orbital momentum in heavy ion collisions are briefly reviewed. A possible connection between the global polarization and the chiral…
Exclusive $\rho^0$-meson electroproduction is studied by the HERMES experiment, using the 27.6 GeV longitudinally polarized electron/positron beam of HERA and a transversely polarized hydrogen target, in the kinematic region 1.0…
We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $\rho ^0$ meson muoproduction at COMPASS using 160~GeV/$c$ polarised $ \mu ^{+}$ and $ \mu ^{-}$ beams impinging on a liquid hydrogen target. The…