Leveraging its precise vertex reconstruction and advanced particle identification, the LHCb detector offers a unique environment to study spin dynamics and hadronization in high-energy collisions. Measurements of baryon polarization in unpolarized proton-nucleus collisions probe how quark spins contribute to the final-state hadron, providing insight into parton spin transfer and fragmentation...
We study the local spin polarization of quarks induced by color-field correlators stemming from the correlation of chromo-Lorentz force and chromo-magnetic polarization or chromo-spin Hall effect in the presence of momentum anisotropy.
Such effects can trigger longitudinal polarization from fluctuating color fields in glasma or quark gluon plasma phases with transverse expansion for...
The observation of hyperon polarization in heavy-ion collisions has established spin phenomena as powerful probes of the properties of the quark-gluon plasma (QGP) and the dynamics of strongly interacting matter. Global polarization reflects the medium’s overall vorticity, while local polarization is expected to arise from anisotropic flow–induced vorticities, although current theoretical...
Ultra-relativistic nuclear collisions create strongly interacting matter at extreme temperatures and energy densities, forming a quark–gluon plasma (QGP). Its space-time evolution is characterized by strong collective expansion, giving rise to anisotropic flow and demonstrating its nearly perfect fluid nature. This anisotropic motion generates local shear and vorticity along the beam...
Over fifty years after the first observation of unexpectedly large transverse Λ polarization, the underlying mechanism remains a long-standing puzzle seen across many collision systems, from e⁺e⁻ to proton–nucleus collisions. Only in heavy-ion collisions has this phenomenon been understood in terms of strong vorticity in the Quark Gluon Plasma. In this talk, we present an alternative...
We have developed a relativistic resistive magnetohydrodynamic (RRMHD) model to tackle an important problem of heavy-ion physics: understanding the impact of the strong electromagnetic (EM) fields on the quark-gluon plasma (QGP) medium. Our model simulates the evolution and interaction between charges in the QGP and EM fields. This leads to modifications of electrically charged observables. In...
In relativistic heavy-ion collisions, charged particles are accelerated to nearly the speed of light, and their external electromagnetic fields can be effectively approximated as quasi-real photons. These photons interact with another nucleus via photon-nuclear interactions, producing vector mesons. These vector mesons possess extremely low transverse momentum ($p_T\sim0.1$ GeV/$c$),...
We develop a relativistic framework for resistive magnetohydrodynamics for a two-component plasma composed of oppositely charged massless particles. Starting from the Boltzmann–Vlasov equation, the 14-moment method is used to derive coupled evolution equations for the charge–diffusion current and the shear–stress tensor. The formulation captures nonlinear feedback between electromagnetic...
Quantum kinetic theory (QKT) of relativistic fermions is one of useful theoretical frameworks to track non-equilibrium evolution of spin transport albeit in weakly coupled systems. Except for the quantum corrections, characterized by the gradient expansion in phase space, from the imaginary part of (retarded and advanced) self-energies responsible for the spin-orbit interaction in collisions,...
The Lorentz-boosted electromagnetic fields of relativistic heavy ions serve as intense sources of linearly polarized quasi-real photons. Under the $s$-channel helicity conservation hypothesis, a coherently photoproduced vector meson inherits this polarization, leading to a characteristic second-harmonic ($cos2\phi$) modulation in the azimuthal distribution of its decay products. Such...
Chirality is a fundamental element in the construction of the Standard Model and a key feature for understanding non-perturbative aspects of Quantum Chromodynamics (QCD). Chiral Magnetic Effect (CME) provides a unique access for experimental probe of chirality in heavy ion collisions. Recent measurements from Beam Energy Scan II data by the STAR Collaboration demonstrate very interesting beam...
The Chiral Magnetic Effect (CME)—a QCD-anomaly–driven charge separation in the strong magnetic fields of non-central heavy-ion collisions—remains extremely difficult to isolate because flow-related backgrounds, especially from resonance decays, can mimic CME-like correlations. To address this weak-signal in a complicated background problem, we explore Transformer-based Artificial Intelligence...
A significant global spin alignment ($\rho_{00}$) signal for $\phi$-mesons was observed by the STAR collaboration in Au+Au collisions using the data from the first phase of the Beam Energy Scan at RHIC (BES-I) [1]. Conventional physical mechanisms which contribute to $\rho_{00}$ fail to explain the observed signal; however, it may be attributable to the presence of a $\phi$-meson strong force...
Ultra-relativistic heavy-ion collisions create a unique environment for studying the quark–gluon plasma (QGP). In non-central collisions, the large initial orbital angular momentum can be transferred to the medium as vorticity, inducing a global polarization of produced particles. Furthermore, the strong initial magnetic field generated in heavy-ion collisions can contribute to the global...
The STAR Collaboration reported a significant $\phi$-meson global spin alignment ($\rho_{00}$) signal in Au+Au collisions at $\sqrt{s_{NN}}\leq62$ GeV by measuring the one dimensional (1D) polar angle distribution of $\phi$-meson daughters with respect to the orbital angular momentum direction of the collision system [1].
This talk summarizes methodological developments from a recent paper on...
