Conveners
Joint Nuclear/Heavy Ion
- Ian Cloet (Argonne National Laboratory)
STAR collaboration observed a global spin alignment of φ-mesons in Au+Au collisions using the data from the first phase of the RHIC Beam Energy Scan program (BES- I) [1]. This cannot be explained by conventional mechanisms but may be attributable to the influence of vector meson force fields. In this talk, we present new measurements of vector meson global spin alignment by the STAR...
Transverse $\Lambda$ (uds) polarization observed over four decades ago contradicted expectations from early leading-order perturbative QCD calculations. Measurements of $\Lambda$ polarization from unpolarized pp and pA collisions have been previously observed to increase as a function of $x_F$ and $p_T$ up to a few GeV range and approximately independent of beam energy. Recent studies have...
Unpolarized protons can generate transversely polarized quarks or linearly polarized gluons through a distribution known as the Boer-Mulders' function. The fragmentation of similarly polarized partons to unpolarized hadrons is called the Collins' function. Both of these functions include correlations between the spin or polarization and the relative transverse momentum of the incoming or...
