Speaker
Description
Spin correlations of back-to-back dihadrons can emerge in unpolarized high-energy collisions, offering opportunities for unpolarized experiments to access spin-dependent fragmentation functions. In particular, transverse spin correlations of a partonic $q\bar q$ pair can manifest themselves through di-hadron production, providing a novel probe of the chiral-odd fragmentation function $H_{1T}(z)$. While produced gluons can also exhibit linear polarization correlations, such effects cannot be accessed through $\Lambda\bar{\Lambda}$ pairs at leading twist. We therefore propose a different method to probe gluon linear polarization using energy correlations in hard scattering processes. By performing an all-order CCFM analysis, we exploit the characteristic $\cos 2\phi$ azimuthal modulation of energy-energy correlators (EECs) initiated by polarized gluons to extract information on their linear polarization. These predictions can be tested at current and future facilities, including the LHC, RHIC, HERA, and the EIC.
References:
[1] Lei Yang, Yu-Kun Song, Shu-Yi Wei, Phys. Rev. D 111 (2025) 054035;
[2] Yu-Kun Song, Shu-Yi Wei, Lei Yang, Jian Zhou, Phys. Rev. Lett. 136 (2026) 131901.
