Correlations of dihadron polarization in central, peripheral, and ultraperipheral heavy-ion collisions

While jet quenching in relativistic heavy-ion collisions has been extensively studied over decades, the polarization of quenched hadrons has rarely been discussed. It has recently been proposed that the correlations of dihadron polarization in e+e- and pp collisions provide a novel probe of the longitudinal spin transfer from hard partons to hadrons without requiring the colliding beams to be polarized. To support realistic experimental measurement of dihadron polarization with sufficient luminosity, we extend the aforementioned study to relativistic heavy-ion collisions by convoluting the vacuum fragmentation of partons with their energy loss inside the quark-gluon plasma. We find that while the correlation functions of Lambda-Lambda (or Lambda- over bar Lambda) polarization in peripheral collisions is consistent with those in pp collisions, clear enhancement can be seen in central collisions. These correlation functions appear sensitive to different assumptions in the de Florian-Stratmann-Vogelsang (DSV) of parton fragmentation functions and, therefore, could place additional constraints on the spin-dependent fragmentation functions of quarks and gluons. The correlation of dihadron polarization has also been explored in ultraperipheral heavy-ion collisions, which provides a cleaner probe of fragmentation functions of quarks produced by energetic photon-photon and photon-Pomeron interactions.