The emergence of spin correlations through quantum entanglement in unpolarized high-energy collisions offers a unique opportunity to investigate spin-dependent fragmentation functions, even with unpolarized experiments. In a series of studies [1-5], we investigated the longitudinal and transverse spin correlations of back-to-back dihadrons produced in unpolarized $e^+e^-$, $pp$ and $ep$...
The quantum rigidity of Bell nonlocality in device-independent self-testing scenarios for qutrit systems is established using the sum-over-squares method. It is demonstrated that when the quantum upper bound of the generalized Bell inequality is achieved, the underlying entangled state is required to be maximally entangled, and the measurement observables are uniquely specified.
