We estimate the Collins fragmentation function by introducing the effect of gluon rescattering in a model calculation of the fragmentation process. We include all necessary diagrams to the one-loop level and compute the nontrivial phases giving rise to the Collins function. We compare our results to the ones obtained from pion rescattering. We conclude that three out of four one-loop diagrams give sizeable contributions to the Collins function, and that the effect of gluon rescattering has a magnitude comparable to that of pion rescattering, but has opposite sign

The gear test bench is important equipment for analyzing gear performance, detecting gear quality, and providing basic data for gear design and machining. In order to monitor the running state of the gear test bench, predict its running performance both timely and effectively, and guarantee its stable operation, a digital twin-based state monitoring method of the gear test bench is proposed in this paper. The state monitoring system of the gear test bench based on the digital twin model is constructed to simulate its normal running state in real time. On this basis, through the acquisition of physical information of the gear test bench, the developing of the state monitoring system, and the simulation of the digital twin model, the real-time state monitoring of the normal operation gear test bench is realized. The test results of the closed power flow gear test bench show that the digital twin simulation results of the gear test bench are basically consistent with it. The proposed state monitoring system can map the normal running state of the gear test bench, so as to realize the running state monitoring of the gear test bench.

We use a simple quark-diquark model to describe unpolarized, longitudinally polarized, and transversely polarized fragmentation functions for the octet baryons. All free parameters of the model are determined based on the experimental data on octet baryon B production in the $e^{+}{e}^{-}\to \mathrm{BX}$ process. The SU(3) flavor symmetry breaking effect in the octet baryon fragmentation functions is investigated. The strangeness suppression effect in hyperon production of $e^{+}{e}^{-}$ annihilation is found to be significant, and its relevant consequences for the cross sections of octet hyperon production in $\mathrm{pp}$ collisions are estimated. In order to check the flavor structure of the octet hyperon fragmentation functions, hyperon-antihyperon asymmetries in $k^{+}p$ collisions are provided. Furthermore, we find that the spin observables calculated with the $\Lambda$ fragmentation functions are compatible with available experimental data on the longitudinally polarized $\Lambda$ production. Spin observables for other octet baryons produced in various inclusive processes are also predicted for future experiments.