Keating, D. A.Manson, S TDolmatov, V KMandal, ADeshmukh, P CNaseem, FaizaKheifets, Anatoli2020-05-182020-05-182469-9926http://hdl.handle.net/1885/204398We predict an observable Wigner time delay in outer atomic shell photoionization near inner shell thresholds. The near-threshold increase of time delay is caused by intershell correlation and serves as a sensitive probe of this effect. The time delay increase is present even when the inner and outer shell thresholds are hundreds of electron volts apart. We illustrate this observation by several prototypical examples in noble gas atoms from Ne to Kr. In our study, we employ the random phase approximation with exchange and its relativistic generalization. We also support our findings by a simplified, yet quite insightful, treatment within the lowest-order perturbation theory.S.T.M. acknowledges the support of the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, US Department of Energy, under Grant No. DE-FG02-03ER15428.10 pagesapplication/pdfen-AU© 2018 American Physical Society. D. A. Keating, S. T. Manson, V. K. Dolmatov, A. Mandal, P. C. Deshmukh, Faiza Naseem, and A. S. Kheifets, Intershell-correlation-induced time delay in atomic photoionization, Phys. Rev. A 98, 013420 – Published 24 July 2018, doi 10.1103/PhysRevA.98.013420photoemissionultrafast phenomena2018-07-2410.1103/PhysRevA.98.0134202019-12-19