12,642 research outputs found
Holographic interference in atomic photoionization from a semiclassical standpoint
A theoretical study of the interference pattern imprinted on the doubly differential momentum distribution of the photoelectron due to atomic ionization induced by a short laser pulse is developed from a semiclassical standpoint. We use the semiclassical two-step model of Shvetsov-Shilovski et al. [Phys. Rev. A 94, 013415 (2016)2469-992610.1103/PhysRevA.94.013415] to elucidate the nature of the holographic structure. Three different types of trajectories are characterized during the ionization process by a single-cycle pulse with three different types of interferences. We show that the holographic interference arises from the ionization yield only during the first half cycle of the pulse, whereas the coherent superposition of electron trajectories during the first half cycle and the second half cycle gives rise to two other kinds of intracycle interference. Although the picture of interference of a reference beam and a signal beam is adequate, we show that our results for the formation of the holographic pattern agree with the glory rescattering theory of Xia et al. [Phys. Rev. Lett. 121, 143201 (2018)10.1103/PhysRevLett.121.143201]. We probe the two-step semiclassical model by comparing it to the numerical results of the time-dependent Schrödinger equation.Fil: López, Sebastián David. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Arbo, Diego. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin
Document Distance for the Automated Expansion of Relevance Judgements for Information Retrieval Evaluation
This paper reports the use of a document distance-based approach to
automatically expand the number of available relevance judgements when these
are limited and reduced to only positive judgements. This may happen, for
example, when the only available judgements are extracted from a list of
references in a published review paper. We compare the results on two document
sets: OHSUMED, based on medical research publications, and TREC-8, based on
news feeds. We show that evaluations based on these expanded relevance
judgements are more reliable than those using only the initially available
judgements, especially when the number of available judgements is very limited.Comment: SIGIR 2014 Workshop on Gathering Efficient Assessments of Relevanc
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