Mélange de transitions M1 et E2

Remarks on E1-E2 and E1-M1 two-photon transitions

2014 We investigate the possibility to observe Doppler-free two-photon transitions in the case where one of the transitions is an electric dipole transition and the other one is a magnetic dipole or an electric quadrupole transition. We show that it is not possible to obtain Doppler-free lines by reflecting the beam on itself. On the other hand, such an effect should be observable if the two co...

Extraction d'un vocabulaire de surprise par mélange de filtrage collaboratif et d'analyse de sentiments

Computer science is undergoing a profound transformation: gains in computing power and the availability of large datasets provide a fertile ground for machine learning research. One challenge in this context is to take account of user preferences to provide personalized access to information.Recommender systems create user and item profiles using past user reviews, profiles that reflect user pr...

E1, E2, M1, and M2 transitions in the nickel isoelectronic sequence

A relativistic many-body method is developed to calculate energy and transition rates for multipole transitions in many-electron ions. This method is based on relativistic many-body perturbation theory (RMBPT), agrees with MCDF calculations in lowest order, includes all second-order correlation corrections, and includes corrections from negative-energy states. Reduced matrix elements, oscillato...

The E2/m1 Ratio, a Status Report

Recent determinations of the E2/M1 ratio are reviewed. Many aspects of these studies have been questioned. Here we focus on the selection of a database, methods used in the extraction of this ratio, and interpretation(s) of the results. I. THE DATA: OLD VS NEW Soon after the Baryons ’92 conference, the VPI group wrote a short note [1] claiming a value of −1.5± 0.5% for the E2/M1 ratio a value i...

Etude preliminaire de l'association de vaccins antiaphteux et antibrucellique