Photoexcitation of a dipole-forbidden resonance in helium

We have observed photoexcitation of the dipole-forbidden 1s(2) 1S0-->2p(2) 1D2 resonance in helium by measuring the nondipolar forward-backward asymmetry of photoelectron angular distributions in the 2l2l(') autoionizing region. By exploiting the electric dipole-quadrupole interference in th...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2002-05, Vol.88 (20), p.203002-203002, Article 203002
Main Authors: Krässig, B, Kanter, E P, Southworth, S H, Guillemin, R, Hemmers, O, Lindle, D W, Wehlitz, R, Martin, N L S
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We have observed photoexcitation of the dipole-forbidden 1s(2) 1S0-->2p(2) 1D2 resonance in helium by measuring the nondipolar forward-backward asymmetry of photoelectron angular distributions in the 2l2l(') autoionizing region. By exploiting the electric dipole-quadrupole interference in the excitation of both the 2s2p 1P1 and 2p(2) 1D2 levels, we have observed the quadrupole resonance in photoabsorption and extracted its Fano line shape parameters and the relative phase of the 1sEp and 1sEd continua. We find the quadrupole line profile index q(2) to be markedly different from theoretical expectations.
ISSN:0031-9007
1079-7114
DOI:10.1103/PhysRevLett.88.203002