Spectral Shape of the Two-Photon Decay of the 2 1S0 State in He-Like Tin

Sergiy Trotsenko (1) , A. Kumar , A. V. Volotka (2) , D. Banas , Heinrich Beyer (1) , Harald Bräuning (1) , Sephan Fritzsche (1) , Alexander Gumberidze (1) , S. Hagmann (1) , S. Hess , Pawel Jagodzinski (3) , Christophor Kozhuharov (1) , Regina Reuschl (1, 4) , S. Salem , A. Simon , Uwe Spillmann (1) , Martino Trassinelli (4) , L. Tribedi (5) , G. Weber (1) , Danyal Winters (1) , Thomas Stöhlker (1, 6)

1 GSI - Helmholtz zentrum für Schwerionenforschung GmbH
2 USP - Department of Physics
3 Institute of Physics
4 INSP - Institut des Nanosciences de Paris
5 Tata Institution of Fundamental Research
6 Institut für Kernphysik

The spectral distribution of the 1s2s 1S0→1s2 1S0 two-photon decay of He-like tin was measured using a novel approach at the gas-jet target of the ESR storage ring. Relativistic collisions of Li-like projectiles with low-density gaseous matter have been exploited to selectively populate the desired 1s2s state. Compared to conventional techniques, this approach results in a substantial gain in statistical and systematic accuracy, which allowed us to achieve for the first time a sensitivity to relativistic effects on the two-photon decay spectral shape as well as to discriminate the measured spectrum for Sn from theoretical shapes for different elements along the He-isoelectronic sequence.

Domaines: Physique Atomique [physics.atom-ph]

Sergiy Trotsenko, A. Kumar, A. V. Volotka, D. Banas, Heinrich Beyer, et al.. Spectral Shape of the Two-Photon Decay of the 2 1S0 State in He-Like Tin. Physical Review Letters, 2010, 104 (3), pp.033001. ⟨10.1103/PhysRevLett.104.033001⟩. ⟨hal-00537620⟩