title: Exploring relativistic many-body recoil effects in highly charged ions.
abstract: The relativistic recoil effect has been the object of experimental investigations using highly charged ions at the Heidelberg electron beam ion trap. Its scaling with the nuclear charge Z boosts its contribution to a measurable level in the magnetic-dipole (M1) transitions of B- and Be-like Ar ions. The isotope shifts of 36Ar versus 40Ar have been detected with sub-ppm accuracy, and the recoil effect contribution was extracted from the 1s(2)2s(2)2p 2P(1/2) - 2P(3/2) transition in Ar13+ and the 1s(2)2s2p 3P1-3P2 transition in Ar14+. The experimental isotope shifts of 0.00123(6) nm (Ar13+) and 0.00120(10) nm (Ar14+) are in agreement with our present predictions of 0.00123(5) nm (Ar13+) and 0.00122(5) nm (Ar14+) based on the total relativistic recoil operator, confirming that a thorough understanding of correlated relativistic electron dynamics is necessary even in a region of intermediate nuclear charges.
authors.affiliation: Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
authors.forename: R Soria
authors.initials: RS
authors.lastname: Orts
authors.forename: Z
authors.initials: Z
authors.lastname: Harman
authors.forename: J R Crespo
authors.initials: JR
authors.lastname: López-Urrutia
authors.forename: A N
authors.initials: AN
authors.lastname: Artemyev
authors.forename: H
authors.initials: H
authors.lastname: Bruhns
authors.forename: A J González
authors.initials: AJ
authors.lastname: Martínez
authors.forename: U D
authors.initials: UD
authors.lastname: Jentschura
authors.forename: C H
authors.initials: CH
authors.lastname: Keitel
authors.forename: A
authors.initials: A
authors.lastname: Lapierre
authors.forename: V
authors.initials: V
authors.lastname: Mironov
authors.forename: V M
authors.initials: VM
authors.lastname: Shabaev
authors.forename: H
authors.initials: H
authors.lastname: Tawara
authors.forename: I I
authors.initials: II
authors.lastname: Tupitsyn
authors.forename: J
authors.initials: J
authors.lastname: Ullrich
authors.forename: A V
authors.initials: AV
authors.lastname: Volotka