Volume 85, Number 5, March 2009
Article Number 50005
Number of page(s) 6
Section General
Published online 17 March 2009
EPL, 85 (2009) 50005
DOI: 10.1209/0295-5075/85/50005

Coulomb energy contribution to the excitation energy in 229Th and enhanced effect of $\chem{\alpha}$ variation

V. V. Flambaum1, 2, N. Auerbach3 and V. F. Dmitriev1, 3, 4, 5

1   School of Physics, The University of New South Wales - Sydney, NSW 2052, Australia
2   New Zealand Institute for Advanced Study, Massey University - Auckland, New Zealand
3   School of Physics and Astronomy, Tel Aviv University - Tel Aviv, 69978, Israel
4   Budker Institute of Nuclear Physics - 630090, Novosibirsk-90, Russia
5   Novosibirsk State University - 630090, Novosibirsk-90, Russia

received 13 October 2008; accepted in final form 13 February 2009; published March 2009
published online 17 March 2009

We estimated the polarization contribution of Coulomb energy to the spacing between the ground and first excited state of the 229Th nucleus as a function of the deformation parameter $\delta $. We show that despite the fact that the odd particle is a neutron, the change in Coulomb energy $\Delta U_{C}$ between these two states can reach several hundreds keV from this contribution. This means that the effect of the variation of the fine-structure constant $\alpha=e^2/\hbar c $ may be enhanced $\Delta U_{C}/E\sim 10^{4}$ times in the E = 7.6 eV “nuclear clock” transition between the ground and first excited states in the 229Th nucleus. To extract the full value of $\Delta U_{C}$, we propose to measure isomeric shift of atomic levels and nuclear electric quadrupole moments in 229Th.

06.20.Jr - Determination of fundamental constants.
21.10.Sf - Coulomb energies, analogue states.

© EPLA 2009