1202.4873 (Andreas Krieger et al.)

Nuclear Charge Radius of $^{12}$Be    [PDF]

Andreas Krieger, Klaus Blaum, Mark L. Bissell, Nadja Frömmgen, Christopher Geppert, Michael Hammen, Kim Kreim, Magdalena Kowalska, Jörg Krämer, Thomas Neff, Rainer Neugart, Gerda Neyens, Wilfried Nörtershäuser, Christian Novotny, Rodolfo Sanchez, Deyan T. Yordanov

The nuclear charge radius of $^{12}$Be was precisely determined using the
technique of collinear laser spectroscopy on the $2s_{1/2}\rightarrow 2p_{1/2,
3/2}$ transition in the Be$^{+}$ ion. The mean square charge radius increases
from $^{10}$Be to $^{12}$Be by $\delta ^{10,12} = 0.69(5) \fm^{2}$
compared to $\delta ^{10,11} = 0.49(5) \fm^{2}$ for the
one-neutron halo isotope $^{11}$Be. Calculations in the fermionic molecular
dynamics approach show a strong sensitivity of the charge radius to the
structure of $^{12}$Be. The experimental charge radius is consistent with a
breakdown of the N=8 shell closure.

View original: http://arxiv.org/abs/1202.4873