Nuclear Charge Radii ofLi9,11: The Influence of Halo Neutrons

Abstract

The nuclear charge radius of 11Li has been determined for the first time by high-precision laser spectroscopy. On-line measurements at TRIUMF-ISAC yielded a 7Li-11Li isotope shift (IS) of 25 101.23(13) MHz for the Doppler-free [FORMULA: SEE TEXT]transition. IS accuracy for all other bound Li isotopes was also improved. Differences from calculated mass-based IS yield values for change in charge radius along the isotope chain. The charge radius decreases monotonically from 6Li to 9Li, and then increases from 2.217(35) to 2.467(37) fm for 11Li. This is compared to various models, and it is found that a combination of halo neutron correlation and intrinsic core excitation best reproduces the experimental results.

Nuclear structure in the framework of the Unitary Correlation Operator Method

“…6 He, 6 Li and 7 Li as a function of model space size for different oscillator frequencies using the UCOM(SRG) interaction. Experimental values from [78] and [79]. 6 Li UCOM SRG the saturation properties of the interaction as the radii for these nuclei depend strongly on the asymptotic behavior of the wave function due to their halo or cluster nature.…”

Proton Radius of 14Be from Measurement of Charge-Changing Cross Sections

“…1 show that the Glauber results for the harmonic oscillator density distribution for [10][11][12] Be reproduce the measured proton radii. They exhibit the same behavior as the scaled FMD calculation results, with only an approximate 5% difference from the experimental values.…”

“…1 by open circles. However, this could be due to the fact that the proton radii for the FMD model are smaller than the observed values [12] for 10,11,12 Be as shown in Fig. 2.…”

“…Assuming that R Ip and the proton rms radius R p are proportional to each other, the ratio Γ=R p /R Ip can be used as a scaling factor. The average value of the ratio for 9 Be, 10 Be, 11 Be, and 12 Be is Γ av =1.142±0.026, where the standard deviation is only about 2%. Next, R p for 14 Be is determined from the measured value of σ cc to be Γ av R Ip ( 14 Be)=2.40±0.07 fm.…”

“…The field shift related to the radius can only be obtained by subtracting the theoretical mass shift from the observed value. However, due to recent developments in ISOL techniques [9,10,11,12,13] and in atomic theory [14,15], it has become possible to determine the charge radius for He, Li, and Be isotopes. Nevertheless, it is very difficult to produce nuclei that are far from the stability line, such as 14 Be.…”