Nuclear radii of 17,19B and 14Be

Abstract

The interaction cross sections ( σ I ) of light radioactive nuclei close to the neutron drip line ( 17,19B, 14Be) have been measured at around 800 A MeV. The effective root-mean-square (r.m.s.) matter radii of these nuclei have been deduced from σ I by two different methods, a Glauber-type calculation based on the optical limit approximation and a few-body reaction model. The deduced radii from both approaches agree with each other within experimental uncertainty. The r.m.s. radii of 17B (2.99±0.09 fm) and of 14Be (3.10±0.15 fm) in this work are consistent with the previously determined values, and have a higher accuracy. The r.m.s. radius of 19B (3.11±0.13 fm) was newly determined. Assuming a “core plus 2n” structure in 17B and 14Be, the mixing of ν(2 s 1/2) and ν(1 d 5/2) was studied and the s-wave spectroscopic factor is found to be 36±19% and 47±25%, respectively. A valence radius analysis suggests a “core plus 4n” structure in 19B.