Core Excitation in \u3csup\u3e14\u3c/sup\u3eC and Two-proton Pickup

In two-proton pickup from 14C, the calculated cross-section ratio for the first two 0+ states of 12Be depends on the configuration mixing in these two states and on the amount of core excitation in the ground state (g.s.) of 14C. Using the 12Be wave functions that are reasonably well known, I have calculated this ratio as a function of the core excitation in 14C(g.s.). A measurement of this ratio should allow an independent determination of the 14C mixing—previously estimated to be about 12%

Properties of the Lowest 1/2\u3csup\u3e+\u3c/sup\u3e, \u3cem\u3eT\u3c/em\u3e = 3/2 States in \u3cem\u3eA\u3c/em\u3e = 11 Nuclei

Analysis of energies and widths of the lowest 1/2+ T = 3/2 states in A = 11 nuclei suggests that the excitation energy in 11C should be about 200 keV below the energy in the literature, and the width should be 4 to 5 times the literature value. Properties of the state in 11B and 11N are in agreement with the present model

Properties of 3.89/3.96-MeV states in \u3csup\u3e11\u3c/sup\u3eBe

I have reanalyzed previous data from the 9Be(t,p) reaction to extract energies and widths for the two states near 3.9 MeV. Results are energies of 3889.27 ± 1.03 and 3954.53 ± 1.16 and widths of 3.2(8) and 7.9(7), all in keV, for the 5/2− and 3/2− states, respectively

Widths in \u3csup\u3e15\u3c/sup\u3eC and \u3csup\u3e15\u3c/sup\u3eF

Earlier data for the reaction 13C(t,p) have been analyzed to extract widths for several states of 15C. Results affect predictions of widths in 15F

Constraints on energies of \u3csup\u3e15\u3c/sup\u3eF(g.s.), \u3csup\u3e15\u3c/sup\u3eO(1/2\u3csup\u3e+\u3c/sup\u3e , \u3cem\u3eT\u3c/em\u3e = 3/2 ), and \u3csup\u3e16\u3c/sup\u3eF(0\u3csup\u3e+\u3c/sup\u3e, \u3cem\u3eT\u3c/em\u3e = 2)

Coulomb energy calculations for the lowest 0+ , T = 2 state in A = 16 nuclei allow tight constraints on the masses of the lowest 1/2+ , T = 3/2 state in 15O and 15F, and of the 0+ , T = 2 state in 16F

\u3cem\u3eB\u3c/em\u3e(\u3cem\u3eE\u3c/em\u3e2) Values in \u3csup\u3e12\u3c/sup\u3eBe and Core Excitation

I have examined the B(E2)’s in 12Be connecting the first 2+ state to the first two 0+ states. I find that they can be understood in the simple model that has been successful for a variety of other observables in this nucleus, but only if the 2+ state has an excited-core component

Comment on “Neutron knockout of \u3csup\u3e12\u3c/sup\u3eBe populating neutron-unbound states in \u3csup\u3e11\u3c/sup\u3eBe”

A recent paper [Phys. Rev. C 83, 057304 (2011)] used knockout from 12Be to populate two states near 3.9 MeV in 11Be and observed their neutron decay—but treated the two as a single state. The authors used a branching ratio for the upper state from an experiment that also did not separate the two states. Thus, their energy for 11Be(3.96 MeV) and the spectroscopic factor connecting it to 12Be(gs) are questionable

\u3cem\u3eB\u3c/em\u3e(\u3cem\u3eE\u3c/em\u3e2) Value and Configuration Mixing in \u3csup\u3e32\u3c/sup\u3eMg

I demonstrate that the B(E2) value in 32Mg can be understood with a model in which both the ground and 2+ first-excited states are predominantly of sd-shell character

Branching Ratio of \u3csup\u3e18\u3c/sup\u3eNe(7.06 MeV, 4\u3csup\u3e+\u3c/sup\u3e)

The recently reported branching ratio (BR) for the 4+ state in 18Ne at Ex = 7.06 MeV strongly disagrees with the BR computed using the known properties of this state

Intruder–normal-state mixing in \u3csup\u3e30\u3c/sup\u3eMg

In 30Mg, existing data for B(E2) strengths connecting the ground and excited 0+ states to the first 2+ state have been used, together with earlier shell-model predictions of normal and intruder E2 strengths, to estimate the intruder-normal state mixing in the 0+ and 2+ states. Resulting mixing is small, as expected, and for the ground state my value of 0.11(7) has a larger uncertainty, but is in quantitative agreement with the estimate of 0.0319(76) obtained earlier from the measured E0 strength connecting the 0+ states