${}^{15}\mathbf{C}(d,p){}^{16}\mathbf{C}$ Reaction and Exotic Behavior in ${}^{16}\mathbf{C}$

We have studied the ${}^{15}\mathrm{C}(d,p){}^{16}\mathrm{C}$ reaction in inverse kinematics using the Helical Orbit Spectrometer at Argonne National Laboratory. Prior studies of electromagnetic-transition rates in ${}^{16}\mathrm{C}$ suggested an exotic decoupling of the valence neutrons from the core in that nucleus. Neutron-adding spectroscopic factors give a different probe of the wave functions of the relevant states in ${}^{16}\mathrm{C}$. Shell-model calculations reproduce both the present transfer data and the previously measured transition rates, suggesting that ${}^{16}\mathrm{C}$ may be described without invoking very exotic phenomena.

Figure 1

(a) Proton energy versus position spectrum for the ${}^{15}\mathrm{C}(d,p){}^{16}\mathrm{C}$ reaction measured in inverse kinematics with HELIOS. The target is at $z=0\mathrm{mm}$, and $z$ increases in the beam direction. The different groups correspond to different final states in ${}^{16}\mathrm{C}$, as is indicated on the figure. (b) ${}^{16}\mathrm{C}$ excitation-energy spectrum.

Figure 2

Angular distributions for different transitions in ${}^{15}\mathrm{C}(d,p){}^{16}\mathrm{C}$. The curves represent distorted-wave Born approximation calculations described in the text, using optical-model parameters from Refs. 27 (solid line), 28 (dashed line), 29 (dot-dashed line), and 30 (dotted line). The cross-section uncertainties are statistical and do not reflect systematic errors in the absolute scale, as described in the text.