Structure of the ¹⁰Li nucleus investigated via the ⁹Li(d,p)¹⁰Li reaction

The structure of the particle unbound nucleus ¹⁰Li was investigated in a kinematically complete experiment using the ⁹Li(d,p)¹⁰Li reaction in inverse kinematics at an incident ⁹Li energy of 20 MeV/nucleon. The experiment utilized the S800 Spectrograph at the National Superconducting Cyclotron Laboratory to measure the outgoing ⁹Li from the breakup of ¹⁰Li in coincidence with the recoiling protons from the (d,p) reaction which were measured using an array of silicon detectors. Based on the kinematics of the recoiling protons from the ⁹Li(d,p) reaction, we measured a lower limit of Δ=33.10±0.08 MeV (i.e., Δ>33.02 MeV) for the mass excess of ¹⁰Li which is consistent with previous measurements. Through the complete reconstruction of the breakup kinematics, the structure of ¹⁰Li associated with a ground state ⁹Li core was distinguishable from structure associated with a ⁹Li core in its first excited state. The observed ratio of ⁹Li^* core events to the total number of ¹⁰Li events that were detected in the experiment was 0.10±0.04 at forward center of mass angles (2.7° to 9.5°), and 0.24±0.03 at more backward center of mass angles (11° to 26°). The resulting Q-value spectra was best fit with either a single resonance located at Q=-2.58(11) MeV [corresponding to a neutron separation energy S_n=-0.35(11) MeV] or two resonances located at Q=-3.00(24) MeV [S_n=-0.77(24) MeV] and Q>-2.43 MeV (S_n>-0.2 MeV).