Structure of the10Linucleus investigated via the9Li(d,p)10Lireaction

Abstract

The structure of the particle unbound nucleus ${}^{10}\mathrm{Li}$ was investigated in a kinematically complete experiment using the ${}^{9}\mathrm{Li}{(d,p)}^{10}\mathrm{Li}$ reaction in inverse kinematics at an incident ${}^{9}\mathrm{Li}$ energy of 20 MeV/nucleon. The experiment utilized the S800 Spectrograph at the National Superconducting Cyclotron Laboratory to measure the outgoing ${}^{9}\mathrm{Li}$ from the breakup of ${}^{10}\mathrm{Li}$ 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 ${}^{9}\mathrm{Li}(d,p)$ reaction, we measured a lower limit of $\ensuremath{\Delta}=33.10\ifmmode\pm\else\textpm\fi{}0.08$ MeV (i.e., $\ensuremath{\Delta}g33.02$ MeV) for the mass excess of ${}^{10}\mathrm{Li}$ which is consistent with previous measurements. Through the complete reconstruction of the breakup kinematics, the structure of ${}^{10}\mathrm{Li}$ associated with a ground state ${}^{9}\mathrm{Li}$ core was distinguishable from structure associated with a ${}^{9}\mathrm{Li}$ core in its first excited state. The observed ratio of ${}^{9}{\mathrm{Li}}^{*}$ core events to the total number of ${}^{10}\mathrm{Li}$ events that were detected in the experiment was $0.10\ifmmode\pm\else\textpm\fi{}0.04$ at forward center of mass angles $(2.7\ifmmode^\circ\else\textdegree\fi{}$ to $9.5\ifmmode^\circ\else\textdegree\fi{}),$ and $0.24\ifmmode\pm\else\textpm\fi{}0.03$ at more backward center of mass angles $(11\ifmmode^\circ\else\textdegree\fi{}$ to $26\ifmmode^\circ\else\textdegree\fi{}).$ The resulting Q-value spectra was best fit with either a single resonance located at $Q=\ensuremath{-}2.58(11)$ MeV [corresponding to a neutron separation energy ${S}_{n}=\ensuremath{-}0.35(11)$ MeV] or two resonances located at $Q=\ensuremath{-}3.00(24)$ MeV $[{S}_{n}=\ensuremath{-}0.77(24)$ MeV] and $Qg\ensuremath{-}2.43$ MeV ${(S}_{n}g\ensuremath{-}0.2$ MeV).