Structure of 9C through proton resonance scattering with Texas Active Target detector

Abstract

Background: Level structure of the most neutron deficient nucleon-bound carbon isotope, 9C, is not well known. Definitive spin-parity assignments are only available for two excited states. No positive parity states have been conclusively identified so far and the location of the sd-shell in A=9 T=3/2 isospin quadruplet is not known. Purpose: We have studied the level structure of exotic nucleus 9C at excitation energies below 6.4 MeV. Methods: Excited states in 9C were populated in 8B+p resonance elastic scattering and excitation functions were measured using active target approach. Results: Two excited states in 9C were conclusively observed, and R-matrix analysis of the excitation functions was performed to make the spin-parity assignments. The first positive parity state in A=9 T=3/2 nuclear system, the 5/2+ resonance at 4.3 MeV, has been identified. Conclusions: The new 5/2+ state at 4.3 MeV in 9C is a single-particle L=0 broad resonance and it determines the energy of the 2s shell. The 2s shell in this exotic nucleus appears well within the region dominated by the p-shell states.

arXiv comment9 pages, 12 figures

References in corpus (14)

• Quantum Monte Carlo Calculations of $A\le 6$ Nuclei
• Quantum Monte Carlo calculations of $A=9,10$ nuclei
• Structure of Light Unstable Nuclei Studied with Antisymmetrized Molecular Dynamics
• Ab initio no-core full configuration calculations of light nuclei
• Coupled-cluster theory for three-body Hamiltonians
• Large-basis shell-model calculations for p-shell nuclei
• Quantum Monte Carlo calculations of electromagnetic moments and transitions in A <= 9 nuclei with meson-exchange currents derived from chiral effective field theory
• Ab initio many-body calculation of the 7Be(p,gamma)8B radiative capture
• Few- and many-nucleon systems with semilocal coordinate-space regularized chiral nucleon-nucleon forces
• Bound, virtual and resonance $S$-matrix poles from the Schrödinger equation
• Ab initio calculations of nuclear widths via an integral relation
• Structure of 10N in 9C+p resonance scattering
• Spectroscopy of 9C via resonance scattering of protons on 8B
• Nuclear structure beyond the neutron drip line: the lowest energy states in ${}^9$He via their T=5/2 isobaric analogs in ${}^9$Li

Cited by in corpus (4)

• Texas Active Target (TexAT) detector for experiments with rare isotope beams
• Microscopic investigation of the ${}^8$Li($n,\gamma$)${}^9$Li reaction
• Three-body description of ${}^9$C: Role of low-lying resonances in breakup reactions
• Observation of T=3/2 Isobaric Analog States in 9Be using p+8Li resonance scattering