New measurement of the excited states in $^{11}$B via the elastic resonance scattering of $^{10}$Be + p

TL;DR

This study measured excited states in $^{11}$B using elastic resonance scattering of $^{10}$Be + p, determining their energies, spins, and widths with improved techniques and comparing them to previous data.

Contribution

The paper provides new measurements of $^{11}$B excited states using inverse kinematics and R-matrix analysis, refining resonance parameters and state assignments.

Findings

Identified resonant states at 14.55, 14.74, and 16.18 MeV in $^{11}$B.

Determined resonance energies, spins, and partial widths for these states.

Compared results with previous measurements, noting discrepancies and possible new state observations.

Abstract

The elastic resonance scattering protons decayed from $^{11}$B to the ground state of $^{10}$Be were measured using the thick-target technique in inverse kinematics at the Heavy Ion Research Facility in Lanzhou (HIRFL). The obtained excitation functions were well described by a multichannel R-matrix procedure under the kinematics process assumption of resonant elastic scattering. The excitation energy of the resonant states ranges from 13.0 to 17.0 MeV, and their resonant parameters such as the resonant energy E$_{x}$, the spin-parity J$^\pi$, and the proton-decay partial width $\Gamma_p$ were determined from R-matrix fits to the data. Two of these states around E$_{x}$ = 14.55 MeV [J$^\pi$ = (3/2$^+$, 5/2$^+$), $\Gamma_p$ = 475 $\pm$ 80 keV] and E$_{x}$ = 14.74 MeV [J$^\pi$ = 3/2$^-$, $\Gamma_p$ = 830 $\pm$ 145 keV], and a probably populated state at E$_x$ = 16.18 MeV [J$^\pi$ =(1/2$^-$, 3/2$^-$), $\Gamma_p$ $<$ 60 keV], are respectively assigned to the well-known states in $^{11}$B at 14.34 MeV, 15.29 MeV, and 16.43 MeV. The isospin of these three states were previously determined to be T = 3/2, but discrepancies exist in widths and energies due to the current counting statistics and energy resolution. We have compared these states with previous measurements, and the observation of the possibly populated resonance is discussed.