Speaker
Description
We present investigations of resonant states of exotic $^7$He nucleus and calculations of bound states and resonances of $^9$Li nucleus. Our results are obtained within an analysis of the $S$-matrix based on calculations within the no-core shell model (SS-HORSE-NCSM approach [1, 2]) using the realistic nucleon-nucleon interaction Daejeon16 [3].
Results for the $5/2^-$ and low-lying $3/2^-$ resonances in $^7$He are in reasonable agreement with experiment. There is a contradictory experimental information about energy and width of the $1/2^-$ resonance in $^7$He. In our calculations, the energy $E_{r}$ of this resonance is 2.7 MeV and the width $\Gamma$ is about 4 MeV. We predict in $^7$He also wide overlapping resonances $3/2^-$, $3/2^+$ and $5/2^+$ with energies around 4-5 MeV which are supposed to form an experimentally observed wide resonance at 6 MeV of unknown spin-parity.
The binding energy of the $^9$Li ground state is in reasonable agreement with experimental data. The calculated excitation energy of the first exited state of $^9$Li is 3.54 MeV which is larger than the experimental value of 2.691 MeV. We predict in our approach also the asymptotic normalization coefficients for these bound states. Experimentally there are $^9$Li resonances of unknown spin-parity with $E_r=0.232$ MeV and $\Gamma=0.1$ MeV and $E_r=1.316$ MeV and $\Gamma=0.6$ MeV; we obtain $^9$Li resonant states $5/2^-$ ($E_r=0.27$ MeV, $\Gamma=0.21$ MeV) and $3/2^-$ ($E_r= 1.53$ MeV, $\Gamma=2.39$ MeV).
References:
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A. M. Shirokov, A. I. Mazur, I. A. Mazur and J. P. Vary, Phys. Rev. C 94, 064320 (2016).
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A. M. Shirokov, A. I. Mazur, V. A. Kulikov, Phys. At. Nucl. 84, 131 (2021).
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A. M. Shirokov, I. J. Shin, Y. Kim, M. Sosonkina, P. Maris and J. P. Vary, Phys. Lett. B 761, 87 (2016).
