| Title: |
Study of $\Delta$ excitations in medium-mass nuclei with peripheral heavy ion charge-exchange reactions |
| Authors: |
Rodriguez-Sanchez, J. L., Benlliure, J., Vidaña, I., Lenske, H., Scheidenberger, C., Vargas, J., Alvarez-Pol, H., Ayyad, Y., Atkinson, J., Aumann, T., Beceiro-Novo, S., Boretzky, K., Caamaño, M., Casarejos, E., Cortina-Gil, D., Fernandez, P. Diaz, Estrade, A., Geissel, H., Haettner, E., Kelic-Heil, A., Litvinov, Yu. A., Paradela, C., Perez-Loureiro, D., Pietri, S., Prochazka, A., Takechi, M., Tanaka, Y. K., Weick, H., Winfield, J. S. |
| Publication Year: |
2020 |
| Collection: |
Nuclear Experiment
Nuclear Theory |
| Subject Terms: |
Nuclear Experiment, Nuclear Theory |
| More Details: |
Isobaric single charge-exchange reactions, changing nuclear charges by one unit but leaving the mass partitions unaffected, have been for the first time investigated by peripheral collisions of $^{112}$Sn ions accelerated up to 1\textit{A} GeV at the GSI facilities. The high-resolving power of the FRS spectrometer allows us to obtain $(p, n)$-type isobaric charge-exchange cross sections with an uncertainty of $3.5\%$ and to separate quasi-elastic and inelastic components in the missing-energy spectra of the ejectiles. The inelastic component is associated to the excitation of the $\Delta$(1232) isobar resonance and the emission of pions in s-wave both in the target and projectile nucleus, while the quasi-elastic contribution is associated to the nuclear spin-isospin response of nucleon-hole excitations. An apparent shift of the $\Delta$-resonance peak of $\sim$63 MeV is observed when comparing the missing-energy spectra obtained from the measurements with proton and carbon targets. A detailed analysis, performed with a theoretical model for the reactions, indicates that this observation can be simply interpreted as a change in the relative magnitude between the contribution of the excitation of the resonance in the target and in the projectile. |
| Document Type: |
Working Paper |
| DOI: |
10.1016/j.physletb.2020.135565 |
| Access URL: |
http://arxiv.org/abs/2004.06404 |
| Accession Number: |
edsarx.2004.06404 |
| Database: |
arXiv |
