@article{3032929, title = "O-18 + Se-76 elastic and inelastic scattering at 275 MeV", author = "La Fauci, L. and Spatafora, A. and Cappuzzello, F. and Agodi, C. and and Carbone, D. and Cavallaro, M. and Lubian, J. and Acosta, L. and and Amador-Valenzuela, P. and Borello-Lewin, T. and Brischetto, G. A. and and Calabrese, S. and Calvo, D. and Capirossi, V and Chavez Lomeli, E. R. and and Ciraldo, I and Cutuli, M. and Delaunay, F. and Djapo, H. and Eke, C. and and Finocchiaro, P. and Firat, S. and Fisichella, M. and Foti, A. and and Guazzelli, M. A. and Hacisalihoglu, A. and Iazzi, F. and Linares, R. and and Ma, J. and Medina, N. H. and Moralles, M. and Oliveira, J. R. B. and and Pakou, A. and Pandola, L. and Petrascu, H. and Pinna, F. and Ries, P. C. and and Russo, G. and Sgouros, O. and Solakci, S. O. and Soukeras, V and and Souliotis, G. and Torresi, D. and Tudisco, S. and Wang, J. and Yang, Y. and and Yildirin, A. and Zagatto, V. A. B. and NUMEN Collaboration", journal = "Physical Review C", year = "2021", volume = "104", number = "5", publisher = "AMER PHYSICAL SOC", issn = "2469-9985, 2469-9993", doi = "10.1103/PhysRevC.104.054610", abstract = "Background: An accurate description of the initial and final state interactions in the O-18 + Se-76 collision is demanded by the NUMEN project. The study of single and double charge exchange nuclear reactions is the main purpose for NUMEN, since these can be used as tools to provide experimentally driven information about nuclear matrix elements of interest in the context of neutrinoless double-beta decay. To date, the details of the optical potentials and nuclear response to isospin operators for many of the projectile-target systems proposed for the NUMEN double charge exchange studies are poorly known. The O-18 + Se-76 case, here under study, is particularly relevant due to its connection with the Ge-76 neutrinoless double-beta decay. Purpose: In this work the authors want to characterize the initial-state interaction for the O-1(8) + Se-76 reactions at 275 MeV incident energy determining the optical potential and evaluating the effect of couplings with the inelastic scattering on the elastic channel. Methods: The angular distributions of differential cross section were measured in the angular region between 4 degrees and 22 degrees in the center-of-mass reference frame. The cross sections were compared with theoretical calculations, that adopt different optical potentials. Coupling effects on the elastic channel were determined into the coupled channels formalism. Results: The excitation energy spectrum of the colliding nuclei and the cross section angular distributions were measured with satisfactory energy resolution. The elastic scattering cross section is not well reproduced in the full angular range explored when the optical model approach is adopted. A good agreement is found using coupled channel calculations. The initial state interaction for the O-18 + Se-76 nuclear reactions at 275 MeV is determined. Conclusions: Coupled channels effects are crucial to obtain a good description of the measured elastic and inelastic channels cross sections, even at large transferred momenta where the optical model approach fails in reproducing the experimental data. The role of channel coupling could be relevant also in the analysis of other open reaction channels in the same collision and should be accounted for in double charge exchange analyses as well." }