Περίληψη:
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.
Συγγραφείς:
La Fauci, L.
Spatafora, A.
Cappuzzello, F.
Agodi, C. and
Carbone, D.
Cavallaro, M.
Lubian, J.
Acosta, L. and
Amador-Valenzuela, P.
Borello-Lewin, T.
Brischetto, G. A. and
Calabrese, S.
Calvo, D.
Capirossi, V
Chavez Lomeli, E. R.
and Ciraldo, I
Cutuli, M.
Delaunay, F.
Djapo, H.
Eke, C.
and Finocchiaro, P.
Firat, S.
Fisichella, M.
Foti, A. and
Guazzelli, M. A.
Hacisalihoglu, A.
Iazzi, F.
Linares, R. and
Ma, J.
Medina, N. H.
Moralles, M.
Oliveira, J. R. B. and
Pakou, A.
Pandola, L.
Petrascu, H.
Pinna, F.
Ries, P. C.
and Russo, G.
Sgouros, O.
Solakci, S. O.
Soukeras, V and
Souliotis, G.
Torresi, D.
Tudisco, S.
Wang, J.
Yang, Y.
and Yildirin, A.
Zagatto, V. A. B.
NUMEN Collaboration
