IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Neutrino and antineutrino charge-exchange reactions on 12C
Autor/es:
A. R. SAMANA,; F. KRMPOTIC; N. PAAR; C. A. BERTULANI
Revista:
PHYS. REV. - C
Editorial:
AMER PHYSICAL SOC
Referencias:
Año: 2011 vol. 83 p. 243031 - 2430319
ISSN:
0556-2813
Resumen:
 We extend the  formalism of weak interaction processes, obtaining new  expressionsfor the transition rates,  which  greatly facilitate numerical calculations, both for neutrino-nucleus reactions and muon capture. Explicit violation of CVC hypothesis by the Coulomb field, as well as development of a sum rule approachfor the inclusive cross sections have been worked out. We have done a thorough  study of exclusive (ground state) properties of  12B and12N  within  the projected quasiparticle random phaseapproximation (PQRPA). Good agreement with experimental data achieved  in this way put in evidence the limitationsof standard  RPA and the QRPA models, which come from the inability ofthe RPA in opening the p3/2 shell, and from the non-conservation of the number of particles in the QRPA.The inclusive neutrino/antineutrino reactions on  12C are calculated within both the PQRPA,  and the relativistic QRPA (RQRPA). It is found that the magnitudes of the resulting cross-sections: i) are  close to the sum-rule limitat low energy, but significantly smaller than this limitat high energies both for neutrino and antineutrino,ii) they steadily increase when the  size of the configuration space is augmented,and particulary for  energies > 200 MeV,and iii) converge  for sufficiently large configuration space and  final state spin.  We study the decomposition of the inclusivecross-section based on the degree of forbiddenness  of different multipoles. The neutrino-12C charge-exchange reactions related with astrophysical applications are briefly discussed.