TY  - JOUR
AU  - Tonev, D. et al
AU  - Gadea, A.
PY  - 2021
DA  - 2021//
TI  - Transition probabilities in P-31 and S-31: A test for isospin symmetry
T2  - Phys. Lett. B
JO  - Physics Letters B
SP  - 136603
EP  - 6pp
VL  - 821
PB  - Elsevier
KW  - Mirror nuclei
KW  - Lifetime measurements
KW  - Transition probabilities
KW  - Isospin symmetry
KW  - Microscopic multiphonon model
AB  - Excited states in the mirror nuclei P-31 and S-31 were populated in the 1p and 1n exit channels of the reaction Ne-20 + C-12, at a beam energy of 33 MeV. The Ne-20 beam was delivered for the first time by the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. Angular correlations of coincident gamma-rays and Doppler-shift attenuation lifetime measurements were performed using the multi-detector array GASP in conjunction with the EUCLIDES charged particle detector. In the observed B(E1) strengths, the isoscalar component, amounting to 24% of the isovector one, provides strong evidence for breaking of the isospin symmetry in the A = 31 mass region. Self-consistent beyond mean field calculations using Equation of Motion method based on a chiral potential and including two- and three-body forces reproduce well the experimental B(E1) strengths, reinforcing our conclusion. Coherent mixing from higher-lying states involving the Giant Isovector Monopole Resonance accounts well for the effect observed. The breaking of the isospin symmetry originates from the violation of the charge symmetry of the two- and three-body parts of the potential, only related to the Coulomb interaction.
SN  - 0370-2693
UR  - https://doi.org/10.1016/j.physletb.2021.136603
DO  - 10.1016/j.physletb.2021.136603
LA  - English
N1  - WOS:000734909800003
ID  - Tonev+Gadea2021
ER  -