Physics Letters B (Oct 2021)
Transition probabilities in 31P and 31S: A test for isospin symmetry
- D. Tonev,
- G. de Angelis,
- I. Deloncle,
- N. Goutev,
- G. De Gregorio,
- P. Pavlov,
- I.L. Pantaleev,
- S. Iliev,
- M.S. Yavahchova,
- P.G. Bizzeti,
- A. Demerdjiev,
- D.T. Dimitrov,
- E. Farnea,
- A. Gadea,
- E. Geleva,
- C.Y. He,
- H. Laftchiev,
- S.M. Lenzi,
- S. Lunardi,
- N. Marginean,
- R. Menegazzo,
- D.R. Napoli,
- F. Nowacki,
- R. Orlandi,
- H. Penttilä,
- F. Recchia,
- E. Sahin,
- R.P. Singh,
- M. Stoyanova,
- C.A. Ur,
- H.-F. Wirth
Affiliations
- D. Tonev
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria; Corresponding author.
- G. de Angelis
- INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy
- I. Deloncle
- CSNSM, CNRS/Université, Paris-Sud XI, 91405 Orsay Campus, France
- N. Goutev
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
- G. De Gregorio
- Dipartimento di Matematica e Fisica, Università degli Studi della Campania “Luigi Vanvitelli”, I-8110 Caserta, Italy; INFN, Sezione di Napoli, I-80126 Napoli, Italy
- P. Pavlov
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
- I.L. Pantaleev
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
- S. Iliev
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
- M.S. Yavahchova
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
- P.G. Bizzeti
- Dipartimento di Fisica e Astronomia, Università di Firenze, I-50019 Sesto Fiorentino Firenze, Italy; INFN, Sezione di Firenze, I-50019 Sesto Fiorentino Firenze, Italy
- A. Demerdjiev
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
- D.T. Dimitrov
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
- E. Farnea
- INFN, Sezione di Padova, I-35131 Padova, Italy; Dipartimento di Fisica e Astronomia, Università di Padova, I-35131 Padova, Italy
- A. Gadea
- Instituto de Fisica Corpuscular, CSIC-Universitat de Valencia, E-46980 Valencia, Spain
- E. Geleva
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
- C.Y. He
- Department of Nuclear Physics, CIAE, 102413 Beijing, PR China
- H. Laftchiev
- Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784, Sofia, Bulgaria
- S.M. Lenzi
- INFN, Sezione di Padova, I-35131 Padova, Italy; Dipartimento di Fisica e Astronomia, Università di Padova, I-35131 Padova, Italy
- S. Lunardi
- INFN, Sezione di Padova, I-35131 Padova, Italy; Dipartimento di Fisica e Astronomia, Università di Padova, I-35131 Padova, Italy
- N. Marginean
- Horia Holubei National Institute of Physics and Nuclear Engineering, 077125 Bucharest-Magurele, Romania
- R. Menegazzo
- INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy
- D.R. Napoli
- INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy
- F. Nowacki
- Université de Strasbourg, CNRS, IPHC, F-67000, Strasbourg, France
- R. Orlandi
- Advanced Science Research Center, JAEA, Tokai, Ibaraki 319-1195, Japan
- H. Penttilä
- University of Jyväskylä, FI-40014 Jyväskylä, Finland
- F. Recchia
- INFN, Sezione di Padova, I-35131 Padova, Italy; Dipartimento di Fisica e Astronomia, Università di Padova, I-35131 Padova, Italy
- E. Sahin
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- R.P. Singh
- Inter-University Accelerator Center, New Delhi, India
- M. Stoyanova
- Faculty of Physics, Sofia University, BG-1164, Sofia, Bulgaria
- C.A. Ur
- ELI-NP, Bucharest-Magurele, Romania
- H.-F. Wirth
- Fakultät für Physik, Ludwig-Maximilians Universität München, D-85748, Garching, Germany
- Journal volume & issue
-
Vol. 821
p. 136603
Abstract
Excited states in the mirror nuclei 31P and 31S were populated in the 1p and 1n exit channels of the reaction 20Ne + 12C, at a beam energy of 33 MeV. The 20Ne beam was delivered for the first time by the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. Angular correlations of coincident γ-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.
