Nuclear structure studies in mirror nuclei

International audienceThe nuclear structure of the A=31 and A=47 mirror couples produced by two fusion evaporation reactions has been elaborated, utilizing the Doppler-shift attenuation method. Excited states in $^{31}$P and $^{31}$S were populated using the 1p and 1n exit channels, respectively, of the reaction $^{20}$Ne + $^{12}$C, while in $^{47}$Cr and $^{47}$V couple excited states were populated based on $^{28}$Si + $^{28}$Si reaction, as products of 2αn and 2αp exit channels. The A=31 mirror couple was studied utilizing Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro with GASP multidetector array and for A=47 one - with the EUROBALL array using XTU Tandem also in Legnaro. In both cases the lifetime measurements in mirror couples at the same experiment open possibilities for investigations of isospin symmetry. Determined B(E1) strengths in the mirror nuclei $^{31}$P and $^{31}$S allow to extract the isoscalar component, which can reach up to 24% of the isovector one. The B(E1) values can be modeled by the Equation of motion method. In the case of A=47 mirror couple, the quadrupole moments can be described by shell-model calculations

Nuclear structure studies in mirror nuclei

The nuclear structure of the A=31 and A=47 mirror couples produced by two fusion evaporation reactions has been elaborated, utilizing the Doppler-shift attenuation method. Excited states in 31P and 31S were populated using the 1p and 1n exit channels, respectively, of the reaction 20Ne + 12C, while in 47Cr and 47V couple excited states were populated based on 28Si + 28Si reaction, as products of 2an and 2ap exit channels. The A=31 mirror couple was studied utilizing Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro with GASP multidetector array and for A=47 one - with the EUROBALL array using XTU Tandem also in Legnaro. In both cases the lifetime measurements in mirror couples at the same experiment open possibilities for investigations of isospin symmetry. Determined B(E1) strengths in the mirror nuclei 31P and 31S allow to extract the isoscalar component, which can reach up to 24% of the isovector one. The B(E1) values can be modeled by the Equation of motion method. In the case of A=47 mirror couple, the quadrupole moments can be described by shell-model calculations

Symmetries in mirror nuclei 31S and 31P

Excited states in mirror nuclei 31S and 31P were populated in the 1n and 1p exit channels, respectively, of the reaction 20Ne + 12C. The beam of 20Ne, with an energy of 33 MeV, was delivered for the first time by the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. Angular correlations of coincident pairs and Doppler-shift attenuation lifetime measurements in 31S and 31P were performed using the multidetector array GASP in conjunction with the EUCLIDES charged particle detector. A comparison of the determined B(E1) strengths of the analog mirror 7/2- → 5/2+ transitions indicates the presence of a violation of isospin symmetry

Lifetime measurements in mass regions A=100 and A=130 as a test for chirality in nuclear systems

Two odd-odd nuclei from the A ~ 100 and A ~ 130 regions, namely 102Rh and 134Pr have been studied in search for chiral doublet bands via 94Zr(11B,3n)102Rh and 119Sn(19F,4n)134Pr reactions, respectively. Two nearly degenerate bands built on the πg9/2 ⊗ vh11/2 configuration have been identified in 102Rh and on the πg11/2 ⊗ vh11/2 configuration for 134Pr. Lifetimes of excited nuclear states were measured using Dopplershift attenuation method and recoil distance Doppler-shift method. The deexciting gamma rays were registered by the Indian National Gamma Array for 102Rh and using the EUROBALL IV detector array with an inner Bismuth Germanate (BGO) ball for 134Pr, respectively. Polarization and angular correlation measurements have been performed to establish the spin and parity assignments for these bands. The derived reduced transition probabilities are compared to the predicitons of the two quasiparticles + triaxial rotor and interacting boson fermion-fermion models

Lifetime measurements in mass regions A=100 and A=130 as a test for chirality in nuclear systems

Two odd-odd nuclei from the A ~ 100 and A ~ 130 regions, namely 102Rh and 134Pr have been studied in search for chiral doublet bands via 94Zr(11B,3n)102Rh and 119Sn(19F,4n)134Pr reactions, respectively. Two nearly degenerate bands built on the πg9/2 ⊗ vh11/2 configuration have been identified in 102Rh and on the πg11/2 ⊗ vh11/2 configuration for 134Pr. Lifetimes of excited nuclear states were measured using Dopplershift attenuation method and recoil distance Doppler-shift method. The deexciting gamma rays were registered by the Indian National Gamma Array for 102Rh and using the EUROBALL IV detector array with an inner Bismuth Germanate (BGO) ball for 134Pr, respectively. Polarization and angular correlation measurements have been performed to establish the spin and parity assignments for these bands. The derived reduced transition probabilities are compared to the predicitons of the two quasiparticles + triaxial rotor and interacting boson fermion-fermion models

Symmetries in mirror nuclei 31S and 31P

Excited states in mirror nuclei 31S and 31P were populated in the 1n and 1p exit channels, respectively, of the reaction 20Ne + 12C. The beam of 20Ne, with an energy of 33 MeV, was delivered for the first time by the Piave-Alpi accelerator of the Laboratori Nazionali di Legnaro. Angular correlations of coincident pairs and Doppler-shift attenuation lifetime measurements in 31S and 31P were performed using the multidetector array GASP in conjunction with the EUCLIDES charged particle detector. A comparison of the determined B(E1) strengths of the analog mirror 7/2− → 5/2+ transitions indicates the presence of a violation of isospin symmetry.peerReviewe

Transition probabilities in 31P and 31S: A test for isospin symmetry

none31siExcited 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.openTonev D.; de Angelis G.; Deloncle I.; Goutev N.; De Gregorio G.; Pavlov P.; Pantaleev I.L.; Iliev S.; Yavahchova M.S.; Bizzeti P.G.; Demerdjiev A.; Dimitrov D.T.; Farnea E.; Gadea A.; Geleva E.; He C.Y.; Laftchiev H.; Lenzi S.M.; Lunardi S.; Marginean N.; Menegazzo R.; Napoli D.R.; Nowacki F.; Orlandi R.; Penttila H.; Recchia F.; Sahin E.; Singh R.P.; Stoyanova M.; Ur C.A.; Wirth H.-F.Tonev, D.; de Angelis, G.; Deloncle, I.; Goutev, N.; De Gregorio, G.; Pavlov, P.; Pantaleev, I. L.; Iliev, S.; Yavahchova, M. S.; Bizzeti, P. G.; Demerdjiev, A.; Dimitrov, D. T.; Farnea, E.; Gadea, A.; Geleva, E.; He, C. Y.; Laftchiev, H.; Lenzi, S. M.; Lunardi, S.; Marginean, N.; Menegazzo, R.; Napoli, D. R.; Nowacki, F.; Orlandi, R.; Penttila, H.; Recchia, F.; Sahin, E.; Singh, R. P.; Stoyanova, M.; Ur, C. A.; Wirth, H. -F

Transition probabilities in 31P and 31S : A test for isospin symmetry

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 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.peerReviewe