β-delayed γ-proton decay in 56Zn: analysis of the charged-particle spectrum

A study of the beta decay of the proton-rich T-z = 2 nucleus Zn-56 has been reported in a recent publication. A rare and exotic decay mode, beta-delayed gamma-proton decay, has been observed there for the first time in the fp shell. Here, we expand on some of the details of the data analysis, focussing on the charged particle spectrum

Un estudio de estereotipos de género en alumnado de secundaria en el marco de Proyecto Meitner

[ES] Este artículo presenta Proyecto Meitner como una acción de divulgación científica diseñada para abordar, entre otras cuestiones, la problemática de las mujeres en Física a través de las artes escénicas. Se presenta, también, un estudio de sesgos y estereotipos de género en ciencia realizado al alumnado de los centros de secundaria de la Comunitat Valenciana que participaron en dos sesiones matinales de la obra de teatro Proyecto Meitner. Se utilizó un cuestionario que rellenaron 134 estudiantes estudiantes antes de las funciones. Las respuestas revelan una perpetuación de los estereotipos asociados al personal científico, definido principalmente como muy inteligente, culto, occidental, hombre, mayor, solitario y con bata. Además, el alumnado encuestado cree que los chicos tienen mejores aptitudes que las chicas para las carreras universitarias aun cuando las capacidades en ambos casos son las mismas

β-decay spectroscopy of neutron-deficient nuclei

A systematic study of the β-decay of neutron-deficient nuclei has been carried out and has provided spectroscopic information of importance for both nuclear structure and nuclear astrophysics. Following an overview of the most relevant achievements, we focus on the latest results on the β decay of 60Ge and 62Ge. We also summarise our results on the mass excesses in comparison with systematics and a recent measurement. Finally, we present updated half-life trends for Tz = -1/2, -1 and -2 neutron-deficient nuclides

Gamow–Teller Beta Decay and Pseudo-SU(4) Symmetry

International audienceWe report on recent experimental results on β decay into self-conjugate (N=Z) nuclei with mass number 58≤A≤70. Super-allowed β decays from the Jπ=0+ ground state of a Z=N+2 parent nucleus are to the isobaric analogue state through so-called Fermi transitions and to Jπ=1+ states by way of Gamow–Teller (GT) transitions. The operator of the latter decay is a generator of Wigner’s SU(4) algebra and as a consequence GT transitions obey selection rules associated with this symmetry. Since SU(4) is progressively broken with increasing A, mainly as a consequence of the spin–orbit interaction, this symmetry is not relevant for the nuclei considered here. We argue, however, that the pseudo-spin–orbit splitting can be small in nuclei with 58≤A≤70, in which case nuclear states exhibit an approximate pseudo-SU(4) symmetry. To test this conjecture, GT decay strength is calculated with use of a schematic Hamiltonian with pseudo-SU(4) symmetry. Some generic features of the GT β decay due to pseudo-SU(4) symmetry are pointed out. The experimentally observed GT strength indicates a restoration of pseudo-SU(4) symmetry for A=70.</jats:p

Gamow–Teller Beta Decay and Pseudo-SU(4) Symmetry

We report on recent experimental results on β decay into self-conjugate (N=Z) nuclei with mass number 58≤A≤70. Super-allowed β decays from the Jπ=0+ ground state of a Z=N+2 parent nucleus are to the isobaric analogue state through so-called Fermi transitions and to Jπ=1+ states by way of Gamow–Teller (GT) transitions. The operator of the latter decay is a generator of Wigner’s SU(4) algebra and as a consequence GT transitions obey selection rules associated with this symmetry. Since SU(4) is progressively broken with increasing A, mainly as a consequence of the spin–orbit interaction, this symmetry is not relevant for the nuclei considered here. We argue, however, that the pseudo-spin–orbit splitting can be small in nuclei with 58≤A≤70, in which case nuclear states exhibit an approximate pseudo-SU(4) symmetry. To test this conjecture, GT decay strength is calculated with use of a schematic Hamiltonian with pseudo-SU(4) symmetry. Some generic features of the GT β decay due to pseudo-SU(4) symmetry are pointed out. The experimentally observed GT strength indicates a restoration of pseudo-SU(4) symmetry for A=70

Isomeric Lifetime Measurement in the Neutron-rich 189^{189}Ta

International audienceIsomeric states of the neutron-rich isotope 18973Ta116 were populated via fragmentation of a primary beam of 208Pb ions at 1 GeV/u impinging on a 9Be target at GSI, Darmstadt, Germany. The isotopes of interest were separated, identified and delivered to the DESPEC setup. Two isomers were deduced in 189Ta116 and their lifetimes were measured based on the γ-ray time distributions