The lifetimes of low-lying excited states below the <math altimg='si1.svg'><msup><mrow><mn>8</mn></mrow><mrow><mo linebreak='badbreak' linebreakstyle='after'>+</mo></mrow></msup></math> seniority isomer were directly measured using fast timing detectors in the neutron-deficient isotopes 98,100Cd. This experiment was conducted with the DEcay SPECtroscopy (DESPEC) setup at GSI, where the ions of interest were produced via a fragmentation reaction and identified using the FRagment Separator (FRS) before being implanted in the AIDA active stopper system, and the <italic>&#947;</italic> rays emitted during the de-excitation of isomeric states were detected by the LaBr <inf>3</inf> FATIMA Array. The newly deduced values for the reduced transition probabilities were compared with shell-model calculations using different interactions and effective charges. The results indicate that, while 98Cd aligns well with a seniority scheme description, in 100Cd the transition strengths among low-lying states are not fully reproduced, and the nature of these states remains an open problem within the present theoretical description. Ultimately, a key element in the description of this region, crucial for nuclear physics and astrophysics, appears to be the proton-neutron term of the nuclear effective interaction.

China

Italy

G. Zhang

M. Polettini

D. Mengoni

G. Benzoni

Z. Huang

Germany

M. Górska

A. Blazhev

Spain

L.M. Fraile

A. Gargano

G. De Gregorio

France

F. Nowacki

G. Aggez

U. Ahmed

Sweden

O. Aktas

Saudi Arabia

M. Al-Aqeel

United Kingdom

B. Alayed

H.M. Albers

A. Algora

S. Alhomaidhi

F. Amjad

C. Appleton

T. Arıcı

M. Armstrong

B.Q. Arnés

A. Astier

M. Balogh

A. Banerjee

D. Bazzacco

J. Benito Garcìa

S. Bottoni

P. Boutachkov

A. Bracco

A. Bruce

D. Brugnara

C. Bruno

F. Camera

B. Cederwall

M. Cicerchia

M.M.R. Chishti

A. Corsi

M.L. Cortes

D. Cox

F.C.L. Crespi

B. Das

T. Davidson

G. de Angelis

T. Dickel

M. Doncel

A. Ertoprak

A. Esmaylzadeh

L. Gaffney

F. Galtarossa

E.R. Gamba

J. Garbe

D. Genna

J. Gerl

A. Goasduff

A. Gottardo

A. Gozzelino

Finland

T. Grahn

J. Ha

E. Haettner

O. Hall

L. Harkness-Brennan

H. Heggen

C. Hornung

Y. Hrabar

S.P. Hu

N. Hubbard

K.E. Ide

A. Illana

S. Jazrawi

P.R. John

J. Jolie

C. Jones

D. Joss

D. Judson

V. Karayonchev

E. Kazantseva

R. Kern

Hungary

G.G. Kiss

L. Knafla

R. Knöbel

I. Kojouharov

Poland

A. Korgul

W. Korten

P. Koseoglou

D. Kostyleva

T. Kurtukian-Nieto

Slovenia

G. Kosir

N. Kurz

I. Kuti

M. Labiche

S.M. Lenzi

S. Leoni

G.S. Li

Z. Liu

M. Llanos Expósito

R. Lozeva

J.B. Lu

Approaching 100Sn: Structural evolution in 98,100Cd via lifetime measurements

The β-decay of the even-even nucleus $^{70}$Kr with <math><mi>Z</mi><mo>=</mo><mi>N</mi><mo>+</mo><mn>2</mn></math>, has been investigated at the Radioactive Ion Beam Factory (RIBF) of the RIKEN Nishina Center using the BigRIPS fragment separator, the ZeroDegree Spectrometer, the WAS3ABI implantation station and the EURICA HPGe cluster array. Fifteen γ-rays associated with the β-decay of $^{70}$Kr into $^{70}$Br have been identified for the first time, defining ten populated states below <math><msub><mrow><mi>E</mi></mrow><mrow><mi>exc</mi></mrow></msub><mo>=</mo><mn>3300</mn></math> keV. The half-life of $^{70}$Kr was derived with increased precision and found to be <math><msub><mrow><mi>t</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>=</mo><mn>45.19</mn><mo>±</mo><mn>0.14</mn></math> ms. The β-delayed proton emission probability has also been determined as <math><msub><mrow><mi>ε</mi></mrow><mrow><mi>p</mi></mrow></msub><mo>=</mo><mn>0.545</mn><mo>(</mo><mn>23</mn><mo>)</mo><mtext>%</mtext></math>. An increase in the β-strength to the yrast 1$^{+}$ state in comparison with the heaviest <math><mi>Z</mi><mo>=</mo><mi>N</mi><mo>+</mo><mn>2</mn></math> system studied so far ($^{62}$Ge decay) is observed that may indicate increased np correlations in the <math><mi>T</mi><mo>=</mo><mn>0</mn></math> channel. The β-decay strength deduced from the results is interpreted in terms of the proton-neutron quasiparticle random-phase approximation (pnQRPA) and also with a schematic model that includes isoscalar and isovector pairing in addition to quadrupole deformation. The application of this last model indicates an approximate realization of pseudo-SU(4) symmetry in this system.

A. Vitéz-Sveiczer

A.I. Morales

B. Rubio

Japan

P. Sarriguren

P. Van Isacker

F. Recchia

S. Nishimura

J. Agramunt

V. Guadilla

A. Montaner-Pizá

S.E.A. Orrigo

A. Horváth

D. Napoli

S. Lenzi

A. Boso

Vietnam

V.H. Phong

J. Wu

Romania

P.A. Söderström

T. Sumikama

H. Suzuki

H. Takeda

D.S. Ahn

H. Baba

P. Doornebal

N. Fukuda

N. Inabe

T. Isobe

T. Kubo

S. Kubono

H. Sakurai

Y. Shimizu

C. Sidong

B. Blank

P. Ascher

M. Gerbaux

T. Goigoux

J. Giovinazzo

S. Grévy

T. Kurtukián Nieto

C. Magron

W. Gelletly

Zs. Dombrádi

Y. Fujita

M. Tanaka

Chile

P. Aguilera

F. Molina

J. Eberth

F. Diel

D. Lubos

C. Borcea

Türkiye

E. Ganioglu

D. Nishimura

H. Oikawa

Y. Takei

S. Yagi

G. de France

P. Davies

Hong Kong

J. Liu

J. Lee

T. Lokotko

H. Shaffner

A. Petrovici

The -decay of Kr into Br: Restoration of the pseudo-SU(4) symmetry

Theoretical models of β-delayed neutron emission are used as crucial inputs in r-process calculations. Benchmarking the predictions of these models is a challenge due to a lack of currently available experimental data. In this work the β-delayed neutron emission probabilities of 33 nuclides in the important mass regions south and south-west of $^{132}$Sn are presented, 16 for the first time. The measurements were performed at RIKEN using the Advanced Implantation Detector Array (AIDA) and the BRIKEN neutron detector array. The <math><msub><mrow><mi>P</mi></mrow><mrow><mn>1n</mn></mrow></msub></math> values presented constrain the predictions of theoretical models in the region, affecting the final abundance distribution of the second r-process peak at <math><mi>A</mi><mo>≈</mo><mn>130</mn></math>.