Half-life of the yrast 2

The half-life of the yrast I π = 2+ state in the neutron-rich nucleus 188W has been measured using fast-timing techniques with the HPGe and LaBr3:Ce array at the National Institute of Physics and Nuclear Engineering, Bucharest. The resulting value of t1/2 = 0.87(12) ns is equivalent to a reduced transition probability of B(E2; 2+ 1 → 0+ 1 ) = 85(12) W.u. for this transition. The B(E2; 2+ 1 → 0+ 1 ) is compared to neighboring tungsten isotopes and nuclei in the Hf, Os, and Pt isotopic chains. Woods-Saxon potential energy surface (PES) calculations have been performed for nuclei in the tungsten isotopic chain and predict prolate deformed minima with rapidly increasing γ softness for 184–192W and an oblate minimum for 194W

Raising the Bar: Improving Methodological Rigour in Cognitive Alcohol Research

Background and Aims: A range of experimental paradigms claim to measure the cognitive processes underpinning alcohol use, suggesting that heightened attentional bias, greater approach tendencies and reduced cue-specific inhibitory control are important drivers of consumption. This paper identifies methodological shortcomings within this broad domain of research and exemplifies them in studies focused specifically on alcohol-related attentional bias. Argument and analysis: We highlight five main methodological issues: (i) the use of inappropriately matched control stimuli; (ii) opacity of stimulus selection and validation procedures; (iii) a credence in noisy measures; (iv) a reliance on unreliable tasks; and (v) variability in design and analysis. This is evidenced through a review of alcohol-related attentional bias (64 empirical articles, 68 tasks), which reveals the following: only 53% of tasks use appropriately matched control stimuli; as few as 38% report their stimulus selection and 19% their validation procedures; less than 28% used indices capable of disambiguating attentional processes; 22% assess reliability; and under 2% of studies were pre-registered. Conclusions: Well-matched and validated experimental stimuli, the development of reliable cognitive tasks and explicit assessment of their psychometric properties, and careful consideration of behavioural indices and their analysis will improve the methodological rigour of cognitive alcohol research. Open science principles can facilitate replication and reproducibility in alcohol research

Probing the Low-Energy Structure of A = 109 Ru – Pd

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New insights into triaxiality and shape coexistence from odd-mass 109^{109}Rh

International audienceRapid shape evolutions near A=100 are now the focus of much attention in nuclear science. Much of the recent work has been centered on isotopes with Z≤40, where the shapes are observed to transition between near-spherical to highly deformed with only a single pair of neutrons added. At higher Z, the shape transitions become more gradual as triaxiality sets in, yet the coexistence of varying shapes continues to play an important role in the low-energy nuclear structure, particularly in the odd-Z isotopes. This work aims to characterize competing shapes in the triaxial region between Zr and Sn isotopes using ultrafast timing techniques to measure lifetimes of excited states in the neutron-rich nucleus Rh109. The measurements confirm the persistence at higher Z of similarly large deformations observed near Z=40. Moreover, we show that new self-consistent mean-field calculations, with proper treatment of the odd nucleon, are able to reproduce the coexisting triaxial and highly deformed configurations revealing, for the first time, the important contribution of the unpaired nucleon to these different shapes based on the blocking of specific single-particle orbitals

New lifetime measurements in 109Pd and the onset of deformation at N = 60

International audienceSeveral new subnanosecond lifetimes were measured in 109Pd using the fast-timing βγ γ (t ) method. Fissionfragments of the A = 109 mass chain were produced by bombarding natural uranium with 30 MeV protons atthe Jyv¨askyl¨a Ion Guide Isotope Separator On-Line (IGISOL) facility. Lifetimes were obtained for excited statesin 109Pd populated following β decay of 109Rh. The new lifetimes provide some insight into the evolution ofnuclear structure in thismass region. In particular, the distinct structure of the two low-lying 7/2+ states occurringsystematically across the Pd isotopic chain is supported by the new lifetime measurements. The available nucleardata indicate a sudden increase in deformation at N = 60 which is related to the strong p-n interaction betweenπg9/2 and νg7/2 valence nucleons expected in this region