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1. Relevance of the Nuclear Structure of the Stable Ge Isotopes to the Neutrino-less Double-Beta Decay of ⁷⁶ Ge

   https://doi.org/10.1051/epjconf/202023204011  

   Yates, S. W.; Peters, E. E.; Crider, B. P.; Mukhopadhyay, S.; Ramirez, A. P.; Mitchell, A.J.; Pavetich, S.; Koll, D. (January 2020, EPJ Web of Conferences)

   Gamma-ray detection following the inelastic neutron scattering reaction on isotopically enriched material was used to study the nuclear structure of 74 Ge. From these measurements, low-lying, low-spin excited states were characterized, new states and their decays were identified, level lifetimes were measured with the Doppler-shift attenuation method (DSAM), multipole mixing ratios were established, and transition probabilities were determined. New structural features in 74 Ge were identified, and the reanalysis of older 76 Ge data led to the placement of the 2 + member of the intruder band. In addition, a number of previously placed states in 74 Ge were shown not to exist. A procedure for future work, which will lead to meaningful data for constraining calculations of the neutrinoless double-beta decay matrix element, is suggested. 

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2. Unveiling New States in ⁹⁸ Zr: Insights from β -decay and γ-γ Angular-Correlation Studies

   https://doi.org/10.1051/epjconf/202532901012  

   Mashtakov, K R; Garrett, P E; Olaizola, B; Andreoiu, C; Ball, G C; Bender, P; Bildstein, V; Chester, A; Cross, D S; Dawkins, H; et al (January 2025, EPJ Web of Conferences)

   Jentschel, M (Ed.)

   The nuclear structure of the⁹⁸Zr nucleus was studied through theβ⁻decay of⁹⁸Y_g.s.at the TRIUMF-ISAC facility. The use of the 8π γ-ray spectrometer with its ancillary detectors SCEPTAR and PACES enabled γ-γ and γ-e⁻coincidence measurements as well as γ-γ angular correlations. The level spin assignments and transition mixing ratios obtained in this study were in good agreement with previous results. Furthermore, 12 previously unknown states in the low-energy region of⁹⁸Zr were identified, including the 0⁺₅and 0⁺₆levels at 2418 and 2749 keV, respectively. The 2⁺and I=1 natures for multiple newly observed and previously known (but not firmly assigned) states have been established. Additionally, the previously assumed pureE2 character of the 2⁺₂→ 2⁺₁367.8-keV transition was confirmed. 

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3. Maturation of Silicate Weathering Pathways Revealed by Germanium‐Silicon Ratios

   https://doi.org/10.1029/2025GL118410  

   Guertin, Andrew; Cunningham, Charlie; Bouchez, Julien; Gelin, Marine; Chorover, Jon; Derry, Louis A; Druhan, Jennifer L (October 2025, Geophysical Research Letters)

   Abstract We document the evolution of fresh basalt subject to roughly a decade of chemical weathering through systematic temporal shifts in aqueous germanium‐silicon ratios (Ge/Si) in a unique set of meso‐scale artificial hillslopes. Elevated dissolved Ge/Si signatures relative to bedrock in this young system are associated with formation of high‐Si amorphous phase(s) that preferentially exclude Ge. Over several years, dissolved Ge/Si ratios decrease, approaching those of natural watersheds, consistent with a shift toward formation of Ge‐enriched secondary phases. Our study points to the critical control of secondary phase speciation on Ge/Si partitioning, while in contrast, stable silicon isotope ratios (δ³⁰Si) in the same samples show fractionation comparable to natural systems. Paired consideration of Ge/Si and δ³⁰Si tracers may thus offer a previously unrecognized means of interrogating the progression of secondary phase speciation in young landscapes, for example, following deglaciation, volcanism, and landslides, and in engineering applications such as enhanced weathering. 

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4. Large-scale Mapping Observations of DCN and DCO ⁺ toward Orion KL

   https://doi.org/10.3847/1538-4357/ad1e5a  

   Taniguchi, Kotomi; Rayalacheruvu, Prathap; Yonetsu, Teppei; Takekoshi, Tatsuya; Hatsukade, Bunyo; Kohno, Kotaro; Oshima, Tai; Tamura, Yoichi; Yoshimura, Yuki; Gómez-Rivera, Víctor; et al (February 2024, The Astrophysical Journal)

   Abstract We present emission maps ( $1.\prime 5\times 1.\prime 5$scale, corresponding to 0.18 pc) of the DCN (J= 2 − 1) and DCO⁺(J= 2 − 1) lines in the 2 mm band toward the Orion KL region obtained with the 2 mm receiver system named B4R installed on the Large Millimeter Telescope. The DCN emission shows a peak at the Orion KL hot core position, whereas no DCO⁺emission has been detected there. The DCO⁺emission shows enhancement at the west side of the hot core, which is well shielded from the UV radiation from OB massive stars in the Trapezium cluster. We have derived the abundance ratio of DCN/DCO⁺at three representative positions where both species have been detected. The gas components withV_LSR≈ 7.5–8.7 km s⁻¹are associated with low abundance ratios of ∼4–6, whereas much higher abundance ratios (∼22–30) are derived for the gas components withV_LSR≈ 9.2–11.6 km s⁻¹. We have compared the observed abundance ratio to our chemical models and found that the observed differences in the DCN/DCO⁺abundance ratios are explained by different densities. 

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5. Level lifetimes in ⁵² Cr from DSAM following inelastic neutron scattering: Implications for shape coexistence and E 0 strengths

   https://doi.org/10.1051/epjconf/202532901011  

   Dowie, JTH; Kibédi, T; Peters, EE; Yates, SW (January 2025, EPJ Web of Conferences)

   Jentschel, M (Ed.)

   Nuclear shape coexistence is a widespread but not yet well understood phenomenon. Electric monopole (E0) transitions are a particularly sensitive probe of shape coexistence. The firstE0measurements on the Cr isotopes were performed at The Australian National University, but were hampered by missing and imprecise data of the key spectroscopic quantities such as level lifetimes. To address these needs, the low-lying states in⁵²Cr were investigated at the University of Kentucky Accelerator Laboratory with inelastic neutron scattering. γ-ray angular distribution and excitation function measurements were performed to determine level lifetimes, spins and parities, transition mixing ratios, and γ-ray branching ratios. We present new level lifetimes for three states in⁵²Cr along with the implications for E0 transition strengths and shape coexistence in⁵²Cr. 

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