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1. Precision measurement of lifetime and branching ratios of the $4f^{13}5d6s^1{[5/2]}_{5/2}$ state in ${\mathrm{Yb}}^{+}$ ions

   https://doi.org/10.1103/mwwc-kng1  

   Duraisamy_Suganthi, Midhuna; So, Visal; Menon, Abhishek; Tomaras, George; Zhuravel, Roman; Pagano, Guido (December 2025, Physical Review Research)

   We report spectroscopic and time-resolved experimental observations to characterize the $\left[\mathrm{Xe}\right]4f^{13}\left({}^{2}F_{5/2}^o\right)5d6s\left({}^{1}D\right){}^1{[5/2]}_{5/2}^o$state in ${}^{172}\mathrm{Yb}^{+}$ ions. We access this state from the metastable $4f^{14}5d\left({}^{2}D_{3/2,5/2}\right)$manifold and observe an unexpectedly long lifetime of $\tau =37.9\left(9\right)\mu \mathrm{s}$ that allows visible Rabi oscillations and resolved-sideband spectroscopy. Using a combination of coherent population dynamics, high-fidelity detection and heralded state preparation, and optical pumping methods, we measure the branching ratios to the ${}^{2}D_{3/2}, {}^{2}D_{5/2}$, and ${}^{2}S_{1/2}$states to be $0.359\left(2\right)$, 0.639(2), and $0.0023\left(16\right)$, respectively. The branching ratio to the $4f^{13}6s^2\left({{}^{2}F}_{7/2}\right)$is compatible with zero within our experimental resolution. We also report measurements of Landé $g$-factor of the ${}^1{[5/2]}_{5/2}^o$state. Further, the branching ratio of the ${}^{2}D_{5/2}$to ${}^{2}S_{1/2}$decay in ${}^{172}\mathrm{Yb}^{+}$ was measured to be 0.188(3), improving its relative uncertainty by an order of magnitude. Our measurements provide experimental benchmarks for better understanding the atomic structure of ${\mathrm{Yb}}^{+}$ ions, which still lacks accurate numerical descriptions, and the use of high-lying excited states for partial detection and qubit manipulation in the architecture. 

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2. Natural-linewidth measurements of the $3C$ and $3D$ soft-x-ray transitions in Ni xix

   https://doi.org/10.1103/PhysRevA.109.063108  

   Shah, Chintan; Kühn, Steffen; Bernitt, Sonja; Steinbrügge, René; Togawa, Moto; Berger, Lukas; Buck, Jens; Hoesch, Moritz; Seltmann, Jörn; Kozlov, Mikhail G; et al (June 2024, Physical Review A)

   We used the monochromatic soft-x-ray beamline P04 at the synchrotron-radiation facility PETRA III to resonantly excite the strongest $2p\text{−}3d$transitions in neonlike $\mathrm{Ni}$ions, ${\left[2p^6\right]}_{J=0}\to {\left[{\left(2p^5\right)}_{1/2}3d_{3/2}\right]}_{J=1}$and ${\left[2p^6\right]}_{J=0}\to {\left[{\left(2p^5\right)}_{3/2}3d_{5/2}\right]}_{J=1}$, respectively dubbed $3C$and $3D$, achieving a resolving power of 15 000 and signal-to-background ratio of 30. We obtain their natural linewidths, with an accuracy of better than 10%, as well as the oscillator-strength ratio $f\left(3C\right)/f\left(3D\right)=2.51\left(11\right)$from analysis of the resonant fluorescence spectra. These results agree with those of previous experiments, earlier predictions, and our own advanced calculations. Published by the American Physical Society2024 

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3. Measurement of Electron Antineutrino Oscillation Amplitude and Frequency via Neutron Capture on Hydrogen at Daya Bay

   https://doi.org/10.1103/PhysRevLett.133.151801  

   An, F P; Bai, W D; Balantekin, A B; Bishai, M; Blyth, S; Cao, G F; Cao, J; Chang, J F; Chang, Y; Chen, H S; et al (October 2024, Physical Review Letters)

   This Letter reports the first measurement of the oscillation amplitude and frequency of reactor antineutrinos at Daya Bay via neutron capture on hydrogen using 1958 days of data. With over 3.6 million signal candidates, an optimized candidate selection, improved treatment of backgrounds and efficiencies, refined energy calibration, and an energy response model for the capture-on-hydrogen sensitive region, the relative ${\overline{\nu }}_e$rates and energy spectra variation among the near and far detectors gives ${\sin }^{2}2{\theta }_{13}=0.0759_{-0.0049}^{+0.0050}$and $\mathrm{\Delta }{m}_{32}^2=\left(2.72_{-0.15}^{+0.14}\right)\times {10}^{-3}{\mathrm{eV}}^2$assuming the normal neutrino mass ordering, and $\mathrm{\Delta }{m}_{32}^2=(-2.83_{-0.14}^{+0.15})\times {10}^{-3}{\mathrm{eV}}^2$for the inverted neutrino mass ordering. This estimate of ${\sin }^{2}2{\theta }_{13}$is consistent with and essentially independent from the one obtained using the capture-on-gadolinium sample at Daya Bay. The combination of these two results yields ${\sin }^{2}2{\theta }_{13}=0.0833\pm 0.0022$, which represents an 8% relative improvement in precision regarding the Daya Bay full 3158-day capture-on-gadolinium result. Published by the American Physical Society2024 

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4. Magneto-optical trap of titanium atoms

   https://doi.org/10.1103/PhysRevResearch.7.023025  

   Eustice, Scott; Schrott, Jackson; Stöltzel, Anke; Wolf, Julian; Novoa, Diego; Cassella, Kayleigh; Stamper-Kurn, Dan M (April 2025, Physical Review Research)

   We realize a magneto-optical trap (MOT) of titanium (Ti) atoms, performing laser cooling on the 498 nm transition between the long-lived $3{\mathrm{d}}^3\left({}^4\mathrm{F}\right)4\mathrm{s}{\mathrm{a}}^5{\mathrm{F}}_5$metastable state and the $3{\mathrm{d}}^3\left({}^4\mathrm{F}\right)4\mathrm{p}{\mathrm{y}}^5{\mathrm{G}}_6^{\mathrm{o}}$excited state. Without the addition of any repumping light, we observe MOTs of the three stable, $I=0$bosonic isotopes, ${}^{46}\mathrm{Ti}, {}^{48}\mathrm{Ti}$, and ${}^{50}\mathrm{Ti}$. Up to $8.30\left(26\right)\times {10}^5{}^{48}\mathrm{Ti}$atoms are trapped at a maximum density of $1.3\left(4\right)\times {10}^{11}{\mathrm{cm}}^{-3}$and at a temperature of $90\left(15\right)\mu \mathrm{K}$. By measuring the decay of the MOT, we constrain the leakage branching ratio of the cooling transition ( $\le 2.5\times {10}^{-6}$) and the two-body loss coefficient ( $\le 2\times {10}^{-10}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$). Our approach to laser cooling Ti can be applied to other transition metals, enabling a significant expansion of the elements that can be laser cooled. Published by the American Physical Society2025 

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5. Electron-impact excitation of the 5$$\varvec{^2\textbf{S}_{1/2} \rightarrow 5^2\textbf{P}_{1/2}}$$ and 5$$\varvec{^2\textbf{P}_{3/2}}$$ transitions in rubidium by 40 eV electrons: theory and experiment

   https://doi.org/10.1140/epjd/s10053-022-00413-7  

   Hamilton, K. R.; Zatsarinny, O.; Bartschat, K.; Predojević, B.; Šević, D.; Marinković, B. P.; Brunger, M. J. (May 2022, The European Physical Journal D)

   AbstractWe report on a series of detailed Breit-Pauli and Dirac B-spline R-matrix (DBSR) differential cross section (DCS) calculations for excitation of the$$5\,^2\textrm{S}_{1/2} \rightarrow 5\,^2\textrm{P}_{1/2}$$ $5{}^2{\text{S}}_{1/2}\to 5{}^2{\text{P}}_{1/2}$and$$5\,^2\textrm{S}_{1/2}\rightarrow 5\,^2\textrm{P}_{3/2}$$ $5{}^2{\text{S}}_{1/2}\to 5{}^2{\text{P}}_{3/2}$states in rubidium by 40 eV incident electrons. The early BP computations shown here were carried out with both 5 states and 12 states, while the DBSR models coupled 150 and 325 states, respectively. We also report corresponding results from a limited set of DCS measurements on the unresolved$$5\,^2\textrm{P}_{1/2,3/2}$$ $5{}^2{\text{P}}_{1/2,3/2}$states, with the experimental data being restricted to the scattered electron angular range 2–$$10^\circ $$ ${10}^{\circ }$. Typically, good agreement is found between our calculated and measured DCS for excitation of the unresolved$$5\,^2\textrm{P}_{1/2,3/2}$$ $5{}^2{\text{P}}_{1/2,3/2}$states, with best accord being found between the DBSR predictions and the measured data. The present theoretical and experimental results are also compared with predictions from earlier 40 eV calculations using the nonrelativistic Distorted-Wave Born Approximation and a Relativistic Distorted-Wave model. Graphic abstract 

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