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1. Absolute frequency measurement of the $2p^2{(}^{3}P)3s{}^{2}P–2p^2{(}^{3}P)3p{}^2{D}^o$ transitions in neutral ${}^{14}\mathrm{N}$

   https://doi.org/10.1103/PhysRevA.108.042815  

   Ahrendsen, K J; Maruko, C; Albert-Aranovich, K R; Berfield-Brewer, Q; Esseln, A; Guo, L; Ishimwe, A E; Kuzniar, Y; McKenna, A E; Villarreal, K_J Soto; et al (October 2023, Physical Review A)

   We report absolute frequency measurements on the three excited-state transitions connecting the 2p2 (3P)3s 2P1/2,3/2 and 2p2 (3P)3p 2D◦ 3/2,5/2 states in neutral 14N using saturated absorption spectroscopy in a glass cell filled with a mixture of nitrogen and argon gas and driven with a radio-frequency electric field. The absolute transition frequencies are found to be 319 288 834(150), 319 085 445(125), and 316 795 808(140) MHz for the 1/2–3/2, 3/2–5/2, and 3/2–3/2 transitions, respectively. This work represents the saturated absorption measurements for these transitions. These results are approximately a factor of 5 improvement over previous results, despite being conservative estimates. We found that the overlapping hyperfine structure prevented fitting individual spectral features, presenting difficulties for possible future tests of quantum electrodynamics in seven-electron systems. A better understanding of the amplitude behavior of a merged hyperfine structure will allow the extrapolation of the center of gravity frequencies for these transitions to sub-MHz precision using our collected data. 

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2. Measurement of the Static Stark Shift of the $7s{{}^{2}S}_{1/2}$ Level in Atomic Cesium

   https://doi.org/10.1103/PhysRevLett.132.233201  

   Quirk, Jonah A; Jacobsen, Aidan; Damitz, Amy; Tanner, Carol E; Elliott, D S (June 2024, Physical Review Letters)

   We report a new precision measurement of the dc Stark shift of the $$6s\hspace{1mm} ^2S_{1/2} \rightarrow 7s\hspace{1mm}^2S_{1/2}$$ transition in atomic cesium-133. Our result is 0.72246 (29) $$\textrm{Hz}(\textrm{V}/\textrm{cm})^{-2}$$. This result differs from a previous measurement of the Stark shift by $$\sim$$0.5\%, or 4.7$$\sigma$$. We use this value to recalculate the magnitude of the reduced dipole matrix elements $$\langle7s ||r||7p_{j}\rangle$$, as well as the vector transition polarizability for the $$6s \rightarrow 7s$$ transition, $$\tilde{\beta} = 27.043 \: (36) \ a_0^3$$. This determination helps resolve a critical discrepancy between two techniques for determining the vector polarizability. 

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3. 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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4. Measurement of the ratio of the scalar polarizability to the vector polarizability for the $6s{}^{2}S_{1/2}\to 7s{}^{2}S_{1/2}$ transition in cesium

   https://doi.org/10.1103/PhysRevA.109.062809  

   Quirk, Jonah A; Tanner, Carol E; Elliott, D S (June 2024, Physical Review A)

   We report measurements of the ratio of the scalar polarizability $$\alpha$$ to the vector polarizability $$\beta$$ for the $$6s ^2S_{1/2} \rightarrow 7s ^2S_{1/2}$$ transition in atomic cesium. These measurements are motivated by a discrepancy between the values of the vector transition polarizability as determined using two separate methods. In the present measurement, we use a two-pathway, coherent-control technique in which we observe the interference between a two-photon interaction driven by infrared light at 1079 nm and a linear Stark-induced interaction driven by the mutually-coherent second harmonic of this infrared beam at 540 nm. The result of our measurements is $$\alpha/\beta = -9.902 \: (9)$$, in good agreement with the previous determination of this ratio. This measurement, critical to the study of atomic parity violation in cesium, does not reduce the discrepancy between the two methods for the determination of the vector polarizability $$\beta$$ for this transition. 

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5. First measurement of $D_{s1}\left(1^{+}\right)(2536{)}^{+}$ and $D_{s2}^{*}\left(2^{+}\right)(2573{)}^{+}$ production in proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$ at the LHC

   https://doi.org/10.1103/PhysRevD.111.112005  

   Acharya, S; Agarwal, A; Aglieri_Rinella, G; Aglietta, L; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahn, S U; Ahuja, I; et al (June 2025, Physical Review D)

   The production yields of the orbitally excited charm-strange mesons ${\mathrm{D}}_{\mathrm{s}1}\left(1^{+}\right)(2536{)}^{+}$and ${\mathrm{D}}_{\mathrm{s}2}^{*}\left(2^{+}\right)(2573{)}^{+}$were measured for the first time in proton-proton (pp) collisions at a center-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$with the ALICE experiment at the LHC. The ${\mathrm{D}}_{\mathrm{s}1}^{+}$and ${\mathrm{D}}_{\mathrm{s}2}^{*+}$mesons were measured at midrapidity ( $\left|y\right|<0.5$) in minimum-bias and high-multiplicity pp collisions in the transverse-momentum interval $2<p_{\mathrm{T}}<24\mathrm{GeV}/c$. Their production yields relative to the ${\mathrm{D}}_{\mathrm{s}}^{+}$ground-state yield were found to be compatible between minimum-bias and high-multiplicity collisions, as well as with previous measurements in ${\mathrm{e}}^{\pm }\mathrm{p}$and ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$collisions. The measured ${\mathrm{D}}_{\mathrm{s}1}^{+}/{\mathrm{D}}_{\mathrm{s}}^{+}$and ${\mathrm{D}}_{\mathrm{s}2}^{*+}/{\mathrm{D}}_{\mathrm{s}}^{+}$yield ratios are described by statistical hadronization models and can be used to tune the parameters governing the production of excited charm-strange hadrons in Monte Carlo generators, such as 8. 

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