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1. Search for axionlike dark matter using liquid-state nuclear magnetic resonance

   https://doi.org/10.1103/39nc-vr9m  

   Walter, Julian; Maliaka, Olympia; Zhang, Yuzhe; Blanchard, John W; Centers, Gary; Dogan, Arian; Engler, Martin; Figueroa, Nataniel L; Kim, Younggeun; Kimball, Derek_F Jackson; et al (September 2025, Physical Review D)

   We search for dark matter in the form of axionlike particles (ALPs) in the mass range $5.576741\mathrm{neV}/{\mathrm{c}}^2-5.577733\mathrm{neV}/{\mathrm{c}}^2$by probing their possible coupling to fermion spins through the ALP field gradient. This is achieved by performing proton nuclear magnetic resonance spectroscopy on a sample of methanol as a technical demonstration of the Cosmic Axion Spin Precession Experiment Gradient (CASPEr-Gradient) Low-Field apparatus. Searching for spin-coupled ALP dark matter in this mass range with associated Compton frequencies in a 240 Hz window centered at 1.348570 MHZ resulted in a sensitivity to the ALP-proton coupling constant of $g_{\mathrm{ap}}\approx 3\times {10}^{-2}{\mathrm{GeV}}^{-1}$. This narrow-bandwidth search serves as a proof-of-principle and a commissioning measurement, validating our methodology and demonstrating the experiment’s capabilities. CASPEr-Gradient Low-Field will probe the mass range from $4.1\mathrm{peV}/{\mathrm{c}}^2$to $17\mathrm{neV}/{\mathrm{c}}^2$with hyperpolarized samples to boost the sensitivity beyond the astronomical limits. 

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2. Probing Gluon Fluctuations in Nuclei with the First Energy-Dependent Measurement of Incoherent $J/\psi$ Photoproduction in Ultraperipheral PbPb Collisions

   https://doi.org/10.1103/w9kp-f8xr  

   Chekhovsky, V; Hayrapetyan, A; Makarenko, V; Tumasyan, A; Adam, W; Andrejkovic, J W; Benato, L; Bergauer, T; Chatterjee, S; Damanakis, K; et al (September 2025, Physical Review Letters)

   Incoherent $J/\psi$photoproduction in heavy ion ultraperipheral collisions (UPCs) provides a sensitive probe of localized, fluctuating gluonic structures within heavy nuclei. This Letter reports the first measurement of the photon-nucleon center-of-mass energy ( $W_{\gamma \mathrm{N}}$) dependence of this process in PbPb UPCs at a nucleon-nucleon center-of-mass energy of 5.02 TeV, using $1.52{\mathrm{nb}}^{-1}$of data recorded by the CMS experiment. The measurement covers a wide $W_{\gamma \mathrm{N}}$range of $\approx 40–400\mathrm{GeV}$, probing gluons carrying a fraction $x$of nucleon momentum down to an unexplored regime of $6.5\times {10}^{-5}$. Compared to baseline predictions neglecting nuclear effects, the measured cross sections exhibit significantly greater suppression at lower $x$. Additionally, the ratio of incoherent to coherent photoproduction is found to be constant across the probed $W_{\gamma \mathrm{N}}$and $x$range, disfavoring the establishment of the black disk limit. This Letter provides critical insights into the $x$-dependent evolution of fluctuating gluonic structures within nuclei and calls for further advancements in theoretical models incorporating nuclear shadowing and gluon saturation. 

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3. Search for high-mass exclusive diphoton production with tagged protons in proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$

   https://doi.org/10.1103/PhysRevD.110.012010  

   Tumasyan, A; Adam, W; Andrejkovic, J W; Bergauer, T; Chatterjee, S; Damanakis, K; Dragicevic, M; Escalante_Del_Valle, A; Hussain, P S; Jeitler, M; et al (July 2024, Physical Review D)

   A search is presented for high-mass exclusive diphoton production via photon-photon fusion in proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$in events where both protons survive the interaction. The analysis utilizes data corresponding to an integrated luminosity of $103{\mathrm{fb}}^{-1}$collected in 2016–2018 with the central CMS detector and the CMS and TOTEM precision proton spectrometer (PPS). Events that have two photons with high transverse momenta ( $p_{\mathrm{T}}^{\gamma }>100\mathrm{GeV}$), back-to-back in azimuth, and with a large diphoton invariant mass ( $m_{\gamma \gamma }>350\mathrm{GeV}$) are selected. To remove the dominant inclusive diphoton backgrounds, the kinematic properties of the protons detected in PPS are required to match those of the central diphoton system. Only events having opposite-side forward protons detected with a fractional momentum loss between 0.035 and 0.15 (0.18) for the detectors on the negative (positive) side of CMS are considered. One exclusive diphoton candidate is observed for an expected background of 1.1 events. Limits at 95% confidence level are derived for the four-photon anomalous coupling parameters $\left|{\zeta }_1\right|<0.073{\mathrm{TeV}}^{-4}$and $\left|{\zeta }_2\right|<0.15{\mathrm{TeV}}^{-4}$, using an effective field theory. Additionally, upper limits are placed on the production of axionlike particles with coupling strength to photons $f^{-1}$that varies from $0.03{\mathrm{TeV}}^{-1}$to $1{\mathrm{TeV}}^{-1}$over the mass range from 500 to 2000 GeV. © 2024 CERN, for the CMS and TOTEMs Collaboration2024CERN 

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4. Electromagnetic modeling and science reach of $\text{DMRadio-}{\mathrm{m}}^3$

   https://doi.org/10.1103/bwgd-kxsb  

   AlShirawi, A; Ankel, V; Bartram, C; Begin, J; Bell, C; Benabou, J N; Brouwer, L; Chaudhuri, S; Cho, H-M; Corbin, J; et al (September 2025, Physical review D)

   $\text{DMRadio-}{\mathrm{m}}^3$is an experimental search for dark matter axions. It uses a solenoidal dc magnetic field to convert an axion dark-matter signal to an ac electromagnetic response in a coaxial copper pickup. The current induced by this axion signal is measured by dc SQUIDs. $\text{DMRadio-}{\mathrm{m}}^3$is designed to be sensitive to Kim-Shifman-Vainshtein-Zakharov (KSVZ) and Dine-Fischler-Srednicki-Zhitnisky (DFSZ) QCD axion models in the 10–200 MHz ( $41\mathrm{neV}/c^2–0.83\mathrm{\mu }\mathrm{eV}/c^2$) range, and to axions with $g_{a\gamma \gamma }=g_{a\gamma \gamma ,\mathrm{DFSZ}}\left(30\mathrm{MHz}\right)=1.87\times {10}^{-17}{\mathrm{GeV}}^{-1}$over 5–30 MHz as an extended goal. In this work, we present the electromagnetic modeling of the response of the experiment to an axion signal over the full frequency range of $\text{DMRadio-}{\mathrm{m}}^3$, which extends from the low-frequency, lumped-element limit to a regime where the axion Compton wavelength is only a factor of 2 larger than the detector size. With these results, we determine the live time and sensitivity of the experiment. The primary science goal of sensitivity to DFSZ axions across 30–200 MHz can be achieved with a $3\sigma$live scan time of 2.9 years. 

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5. Observation of $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }\left(2S\right)$ and search for $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }\left(1S\right)$ , $\gamma X_b$ at $\sqrt{s}$ near 10.75 GeV

   https://doi.org/10.1103/9f61-rmvx  

   Adachi, I; Aggarwal, L; Ahmed, H; Ahn, Y; Aihara, H; Akopov, N; Alghamdi, S; Alhakami, M; Aloisio, A; Althubiti, N; et al (March 2026, Physical Review D)

   We present an analysis of the processes $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }\left(1S\right)$, $\eta \mathrm{\Upsilon }\left(2S\right)$, and $\gamma X_b$with $X_b\to {\pi }^{+}{\pi }^{-}{\chi }_{bJ},{\chi }_{bJ}\to \gamma \mathrm{\Upsilon }\left(1S\right)$( $J=1$, 2) reconstructed from $\gamma \gamma {\pi }^{+}{\pi }^{-}{\ell }^{+}{\ell }^{-}$ $(\ell =e,\mu )$final states in $19.6{\mathrm{fb}}^{-1}$of Belle II data collected at four energy points near the peak of the $\mathrm{\Upsilon }\left(10753\right)$resonance. Here, $X_b$is a hypothetical bottomonium-sector partner of the $X\left(3872\right)$. In the process $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }\left(2S\right)$, we observe a signal with a significance that exceeds $6.0\sigma$when all energy points are combined. A signal with a significance of $4.2\sigma$is observed at a center-of-mass energy of 10.653 GeV, close to the $B^{*}{\overline{B}}^{*}$threshold. At this energy, we measure $\sigma \left(\eta \mathrm{\Upsilon }\right(2S\left)\right)/\sigma \left({\pi }^{+}{\pi }^{-}\mathrm{\Upsilon }\right(2S\left)\right)>23$at the 90% confidence level, indicating a strong violation of heavy-quark spin symmetry. No significant signal is observed for $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }\left(1S\right)$or $\gamma X_b$. Upper limits on the Born cross sections for the processes $e^{+}{e}^{-}\to \eta \mathrm{\Upsilon }\left(1S\right)$and $e^{+}{e}^{-}\to \gamma X_b$with $X_b\to {\pi }^{+}{\pi }^{-}{\chi }_{bJ}$are determined. 

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