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1. Search for high-mass resonances in final states with a $\tau$ -lepton and missing transverse momentum with the ATLAS detector

   https://doi.org/10.1103/PhysRevD.109.112008  

   Aad, G; Abbott, B; Abbott, D C; Abed_Abud, A; Abeling, K; Abhayasinghe, D K; Abidi, S H; Abramowicz, H; Abreu, H; Abulaiti, Y; et al (June 2024, Physical Review D)

   A search for high-mass resonances decaying into a $\tau$-lepton and a neutrino using proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$is presented. The full run 2 data sample corresponding to an integrated luminosity of $139{\mathrm{fb}}^{-1}$recorded by the ATLAS experiment in the years 2015–2018 is analyzed. The $\tau$-lepton is reconstructed in its hadronic decay modes and the total transverse momentum carried out by neutrinos is inferred from the reconstructed missing transverse momentum. The search for new physics is performed on the transverse mass between the $\tau$-lepton and the missing transverse momentum. No excess of events above the Standard Model expectation is observed and upper exclusion limits are set on the $W^{\prime }\to \tau \nu$production cross section. Heavy $W^{\prime }$vector bosons with masses up to 5.0 TeV are excluded at 95% confidence level, assuming that they have the same couplings as the Standard Model $W$boson. For nonuniversal couplings, $W^{\prime }$bosons are excluded for masses less than 3.5–5.0 TeV, depending on the model parameters. In addition, model-independent limits on the visible cross section times branching ratio are determined as a function of the lower threshold on the transverse mass of the $\tau$-lepton and missing transverse momentum. © 2024 CERN, for the ATLAS Collaboration2024CERN 

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2. Measurement of the branching fraction and $CP$ -violating asymmetry of the decay $B^0\to {\pi }^0{\pi }^0$ using 387 million $\mathrm{\Upsilon }\left(4S\right)$ decays in Belle II data

   https://doi.org/10.1103/PhysRevD.111.L071102  

   Adachi, I; Aggarwal, L; Ahmed, H; Aihara, H; Alhakami, M; Aloisio, A; Althubiti, N; Anh_Ky, N; Asner, D M; Atmacan, H; et al (April 2025, Physical Review D)

   We measure the branching fraction and $CP$-violating flavor-dependent rate asymmetry of $B^0\to {\pi }^0{\pi }^0$decays reconstructed using the Belle II detector in an electron-positron collision sample containing $387\times {10}^6\mathrm{\Upsilon }\left(4S\right)$mesons. Using an optimized event selection, we find $125\pm 20$signal decays in a fit to background-discriminating and flavor-sensitive distributions. The resulting branching fraction is $(1.25\pm 0.23)\times {10}^{-6}$and the $CP$-violating asymmetry is $0.03\pm 0.30$. Published by the American Physical Society2025 

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3. First Search for Ultralight Dark Matter Using a Magnetically Levitated Particle

   https://doi.org/10.1103/PhysRevLett.134.251001  

   Amaral, Dorian_W P; Uitenbroek, Dennis G; Oosterkamp, Tjerk H; Tunnell, Christopher D (June 2025, Physical Review Letters)

   We perform the first search for ultralight dark matter using a magnetically levitated particle. A submillimeter permanent magnet is levitated in a superconducting trap with a measured force sensitivity of $0.2\mathrm{fN}/\sqrt{\mathrm{Hz}}$. We find no evidence of a signal and derive limits on dark matter coupled to the difference between baryon and lepton number, $B-L$, in the mass range $(1.10360-1.10485)\times {10}^{-13}\mathrm{eV}/c^2$. Our most stringent limit on the coupling strength is $g_{B-L}\lesssim 2.98\times {10}^{-21}$. We propose the POLONAISE (Probing Oscillations using Levitated Objects for Novel Accelerometry In Searches of Exotic physics) experiment, which features short-, medium-, and long-term upgrades that will give us leading sensitivity in a wide mass range, demonstrating the promise of this novel quantum sensing technology in the hunt for dark matter. Published by the American Physical Society2025 

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4. Large extra dimensions from higher-dimensional inflation

   https://doi.org/10.1103/PhysRevD.109.103508  

   Anchordoqui, Luis A; Antoniadis, Ignatios (May 2024, Physical Review D)

   We propose the possibility that compact extra dimensions can obtain large size by higher-dimensional inflation, relating the weakness of the actual gravitational force to the size of the observable Universe. Solution to the horizon problem implies that the fundamental scale of gravity is smaller than ${10}^{13}\mathrm{GeV}$, which can be realized in a braneworld framework for any number of extra dimensions. However, requirement of an (approximate) flat power spectrum of primordial density fluctuations consistent with present observations makes this simple proposal possible only for one extra dimension at around the micron scale. After the end of five-dimensional inflation, the radion modulus can be stabilized at a vacuum with positive energy of the order of the present dark energy scale. An attractive possibility is based on the contribution to the Casimir energy of right-handed neutrinos with a mass at a similar scale. Published by the American Physical Society2024 

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5. Bayesian Search of Massive Scalar Fields from LIGO-Virgo-KAGRA Binaries

   https://doi.org/10.1103/PhysRevLett.134.191402  

   Xie, Yiqi; Chung, Adrian Ka-Wai; Sotiriou, Thomas P; Yunes, Nicolás (May 2025, Physical Review Letters)

   Massive scalar fields are promising candidates for addressing many unresolved problems in fundamental physics. We report the first model-agnostic Bayesian search of massive scalar fields that are nonminimally coupled to gravity in LIGO/Virgo/KAGRA gravitational-wave data. We find no evidence for such fields and place the most stringent upper limits on their coupling for scalar masses $\lesssim 2\times {10}^{-12}\mathrm{eV}$. We exemplify the strength of these bounds by applying them to massive scalar-Gauss-Bonnet gravity, finding the tightest constraints on the coupling constant to date, $\sqrt{{\alpha }_{\mathrm{GB}}}\lesssim 1\mathrm{km}$for scalar masses $\lesssim {10}^{-13}\mathrm{eV}$to 90% credible level. Published by the American Physical Society2025 

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