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Tian, M. S., Gao, X. T., Jing, B. X., Sun, F. X., Fadel, M., Gessner, M., et al. (2025). Characterizing the Multipartite Entanglement Structure of Non-Gaussian Continuous-Variable States with a Single Evolution Operator. Phys. Rev. Lett., 135(14), 140201–7pp.
Abstract: Multipartite entanglement is an essential resource for quantum information tasks, but characterizing entanglement structures in continuous-variable systems remains challenging, especially in multimode nonGaussian scenarios. In this Letter, we introduce an efficient method for detecting multipartite entanglement structures in continuous-variable states. Based on the quantum Fisher information, we propose a systematic approach to identify an encoding operator that can efficiently capture the quantum correlations in multimode non-Gaussian states. We demonstrate the effectiveness of our method on over 105 randomly generated multimode-entangled quantum states, achieving a very high success rate in entanglement detection. Additionally, the robustness of our method can be considerably enhanced against losses by expanding the set of accessible operators. This Letter provides a general framework for characterizing entanglement structures in diverse continuous-variable systems, enabling a number of experimentally relevant applications.
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Maura, V., Stefanek, B., & You, T. V. (2025). Higgs Self-Coupling at the Future Circular e plus e-Collider. Phys. Rev. Lett., 135(14), 141802–7pp.
Abstract: Single Higgs production at FCC-ee probes the Higgs self-coupling at next-to-leading order (NLO). Extracting a bound requires a global analysis accounting for other possible new physics contributions up to NLO. We determine the FCC-ee sensitivity to Higgs self-coupling modifications delta kappa lambda within the standard model effective field theory framework, including for the first time flavor, LEP, LHC, and FCC-ee observables in a global analysis with all leading NLO effects via one-loop renormalization group evolution, as well as incorporating finite NLO contributions to electroweak precision and ZH observables. The global sensitivity to delta kappa lambda is estimated by marginalizing over the effects of all other operators, bringing flavor considerations to the fore. We find that, under reasonable assumptions, FCC-ee sensitivity to delta kappa lambda can exceed that of the HL-LHC.
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Mandic, I., Cindro, V., Mikuz, M., Novak, B., Federicová, P., Jirásek, R., et al. (2026). Radiation effects of CERN-PS 24 GeV/c protons in silicon strip sensors, evaluated with ATLAS18 ITk strip sensor test structures. Nucl. Instrum. Methods Phys. Res. A, 1082, 170917–9pp.
Abstract: Test structures from the ATLAS18 ITk strip detector wafers were irradiated with 24 GeV/c protons. These test structures were positioned at various angles with respect to the proton beam. Blocks of G10 material were placed in front of these test structures to study the effect of scattering of primary protons on the received particle fluence. The results confirm that both the incidence angle of the beam and scattering significantly influence the actual fluence to which the samples are exposed. Miniature strip detectors, first irradiated with protons, were also irradiated with reactor neutrons, to a combined fluence of Phi(neq) = 1.6 x 10(15) cm(-2). The combination of proton and neutron fluences matched the combination expected in the most exposed part of the strip detector in the ALTAS Inner Tracker (ITk). Good charge collection was measured confirming that the strip detectors are sufficiently radiation hard for successful operation to highest fluences expected at the HL-LHC.
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Fadel, M., Roux, N., & Gessner, M. (2025). Quantum metrology with a continuous-variable system. Rep. Prog. Phys., 88(10), 106001–46pp.
Abstract: As one of the main pillars of quantum technologies, quantum metrology aims to improve measurement precision using techniques from quantum information. The two main strategies to achieve this are the preparation of nonclassical states and the design of optimized measurement observables. We discuss precision limits and optimal strategies in quantum metrology and sensing with a single mode of quantum continuous variables. We focus on the practically most relevant cases of estimating displacements and rotations and provide the sensitivities of the most important classes of states that includes Gaussian states and superpositions of Fock states or coherent states. Fundamental precision limits that are obtained from the quantum Fisher information are compared to the precision of a simple moment-based estimation strategy based on the data obtained from possibly sub-optimal measurement observables, including homodyne, photon number, parity and higher moments. Finally, we summarize some of the main experimental achievements and present emerging platforms for continuous-variable sensing. These results are of particular interest for experiments with quantum light, trapped ions, mechanical oscillators, and microwave resonators.
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Wang, D., Mena, O., Di Valentino, E., & Gariazzo, S. (2025). Scale and redshift dependent limits on cosmic neutrino properties. Phys. Rev. D, 112(6), 063555–16pp.
Abstract: Cosmological neutrino mass and abundance measurements are reaching unprecedented precision. Testing their stability versus redshift and scale is a crucial issue, as it can serve as a guide for optimizing ongoing and future searches. Here, we perform such analyses, considering a number of redshift, scale, and redshift-and-scale nodes. Concerning the k-space analysis of P m nu, cosmic microwave background (CMB) observations are crucial, as they lead the neutrino mass constraints. Interestingly, some data combinations suggest a nonzero value for the neutrino mass with 26 significance. The most constraining bound we find is Sigma m(nu ) <0.54 eV at 95% confidence level (CL) in the [10(-3), 10(-2)] h/Mpc k-bin, a limit that barely depends on the data combination. Regarding the redshift-and scale-dependent neutrino mass constraints, high redshifts (z > 100) and scales in the range [10-3, 10(-1)] h/Mpc provide the best constraints. The least constraining bounds are obtained at very low redshifts [0, 0.5] and also at very small scales (k > 0.1 h/Mpc) due to the absence of observations. Highly relevant is the case of the [100, 1100], [10(-2), 10(-1)] h/Mpc redshift-scale bin, where a 2-36 evidence for a nonzero neutrino mass is obtained for all data combinations. The bound from CMB alone at 68% CL is 0.63(-0.24)(+0.20) eV, and the one for the full dataset is 0.56(-0.23)(+0.20) eV, clearly suggesting a nonzero neutrino mass at these scales, possibly related to a deviation of the integrated Sachs-Wolfe amplitude in this redshift range. Concerning the analysis of N(eff )in the k-space, at intermediate scales ranging from k = 10(-3) h/Mpc to k = 10(-1) h/Mpc, accurate CMB data provide very strong bounds, the most robust one being N-eff = 3.09 + 0.14, comparable to the standard expected value without a k-bin analysis. If a nonzero neutrino mass is considered, the bounds on the Neff values at the different k-bins are largely unaffected, and the 95% CL tightest limit we find for the neutrino mass in this case is Sigma m(nu )< 0.205 eV from the full dataset. Finally, the z and k analyses of Neff indicate a high constraining power of cosmological observations at high redshifts and intermediate scales [10(-2), 10(-1)] h/Mpc when extracting the binned values of this parameter.
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