Centrone, F., & Gessner, M. (2024). Breaking local quantum speed limits with steering. Phys. Rev. Res., 6(4), L042067–5pp.
Abstract: We show how quantum correlations allow us to break the local speed limits of physical processes using only local measurements and classical communication between two parties that share an entangled state. Inequalities that bound the minimal time of evolution of a quantum state by energy fluctuations can be violated in the presence of steering by conditioning on the measurement outcomes of a remote system. Our results open up pathways for studying how quantum correlations influence the dynamical properties of states and observables.
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ATLAS Collaboration(Aad, G. et al), Aikiot, A., Amos, K. R., Aparisi Pozo, J. A., Bailey, A. J., Bouchhar, N., et al. (2024). Simultaneous energy and mass calibration of large-radius jets with the ATLAS detector using a deep neural network. Mach. Learn.-Sci. Technol., 5(3), 035051–37pp.
Abstract: The energy and mass measurements of jets are crucial tasks for the Large Hadron Collider experiments. This paper presents a new calibration method to simultaneously calibrate these quantities for large-radius jets measured with the ATLAS detector using a deep neural network (DNN). To address the specificities of the calibration problem, special loss functions and training procedures are employed, and a complex network architecture, which includes feature annotation and residual connection layers, is used. The DNN-based calibration is compared to the standard numerical approach in an extensive series of tests. The DNN approach is found to perform significantly better in almost all of the tests and over most of the relevant kinematic phase space. In particular, it consistently improves the energy and mass resolutions, with a 30% better energy resolution obtained for transverse momenta p(T) > 500 GeV.
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NEXT Collaboration(Byrnes, N. K. et al), Ayet, A., Carcel, S., Kellerer, F., Lopez-March, N., Mano, R. D. P., et al. (2024). Fluorescence imaging of individual ions and molecules in pressurized noble gases for barium tagging in 136Xe. Nat. Commun., 15(1), 10595–13pp.
Abstract: The imaging of individual Ba2+ ions in high pressure xenon gas is one possible way to attain background-free sensitivity to neutrinoless double beta decay and hence establish the Majorana nature of the neutrino. In this paper we demonstrate selective single Ba2+ ion imaging inside a high-pressure xenon gas environment. Ba2+ ions chelated with molecular chemosensors are resolved at the gas-solid interface using a diffraction-limited imaging system with scan area of 1 x 1 cm2 located inside 10 bar of xenon gas. This form of microscopy represents key ingredient in the development of barium tagging for neutrinoless double beta decay searches in 136Xe. This also provides a new tool for studying the photophysics of fluorescent molecules and chemosensors at the solid-gas interface to enable bottom-up design of catalysts and sensors.
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Castillo-Felisola, O., Grez, B., Morocho-Lopez, M., Perdiguero, J., Skirzewski, A., Vaca-Santana, J., et al. (2025). Polynomial Affine Model of Gravity: After 10 Years. Universe, 11(3), 102–42pp.
Abstract: The polynomial affine model of gravity was proposed as an alternative to metric and metric-affine gravitational models. What, in the beginning, was thought to be a source of unpredictability-the presence of many terms in the action-turned out to be a milestone since it contains all possible combinations of the fields compatible with the covariance under diffeomorphisms. Here, we present a review of the advances in the analysis of the model after 10 years of its proposal and sketch the guidelines for our future perspectives.
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Montani, G., De Angelis, M., Bombacigno, F., & Carlevaro, N. (2024). Metric f(R) gravity with dynamical dark energy as a scenario for the Hubble tension. Mon. Not. Roy. Astron. Soc., 527, L156–L161.
Abstract: We introduce a theoretical framework to interpret the Hubble tension, based on the combination of a metric f(R) gravity with a dynamical dark energy contribution. The modified gravity provides the non-minimally coupled scalar field responsible for the proper scaling of the Hubble constant, in order to accommodate for the local SNIa pantheon+ data and Planck measurements. The dynamical dark energy source, which exhibits a phantom divide line separating the low redshift quintessence regime (−1 < w < −1/3) from the phantom contribution (w < −1) in the early Universe, guarantees the absence of tachyonic instabilities at low redshift. The resulting H0(z) profile rapidly approaches the Planck value, with a plateau behaviour for z ≳ 5. In this scenario, the Hubble tension emerges as a low redshift effect, which can be in principle tested by comparing SNIa predictions with far sources, like QUASARS and gamma ray bursts.
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Barenboim, G., Del Debbio, L., Hirn, J., & Sanz, V. (2024). Exploring how a generative AI interprets music. Neural Comput. Appl., 36, 17007–17022.
Abstract: We aim to investigate how closely neural networks (NNs) mimic human thinking. As a step in this direction, we study the behavior of artificial neuron(s) that fire most when the input data score high on some specific emergent concepts. In this paper, we focus on music, where the emergent concepts are those of rhythm, pitch and melody as commonly used by humans. As a black box to pry open, we focus on Google’s MusicVAE, a pre-trained NN that handles music tracks by encoding them in terms of 512 latent variables. We show that several hundreds of these latent variables are “irrelevant” in the sense that can be set to zero with minimal impact on the reconstruction accuracy. The remaining few dozens of latent variables can be sorted by order of relevance by comparing their variance. We show that the first few most relevant variables, and only those, correlate highly with dozens of human-defined measures that describe rhythm and pitch in music pieces, thereby efficiently encapsulating many of these human-understandable concepts in a few nonlinear variables.
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Gonzalez-Iglesias, D., Gimeno, B., Esperante, D., Martinez-Reviriego, P., Martin-Luna, P., Pedraza, L. K., et al. (2024). A rapid method for prediction of the non-resonant ultra-fast multipactor regime in high gradient RF accelerating structures. Results Phys., 64, 107921–9pp.
Abstract: The purpose of this work is to present an analytical method that allows to estimate in an approximate and fast way the presence of the non-resonant and ultra-fast multipactor effect in RF accelerating structures in the presence of high gradient electromagnetic fields. This single-surface multipactor regime, which has been little studied in the scientific literature, is characterised by appearing only under conditions of very strong RF electric fields (of the order of tens or hundreds of MV/m), where it is predominant over other types of single- or dual-surface resonance described in classical multipactor theory. This type of multipactor causes a rapid growth of the electron population and poses a serious drawback in the operation of RF accelerator components operating under high gradient conditions. Specifically, in dielectric-assist accelerating structures (DAA) it has been experimentally found that the presence of multipactor limits the maximum operating gradient of these components due to a significant increase in the reflected power due to the discharge, being this phenomenon the main problem to overcome. In a previous work, we found and described in detail by means of numerical simulations the presence of this non-resonant and ultra-fast multipactor regime in a DAA structure design for hadrontherapy. Here we aim to present a simple and fast method to predict the presence of this non-resonant and ultra-fast multipactor regime in RF accelerator structures with cylindrical revolution symmetry around the acceleration axis. This method is especially useful in the design stages of accelerating structures as it provides much faster results than numerical simulations of the multipactor, with quite good accuracy in a wide range of cases as shown in this paper.
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ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2025). Search for the associated production of charm quarks and a Higgs boson decaying into a photon pair with the ATLAS detector. J. High Energy Phys., 02(2), 045–36pp.
Abstract: A search for the production of a Higgs boson and one or more charm quarks, in which the Higgs boson decays into a photon pair, is presented. This search uses proton-proton collision data with a centre-of-mass energy of root s = 13TeV and an integrated luminosity of 140 fb(-1) recorded by the ATLAS detector at the Large Hadron Collider. The analysis relies on the identification of charm-quark-containing jets, and adopts an approach based on Gaussian process regression to model the non-resonant di-photon background. The observed (expected, assuming the Standard Model signal) upper limit at the 95% confidence level on the cross-section for producing a Higgs boson and at least one charm-quark-containing jet that passes a fiducial selection is found to be 10.6 pb (8.8 pb). The observed (expected) measured cross-section for this process is 5.3 +/- 3.2 pb (2.9 +/- 3.1 pb).
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Houarner, C., Boujrad, A., Tripon, M., Bezard, M., Blaizot, M., Bourgault, P., et al. (2025). NUMEXO2: a versatile digitizer for nuclear physics. J. Instrum., 20(5), T05004–21pp.
Abstract: NUMEXO2 is a 16 channels 14 bit/200 MHz digitizer and processing board initially developed for gamma-ray spectroscopy (for EXOGAM: EXOtic nuclei GAMma ray). NUMEXO2 has been gradually extended and improved as a general purpose digitizer to fulfill various needs in nuclear physics detection at GANIL. This was possible thanks to reprogrammable components like FPGAs and the optimization of different algorithms. The originality of this work compared to similar systems is that all numerical operations follow the digital data flow from ADCs, without any storage step of samples. Some details are given on digital processing of the signals, delivered by a large variety of detectors: HPGe, silicon strip detector, ionisation chamber, liquid and plastic scintillators read-out with photomultipliers, Multi Wire Proportional Counter and drift chamber. Thanks to this high versatility, the NUMEXO2 digitizer is extensively used at GANIL (Grand Acc & eacute;l & eacute;rateur National d'Ions Lourds). Some of the performances of the module are also reported.
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LHCb Collaboration(Aaij, R. et al), Fernandez Casani, A., Jaimes Elles, S. J., Jashal, B. K., Libralon, S., Martinez-Vidal, F., et al. (2025). Measurement of the CKM angle γ in B± → DK*(892)± decays. J. High Energy Phys., 02(2), 113–37pp.
Abstract: Measurements of CP observables and the CKM angle gamma are performed in B-+/- -> DK*(892)(+/-) decays, where D represents a superposition of D-0 and (D) over bar (0) states, using the LHCb dataset collected during Run 1 (2011-2012) and Run 2 (2015-2018). A study of this channel is presented with the D meson reconstructed in two-body final states K-+/- pi(+/-), K+ K- and pi(+)pi(-); four-body final states K-+/-pi(-/+) pi(+/-) pi(-/+) and pi(+) pi(-) pi(+)pi(-); and threebody final states K-S(0)pi(+) pi(-) and K-S(0) K+ K-. This analysis includes the first observation of the suppressed B +/-. [pi(+/-) K-+/-](D)K*(+/-) and B +/-. [pi(+/-) K--/+ pi(+/-)pi(-/+)](D)K*(+/-) decays. The combined result gives gamma = (63 +/- 13)degrees.
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