Alexandre, J., Mavromatos, N. E., Mitsou, V. A., & Musumeci, E. (2025). Impact of resummation on the production and experimental bounds of scalar high-electric-charge objects. Phys. Rev. D, 111(7), 076010–17pp.
Abstract: A one-loop Dyson-Schwinger-like resummation scheme is applied to scalar high-electric-charge compact objects (HECOs), extending previous work on spin-1 2 case. The electromagnetic interactions of HECOs are considered within the framework of strongly coupled scalar quan tun electrodynamics. The resummation amounts to determining nontrivial ultraviolet (UV) fixed points, at which the effective Lagrangian, which will lead to the pertinent predictions on the cross sections, is computed. In contrast to the fermionic HECO case, in which the fixed point structure was determined solely by the interactions of the HECOs with the photon field, in the scalar case the existence of nontrivial UV fixed points requires the presence of additional strong self-interactions among the HECOs. Our resummation scheme, which is notably different from a lattice strong-coupling approach, makes the computation of the pertinent scalar-HECO-production cross sections reliable, thus allowing revisiting the mass bounds obtained from searches for such objects in current or future colliders. Our MadGraph implementation of the results leads to enhanced (up to similar to 30%) lower bounds on the mass of scalar HECOs, as compared to those extracted from the tree-level processes typically used in LHC collider searches by ATLAS and MoEDAL experiments.
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Abdallah, J. et al, Cerda Alberich, L., Fiorini, L., Gomez Delegido, A. J., & Valero, A. (2025). Study of the radiation hardness of the ATLAS Tile Calorimeter optical instrumentation with Run 2 data. J. Instrum., 20(6), P06006–29pp.
Abstract: This paper presents a study of the radiation hardness of the hadronic Tile Calorimeter of the ATLAS experiment in the LHC Run 2. Both the plastic scintillators constituting the detector active media and the wavelength-shifting optical fibres collecting the scintillation light into the photodetector readout are elements susceptible to radiation damage. The dedicated calibration and monitoring systems of the detector (caesium radioactive sources, laser and minimum bias integrator) allow to assess the response of these optical components. Data collected with these systems between 2015 and 2018 are analysed to measure the degradation of the optical instrumentation across Run 2. Moreover, a simulation of the total ionising dose in the calorimeter is employed to study and model the degradation profile as a function of the exposure conditions, both integrated dose and dose rate. The measurement of the relative light output loss in Run 2 is presented and extrapolations to future scenarios are drawn based on current data. The impact of radiation damage on the cell response uniformity is also analysed.
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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). Expected tracking performance of the ATLAS Inner Tracker at the High-Luminosity LHC. J. Instrum., 20(2), P02018–49pp.
Abstract: The high-luminosity phase of LHC operations (HL-LHC), will feature a large increase in simultaneous proton-proton interactions per bunch crossing up to 200, compared with a typical leveling target of 64 in Run 3. Such an increase will create a very challenging environment in which to perform charged particle trajectory reconstruction, a task crucial for the success of the ATLAS physics program, and will exceed the capabilities of the current ATLAS Inner Detector (ID). A new all-silicon Inner Tracker (ITk) will replace the current ID in time for the start of the HL-LHC. To ensure successful use of the ITk capabilities in Run 4 and beyond, the ATLAS tracking software has been successfully adapted to achieve state-of-the-art track reconstruction in challenging high-luminosity conditions with the ITk detector. This paper presents the expected tracking performance of the ATLAS ITk based on the latest available developments since the ITk technical design reports.
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Bombacigno, F., De Angelis, M., van de Bruck, C., & Giare, W. (2025). Inflation in non-local hybrid metric-Palatini gravity. J. Cosmol. Astropart. Phys., 05(5), 025–30pp.
Abstract: Within the framework of hybrid metric-Palatini gravity, we incorporate non-localities introduced via the inverse of the d'Alembert operators acting on the scalar curvature. We analyze the dynamical structure of the theory and, adopting a scalar-tensor perspective, assess the stability conditions to ensure the absence of ghost instabilities. Focusing on a special class of well-defined hybrid actions where local and non-local contributions are carried by distinct types of curvature we investigate the feasibility of inflation within the resulting Einstein-frame multi-field scenario. We examine how the non-minimal kinetic couplings between the fields, reflecting the non-local structure of the original frame, influence the number of e-folds and the field trajectories. To clarify the physical interpretation of our results, we draw analogies with benchmark single-field inflation scenarios that include spectator fields.
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Abdalla, A. et al, & Bernabeu, J. (2025). Terrestrial Very-Long-Baseline Atom Interferometry: summary of the second workshop. EPJ Quantum Technol., 12(1), 42–79pp.
Abstract: This summary of the second Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Workshop provides a comprehensive overview of our meeting held in London in April 2024 (Second Terrestrial Very-Long-Baseline Atom Interferometry Workshop, Imperial College, April 2024), building on the initial discussions during the inaugural workshop held at CERN in March 2023 (First Terrestrial Very-Long-Baseline Atom Interferometry Workshop, CERN, March 2023). Like the summary of the first workshop (Abend et al. in AVS Quantum Sci. 6:024701, 2024), this document records a critical milestone for the international atom interferometry community. It documents our concerted efforts to evaluate progress, address emerging challenges, and refine strategic directions for future large-scale atom interferometry projects. Our commitment to collaboration is manifested by the integration of diverse expertise and the coordination of international resources, all aimed at advancing the frontiers of atom interferometry physics and technology, as set out in a Memorandum of Understanding signed by over 50 institutions (Memorandum of Understanding for the Terrestrial Very Long Baseline Atom Interferometer Study).
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Coutinho, A. M., Karan, A., Miralles, V., & Pich, A. (2025). Light scalars within the CP-conserving Aligned-two-Higgs-doublet model. J. High Energy Phys., 02(2), 057–53pp.
Abstract: In this article we study the possibility that neutral and charged scalars lighter than the 125 GeV Higgs boson might exist within the framework of the CP-conserving Aligned-two-Higgs-doublet model. Depending on which new scalar (scalars) is (are) light, seven different scenarios may be considered. Using the open-source code HEPfit, which relies on Bayesian statistics, we perform global fits for all seven light-mass scenarios. The constraints arising from vacuum stability, perturbativity, electroweak precision observables, flavour observables, Higgs signal strengths, and direct-detection results at the LEP and the LHC are taken into account. Reinterpreted data from slepton searches are considered too. It turns out that the seven scenarios contain sizeable regions of their parameter space compatible with all current data. Although not included in the global fits, the possible implications of (g – 2)mu are also addressed.
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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 CP asymmetry in Bs0 → Ds∓ K± decays. J. High Energy Phys., 03(3), 139–33pp.
Abstract: A measurement of the CP-violating parameters in B-s(0) -> D-s(-/+) K-+/- decays is reported, based on the analysis of proton-proton collision data collected by the LHCb experiment corresponding to an integrated luminosity of 6 fb(-1) at a centre-of-mass energy of 13TeV. The measured parameters are obtained with a decay-time dependent analysis yielding C-f = 0.791 +/- 0.061 +/- 0.022, A(f)(Delta Gamma) = -0.051 +/- 0.134 +/- 0.058, A((f) over bar)(Delta Gamma) = -0.303 +/- 0.125 +/- 0.055, S-f = -0.571 +/- 0.084 +/- 0.023 and S-(f) over bar = -0.503 +/- 0.084 +/- 0.025, where the first uncertainty is statistical and the second systematic. This corresponds to CP violation in the interference between mixing and decay of about 8.6 sigma. Together with the value of the B-s(0) mixing phase -2 beta s, these parameters are used to obtain a measurement of the CKM angle gamma equal to (74 +/- 12)degrees modulo 180 degrees, where the uncertainty contains both statistical and systematic contributions. This result is combined with the previous LHCb measurement in this channel using 3 fb(-1) resulting in a determination of gamma = (81(-11)(+12))degrees.
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Arbelaez, C., Gonzalez, M., Hirsch, M., Neill, N. A., & Restrepo, D. (2025). Effective field theory and scalar triplet dark matter. J. High Energy Phys., 04(4), 118–22pp.
Abstract: We discuss an extension of the standard model with a real scalar triplet, T, including non-renormalizable operators (NROs) up to d = 6. If T is odd under a Z2 symmetry, the neutral component of T is a good candidate for the dark matter (DM) of the universe. We calculate the relic density and constraints from direct and indirect detection on such a setup, concentrating on the differences with respect to the simple model for a DM T with only renormalizable interactions. Bosonic operators can change the relic density of the triplet drastically, opening up new parameter space for the model. Indirect detection constraints, on the other hand, rule out an interesting part of the allowed parameter space already today and future CTA data will, very likely, provide a decisive test for this setup.
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Lee, H. M., Park, M., & Sanz, V. (2025). Gravity-Mediated Dark Matter at a low reheating temperature. J. High Energy Phys., 05(5), 126–26pp.
Abstract: We present a new study on the Gravity-Mediated Dark Matter (GMDM) scenario, where interactions between dark matter (DM) and the Standard Model are mediated by spin-two particles. Expanding on this established framework, we explore a novel regime characterized by a low reheating temperature that offers an alternative to the conventional thermal relic paradigm. This approach opens new possibilities for understanding the dynamics of the dark sector, encompassing both the dark matter particles (fermion, scalar and vector) and the spin-two mediators. Our analysis examines the constraints imposed by the relic abundance of DM, collider experiments, and direct detection searches, spanning a wide mass range for the dark sector, from very light to extremely heavy states. This work opens new possibilities for the phenomenology of GMDM.
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Berbig, M. (2025). Kick it like DESI: PNGB quintessence with a dynamically generated initial velocity. J. Cosmol. Astropart. Phys., 03(3), 015–46pp.
Abstract: Motivated by the hint for time-dependent dynamical dark energy from an analysis of the DESI Baryon Accoustic Oscillation (BAO) data together with information from the Cosmic Microwave Background (CMB) and Supernovae (SN), we relax the assumption of a vanishing initial velocity for a quintessence field. In particular we focus on pseudo-NambuGoldstone-Boson (PNGB) quintessence in the form of an axion like particle, that can arise as the phase of a complex scalar and could possess derivative couplings to fermions or topological couplings to abelian gauge fields, without upsetting the necessary flatness of its potential. We discuss mechanisms from the aforementioned interactions for sourcing an initial axion field velocity theta(center dot)i at redshifts 3 <= z <= 10, that will “kick” it into motion. Driven by this initial velocity the axion will first roll up in its potential, similar to “freezing” dark energy. After it has reached the pinnacle of its trajectory, it will start to roll down, and behave as “thawing” quintessence. As a proof of concept we undertake a combined fit to BAO, SN and CMB data at the background level. We find that a scenario with theta(center dot)i = O (1) ma, where ma is the axion mass, is slightly preferred over both Lambda CDM and the conventional “thawing” quintessence with theta(center dot)i = 0. The best fit points for this case exhibit transplanckian decay constants and very flat potentials, which both are in tension with conjectures from string theory.
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