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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Rosario, I., Campanario, F., & Plaetzer, S. (2025). NLO QCD parton shower matching for pp → e+ νe μ- barνμ γ plus X 2,3,‡. Phys. Rev. D, 111(9), 094044–11pp.
Abstract: We present the implementation of a new interface in VBFNLO 3.0 supporting all diboson and triboson processes with fully leptonic final states, enabling next-to-leading order (NLO) + parton shower (PS) matched calculations. To demonstrate its capabilities, we study parton shower effects in the triboson production process pp -> e+nu e mu-nu<overline>mu gamma + X using Herwig 7.3 with NLO QCD amplitudes from VBFNLO 3.0. We estimate uncertainties from scale variations and analyze the impact of generation-level cuts on parton shower events. This study showcases the new interface's potential and provides insights into the interplay between fixed-order calculations and parton shower effects in multiboson production processes, crucial for precision measurements and beyond the Standard Model searches at the LHC and future colliders.
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Lessa, L. A., & Olmo, G. J. (2025). On the structure of black bounces sourced by anisotropic fluids. J. Cosmol. Astropart. Phys., 03(3), 019–18pp.
Abstract: The field equations of static, spherically symmetric geometries generated by anisotropic fluids is investigated with the aim of better understanding the relation between the matter and the emergence of minimal area throats, like in wormhole and black bounce scenarios. Imposing some simplifying restrictions on the matter, which amounts to considering nonlinear electromagnetic sources, we find analytical expressions that allow one to design the type of sought geometries. We illustrate our analysis with several examples, including an asymmetric, bounded black bounce spacetime which reproduces the standard ReissnerNordstr & ouml;m geometry on the outside all the way down to the throat.
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Grinstein, B., Lu, X. C., Miro, C., & Quilez, P. (2025). Accidental symmetries, Hilbert series, and friends. J. High Energy Phys., 03(3), 172–86pp.
Abstract: Accidental symmetries in effective field theories can be established by computing and comparing Hilbert series. This invites us to study them with the tools of invariant theory. Applying this technology, we spotlight three classes of accidental symmetries that hold to all orders for non-derivative interactions. They are broken by derivative interactions and become ordinary finite-order accidental symmetries. To systematically understand the origin and the patterns of accidental symmetries, we introduce a novel mathematical construct – a (non-transitive) binary relation between subgroups that we call friendship. Equipped with this, we derive new criteria for all-order accidental symmetries in terms of friends, and criteria for finite-order accidental symmetries in terms of friends ma non troppo. They allow us to verify and identify accidental symmetries more efficiently without computing the Hilbert series. We demonstrate the success of our new criteria by applying them to a variety of sample accidental symmetries, including the custodial symmetry in the Higgs sector of the Standard Model effective field theory.
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Singha, M., Yokoyama, R., Grzywacz, R., Keeler, A., King, T. T., Agramunt, J., et al. (2025). YSO implantation detector for beta-delayed neutron spectroscopy. Nucl. Instrum. Methods Phys. Res. A, 1073, 170239–14pp.
Abstract: A segmented-scintillator-based implantation detector was developed to study the energy distribution of /1- delayed neutrons emitted from exotic isotopes. The detector comprises a 34 x 34 YSO scintillator coupled to an 8 x 8 anode Position-Sensitive Photo-Multiplier Tube (PSPMT) via a tapered light guide. The detector was used at RIBF, RIKEN for time-of-flight-based neutron spectroscopy measurement in the 78Ni region. The detector provides the position and timing resolution necessary for ion-beta correlations and time of flight measurements. The detector provides a high similar to 80% beta-detection efficiency and a sub-nanosecond timing resolution. This contribution discusses the details of the design, operation, implementation, and analysis developed to obtain neutron time-of-flight spectrum and the analysis methods in the context of neutron-rich nuclei in the 78Ni region.
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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). Measurement of off-shell Higgs boson production in the H*→ZZ→4l decay channel using a neural simulation-based inference technique in 13 TeV pp collisions with the ATLAS detector. Rep. Prog. Phys., 88(5), 057803–38pp.
Abstract: A measurement of off-shell Higgs boson production in the H*-> ZZ -> 4l decay channel is presented. The measurement uses 140 fb-1 of proton-proton collisions at s=13 TeV collected by the ATLAS detector at the Large Hadron Collider and supersedes the previous result in this decay channel using the same dataset. The data analysis is performed using a neural simulation-based inference method, which builds per-event likelihood ratios using neural networks. The observed (expected) off-shell Higgs boson production signal strength in the ZZ -> 4l decay channel at 68% CL is 0.87-0.54+0.75 ( 1.00-0.95+1.04). The evidence for off-shell Higgs boson production using the ZZ -> 4l decay channel has an observed (expected) significance of 2.5 sigma (1.3 sigma). The expected result represents a significant improvement relative to that of the previous analysis of the same dataset, which obtained an expected significance of 0.5 sigma. When combined with the most recent ATLAS measurement in the ZZ -> 2l2 nu decay channel, the evidence for off-shell Higgs boson production has an observed (expected) significance of 3.7 sigma (2.4 sigma). The off-shell measurements are combined with the measurement of on-shell Higgs boson production to obtain constraints on the Higgs boson total width. The observed (expected) value of the Higgs boson width at 68% CL is 4.3-1.9+2.7 ( 4.1-3.4+3.5) MeV.
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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). Observation of the Open-Charm Tetraquark Candidate Tcs0* (2870)0 in the B- → D- D0KS0 Decay. Phys. Rev. Lett., 134(10), 101901–13pp.
Abstract: An amplitude analysis of B- -> D- (DKS0)-K-0 decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 9 fb(-1), collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. A resonant structure of spin-parity 0(+) is observed in the (DKS0)-K-0 invariant-mass spectrum with a significance of 5.3s. The mass and width of the state, modeled with a Breit-Wigner line shape, are determined to be 2883 +/- 11 +/- 8 MeV/c(2) and 87(-47)(+22) +/- 17 MeV, respectively, where the first uncertainties are statistical and the second systematic. These properties and the quark content are consistent with those of the open-charm tetraquark candidate T-cs0(*)(2870)(0) observed previously in the D+K- final state of the B- -> D-D+K- decay. This result confirms the existence of the T-cs0(*)(2870)(0) state in a new decay mode. The T-c10(*) (2900)(0) state, reported in the B- -> D-D+K- decay, is also searched for in the (DKS0)-K-0 invariant-mass spectrum of the B- -> D- (DKS0)-K-0 decay, without finding evidence for it.
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Gao, F., Miramontes, A. S., Papavassiliou, J., & Pawlowski, J. M. (2025). Heavy-light mesons from a flavour-dependent interaction. Phys. Lett. B, 863, 139384–8pp.
Abstract: We introduce a new framework for the physics of heavy-light mesons, whose key element is the effective incorporation of flavour-dependent contributions into the corresponding bound-state and quark gap equations. These terms originate from the fully-dressed quark-gluon vertices appearing in the kernels of these equations, and provide a natural distinction between “light” and “heavy” quarks. In this approach, only the classical form factor of the quark-gluon vertex is retained, and is evaluated in the so-called “symmetric” configuration. The standard Slavnov-Taylor identity links this form factor to the quark wave-function, allowing for the continuous transition from light to heavy quarks through the mere variation of the current quark mass in the gap equation. The method is used to compute the masses and decay constants of specific pseudoscalars and vector heavy-light systems, showing good overall agreement with both experimental data and lattice simulations.
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