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DUNE Collaboration(Abud, A. A. et al), Amar, H., Amedo, P., Antonova, M., Barenboim, G., Benitez Montiel, C., et al. (2024). The DUNE far detector vertical drift technology Technical design report. J. Instrum., 19(8), T08004–418pp.
Abstract: DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model.
The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise.
In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered.
This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals.
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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Libralon, S., Martinez-Vidal, F., Oyanguren, A., et al. (2024). First observation of the Λb0→ D+D-Λ decay. J. High Energy Phys., 07(7), 140–22pp.
Abstract: The Lambda(0)(b) -> D+D-Lambda decay is observed for the first time using proton-proton collision data collected by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.3 fb(-1). Using the B-0 -> (D+D-KS0) decay as a reference channel, the product of the relative production cross-section and decay branching fractions is measured to be R = sigma(Lambda b0)/sigma(B0) x B(Lambda(0)(b) -> D+D-Lambda)/B(B-0 -> (D+D-KS0))=0.179 +/- 0.022 +/- 0.014, where the first uncertainty is statistical and the second is systematic. The known branching fraction of the reference channel, B(B-0 -> (D+D-KS0)), and the cross-section ratio, sigma Lambda(b0)/sigma(B0), previously measured by LHCb are used to derive the branching fraction of the Lambda(0)(b)-> D+D-Lambda decay B(Lambda(0)(b) -> D+D-Lambda) = (1.24 +/- 0.15 +/- 0.10 +/- 0.28 +/- 0.11)x10(-4), where the third and fourth contributions are due to uncertainties of B(B-0 -> (D+D-KS0)) and sigma(Lambda b0)/sigma(B0), respectively. Inspection of the D+Lambda and D+D- invariant-mass distributions suggests a rich presence of intermediate resonances in the decay. The Lambda(0)(b) -> D*+D-Lambda decay is also observed for the first time as a partially reconstructed component in the D+D-Lambda invariant mass spectrum.
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Fernandez Navarro, M., King, S. F., & Vicente, A. (2024). Minimal complete tri-hypercharge theories of flavour. J. High Energy Phys., 07(7), 147–36pp.
Abstract: The tri-hypercharge proposal introduces a separate gauged weak hypercharge assigned to each fermion family as the origin of flavour. This is arguably one of the simplest setups for building “gauge non-universal theories of flavour” or “flavour deconstructed theories”. In this paper we propose and study two minimal but ultraviolet complete and renormalisable tri-hypercharge models. We show that both models, which differ only by the heavy messengers that complete the effective theory, are able to explain the observed patterns of fermion masses and mixings (including neutrinos) with all fundamental coefficients being of O(1). In fact, both models translate the complicated flavour structure of the Standard Model into three simple physical scales above electroweak symmetry breaking, completely correlated with each other, that carry meaningful phenomenology. In particular, the heavy messenger sector determines the origin and size of fermion mixing, which controls the size and nature of the flavour-violating currents mediated by the two heavy Z ' gauge bosons of the theory. The phenomenological implications of the two minimal models are compared. In both models the lightest Z ' remains discoverable in dilepton searches at the LHC Run 3.
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Deltoro, J. M. et al, Gadea, A., Perez-Vidal, R. M., Huyuk, T., & Illicachi, R. (2025). Implementation of a double trigger condition system based on charge comparison and TOF measurement for the NEDA detector array. Nucl. Sci. Tech., 36(2), 30–9pp.
Abstract: The NEutron Detector Array (NEDA) is designed to be coupled to gamma-ray spectrometers to enhance the sensitivity of the setup by enabling reaction channel selection through counting of the evaporated neutrons. This article presents the implementation of a double trigger condition system for NEDA, which improves the acquisition of neutrons and reduces the number of gamma rays acquired. Two independent triggers are generated in the double trigger condition system: one based on charge comparison (CC) and the other on time-of-flight (TOF). These triggers can be combined using OR and AND logic, offering four distinct trigger modes. The developed firmware is added to the previous one in the Virtex 6 field programmable gate array (FPGA) present in the system, which also includes signal processing, baseline correction, and various trigger logic blocks. The performance of the trigger system is evaluated using data from the E703 experiment performed at GANIL. The four trigger modes are applied to the same data, and a subsequent offline analysis is performed. It is shown that most of the detected neutrons are preserved with the AND mode, and the total number of gamma rays is significantly reduced. Compared with the CC trigger mode, the OR trigger mode allows increasing the selection of neutrons. In addition, it is demonstrated that if the OR mode is selected, the online CC trigger threshold can be raised without losing neutrons.
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ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2024). Search for heavy Majorana neutrinos in e±e± and e±μ± final states via WW scattering in pp collisions at √s=13 TeV with the ATLAS detector. Phys. Lett. B, 856, 138865–24pp.
Abstract: A search for heavy Majorana neutrinos in scattering of same-sign.. boson pairs in proton-proton collisions at root s = 13 TeV at the LHC is reported. The dataset used corresponds to an integrated luminosity of 140 fb(-1), collected with the ATLAS detector during 2015-2018. The search is performed in final states including a same-sign ee or e μpair and at least two jets with large invariant mass and a large rapidity difference. No significant excess of events with respect to the Standard Model background predictions is observed. The results are interpreted in a benchmark scenario of the Phenomenological Type-I Seesaw model. New constraints are set on the values of the vertical bar V-eN vertical bar(2) and vertical bar VeNV μN*vertical bar parameters for heavy Majorana neutrino masses between 50 GeV and 20 TeV, where V-eN is the matrix element describing the mixing of the heavy Majorana neutrino mass eigenstate with the Standard Model neutrino of flavour l = e, mu. The sensitivity to the Weinberg operator is investigated and constraints on the effective ee and e μMajorana neutrino masses are reported. The statistical combination of the ee and e μchannels with the previously published μμchannel is performed.
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