Catani, S., & Cieri, L. (2022). Multiple soft radiation at one-loop order and the emission of a soft quark-antiquark pair. Eur. Phys. J. C, 82(2), 97–27pp.
Abstract: We consider the radiation of two or more soft partons in QCD hard-scattering at one-loop order. The corresponding scattering amplitude is singular, and the singular behaviour is controlled by a process-independent soft current. Using regularization in d = 4 – 2 epsilon space-time dimensions, we explicitly evaluate the ultraviolet and infrared divergent (epsilon-pole) terms of the one-loop soft current for emission of an arbitrary number of soft partons in a generic hard-scattering process. Then we consider the specific case of soft quark-antiquark (q (q) over bar) emission and we compute the one-loop current by including the finite terms. We find that the one-loop soft-q (q) over bar current exhibits a new type of transverse-momentum singularity, which has a quantum (absorptive) origin and a purely non-abelian character. At the squared amplitude (cross section) level, this transverse-momentum singularity produces contributions to multijet production processes in hadron collisions. The one-loop squared current also leads to charge asymmetry terms, which are a distinctive features of soft-q (q) over bar radiation. We also extend these results to the cases of QED and mixed QCDxQED radiative corrections for soft fermion-antifermion emission.
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Centelles Chulia, S., Cepedello, R., & Medina, O. (2022). Absolute neutrino mass scale and dark matter stability from flavour symmetry. J. High Energy Phys., 10(10), 080–23pp.
Abstract: We explore a simple but extremely predictive extension of the scotogenic model. We promote the scotogenic symmetry Z(2) to the flavour non-Abelian symmetry sigma(81), which can also automatically protect dark matter stability. In addition, sigma(81) leads to striking predictions in the lepton sector: only Inverted Ordering is realised, the absolute neutrino mass scale is predicted to be m(lightest)approximate to 7.5x10(-4) eV and the Majorana phases are correlated in such a way that vertical bar m(ee)vertical bar approximate to 0.018 eV. The model also leads to a strong correlation between the solar mixing angle theta(12) and delta(CP), which may be falsified by the next generation of neutrino oscillation experiments. The setup is minimal in the sense that no additional symmetries or flavons are required.
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Cepedello, R., Esser, F., Hirsch, M., & Sanz, V. (2022). Mapping the SMEFT to discoverable models. J. High Energy Phys., 09(9), 229–34pp.
Abstract: The matching of specific new physics scenarios onto the SMEFT framework is a well-understood procedure. The inverse problem, the matching of the SMEFT to UV scenarios, is more difficult and requires the development of new methods to perform a systematic exploration of models. In this paper we use a diagrammatic technique to construct in an automated way a complete set of possible UV models (given certain, well specified assumptions) that can produce specific groups of SMEFT operators, and illustrate its use by generating models with no tree-level contributions to four-fermion (4F) operators. Those scenarios, which only contribute to 4F at one-loop order, can contain relatively light particles that could be discovered at the LHC in direct searches. For this class of models, we find an interesting interplay between indirect SMEFT and direct searches. We discuss some examples on how this interplay would look like when combining low-energy observables with the SMEFT Higgs-fermion analyses and searches for resonance at the LHC.
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Cervello, A., Carrio, F., Garcia, R., Martos, J., Soret, J., Torres, J., et al. (2022). The TileCal PreProcessor interface with the ATLAS global data acquisition system at the HL-LHC. Nucl. Instrum. Methods Phys. Res. A, 1043, 167492–2pp.
Abstract: The Large Hadron Collider (LHC) has envisaged a series of upgrades towards a High Luminosity LHC (HL-LHC) delivering five times the LHC nominal instantaneous luminosity. It will take place throughout 2026-2028, corresponding to the Long Shutdown 3. During this upgrade, the ATLAS Tile Hadronic Calorimeter (TileCal) will replace completely on-and off-detector electronics adopting a new read-out architecture. Signals captured from TileCal are digitized by the on-detector electronics and transmitted to the TileCal PreProcessor (TilePPr) located off-detector, which provides the interface with the ATLAS trigger and data acquisition systems.TilePPr receives, process and transmits the data from the on-detector system and transmits it to the Front -End Link eXchange (FELIX) system. FELIX is the ATLAS common hardware in all the subdetectors designed to act as a data router, receiving and forwarding data to the SoftWare Read-Out Driver (SWROD) computers. FELIX also distributes the Timing, Trigger and Control (TTC) signals to the TilePPr to be propagated to the on-detector electronics. The SWROD is an ATLAS common software solution to perform detector specific data processing, including configuration, calibration, control and monitoring of the partitionIn this contribution we will introduce the new read-out elements for TileCal at the HL-LHC, the intercon-nection between the off-detector electronics and the FELIX system, the configuration and implementation for the test beam campaigns, as well as future developments of the preprocessing and monitoring status of the calorimeter modules through the SWROD infrastructure.
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Chatterjee, S. S., Miranda, O. G., Tortola, M., & Valle, J. W. F. (2022). Nonunitarity of the lepton mixing matrix at the European Spallation Source. Phys. Rev. D, 106(7), 075016–16pp.
Abstract: If neutrinos get mass through the exchange of lepton mediators, as in seesaw schemes, the neutrino appearance probabilities in oscillation experiments are modified due to effective nonunitarity of the lepton mixing matrix. This also leads to new CP phases and an ambiguity in underpinning the “conventional” phase of the three-neutrino paradigm. We study the CP sensitivities of various setups based at the European Spallation Source neutrino super-beam (ESSnuSB) experiment in the presence of nonunitarity. We also examine its potential in constraining the associated new physics parameters. Moreover, we show how the combination of DUNE and ESSnuSB can help further improve the sensitivities on the nonunitarity parameters.
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Chiera, N. M., Maugeri, E. A., Danilov, I., Balibrea-Correa, J., Domingo-Pardo, C., Koster, U., et al. (2022). Preparation of PbSe targets for Se-79 neutron capture cross section studies. Nucl. Instrum. Methods Phys. Res. A, 1029, 166443–7pp.
Abstract: A methodology for the production of PbSe targets for Se-79 neutron capture cross section studies is presented. PbSe material was synthesized by direct reaction of its constituents at high temperature, and characterized by X-ray diffraction. Thin PbSe targets, produced for cross section experiments with the surrogate reaction method, were obtained by applying a physical vapor deposition technique, and their morphology and composition were analyzed by X-ray fluorescence, Scanning Electron Microscopy, and Energy dispersive X-ray spectroscopy. (PbSe)-Se-79 targets produced for cross section measurements with the Time of Flight method were characterized by gamma-ray spectroscopy. Finally, a procedure for the recovery of Se from PbSe is suggested. The purity of the retrieved Se was determined with Inductively Coupled Plasma Optical Emission Spectroscopy.
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Cirigliano, V., Diaz-Calderon, D., Falkowski, A., Gonzalez-Alonso, M., & Rodriguez-Sanchez, A. (2022). Semileptonic tau decays beyond the Standard Model. J. High Energy Phys., 04(4), 152–61pp.
Abstract: Hadronic tau decays are studied as probe of new physics. We determine the dependence of several inclusive and exclusive tau observables on the Wilson coefficients of the low-energy effective theory describing charged-current interactions between light quarks and leptons. The analysis includes both strange and non-strange decay channels. The main result is the likelihood function for the Wilson coefficients in the tau sector, based on the up-to-date experimental measurements and state-of-the-art theoretical techniques. The likelihood can be readily combined with inputs from other low-energy precision observables. We discuss a combination with nuclear beta, baryon, pion, and kaon decay data. In particular, we provide a comprehensive and model-independent description of the new physics hints in the combined dataset, which are known under the name of the Cabibbo anomaly.
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Coito, L., Faubel, C., Herrero-Garcia, J., Santamaria, A., & Titov, A. (2022). Sterile neutrino portals to Majorana dark matter: effective operators and UV completions. J. High Energy Phys., 08(8), 085–36pp.
Abstract: Stringent constraints on the interactions of dark matter with the Standard Model suggest that dark matter does not take part in gauge interactions. In this regard, the possibility of communicating between the visible and dark sectors via gauge singlets seems rather natural. We consider a framework where the dark matter talks to the Standard Model through its coupling to sterile neutrinos, which generate active neutrino masses. We focus on the case of Majorana dark matter, with its relic abundance set by thermal freeze-out through annihilations into sterile neutrinos. We use an effective field theory approach to study the possible sterile neutrino portals to dark matter. We find that both lepton-number-conserving and lepton-number-violating operators are possible, yielding an interesting connection with the Dirac/Majorana character of active neutrinos. In a second step, we open the different operators and outline the possible renormalisable models. We analyse the phenomenology of the most promising ones, including a particular case in which the Majorana mass of the sterile neutrinos is generated radiatively.
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Coloma, P., Esteban, I., Gonzalez-Garcia, M. C., Larizgoitia, L., Monrabal, F., & Palomares-Ruiz, S. (2022). Bounds on new physics with data of the Dresden-II reactor experiment and COHERENT. J. High Energy Phys., 05(5), 037–33pp.
Abstract: Coherent elastic neutrino-nucleus scattering was first experimentally established five years ago by the COHERENT experiment using neutrinos from the spallation neutron source at Oak Ridge National Laboratory. The first evidence of observation of coherent elastic neutrino-nucleus scattering with reactor antineutrinos has now been reported by the Dresden-II reactor experiment, using a germanium detector. In this paper, we present constraints on a variety of beyond the Standard Model scenarios using the new Dresden-II data. In particular, we explore the constraints imposed on neutrino nonstandard interactions, neutrino magnetic moments, and several models with light scalar or light vector mediators. We also quantify the impact of their combination with COHERENT (CsI and Ar) data. In doing so, we highlight the synergies between spallation neutron source and nuclear reactor experiments regarding beyond the Standard Model searches, as well as the advantages of combining data obtained with different nuclear targets. We also study the possible signal from beyond the Standard Model scenarios due to elastic scattering off electrons (which would pass selection cuts of the COHERENT CsI and the Dresden-II experiments) and find more stringent constraints in certain parts of the parameter space than those obtained considering coherent elastic neutrino-nucleus scattering.
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Coloma, P., Gonzalez-Garcia, M. C., Maltoni, M., Pinheiro, J. P., & Urrea, S. (2022). Constraining new physics with Borexino Phase-II spectral data. J. High Energy Phys., 07(7), 138–35pp.
Abstract: We present a detailed analysis of the spectral data of Borexino Phase II, with the aim of exploiting its full potential to constrain scenarios beyond the Standard Model. In particular, we quantify the constraints imposed on neutrino magnetic moments, neutrino non-standard interactions, and several simplified models with light scalar, pseudoscalar or vector mediators. Our analysis shows perfect agreement with those performed by the collaboration on neutrino magnetic moments and neutrino non-standard interactions in the same restricted cases and expands beyond those, stressing the interplay between flavour oscillations and flavour non-diagonal interaction effects for the correct evaluation of the event rates. For simplified models with light mediators we show the power of the spectral data to obtain robust limits beyond those previously estimated in the literature.
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