Addazi, A., Ricciardi, G., Scarlatella, S., Srivastava, R., & Valle, J. W. F. (2022). Interpreting B anomalies within an extended 331 gauge theory. Phys. Rev. D, 106(3), 035030–14pp.
Abstract: In light of the recent R-K(*) data on neutral current flavor anomalies in B -> K-(*())l(+)l(-) decays, we reexamine their quantitative interpretation in terms of an extended 331 gauge theory framework. We achieve this by adding two extra lepton species with novel 331 charges, while ensuring that the model remains anomaly-free. In contrast to the canonical 331 models, the gauge charges of the first and second lepton families differ from each other, allowing lepton-flavor universality violation. We further expand the model by adding the neutral fermions required to provide an adequate description for small neutrino masses.
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Adolf, P., Hirsch, M., & Päs, H. (2023). Radiative neutrino masses and the Cohen-Kaplan-Nelson bound. J. High Energy Phys., 11(11), 078–14pp.
Abstract: Recently, an increasing interest in UV/IR mixing phenomena has drawn attention to the range of validity of standard quantum field theory. Here we explore the consequences of such a limited range of validity in the context of radiative models for neutrino mass generation. We adopt an argument first published by Cohen, Kaplan and Nelson that gravity implies both UV and IR cutoffs, apply it to the loop integrals describing radiative corrections, and demonstrate that this effect has significant consequences for the parameter space of radiative neutrino mass models.
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Aebischer, J. et al, & Vicente, A. (2024). Computing tools for effective field theories. Eur. Phys. J. C, 84(2), 170–59pp.
Abstract: In recent years, theoretical and phenomenological studies with effective field theories have become a trending and prolific line of research in the field of high-energy physics. In order to discuss present and future prospects concerning automated tools in this field, the SMEFT-Tools 2022 workshop was held at the University of Zurich from 14th-16th September 2022. The current document collects and summarizes the content of this workshop.
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Afonso, V. I., Bejarano, C., Ferraro, R., & Olmo, G. J. (2022). Determinantal Born-Infeld coupling of gravity and electromagnetism. Phys. Rev. D, 105(8), 084067–11pp.
Abstract: We study a Born-Infeld inspired model of gravity and electromagnetism in which both types of fields are treated on an equal footing via a determinantal approach in a metric-aft me formulation. Though this formulation is a priori in conflict with the postulates of metric theories of gravity, we find that the resulting equations can also be obtained from an action combining the Einstein-Hilbert action with a minimally coupled nonlinear electrodynamics. As an example, the dynamics is solved for the charged static black hole.
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Afonso, V. I., Mora-Perez, G., Olmo, G. J., Orazi, E., & Rubiera-Garcia, D. (2022). An infinite class of exact rotating black hole metrics of modified gravity. J. Cosmol. Astropart. Phys., 03(3), 052–14pp.
Abstract: We build an infinite class of exact axisymmetric solutions of a metric-affine gravity theory, namely, Eddington-inspired Born-Infeld gravity, coupled to an anisotropic fluid as a matter source. The solution-generating method employed is not unique of this theory but can be extended to other Ricci-Based Gravity theories (RBGs), a class of theories built out of contractions of the Ricci tensor with the metric. This method exploits a correspondence between the space of solutions of General Relativity and that of RBGs, and is independent of the symmetries of the problem. For the particular case in which the fluid is identified with non-linear electromagnetic fields we explicitly derive the corresponding axisymmetric solutions. Finally, we use this result to work out the counterpart of the Kerr-Newman black hole when Maxwell electrodynamics is set on the metric-affine side. Our results open up an exciting new avenue for testing new gravitational phenomenology in the fields of gravitational waves and shadows out of rotating black holes.
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Afonso, V. I., Olmo, G. J., Orazi, E., & Rubiera-Garcia, D. (2019). Correspondence between modified gravity and general relativity with scalar fields. Phys. Rev. D, 99(4), 044040–15pp.
Abstract: We describe a novel procedure to map the field equations of nonlinear Ricci-based metric-affine theories of gravity, coupled to scalar matter described by a given Lagrangian, into the field equations of general relativity coupled to a different scalar field Lagrangian. Our analysis considers examples with a single and N real scalar fields, described either by canonical Lagrangians or by generalized functions of the kinetic and potential terms. In particular, we consider several explicit examples involving foRthorn theories and the Eddington-inspired Born-Infeld gravity model, coupled to different scalar field Lagrangians. We show how the nonlinearities of the gravitational sector of these theories can be traded to nonlinearities in the matter fields and how the procedure allows to find new solutions on both sides of the correspondence. The potential of this procedure for applications of scalar field models in astrophysical and cosmological scenarios is highlighted.
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Afonso, V. I., Olmo, G. J., Orazi, E., & Rubiera-Garcia, D. (2019). New scalar compact objects in Ricci-based gravity theories. J. Cosmol. Astropart. Phys., 12(12), 044–20pp.
Abstract: Taking advantage of a previously developed method, which allows to map solutions of General Relativity into a broad family of theories of gravity based on the Ricci tensor (Ricci-based gravities), we find new exact analytical scalar field solutions by mapping the free-field static, spherically symmetric solution of General Relativity (GR) into quadratic f(R) gravity and the Eddington-inspired Born-Infeld gravity. The obtained solutions have some distinctive feature below the would-be Schwarzschild radius of a configuration with the same mass, though in this case no horizon is present. The compact objects found include wormholes, compact balls, shells of energy with no interior, and a new kind of object which acts as a kind of wormhole membrane. The latter object has Euclidean topology but connects antipodal points of its surface by transferring particles and null rays across its interior in virtually zero affine time. We point out the relevance of these results regarding the existence of compact scalar field objects beyond General Relativity that may effectively act as black hole mimickers.
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Agaras, M. N. et al, & Fiorini, L. (2023). Laser calibration of the ATLAS Tile Calorimeter during LHC Run 2. J. Instrum., 18(6), P06023–35pp.
Abstract: This article reports the laser calibration of the hadronic Tile Calorimeter of the ATLAS experiment in the LHC Run 2 data campaign. The upgraded Laser II calibration system is described. The system was commissioned during the first LHC Long Shutdown, exhibiting a stability better than 0.8% for the laser light monitoring. The methods employed to derive the detector calibration factors with data from the laser calibration runs are also detailed. These allowed to correct for the response fluctuations of the 9852 photomultiplier tubes of the Tile Calorimeter with a total uncertainty of 0.5% plus a luminosity-dependent sub-dominant term. Finally, we report the regular monitoring and performance studies using laser events in both standalone runs and during proton collisions. These studies include channel timing and quality inspection, and photomultiplier linearity and response dependence on anode current.
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Agarwalla, S. K., & Masud, M. (2020). Can Lorentz invariance violation affect the sensitivity of deep underground neutrino experiment? Eur. Phys. J. C, 80(8), 716–18pp.
Abstract: We examine the impact of Lorentz Invariance Violation (LIV) in measuring the octant of theta(23) and CP phases in the context of the Deep Underground Neutrino Experiment (DUNE). We consider the CPT-violating LIV parameters involving e-mu(a(e mu)) and e-tau (a(e tau)) flavors, which induce an additional interference term in neutrino and antineutrino appearance probabilities. This newinterference term depends on both the standard CP phase delta and the new dynamical CP phase phi(e mu)/phi(e tau), giving rise to new degeneracies among (theta(23), delta, phi). Taking one LIV parameter at-a-time and considering a small value of vertical bar a(e mu)vertical bar = vertical bar a(e tau)vertical bar = 5 x 10(-24) GeV, we find that the octant discovery potential of DUNE gets substantially deteriorated for unfavorable combinations of delta and phi(e mu)/phi(e tau). The octant of theta(23) can only be resolved at 3 sigma if the true value of sin(2) theta(23) less than or similar to 0.42 or >= 0.62 for any choices of delta and phi. Interestingly, we also observe that when both the LIV parameters a(e mu) and a(e tau) are present together, they cancel out the impact of each other to a significant extent, allowing DUNE to largely regain its octant resolution capability. We also reconstruct the CP phases delta and phi(e mu)/phi(e tau). The typical 1 sigma uncertainty on delta is 10-15 degrees. and the same on phi(e mu)/phi(e tau) is 25-30 degrees depending on the choices of their true values.
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AGATA Collaboration(Avigo, R. et al), Domingo-Pardo, C., Gadea, A., & Gonzalez, V. (2020). Low-lying electric dipole gamma-continuum for the unstable Fe-62(,)64 nuclei: Strength evolution with neutron number. Phys. Lett. B, 811, 135951–6pp.
Abstract: The gamma-ray emission from the nuclei Fe-62,Fe-64 following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei Fe-62,Fe-64 were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The gamma decay was detected with AGATA. From the measured gamma-ray spectra the summed E1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1(-) states (three-phonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy.
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