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Yu, Q. X., Liang, W. H., Bayar, M., & Oset, E. (2019). Line shape and D-(*())(D)over-bar(()*()) probabilities of psi(3770) from the e(+) e(-) -> D(D)over-bar reaction. Phys. Rev. D, 99(7), 076002–17pp.
Abstract: We have performed a calculation of the D (D) over bar, D (D) over bar*, D*(D) over bar, D*(D) over bar* components in the wave function of the psi(3770). For this we make use of the P-3(0) model to find the coupling of psi(3770) to these components, that with an elaborate angular momentum algebra can be obtained with only one parameter. Then we use data for the e(+)e(-) -> D (D) over bar reaction, from where we determine a form factor needed in the theoretical framework, as well as other parameters needed to evaluate the meson-meson self-energy of the psi(3770). Once this is done we determine the Z probability to still have a vector core and the probability to have the different meson components. We find Z about 80%-85%, and the individual meson-meson components are rather small, providing new empirical information to support the largely q (q) over bar component of vector mesons, and the psi(3770) in particular. A discussion is done of the meaning of the terms obtained for the case of the open channels where the concept of probability cannot be strictly used.
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Smith, W. A., Glazier, D. I., Mathieu, V., Albaladejo, M., Albrecht, M., Baldwin, Z., et al. (2023). Ambiguities in partial wave analysis of two spinless meson photoproduction. Phys. Rev. D, 108(7), 076001–12pp.
Abstract: We describe the formalism to analyze the mathematical ambiguities arising in partial-wave analysis of two spinless mesons produced with a linearly polarized photon beam. We show that partial waves are uniquely defined when all accessible observables are considered, for a wave set which includes S and D waves. The inclusion of higher partial waves does not affect our results, and we conclude that there are no mathematical ambiguities in partial-wave analysis of two mesons produced with a linearly polarized photon beam. We present Monte Carlo simulations to illustrate our results.
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Cordero-Carrion, I., Hirsch, M., & Vicente, A. (2020). General parametrization of Majorana neutrino mass models. Phys. Rev. D, 101(7), 075032–25pp.
Abstract: We discuss a general formula which allows to automatically reproduce experimental data for Majorana neutrino mass models, while keeping the complete set of the remaining model parameters free for general scans, as necessary in order to provide reliable predictions for observables outside the neutrino sector. We provide a proof of this master parametrization and show how to apply it for several well-known neutrino mass models from the literature. We also discuss a list of special cases, in which the Yukawa couplings have to fulfill some particular additional conditions.
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Alcaide, J., & Mileo, N. I. (2020). LHC sensitivity to singly charged scalars decaying into electrons and muons. Phys. Rev. D, 102(7), 075030–11pp.
Abstract: Current LHC searches for nonsupersymmetric singly charged scalars, based on two-Higgs-doublet models, in general, focus the analysis in third-generation fermions in the final state. However, singly charged scalars in alternative extensions of the scalar sector involve Yukawa couplings not proportional to the mass of the fermions. Assuming the scalar decays into electrons and muons, it can manifest cleaner experimental signatures. In this paper, we suggest that a singly charged scalar singlet, with electroweak production, can start to be probed in the near future with dedicated search strategies. Depending on the strength of the Yukawa couplings, two independent scenarios arc considered: direct pair production (small couplings) and single production via a virtual neutrino exchange (large couplings). We show that, up to a mass as large as 500 GeV, most of the parameter space could be excluded at the 95% C.L. in a high-luminosity phase of the LHC. Our results also apply to other frameworks, provided the singly charged scalar exhibits similar production patterns and dominant decay modes.
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Forero, D. V., Giunti, C., Ternes, C. A., & Tortola, M. (2021). Nonunitary neutrino mixing in short and long-baseline experiments. Phys. Rev. D, 104(7), 075030–11pp.
Abstract: Nonunitary neutrino mixing in the light neutrino sector is a direct consequence of type-I seesaw neutrino mass models. In these models, light neutrino mixing is described by a submatrix of the full lepton mixing matrix and, then, it is not unitary in general. In consequence, neutrino oscillations are characterized by additional parameters, including new sources of CP violation. Here we perform a combined analysis of short and long-baseline neutrino oscillation data in this extended mixing scenario. We did not find a significant deviation from unitary mixing, and the complementary data sets have been used to constrain the nonunitarity parameters. We have also found that the T2K and NOvA tension in the determination of the Dirac CP-phase is not alleviated in the context of nonunitary neutrino mixing.
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Cordero-Carrion, I., Hirsch, M., & Vicente, A. (2019). Master Majorana neutrino mass parametrization. Phys. Rev. D, 99(7), 075019–6pp.
Abstract: After introducing a master formula for the Majorana neutrino mass matrix, we present a master parametrization for the Yukawa matrices automatically in agreement with neutrino oscillation data. This parametrization can be used for any model that induces Majorana neutrino masses. The application of the master parametrization is also illustrated in an example model, with special focus on its lepton flavor violating phenomenology.
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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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Bigaran, I., Felkl, T., Hagedorn, C., & Schmidt, M. A. (2023). Flavor anomalies meet flavor symmetry. Phys. Rev. D, 108(7), 075014–77pp.
Abstract: We construct an extension of the Standard Model with a scalar leptoquark Q iota similar to (3,1, – 13) and the discrete flavor symmetry Gf _ D17 x Z17 to explain anomalies observed in charged-current semileptonic B meson decays and in the muon anomalous magnetic moment, together with the charged fermion masses and quark mixing. The symmetry Zdiag 17 , contained in Gf, remains preserved by the leptoquark couplings, at leading order, and efficiently suppresses couplings of the leptoquark to the first generation of quarks and/or electrons, thus avoiding many stringent experimental bounds. The strongest constraints on the parameter space are imposed by the radiative charged lepton flavor violating decays a -mu y and μ-ey. A detailed analytical and numerical study demonstrates the feasibility to simultaneously explain the data on the lepton flavor universality ratios R(D) and R(D*) and the muon anomalous magnetic moment, while passing the experimental bounds from all other considered flavor observables.
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Domingo, F., Kim, J. S., Martin Lozano, V., Martin-Ramiro, P., & Ruiz de Austri, R. (2020). Confronting the neutralino and chargino sector of the NMSSM with the multilepton searches at the LHC. Phys. Rev. D, 101(7), 075010–29pp.
Abstract: We test the impact of the ATLAS and CMS multilepton searches performed at the LHC with 8 as well as 13 TeV center-of-mass energy (using only the pre-2018 results) on the chargino and neutralino sector of the next-to-minimal supersymmetric Standard Model (NMSSM). Our purpose consists in analyzing the actual reach of these searches for a full model and in emphasizing effects beyond the minimal supersymmetric Standard Model (MSSM) that affect the performance of current (MSSM-inspired) electroweakino searches. To this end, we consider several scenarios characterizing specific features of the NMSSM electroweakino sector. We then perform a detailed collider study, generating Monte Carlo events through PYTHIA and testing against current LHC constraints implemented in the public tool CheckMATE. We find e.g., that supersymmetric decay chains involving intermediate singlino or Higgs-singlet states can modify the naive MSSM-like picture of the constraints by inducing final states with softer or less easily identifiable SM particles-reversely, a compressed configuration with singlino next-to-lightest supersymmetric particle occasionally induces final states that are rich with photons, which could provide complementary search channels.
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Coito, L., Faubel, C., & Santamaria, A. (2020). Composite Higgs bosons from neutrino condensates in an inverted seesaw scenario. Phys. Rev. D, 101(7), 075009–10pp.
Abstract: We present a realization of the idea that the Higgs boson is mainly a bound state of neutrinos induced by strong four-fermion interactions. The conflicts of this idea with the measured values of the top quark and Higgs boson masses are overcome by introducing, in addition to the right-handed neutrino, a new fermion singlet, which, at low energies, implements the inverse seesaw mechanism. The singlet fermions also develop a scalar bound state that mixes with the Higgs boson. This allows us to obtain a small Higgs boson mass even if the couplings are large, as required in composite scalar scenarios. The model gives the correct masses for the top quark and Higgs boson for compositeness scales below the Planck scale and masses of the new particles above the electroweak scale, so that we obtain naturally a low-scale seesaw scenario for neutrino masses. The theory contains additional scalar particles coupled to the neutral fermions, which could be tested in present and near future experiments.
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