skip to main content


Search for: All records

Creators/Authors contains: "Gonzalez-Garcia, M. C."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. A bstract The exchange of a pair of neutrinos with Standard Model weak interactions generates a long-range force between fermions. The associated potential is extremely feeble, ∝ $$ {G}_F^2/{r}^5 $$ G F 2 / r 5 for massless neutrinos, which renders it far from observable even in the most sensitive experiments testing fifth forces. The presence of a neutrino background has been argued to induce a correction to the neutrino propagator that enhances the potential by orders of magnitude. In this brief note, we point out that such modified propagators are invalid if the background neutrino wavepackets have a finite width. By reevaluating the 2- ν exchange potential in the presence of a neutrino background including finite width effects, we find that the background-induced enhancement is reduced by several orders of magnitude. Unfortunately, this pushes the resulting 2- ν exchange potential away from present and near-future sensitivity of tests of new long-range forces. 
    more » « less
    Free, publicly-accessible full text available April 1, 2024
  2. A bstract 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. 
    more » « less
  3. A bstract 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 non-standard 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. 
    more » « less
  4. null (Ed.)
    A bstract We quantify the effect of gauge bosons from a weakly coupled lepton flavor dependent U(1) ′ interaction on the matter background in the evolution of solar, atmospheric, reactor and long-baseline accelerator neutrinos in the global analysis of oscillation data. The analysis is performed for interaction lengths ranging from the Sun-Earth distance to effective contact neutrino interactions. We survey ∼ 10000 set of models characterized by the six relevant fermion U(1) ′ charges and find that in all cases, constraints on the coupling and mass of the Z′ can be derived. We also find that about 5% of the U(1) ′ model charges lead to a viable LMA-D solution but this is only possible in the contact interaction limit. We explicitly quantify the constraints for a variety of models including $$ \mathrm{U}{(1)}_{B-3{L}_e} $$ U 1 B − 3 L e , $$ \mathrm{U}{(1)}_{B-3{L}_{\mu }} $$ U 1 B − 3 L μ , $$ \mathrm{U}{(1)}_{B-3{L}_{\tau }} $$ U 1 B − 3 L τ , $$ \mathrm{U}{(1)}_{B-\frac{3}{2}\left({L}_{\mu }+{L}_{\tau}\right)} $$ U 1 B − 3 2 L μ + L τ , $$ \mathrm{U}{(1)}_{L_e-{L}_{\mu }} $$ U 1 L e − L μ , $$ \mathrm{U}{(1)}_{L_e-{L}_{\tau }} $$ U 1 L e − L τ , $$ \mathrm{U}{(1)}_{L_e-\frac{1}{2}\left({L}_{\mu }+{L}_{\tau}\right)} $$ U 1 L e − 1 2 L μ + L τ . We compare the constraints imposed by our oscillation analysis with the strongest bounds from fifth force searches, violation of equivalence principle as well as bounds from scattering experiments and white dwarf cooling. Our results show that generically, the oscillation analysis improves over the existing bounds from gravity tests for Z′ lighter than ∼ 10 − 8 → 10 − 11 eV depending on the specific couplings. In the contact interaction limit, we find that for most models listed above there are values of g′ and M Z′ for which the oscillation analysis provides constraints beyond those imposed by laboratory experiments. Finally we illustrate the range of Z′ and couplings leading to a viable LMA-D solution for two sets of models. 
    more » « less
  5. null (Ed.)
  6. null (Ed.)