Lepton Flavor Violating Decays and (g-2) Anomalies in 3-3-1 Models with Inverse Seesaw Neutrinos

Keskeiset käsitteet

The 3-3-1 models with inverse seesaw neutrinos can accommodate the experimental data on (g-2) anomalies of charged leptons and constrain the rates of lepton flavor violating decays of the Higgs and Z bosons.

Tiivistelmä

The paper discusses the lepton flavor violating (LFV) decays h, Z→ebea and eb→eaγ in a class of general 3-3-1 models with inverse seesaw neutrinos. The models can explain the experimental data on the (g-2) anomalies of the electron and muon.
The key highlights are:

The 3-3-1 models with the minimal number of inverse seesaw neutrinos (mISS) cannot reach the 1σ range of the (g-2)μ data due to the experimental upper bounds on the decay rates of τ→μγ and μ→eγ.
The features of the LFV decays are presented in detail, focusing on the allowed regions of parameters that successfully explain the 1σ ranges of the (g-2)e,μ data.
Analytical formulas for the dominant one-loop contributions to the (g-2)e,μ anomalies and LFV decay rates are derived, showing a strict relation between Δaμ and Br(τ→μγ) in the 331βmISS framework.
Numerical illustrations for the relations among the LFV decay rates, Δae,μ, and important parameters of the 331βmISS and 331βISS models are provided.

Tilastot

The experimental data used in the analysis:

Δaμ = (2.49 ± 0.48)×10-9 (5.1σ deviation from the SM prediction)
Δae = (3.4 ± 1.6)×10-13 or Δae = (-10.2 ± 2.6)×10-13 (3.9σ deviation from the SM prediction)
Br(μ→eγ) < 3.1×10-13, Br(τ→eγ) < 3.3×10-8, Br(τ→μγ) < 4.2×10-8
Br(h→τμ) < 1.5×10-3, Br(h→τe) < 2×10-3, Br(h→μe) < 4.4×10-5
Br(Z→τ±μ∓) < 6.5×10-6, Br(Z→τ±e∓) < 5.0×10-6, Br(Z→μ±e∓) < 2.62×10-7

Lainaukset

"The models with the minimal number of inverse seesaw neutrinos cannot reach the 1σ range of (g-2)μ data due to the experimental upper bounds on decay rates of (τ→μγ) and (μ→eγ)."
"We show that the models with the minimal number of inverse seesaw neutrinos cannot reach the 1σ range of (g-2)μ data due to the experimental upper bounds on decay rates of (τ→μγ) and (μ→eγ)."

Tärkeimmät oivallukset

$(g-2)_{e,\mu}$ anomalies and decays $h, Z\to e_b e_a $ in 3-3-1 models with inverse seesaw neutrinos

by T.T. Hong, L... klo arxiv.org 10-03-2024

https://arxiv.org/pdf/2404.05524.pdf

Syvällisempiä Kysymyksiä

What other extensions of the 3-3-1 models, beyond the ones considered in this work, could potentially accommodate both the (g-2)e,μ anomalies and the experimental constraints on lepton flavor violating processes?

Beyond the extensions discussed in the provided work, several other theoretical frameworks could potentially accommodate both the (g-2)e,μ anomalies and the experimental constraints on lepton flavor violating (LFV) processes within the 3-3-1 model context. One promising avenue is the incorporation of supersymmetry (SUSY), which introduces superpartners for all Standard Model particles. SUSY can provide additional contributions to the (g-2) anomalies through loop diagrams involving these superpartners, potentially alleviating discrepancies with experimental data.
Another extension could involve the introduction of extra dimensions, where Kaluza-Klein modes of particles could contribute to the effective interactions leading to LFV processes. This framework could also modify the mass spectrum of the particles involved, allowing for new decay channels that could be consistent with both the (g-2) anomalies and LFV constraints.
Additionally, models that include new gauge symmetries or extended Higgs sectors, such as those found in two-Higgs doublet models (2HDM) or multi-Higgs models, could also provide the necessary degrees of freedom to explain the observed anomalies while respecting experimental limits on LFV processes. These models can introduce additional scalar particles that couple differently to leptons, potentially enhancing LFV decay rates without violating existing constraints.

How would the inclusion of additional new particles, such as vectorlike fermions or leptoquarks, affect the correlations between the (g-2) anomalies and the lepton flavor violating decays in the 3-3-1 framework?

The inclusion of additional new particles, such as vectorlike fermions or leptoquarks, would significantly impact the correlations between the (g-2) anomalies and lepton flavor violating decays within the 3-3-1 framework.
Vectorlike fermions can contribute to the (g-2) anomalies through loop diagrams, similar to how the existing fermions do. Their mass and coupling properties can be tuned to enhance the contributions to the (g-2) of both electrons and muons, potentially bringing the theoretical predictions into better agreement with experimental results. However, these same vectorlike fermions can also participate in LFV processes, which may lead to tighter constraints on their masses and couplings. The interplay between their contributions to (g-2) and LFV decays could create a delicate balance, where enhancing one could inadvertently suppress the other, depending on the specific couplings and mass scales involved.
Leptoquarks, on the other hand, provide a direct coupling between leptons and quarks, which can lead to new LFV processes that are not present in the Standard Model. Their presence could enhance LFV decay rates, such as those involving transitions between different lepton flavors. This enhancement could potentially conflict with existing experimental bounds unless their masses are sufficiently high or their couplings are suppressed. Thus, while leptoquarks could provide additional avenues to explore the (g-2) anomalies, they would also necessitate careful consideration of the resulting LFV processes to remain consistent with experimental constraints.

Could the insights gained from this study on the interplay between (g-2) anomalies and lepton flavor violation be applied to other beyond-the-Standard-Model scenarios to guide future experimental searches?

Yes, the insights gained from this study on the interplay between (g-2) anomalies and lepton flavor violation (LFV) can indeed be applied to other beyond-the-Standard-Model (BSM) scenarios to guide future experimental searches. The correlations established in the context of the 3-3-1 models provide a framework that can be adapted to various BSM theories, such as supersymmetry, extra dimensions, or composite Higgs models.
For instance, the methodologies used to analyze the contributions to (g-2) and LFV processes can be employed in SUSY models, where the additional superpartners can lead to similar anomalies. The relationships between the parameters governing these processes can help identify regions of parameter space that are more likely to yield observable effects, guiding experimentalists in their search for new physics.
Moreover, the study's findings can inform the design of future experiments by highlighting specific decay channels or processes that are particularly sensitive to new physics. For example, if certain LFV decays are predicted to be enhanced in a specific BSM scenario, experiments can prioritize these channels for detection.
Additionally, the insights can also be useful in interpreting results from current experiments, such as those at the Large Hadron Collider (LHC) or upcoming high-luminosity colliders. By understanding the potential connections between (g-2) anomalies and LFV, researchers can better assess the implications of their findings and refine their theoretical models accordingly.
In summary, the interplay between (g-2) anomalies and LFV processes provides a rich landscape for exploring new physics, and the insights from this study can significantly contribute to the ongoing search for BSM phenomena.