arXiv subjects

Yukimura Izawa

Publications and source records attributed to Yukimura Izawa.

3 recordsLinked to original sources

arXiv2026

Branched polymers with loops coupled to the critical Ising model

We study the continuum limit of branched polymers (BPs) with loops coupled to Ising spins at the zero-temperature critical point. It is known that the continuum partition function can be represented by a Hermitian two-matrix model, and we propose a string field theory whose Dyson-Schwinger equation coincides with the loop equation of this continuum matrix model. By setting the matrix size to one, we analyze a convergent non-perturbative partition function expressed as a two-dimensional integral, and show that it satisfies a third-order linear differential equation. In contrast, in the absence of coupling to the critical Ising model, the continuum partition function of pure BPs with loops is known to satisfy the Airy equation. From the viewpoint of two-dimensional quantum gravity, we introduce a non-perturbative loop amplitude that serves as a solution to the Wheeler-DeWitt equation incorporating contributions from all genera. Furthermore, we demonstrate that the same Wheeler-DeWitt equation can also be derived through the stochastic quantization.

hep-th↗

arXiv2023

$S_4$ Lepton Flavor Model with 3HDM

We prsent a lepton flavor model with $S_4$ and $U(1)_{\mathrm{FN}}$ symmetry. The left-handed leptons are assigned as a triplet under the $S_4$ symmetry, the right-handed electron and muon as $S_4$ doublets, and the right-handed tauon as an $S_4$ singlet. We introduce three right-handed Majorana neutrinos that are charged under the $S_4$ symmetry and two scalar fields. Additionally, the three Higgs doublets are assigned as an $S_4$ triplet, and we analyze the scalar potential to get the conditions for the Higgs VEVs. We numerically calculate the PMNS matrix, and give strong predictions for the mixing angle $0.486<\sinθ_{23}<0.603$ and the Dirac CP phase $60.12^\circ<|δ_{CP}|<76.47^\circ$. Our predictions for the lightest neutrino mass $m_{light}\simeq5.53~[\mathrm{meV}]$ and the effective Majorana neutrino mass $m_{ee}\simeq6.33~[\mathrm{meV}]$ from the neutrinoless double beta decay experiments are relatively close to upper limits. Lastly, we obtain the sum of neutrino masses $m_1+m_2+m_3\simeq66.1~[\mathrm{meV}]$, and two Majorana phases $η_1$ and $η_2$.

hep-ph↗

arXiv2023

Non-SUSY Lepton Flavor Model with 3HDM

We propose a simple non-supersymmetric lepton flavor model with $A_4$ symmetry. The $A_4$ group is a minimal one which includes triplet irreducible representation. We introduce three Higgs doublets which are assigned as triplet of the $A_4$ symmetry. It is natural that there are three generations of the Higgs fields as same as the standard model fermions. We study the potential analysis and we get the vacuum expectation values for the local minimum. In the vacuum expectation values, we obtain the charged lepton, Dirac neutrino, and right-handed Majorana neutrino mass matrices. By using type-I seesaw mechanism, we get the left-handed Majorana neutrino mass matrix. In the NuFIT 5.1 data, we predict the Dirac CP phase and the Majorana phases for the only inverted neutrino mass hierarchy. Especially, the Dirac CP phase and lepton mixing angle $θ_{23}$ are strongly correlated. If the $θ_{23}$ is more precise measured, the Dirac CP phase is more precise predicted, and vice versa. We also predict the effective mass for neutrino-less double beta decay $m_{ee}\simeq 47.1~[\mathrm{meV}]$ and the lightest neutrino mass $m_3\simeq 0.789$~-~$1.43~[\mathrm{meV}]$. It is testable for our model in the near future neutrino experiments.

hep-ph↗