Flavor symmetries in an SU(5) model of grand unification

We investigate the options for imposing flavor symmetries on a minimal renormalizable non-supersymmetric SU(5) grand unified theory, without introducing additional flavor-related fields. Such symmetries reduce the number of free parameters in the model and therefore lead to more predictive models. We consider the Yukawa sector of the Lagrangian, and search for all possible flavor symmetries. As a result, we find 25 distinct realistic flavor symmetry cases, with ℤ2, ℤ3, ℤ4, and U(1) symmetries, and no non-Abelian cases.

Grand Unified Origin of Gauge Interactions and Families Replication in the Standard Model

The tremendous phenomenological success of the Standard Model (SM) suggests that its flavor structure and gauge interactions may not be arbitrary but should have a fundamental first-principle explanation. In this work, we explore how the basic distinctive properties of the SM dynamically emerge from a unified New Physics framework tying together both flavor physics and Grand Unified Theory (GUT) concepts. This framework is suggested by a novel anomaly-free supersymmetric chiral E6×SU(2)F×U(1)F GUT containing the SM. Among the most appealing emergent properties of this theory is the Higgs-matter unification with a highly-constrained massless chiral sector featuring two universal Yukawa couplings close to the GUT scale. At the electroweak scale, the minimal SM-like effective field theory limit of this GUT represents a specific flavored three-Higgs doublet model consistent with the observed large hierarchies in the quark mass spectra and mixing already at tree level.

Muon anomalous magnetic moment and Higgs potential stability in the 331 model from SU(6)

We consider a $$SU(3)_c \times SU(3)_L \times U(1)_X$$ S U ( 3 ) c × S U ( 3 ) L × U ( 1 ) X model from a SU(6) Grand Unified Theory (GUT). In order to explain the anomalous magnetic moments of muon and electron, we introduce two new scalar triplets without vacuum expectation values (VEVs) so that the leading contributions to $$\Delta a_{\mu }$$ Δ a μ and $$\Delta a_{e}$$ Δ a e can avoid the suppression from small muon mass. In addition, the Higgs potential stability of this 331 model is studied by giving a set of sufficient conditions to ensure the boundedness from below of the potential.

GUT-Monopole Searches by Means of Deep Underwater Baikal Neutrino Telescope

The procedure for Grand Unified Theory (GUT) monopole searches by means of the NT200 Baikal neutrino detector is described. Event-selection and background-suppression algorithms are discussed in detail. Limits on the flux of slow monopoles are presented and are compared with theoretical predictions and with the results of other experiments.

Effective ℒ5 Lagrangian and masses of Majorana neutrinos

Using the fact that neutrinos only participate in weak and gravitational interactions, we explore the possibility of having their masses emerged at the intersection between extended electroweak theory and theory of gravity. We describe how these two seemingly incompatible theories could be embedded in a lepton-number violating 5-dimensional Lagrangian [Formula: see text]. A peculiar feature of this approach is its ability to generate effective Majorana neutrino masses via the spontaneous symmetry breaking (SSB) of Grand Unified Theory (GUT), [Formula: see text] and 4[Formula: see text] symmetric matrix of gravitational couplings. Within the purview of this theoretical framework, we obtain values for the effective Majorana mass [Formula: see text][Formula: see text]meV, and the Majorana neutrino masses [Formula: see text][Formula: see text]meV, [Formula: see text][Formula: see text]meV, [Formula: see text][Formula: see text]meV, [Formula: see text][Formula: see text]meV and [Formula: see text][Formula: see text]eV. Our results are in good agreement with both experimental and cosmological data.

Deep in the Bones Lie Memories and Hopes: A Grand Unified Theory

Christ’s bones are missing at the Holy Sepulchre; St Peter’s bones remain in his basilica; Hagia Sophia was not built on bones. The absence, presence, or lack of bones effects different emphases on memory (anamnesis) and fulfillment (eschatology). In Jerusalem we witness our future glory (eschatology) already revealed in our history (anamnesis); in Rome we recall (anamnesis) the sacrifice of martyrs whose bones remain until the general resurrection (eschatology), even while we venerate the saints in light; at Hagia Sophia liturgy itself, rather than bones, provides the context for remembering the whole Christ in the power of the Spirit. Celebrating liturgy over the bones of martyrs in Rome, while venerating their sacrifice, may have accentuated the sacrificial character of the eucharistic liturgy in the Christian west, whereas in the Christian east the eschatological glory already revealed in our history and in liturgy may have shaped the eschatological character of liturgy.

Proton decay in supersymmetric SU(4)c × SU(2)L × SU(2)R

We discuss proton decay in a recently proposed model of supersymmetric hybrid inflation based on the gauge symmetry SU(4)c× SU(2)L× SU(2)R. A U(1) R symmetry plays an essential role in realizing inflation as well as in eliminating some undesirable baryon number violating operators. Proton decay is primarily mediated by a variety of color triplets from chiral superfields, and it lies in the observable range for a range of intermediate scale masses for the triplets. The decay modes include p → e+(μ+) + π0, $$ p\to \overline{\nu}+{\pi}^{+} $$ p → ν ¯ + π + , p → K0 + e+(μ+), and $$ p\to {K}^{+}+\overline{\nu} $$ p → K + + ν ¯ , with a lifetime estimate of order 1034–1036 yrs and accessible at Hyper-Kamiokande and future upgrades. The unification at the Grand Unified Theory (GUT) scale MGUT (∼ 1016 GeV) of the Minimal Supersymmetric Standard Model (MSSM) gauge couplings is briefly discussed.

Asymmetric tri-bi-maximal mixing and residual symmetries

Asymmetric tri-bi-maximal mixing is a recently proposed, grand unified theory (GUT) based, flavor mixing scheme. In it, the charged lepton mixing is fixed by the GUT connection to down-type quarks and a [Formula: see text] flavor symmetry, while neutrino mixing is assumed to be tri-bi-maximal (TBM) with one additional free phase. Here we show that this additional free phase can be fixed by the residual flavor and CP symmetries of the effective neutrino mass matrix. We discuss how those residual symmetries can be unified with [Formula: see text] and identify the smallest possible unified flavor symmetries, namely [Formula: see text] and [Formula: see text]. Sharp predictions are obtained for lepton mixing angles, CP violating phases and neutrinoless double beta decay.

Enhanced $\Gamma(p\to K^0\mu^+)/\Gamma(p\to K^+\bar{\nu}_\mu)$ as a signature of minimal renormalizable SUSY SO (10) GUT

The ratio of the partial widths of some dimension-5 proton decay modes can be predicted without detailed knowledge of supersymmetric (SUSY) particle masses, and this allows us to experimentally test various SUSY grand unified theory (GUT) models without discovering SUSY particles. In this paper, we study the ratio of the partial widths of the $p\to K^0\mu^+$ and $p\to K^+\bar{\nu}_\mu$ decays in the minimal renormalizable SUSY $SO(10)$ GUT, under only a plausible assumption that the 1st- and 2nd-generation left-handed squarks are mass-degenerate. In the model, we expect that the Wilson coefficients of dimension-5 operators responsible for these modes are on the same order and that the ratio of $p\to K^0\mu^+$ and $p\to K^+\bar{\nu}_\mu$ partial widths is $O(0.1)$. Hence, we may be able to detect both $p\to K^0\mu^+$ and $p\to K^+\bar{\nu}_\mu$ decays at Hyper-Kamiokande, thereby gaining a hint for the minimal renormalizable SUSY $SO(10)$ GUT. Moreover, since this partial width ratio is quite suppressed in the minimal $SU(5)$ GUT, it allows us to distinguish the minimal renormalizable SUSY $SO(10)$ GUT from the minimal $SU(5)$ GUT. In the main body of the paper, we perform a fitting of the quark and lepton masses and flavor mixings with the Yukawa couplings of the minimal renormalizable $SO(10)$ GUT, and derive a concrete prediction for the partial width ratio based on the fitting results. We find that the partial width ratio generally varies in the range $0.05$–$0.6$, confirming the above expectation.

Toward Classical Models of Nucleons and Nuclei

Nuclear models can be complicated and far from first principles. Inspired by Mills' Grand Unified Theory of Classical Physics, we will present a model of the interior of nucleons that predicts their masses well considering its simplicity. Then we will apply Mills' nucleon model to the problem of computing nuclear binding energies. Because the theory is constrained to agree with classical physics including Maxwell's Equations and Newton's Laws, for instance lacking special forces that only operate in the nucleus, the possible compatible nuclear theories are strictly limited which should make finding them easier.