The first string-derived eclectic flavor model with realistic phenomenology

Abstract

Eclectic flavor groups arising from string compactifications combine the power of modular and traditional flavor symmetries to address the flavor puzzle. This top-down scheme determines the representations and modular weights of all matter fields, imposing strict constraints on the structure of the effective potential, which result in controlled corrections. We study the lepton and quark flavor phenomenology of an explicit, potentially realistic example model based on a 𝕋6/ℤ3× ℤ3 orbifold compactification of the heterotic string that gives rise to an Ω(2) eclectic flavor symmetry. We find that the interplay of flavon alignment and the localization of the modulus in the vicinity of a symmetry-enhanced point leads to naturally protected fermion mass hierarchies, favoring normal-ordered neutrino masses arising from a see-saw mechanism. We show that our model can reproduce all observables in the lepton sector with a small number of parameters and deliver predictions for so far undetermined neutrino observables. Furthermore, we extend the fit to quarks and find that Kähler corrections are instrumental in obtaining a successful simultaneous fit to the quark and lepton sectors.

Lessons from eclectic flavor symmetries

“…23,26 Uncontrollable corrections to the Kähler-potential 33 are avoided through the approximate traditional flavor symmetry ∆(54), while controllable corrections allow for a description of the quark sector. 32 The model predicts a see-saw mechanism in the lepton sector and a normal hierarchy for neutrino masses. The best-fit modulus, shown in fig.…”

“…31 They constructed realistic models with standard model gauge group and three families of quarks and leptons and traditional flavor group ∆(54). We selected a specific model 32 where the twisted states are in a 3 2 -representation of ∆(54) as well as a 1 ⊕ 2 ′ of T ′ with modular weight k = −2/3. Observe, that in the top-down approach these representations and the modular weight are restricted to specific values.…”

CP symmetry and symplectic modular invariance

“…The latter affects the fermion mass spectrum [31], except for the case of minimal or flavor universal Kähler potential. Some progress in dealing with this problem has been made with the introduction of eclectic flavour symmetries [32][33][34][35][36][37][38], but the prize is the reintroduction of a nonminimal symmetry-breaking sector [39][40][41][42]. Even considering the lepton sector alone, by exploiting the existing freedom a large number of models correctly reproducing neutrino masses, lepton mixing angles, and predicting leptonic CP-violating phases have been formulated [29,30].…”

Spectral distortions from promising single and multifield inflationary models

“…We now turn our focus to a more interesting model, for which the interactions between the two fields lead to a non-trivial manifold structure, and therefore, to a non-trivial evaluation of the inflationary observables. This model is defined in a no-scale supergravity framework, inspired by orbifold compactifications of strings [81][82][83] in which matter fields have non-vanishing modular weights [84][85][86][87][88][89]. Concretely, it is assumed that the ratios of the (three) orbifold Kähler moduli are fixed at a high scale, so that the Kähler potential can be written as…”