Empirical formulas for the fermion spectra and Yukawa matrices

Ferrandis, Javier

doi:10.1140/epjc/s2004-02032-y

Cited by 8 publications

(18 citation statements)

References 33 publications

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“…As regards the oldest mass matrix relation V us ≈ m d /m s that was proposed forty years ago by Gatto, Sartori and Tonin (GST) [3], it is still in good agreement with the experimental values [1]. A few other empirical relations were proposed in [4]. The absence of enough well established regularities in the fermion mass pattern leaves open the way to many different explanations of the origin of fermion masses, and is probably the main reason why, in spite of all the theoretical efforts, no compelling theory has yet emerged.…”

Section: Introductionmentioning

confidence: 79%

Fermion mass hierarchy and nonhierarchical mass ratios inSU(5)×U(1)F

et al. 2008

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We consider a SU (5) × U (1)F GUT-flavor model in which the number of effects that determine the charged fermions Yukawa matrices is much larger than the number of observables, resulting in a hierarchical fermion spectrum with no particular regularities. The GUT-flavor symmetry is broken by flavons in the adjoint of SU (5), realizing a variant of the Froggatt-Nielsen mechanism that gives rise to a large number of effective operators. By assuming a common mass for the heavy fields and universality of the fundamental Yukawa couplings, we reduce the number of free parameters to one. The observed fermion mass spectrum is reproduced thanks to selection rules that discriminate among various contributions. Bottom-tau Yukawa unification is preserved at leading order, but there is no unification for the first two families. Interestingly, U (1)F charges alone do not determine the hierarchy, and can only give upper bounds on the parametric suppression of the Yukawa operators.

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Section: Introductionmentioning

confidence: 79%

Fermion mass hierarchy and nonhierarchical mass ratios inSU(5)×U(1)F

et al. 2008

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“…[37] for details, we obtain λ = 0.225±0.015 and ω = 0.071 ± 0.018. We note the similarity in the values for λ and ω calculated in the up and down type quark sectors from Eqs.…”

Section: A Quark Massesmentioning

confidence: 79%

“…26 were studied in Refs. [24,25,37]. In this subsection we briefly summarize results included in those references.…”

Section: A Quark Massesmentioning

confidence: 99%

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Solving the supersymmetricCPproblem with flavor breakingFterms

Díaz-Cruz¹,

Ferrandis

2005

Phys. Rev. D

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Supersymmetric flavor models for the radiative generation of fermion masses offer an alternative way to solve the SUSY-CP problem. We assume that the supersymmetric theory is flavor and CP conserving. CP violating phases are associated to the vacuum expectation values of flavor violating susy-breaking fields. As a consequence, phases appear at tree level only in the soft supersymmetry breaking matrices. Using a U (2) flavor model as an example we show that it is possible to generate radiatively the first and second generation of quark masses and mixings as well as the CKM CP phase. The one-loop supersymmetric contributions to EDMs are automatically zero since all the relevant parameters in the lagrangian are flavor conserving and as a consequence real. The size of the flavor and CP mixing in the susy breaking sector is mostly determined by the fermion mass ratios and CKM elements. We calculate the contributions to ǫ, ǫ ′ and to the CP asymmetries in the B decays to ψKs, φKs, η ′ Ks and Xsγ. We analyze a case study with maximal predictivity in the fermion sector. For this worst case scenario the measurements of ∆mK,∆mB and ǫ constrain the model requiring extremely heavy squark spectra.

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“…Here ρ = λ ′′ /λ ′ . Numerically, as a good approximation, m c /m t ≈ λ 3 /2 and m u /m c ≈ λ 4 (at low energy) [16]. Therefore, taking into account that a ≈ λ 2 , a good estimation of the couplings λ ′ and λ ′′ is λ ′ ≈ 3 and λ ′′ ≈ λλ ′ .…”

Section: Determination Of the Parameters Of The Modelmentioning

confidence: 94%

α≃π/2from supersymmetric spontaneous flavor breaking

Ferrandis

2006

Phys. Rev. D

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We propose a flavor model where both CP and flavor symmetries are broken at the supersymmetric level. The model is an effective SU(5) theory based on a U(2) horizontal symmetry. The minimum of the supersymmetric scalar potential can be exactly solved to yield a realistic pattern of charged fermion masses. The Higgs sector contains a symmetric, an antisymmetric and two vector fields, plus their U(2) conjugates. These Higgs fields are the only fields strictly required to break the flavor and CP symmetries and generate masses for all charged fermions including the up-quark. The model predicts the existence of an absolute minimum in the space of CP-phases. The value α ≃ π/2 is predicted in a particular limit of the parameter space of the model.

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Empirical formulas for the fermion spectra and Yukawa matrices

Abstract: We present empirical relations that connect the dimensionless ratios of fermion masses for the charged lepton, up-type quark and down-type quark sectors: |Vus| ≈ m d ms 1 2 ≈ mu mc 1 4 ≈ 3 me mµ 1 2

Cited by 8 publications

References 33 publications

Fermion mass hierarchy and nonhierarchical mass ratios inSU(5)×U(1)F

Fermion mass hierarchy and nonhierarchical mass ratios inSU(5)×U(1)F

Solving the supersymmetricCPproblem with flavor breakingFterms

α≃π/2from supersymmetric spontaneous flavor breaking

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