Natural R-parity, μ-term, and fermion mass hierarchy from discrete gauge symmetries

Babu, K. S.; Gogoladze, Ilia; Wang, Kai

doi:10.1016/s0550-3213(03)00258-x

Cited by 79 publications

(84 citation statements)

References 60 publications

(37 reference statements)

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“…On SM fields P 6 , as defined by the charge assignments in Table 1, acts as a Z 6 symmetry which is the product of baryon triality and matter parity. Proton hexality had been discussed before in [26][27][28][29]. It forbids all dangerous dimension four and five baryon or lepton number violating couplings while phenomenologically desirable couplings are allowed.…”

Section: Proton Hexalitymentioning

confidence: 99%

Proton hexality in local grand unification

et al. 2010

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Section: Proton Hexalitymentioning

confidence: 99%

Proton hexality in local grand unification

et al. 2010

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“…Let us suppose also that the invisible axion is protected against gravitational effects by a local, in the sense of Ref. [16], Z N 's cyclic symmetries [17,18]. In general, these symmetries can be anomalous but we will not address this issue here.…”

mentioning

confidence: 99%

Invisible axion and neutrino masses

Dias¹,

Pleitez²

2006

Phys. Rev. D

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We show that in any invisible axion model due to the effects of effective nonrenormalizable interactions related to an energy scale near the Peccei-Quinn, grand unification or even the Planck scale, active neutrinos necessarily acquire masses in the sub-eV range. Moreover, if sterile neutrinos are also included and if appropriate cyclic Z N symmetries are imposed, it is possible that some of these neutrinos are heavy while others are light. DOI: 10.1103/PhysRevD.73.017701 PACS numbers: 14.80.Mz, 14.60.St, 14.60.Pq A natural and elegant way to explain the small value of the active neutrino's masses is the so-called seesaw mechanism which is implemented when heavy right-handed sterile neutrinos, i. e., transforming as singlet under the standard model SU2 L U1 Y gauge symmetry, are added [1]. Moreover, depending on future neutrino oscillation data, light sterile neutrinos [2] may be a necessary ingredient of the physics beyond the standard model. From neutrino oscillation experiments we already know that active neutrinos have a nonvanishing mass in the sub-eV region [3,4] but, since the Z 0 invisible width implies the existence of only three light active neutrinos, any additional light neutrino has to be sterile and there are several possibilities that keep consistency with LEP data [5,6]. The problem is how to implement, in a natural way, light sterile neutrinos. Since they are not protected by the standard model symmetries, they may acquire Majorana masses of the order of the next (if any) energy scale. A solution is the addition of sterile Higgs scalars and a new exact global symmetry [7,8]. The important point is that such a symmetry forbids the Dirac mass term avoiding in this way the seesaw mechanism and the sterile scalar singlet having a vacuum expectation value chosen just to generate light sterile neutrinos. Light sterile neutrinos may also appear in supersymmetric models [9].On the other hand, the introduction of a global chiral (Peccei-Quinn) symmetry is an elegant solution to the strong CP problem [10] implying in the existence of a pseudo Goldstone boson, the axion [11], which besides solving the strong CP problem it is certainly a leading candidate for dark matter. Searches for the axion have been done over the years. Recently, an upper limit was obtained for the axion-photon coupling g a < 1:16 10 ÿ10 GeV ÿ1 if m a & 0:02 eV [12,13]. In fact, the expected mass for the axion, coming from several experimental or observational constraints, is in the interval 10 ÿ6 < m a < 10 ÿ2 eV, and we see that this interval is near to the neutrino masses required to explain solar and atmospheric neutrino data [3]. This fact suggests the existence of a common new energy scale being responsible for such small masses, which in this case would be that one related to the invisible axion.Although the existence of a relation between the axion and the seesaw mechanism for generating neutrino masses has already been considered, in particular models [14], here we will put forward that it is inevitable that neutrinos get ...

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“…Diquark scalar can be 3 ⊗ 3 = 6 ⊕3 under SU (3) [24], the down type squarkd i can mediated u-channel dd → tt that interferes with the QCD dd → tt.…”

Section: B T-channelmentioning

confidence: 99%

Revisit to top quark forward-backward asymmetry

2012

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We analyze various models for the top quark forward-backward asymmetry (A t F B ) at the Tevatron, using the latest CDF measurements on different A t F B s and the total cross section. The axigluon model in Ref.[5] has difficulties in explaining the large rapidity dependent asymmetry and mass dependent asymmetry simultaneously and the parameter space relevant to A t F B is ruled out by the latest dijet search at ATLAS. In contrast to Ref.[8], we demonstrate that the large parameter space in this model with a U (1) d flavor symemtry is not ruled out by flavor physics.The t-channel flavor-violating Z ′ , W ′ and diquark models all have parameter regions that satisfy different A F B measurements within 1 σ. However, the heavy Z ′ model which can be marginally consistent with the total cross section is severely constrained by the Tevatron direct search of samesign top quark pair. The diquark model suffers from too large total cross section and is difficult to fit the tt invariant mass distribution. The electroweak precision constraints on the W ′ model based on Z ′ -Z mixings is estimated and the result is rather weak (m Z ′ > 450 GeV). Therefore, the heavy W ′ model seems to give the best fit for all the measurements. The W ′ model predicts the tt + j signal from tW ′ production and is 10%-50% of SM tt at the 7 TeV LHC. Such t + j resonance can serve as the direct test of the W ′ model.

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Natural R-parity, μ-term, and fermion mass hierarchy from discrete gauge symmetries

Cited by 79 publications

References 60 publications

Proton hexality in local grand unification

Proton hexality in local grand unification

Invisible axion and neutrino masses

Revisit to top quark forward-backward asymmetry

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