Inclusion of fermions in the locally SU(2) ⊗ U(1)-invariant model with dynamical symmetry breaking

It is shown that dynamic symmetry breaking in the locally SU(2) U(1)-invariant model with mixed inclusion of fermions in a four-fermion interaction leads to a situation in which one collective scalar field, representing the sum of all generations of fermion-antifermion pairs, acts as the total (one-loop) effective Lagrangian. Mass formulas are found for the scalar field and gauge vector fields. The effective Lagrangian obtained coincides in form with the standard Lagrangian in the Glashow-Weinberg-Salam theory of electroweak interactions.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 41–45, July, 1991.     

Non-standard Higgs bosons inSU(2)×U(1) radiative corrections

The 1-loop renormalization of theSU(2)×U(1) electroweak gauge theory with two Higgs doublets is performed in the on-shell scheme with finite self energies and vertices. Assuming different vacuum expectation values for the scalar doublets, which yield enhanced Yukawa couplings to fermions, we calculate the effects of the additional Higgs bosons in the radiative corrections to the leptonic processes:μ-decay,v _μ e-scattering, ande ⁺ e ^?→μ ⁺ μ ^?,τ ⁺ τ ^? with longitudinal polarization at PETRA and LEP/SLC energies. It is found that large effects occur in theM _W ?M _Z mass relation, the determination of sin² θ _w from \(\sigma (v_\mu e)/\sigma (\bar v_\mu e)\) and thee ⁺ e ^? forward-backward and polarization asymmetries, if either the charged Higgs or the additional neutral scalar/pseudoscalar are heavy. Enhancement effects and effects of light neutral bosons can better be observed in thee ⁺ e ^?→τ ⁺ τ ^? integrated cross section.     

Yukawa couplings in SU(3)×SU(2)×U(1)Y orbifold models

We analyze the Yukawa couplings of the first SU(3)×SU(2)×U(1)_Y orbifold models recently obtained. In these models the rank is naturally lowered due to the presence of a Fayet-Iliopoulos term associated with an “anomalous” U(1) in the four-dimensional theory. It is shown that the phenomenological viability of the models selects a favoured class of vacua. In particular, for the specific examples considered, some twisted fields with one moded oscillator acting, must acquire non-vanishing VEVs. However other possibilities may exist. We also find that all the baryon and lepton violating operators can be, in general, avoided in a completely natural way.     

SU(3)_C×SU(2)_I×U(1)_Y复合轻子理论

假定HiggsYukawa耦合是宇称不守恒的唯一来源，通过取三代并引进超对称性，从而建立了一个SU（3）C×SU（2）I×U（1）Y复合轻子理论。     

On superstring-inspired SU(3) × SU(2) × (U(1))2 models with SO(10) unification

Alternative compactification of the heterotic superstring can give rise to a residual four-dimensional SO(10) gauge symmetry for the observable sector. We consider a model with gauge group SU(3) × SU(2) × (U(1))², resulting from the Hosotani breaking of SO(10), study its further gauge symmetry breaking and calculate the particle spectrum. We find that all breakings can occur close to the weak scale; the top mass lies preferentially between 40 and 60 GeV, the second Z boson mass is O(200–400) GeV. The sparticle spectrum is quite heavy, apart possibly from a light chargino, whose mass can be as light as O(30) GeV.     

More flipped SU(5)×U(1) baryosynthesis

We supplement a previous discussion of baryosynthesis in flipped SU(5)×U(1) GUTs by including (1) the large incoherent field energy density which is likely SU(5) is broken, and (2) the possibility of additional Higgs triplet fields suggested by four dimensional string model-building. We consider strong (weak) reheating scenarios in which the Universe is (is not) SU(5) symmetric after inflation. We find an adequate baryon asymmetry subsequent to strong reheating, whatever the number of Higgs triplets (although beware of possible difficulties with quasi-stable relic particles), whereas weak reheating requires at least two Higgs triplets.     

SU(2) ×U(1) Gauge theory of bosonic and fermionic fields inS 3 ×R space-time

The tetradic Lorentz-gauge invariant formulation of the SU(2) × U(1) theory in S³ × R space-time is presented and the general gauge covariant Dirac-Klein-Gordon-Maxwell-Yang-Mills equations are derived. A direct comparison of these equations to those of the SU(2) × U(1) gauge theory on Minkowskian background points out major differences effectively induced by the minimally coupling to S³ × R gravity.     

Spontaneous SU(2) symmetry violation in the SU(2) L × SU(2) R × SU(4) electroweak model

A new approach to electroweak (EW) composite scalars is developed starting from the fundamental gauge interaction on high scale. The latter is assumed to have the group structure SU(2) _L × SU(2) _R × SU(4), where SU(4) is the Pati-Salam color-lepton group. The topological EW vacuum filled by instantons is explicitly constructed and the resulting equations for fermion masses exhibit spontaneous SU(2) flavor symmetry violation with possibility of very large mass ratios.     

SU(4)⊕SU(2)⊕U(1)统一模型

本文提出一种SU(4)SU(2)U(1)统一模型。在此模型中,层子和轻子放于同一个多重态中,所以它们有耦合,但这种耦合不会导致质子衰变,只对高能散射有效应。此模型预言了有两种中性中间玻色子,还算得了sin~2θ_w=0.25,并可使中微子有合理的质量。     

弱电统一理论——SU(3)×U(1)模型

本文提出了一个对称性破缺前不仅左、右对称, 而且中微子(或反中微子)与荷电轻子、反轻子的弱作用也相同的SU(3)×U(1)模型. 这一模型无三角反常; 导出了sin²θ_w≤1/4; 在低能范围内与标准模型一致. 我们反轻子数推广为轻子荷. 证明了只有轻子荷才是严格守恒的, 各代轻子数分别守恒只能近似成立. 夸克不仅带有重子数、电荷, 而且也带有轻子荷. 本模型预言有μ_R→e_R+ν_eL+ν_μR, e^－+e^－→μ^－+μ^－等现象.     

An SU (3)_L×U(1)_X Electroweak Model

We studied an SU(3)_L×U(1)_X electroweak model. By requiring M2z1-M2w/ cos²θw to be less than experimental value we abtain a lower bound on M_Z′ The relation between M_Z′ and M_U (M_V) then gives a lower bound on M_U (M_V). We further consider the K_L－K_S mass difference due to Z′ exchange and obtain stronger lower bounds on M_Z′ and M_U (M_V).     

The phase structure of SU(2) × U(1)Y lattice gauge theory

Using analytic and Monte Carlo techniques, we determine the phase structure and nature of spontaneous symmetry breaking of the SU(2) × U(1)_Y electroweak gauge theory with fixed-length Higgs fields on a lattice. We find that it has two completely separated phases: (a) a disordered, symmetric phase and (b) a phase in which SU(2) × U(1)_Y is spontaneously broken to U(1)_em, which is realized in its deconfined Coulomb phase with massless photons. Exact analytic results and approximate series expansions are given for various special cases of the theory.     

Dynamical symmetry breaking in an SU(2)⊗U(1) model with two right singlets and gauge boson masses

A four-fermion interaction which includes right singlets of both up and down fermions is included in the initial locally SU(2)S(1)-invariant model. In the suitable approximation, the propagators are constructed and the mass spectrum is found of fermi and gauge vector fields as well as of the collective scalar fields due to the dynamical symmetry breakdown.Translated from Izvestiya Uchebnykh Zavedenii, Fizika, No. 4, pp. 98–104, April, 1990.     

SU(3)C×SU(2)I×U(1)Y复合轻子理论

假定HiggsYukawa耦合是宇称不守恒的唯一来源,通过取三代并引进超对称性,从而建立了一个SU(3)_C×SU(2)_I×U(1)_Y复合轻子理论.     

SU(3)C×SU(2)I×U(1)Y Theory of Composite Leptons

Assuming Higgs Assuming coupling to be the only origin of parity non-conservation, an SU(3)_C×SU(2)_I×U(1)_Y theory of composite leptons is established in the Scheme of three generations and supersymmetry.     

SU(3)×SU(3) symmetry breaking, (8, 8) Model and theη→3π decay

It is shown that the (8, 8) model and explicitηπ ⁰ mixing successfully explain theη→3π decay width whereas the decay width calculated from the mass difference is about one order less than the experimental value.     

SU(5) andSU(2)×U(1) radiative breakings inN=1 supergravity unified models

Non-minimalSU(5) supergravity GUTs are analyzed in order to obtain theSU(5) andSU(2)×U(1) breakings à la Coleman-Weinberg as dynamical effects generated by the soft breaking terms, residues of supergravityN=1 (minimally coupled). Solutions are found that predict the existence ofSU(2)-triplets andSU(3)-octets as heavy asO(1 TeV). Supersymmetric Higgs masses, of the same order than the gravitino mass, must be introduced for the heavy, Σ(24), and lightH ₁ (2),H ₂ (2) sectors. Imposing the experimental bound \(m_{\tilde g} \gtrsim 60GeV\) , the lower boundsm _3/2?30 GeV, \(m_{\bar e} > 140GeV\) \(m_{\bar u} > 133GeV\) are obtained.