共查询到20条相似文献,搜索用时 15 毫秒
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A. A. Natale 《Zeitschrift fur Physik C Particles and Fields》1984,21(3):273-276
We show how the use of the so called irregular solution for the fermionic self-energy, enables to raise the extended technicolor mass scale, avoiding the problems of flavor changing neutral currents in dynamically broken gauge theories. 相似文献
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By adding suitable discrete flavor symmetries to SU(2)L ? SU(2)R ? U(1) left-right symmetric gauge models of weak and electromagnetic interactions, we are able to express all the mixing angles between the quark flavors (u, d, s,c) in terms of the quark masses. This enables us to compute the Cabibbo angle and the CP violating phases using plausible values for the quark masses. The CP violating K ar 2π decay amplitude η+? (and η00 in the model is then given purely in terms of the parity violating parameter of the model (mWL+/mWR+)2. 相似文献
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Keyan Yang 《International Journal of Theoretical Physics》1997,36(9):2023-2034
For strong enough Yukawa coupling the electroweak standard model fermion finds it energetically advantageous to transform
itself into a bound state in the hedgehog background of the Higgs field in the semiclassical approximation. By considering
that the bound states give the masses for the lepton and quark, it is found that all fermion masses can be described by the
strongly Yukawa coupling constants which tend to a unitary constant. 相似文献
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It is pointed out that the recent measurement of the angle γ of the unitarity triangle, providing irrefutable evidence for a complex Cabibbo–Kobayashi–Maskawa (CKM) matrix, presents a great challenge for supersymmetric models with spontaneous CP violation. We construct a new minimal extension of the minimal supersymmetric standard model (MSSM), with spontaneous CP breaking, which leads to a complex CKM matrix, thus conforming to present experimental data. This is achieved through the introduction of two singlet chiral superfields and a vector-like quark chiral superfield which mixes with the standard quarks. A Z3 symmetry is introduced in order to have a potential solution to the strong CP problem. 相似文献
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We study CP violation in a multi-Higgs doublet model based on aS
3×Z
3 horizontal symmetry. We consider two mechanisms for CP violation in this model: a) CP violation due to complex Yukawa couplings;
and b) CP violation due to scalarpseudoscalar mixings. We find that the predictions for ε′/ε, CP violation in B decays and
the electric dipole moments of neutron and electron are different between these two mechanisms. These predictions are also
dramatically different from the minimal Standard Model predictions. 相似文献
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We study CP violation in a multi-Higgs doublet model based on aS 3×Z 3 horizontal symmetry. We consider two mechanisms for CP violation in this model: a) CP violation due to complex Yukawa couplings; and b) CP violation due to scalarpseudoscalar mixings. We find that the predictions for ε′/ε, CP violation in B decays and the electric dipole moments of neutron and electron are different between these two mechanisms. These predictions are also dramatically different from the minimal Standard Model predictions. 相似文献
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Y.A. Coutinho J.A. Martins Simões C.M. Porto 《The European Physical Journal C - Particles and Fields》2001,18(4):779-784
In this paper we discuss a left–right symmetric model for elementary particles and their connection with the mass spectrum
of elementary fermions. The model is based on the group . New mirror fermions and a minimal set of Higgs particles that break this symmetry down to are proposed. The model can accommodate a consistent pattern for charged and neutral fermion masses as well as neutrino oscillations.
An important consequence of the model is that the connection between the left and right sectors can be implemented by the
neutral vector gauge boson Z and a new heavy Z'.
Received: 15 June 2000 / Revised version: 14 September 2000 / Published online: 5 February 2001 相似文献
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Many different experiments are being developed to explore the existence of the neutrinoless double beta decay (0νββ) since it would imply fundamental consequences for particle physics. In this work we present results on the evaluation of Timepix detectors with cadmium-telluride sensor material to search for 0νββ in 116Cd. This work was carried out with the COBRA collaboration and the Medipix collaboration. Due to the relatively small pixel dimension of 110×110×1000 μm3 the energy deposited by particles typically extends over several detector pixels leading to a track in the pixel matrix. We investigated the separation power regarding different event-types like α-particles, atmospheric muons, single electrons and electron-positron pairs produced at a single vertex. We achieved excellent classification power for α-particles and muons. In addition, we achieved good separation power between single electron and electron-positron pair production events. These separation abilities indicate a very good background reduction for the 0νββ search. Further, in order to distinguish between 2νββ and 0νββ, the energy resolution is of particular importance. We carried out simulations which demonstrate that an energy resolution of 0.43 % is achievable at the Q-value for 0νββ of 116Cd at 2.814 MeV. We measured an energy resolution of 1.6 % at a nominal energy of 1589 keV for electron-positron tracks which is about two times worse that predicted by our simulations. This deviation is probably due to the problem of detector calibration at energies above 122 keV which is discussed in this paper as well. 相似文献
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《Physics letters. [Part B]》1997,406(4):321-327
The reported anomaly in deep-inelastic scattering at HERA has revived interest in the phenomenology of R-parity violation. From the theoretical point of view, the existence of R-violating interactions poses two considerable problems. The first one concerns the flavour structure of the interactions and the origin of an appropriate suppression of flavour-changing neutral-current processes and lepton-family transitions. The second one concerns the way of embedding R-violating interactions in a grand unified theory (GUT) without introducing unacceptable nucleon decay rates. We show that the second problem can be solved by mechanism which is purely group theoretical and does not rely on details of the flavour theory. We construct explicit GUT models in which our mechanism can be realized. 相似文献
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The extended Cabibbo current with CP-violation in a six quark gauge model is obtained in terms of quark mass ratios and phases in the quark mass matrices. The model predicts a long-lived heavy quark and its selection rule. 相似文献