17,388 research outputs found

    Atomic parity violation in the economical 3-3-1 model

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    The deviation \de Q_{\mathrm{W}} of the weak charge from its standard model prediction due to the mixing of the WW boson with the charged bilepton YY as well as of the ZZ boson with the neutral Z′Z' and the real part of the non-Hermitian neutral bilepton XX in the economical 3-3-1 model is established. Additional contributions to the usual \de Q_\mathrm{W} expression in the extra U(1)\mathrm{U}(1) models and the left-right models are obtained. Our calculations are quite different from previous analyzes in this kind of the 3-3-1 models and give the limit on mass of the Z′Z' boson, the Z−Z′Z-Z' and W−YW-Y mixing angles with the more appropriate values: $M_{Z'} > 564\ \mathrm{GeV}, -0.018<\sin \va < 0and and |\sin \theta| < 0.043$.Comment: replace with version to appear in Phys. Lett.

    Supersymmetric economical 3-3-1 model

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    The supersymmetric extension of the economical 3-3-1 model is presented. The constraint equations and the gauge boson identification establish a relation between the vacuum expectation values (VEVs) at the top and bottom elements of the Higgs triplet χ\chi and its supersymmetric counterpart χ′\chi^\prime. Because of this relation, the exact diagonalization of neutral gauge boson sector has been performed. The gauge bosons and their associated Goldstone ones mix in the same way as in non-supersymmetric version. This is also correct in the case of gauginos. The eigenvalues and eigenstates in the Higgs sector are derived. The model contains a heavy neutral Higgs boson with mass equal to those of the neutral non-Hermitian gauge boson X0X^0 and a charged scalar with mass equal to those of the WW boson in the standard model, i. e. mϱ1=mW m_{\varrho_1} = m_W. This result is in good agreement with the present estimation: mH±>79.3m_{H^\pm} > 79.3 GeV, CL= 95 %. We also show that the boson sector and the fermion sector gain masses in the same way as in the non-supersymmetric case.Comment: 33 page

    A simple model of gauged lepton and baryon charges

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    We argue that simpler fermionic contents, responsible for the extension of the standard model with gauged lepton and baryon charges, can be constructed by assuming existence of so-called leptoquarks (j,k) with exotic electric charges q_j=1/2, q_k=-1/2. Some new features in our model are that (i) as the natural consequences of anomaly cancelation the right-handed neutrinos exist, and the number of the observed fermion families is equal to the number of the fundamental colors; (ii) although the lepton and baryon charges are conserved, the neutrinos can obtain small masses through the type I seesaw mechanism in similarity to the standard context, and the baryogenesis can be generated in several cases. They all are natural results due to the spontaneous breaking of these charges. Some constraints on the new physics via flavor changing and related phenomenologies such as the stable scalar with anomalous electric charge and interested processes at colliders are also discussed.Comment: 13 pages, revised versio

    The entanglement dynamics of interacting qubits embedded in a spin environment with Dzyaloshinsky-Moriya term

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    We investigate the entanglement dynamics of two interacting qubits in a spin environment, which is described by an XY model with Dzyaloshinsky-Moriya (DM) interaction. The competing effects of environmental noise and interqubit coupling on entanglement generation for various system parameters are studied. We find that the entanglement generation is suppressed remarkably in weak-coupling region at quantum critical point (QCP). However, the suppression of the entanglement generation at QCP can be compensated both by increasing the DM interaction and by decreasing the anisotropy of the spin chain. Beyond the weak-coupling region, there exist resonance peaks of concurrence when the system-bath coupling equals to external magnetic field. We attribute the presence of resonance peaks to the flat band of the self-Hamiltonian. These peaks are highly sensitive to anisotropy parameter and DM interaction.Comment: 8 pages, 9 figure
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