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1.
A nonperturbative approach for spontaneous symmetry breaking is proposed. It is based on some conjectural properties of interacting field operators. As the consequences an additional terms like to m 2 A 2 appears in the initial Lagrangian.  相似文献   

2.
We study a few two-dimensional models with massless and massive fermions in the hamiltonian framework and in both conventional and light-front (LF) forms of field theory. The new ingredient is a modification of the canonical procedure by taking into account solutions of the operator field equations. After summarizing the main results for the derivative-coupling and the Thirring models, we briefly compare conventional and LF versions of the Federbush model including the massive current bosonization and a Bogoliubov transformation to diagonalize the Hamiltonian. Then we sketch an extension of our hamiltonian approach to the two-dimensional Nambu–Jona-Lasinio model and the Thirring-Wess model. Finally, we discuss the Schwinger model in a covariant gauge. In particular, we point out that the solution due to Lowenstein and Swieca implies the physical vacuum in terms of a coherent state of massive scalar field and suggest a new formulation of the model’s vacuum degeneracy.  相似文献   

3.
In the standard model, the weak gauge bosons and fermions obtain mass after spontaneous electro-weak symmetry breaking, which is realized by one fundamental scalar field, namely the Higgs field. We study the simplest scalar cold dark matter model in which the scalar cold dark matter also obtains mass by interaction with the weakdoublet Higgs field, in the same way as those of weak gauge bosons and fermions. Our study shows that the correct cold dark matter relic abundance within 3a uncertainty (0.093 〈 Ωdmh^2 〈 0.129) and experimentally allowed Higgs boson mass (114.4 ≤ mh≤ 208 GeV) constrain the scalar dark matter mass within 48 ≤ ms ≤ 78 GeV. This result is in excellent agreement with the result of de Boer et al. (50 ~ 100 GeV). Such a kind of dark matter annihilation can account for the observed gamma rays excess (10σ) at EGRET for energies above 1 GeV in comparison with the expectations from conventional Galactic models. We also investigate other phenomenological consequences of this model. For example, the Higgs boson decays dominantly into scalar cold dark matter if its mass lies within 48 ~ 64 GeV.  相似文献   

4.
We study the hydrodynamics of color-flavor locking phase of three flavors of light quarks in high density QCD with spontaneous symmetry breaking. The basic hydrodynamic equations are presented based on the Poisson bracket method and the Goldstone phonon and the thermo phonon are compared. The dissipative equations are constructed in the frame of the first-order theory and all the transport coefficients are also defined, which could be looked on as the general case including the Landau's theory and the Eckart's theory.  相似文献   

5.
A model with spontaneous symmetry breaking is presented. The exact kink which is stable and kink lattice solutions are obtained. When the parameter of the model λ tends to zero, all the results reduce to those of the well-known Φ4 model.  相似文献   

6.
7.
Non-linear sigma models that arise from the supersymmetric approach to disordered electron systems contain a non-compact bosonic sector. We study the model with target space H2, the two-hyperboloid with isometry group SU(1,1), and prove that in three dimensions moments of the fields are finite in the thermodynamic limit. Thus the non-compact symmetry SU(1,1) is spontaneously broken. The bound on moments is compatible with the presence of extended states.Dedicated to Freeman Dyson on the Occasion of his eightieth birthdayAcknowledgement T. Spencer would like to thank M. Disertori, K. Gawedzki, G. Papanicolau and S.R.S. Varadhan for helpful comments.  相似文献   

8.
Starting with the definition of quaternion gauge theory, we have undertaken the study of SU(2) e ×SU(2) m ×U(1) e ×U(1) m in terms of the simultaneous existence of electric and magnetic charges along with their Yang-Mills counterparts. As such, we have developed the gauge theory in terms of four coupling constants associated with four-gauge symmetry SU(2) e ×SU(2) m ×U(1) e ×U(1) m . Accordingly, we have made an attempt to obtain the abelian and non-Abelian gauge structures for the particles carrying simultaneously the electric and magnetic charges (namely dyons). Starting from the Lagrangian density of two SU(2)×U(1) gauge theories responsible for the existence of electric and magnetic charges, we have discussed the consistent theory of spontaneous symmetry breaking and Higgs mechanism in order to generate the masses. From the symmetry breaking, we have generated the two electromagnetic fields, the two massive vector W ± and Z 0 bosons fields and the Higgs scalar fields.  相似文献   

9.
The effect of spontaneous breaking of gauge symmetry is studied for cosmological models with expansion and rotation with the Bianchi metrics of types II, IV, V, and VI. The conditions are defined wherein the effect is manifested in these models.  相似文献   

10.
We study spontaneous symmetry breaking in a one-dimensional driven two-species stochastic cellular automaton with parallel sublattice update and open boundaries. The dynamics are symmetric with respect to interchange of particles. Starting from an empty initial lattice, the system enters a symmetry broken state after some time T 1 through an amplification loop of initial fluctuations. It remains in the symmetry broken state for a time T 2 through a traffic jam effect. Applying a simple martingale argument, we obtain rigorous asymptotic estimates for the expected times 〈 T 1〉 ∝ Lln L and ln 〈 T 2〉 ∝ L, where L is the system size. The actual value of T 1 depends strongly on the initial fluctuation in the amplification loop. Numerical simulations suggest that T 2 is exponentially distributed with a mean that grows exponentially in system size. For the phase transition line we argue and confirm by simulations that the flipping time between sign changes of the difference of particle numbers approaches an algebraic distribution as the system size tends to infinity.  相似文献   

11.
In the paper we construct the nonsymmetric Jordan-Thiry theory unifying Moffat's theory of gravitation, the Yang-Mills' field, the Higgs' fields and scalar forces in a geometric manner. We discuss spontaneous symmetry breaking, the Higgs' mechanism and mass generation in the theory. The scalar field Ψ (as in classical Jordan-Thiry theory) is connected to the effective gravitational constant. This field is massive and has Yukawa-type behavior. We discuss the relation between R+ invariance and U(1)F from G. U. T. within Einstein λ-transformation, and fermion number conservation. In this way we connect W μ-field from nonsymmetric theory of gravitation with a gauge field A from G. U. T. We derive the equation of motion for a test particle from conservation laws in the hydrodynamic limit.  相似文献   

12.
We study the quantum fluctuations and the amplitude squeezing of a weakly interacting Bose system with spontaneous U(1) symmetry breaking. It is found that this system can exhibit amplitude squeezing.  相似文献   

13.
14.
Using the chiral symmetry spontaneous breaking Lagrangian with mean-field approximation, we investigate the in-medium quark condensate 〈qq〉. It is found that the condensate decreases as the nuclear matter density ρ increases. Meanwhile, the desent deviates from the linear decrease and becomes remarkably slow as the density of the nuclear matter further increases. It shows that the chiral symmetry spontaneous breaking is only partially restored in densed nuclear matter.  相似文献   

15.
Adding a U(1) symmetry breaking term V1/2 a(λ1a0+λ*1a†0)+V1/22b0*2b†0) to Bogoliubov's truncated Hamiltonian HB for a weakly interacting coupled Bose system, by using the mean-field approximation rather than the c-number approximation, we find that, via a Feshbach resonance at zero temperature, the states of the coupled Bose system are generalized SU(1,1) × SU(1,1) coherent states. The Bose-Einsteincondensation occurs in response to the spontaneous U(1) symmetry breaking.  相似文献   

16.
We reexamine the charged AdS domain wall solution to the Einstein-Abelian-Higgs model proposed by Gubser et al. as holographic superconductors at quantum critical points and comment on their statement about the uniqueness of gravity solutions. We generalize their explorations from (3+1)-dimensions to arbitrary n+1Ds and find that the n+1≥qslant5D charged AdS domain walls are unstable against electric perturbations.  相似文献   

17.
18.
Grand symmetry models in noncommutative geometry, characterized by a non-trivial action of functions on spinors, have been introduced to generate minimally (i.e. without adding new fermions) and in agreement with the first order condition an extra scalar field beyond the standard model, which both stabilizes the electroweak vacuum and makes the computation of the mass of the Higgs compatible with its experimental value. In this paper, we use a twist in the sense of Connes-Moscovici to cure a technical problem due to the non-trivial action on spinors, that is the appearance together with the extra scalar field of unbounded vectorial terms. The twist makes these terms bounded and - thanks to a twisted version of the first-order condition that we introduce here - also permits to understand the breaking to the standard model as a dynamical process induced by the spectral action, as conjectured in [24]. This is a spontaneous breaking from a pre-geometric Pati-Salam model to the almost-commutativegeometryofthestandardmodel,withtwoHiggs-likefields: scalar and vector.  相似文献   

19.
We reexamine the charged AdS domain wall solution to the Einstein–Abelian–Higgs model proposed by Gubser et al.as holographic superconductors at quantum critical points and comment on their statement about the uniqueness of gravity solutions.We generalize their explorations from(3+1)-dimensions to arbitrary n+1Ds and find that the n+1 5D charged AdS domain walls are unstable against electric perturbations.  相似文献   

20.
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