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 共查询到20条相似文献,搜索用时 15 毫秒
1.
WU Ning 《理论物理通讯》2002,37(4):427-430
A new mechanism to introduce the mass of U(1) gauge field in supcrsymmctric U(1) gauge theory is discussed.The modelhas the strict local U(1) gauge symmetry and supersymmetry.Because we introduce two vector superfields simultaneously,the model contains a massive U(1) gauge field as well as a massless U(1) gauge field.  相似文献   

2.
The q-coherent states for the quantum superalgebra U(1/1)q, are introduced. Path integrals in the q-coherent state representations of the U(1/1)q, are constructed and applied to the q-deformed Jaynes-Cummings model whose dynamical superalgebra is the quantum superalgebra U(1/1)q.  相似文献   

3.
We establish an exact differential equation for the operator describing time-dependent measurements continuous in time and obtain a series solution. Suppose the projection operator E(t) = U(t)EUdagger(t) is measured continuously from t = 0 to T, where E is a projector leaving the initial state unchanged and U(t) a unitary operator obeying U(0) = 1. We prove that the probability of always finding E(t) = 1 from t = 0 to T is unity. If U(t) not equal1, the watched kettle is sure to "boil."  相似文献   

4.
If chiral U(1) symmetry is a gauge symmetry, CP is automatically conserved despite the instanton effects, and the weak neutral currents have a definite structure. A realistic SU(2) L ?U(1)?U(1) R model contains an axion which is consistent with present data. Furthermore the neutrino interactions to lowest order are identical to the Weinberg-Salam model. Implications for the chiral U(1) currents are discussed.  相似文献   

5.
The Dyson and Holstein-Primakoff boson realizations of the generators of SU(3) algebra have been given for the algebra chain SU(3)⊃U(1)+U(1), and a set of recursion formulae of the transformation matrix, which turn the Dyson onto the Holstein-. Primakoff representation, have been presented. The multiplicity that can occur in the reduction of SU(3)⊃U(1)+U(1) is naturally determined.  相似文献   

6.
《Physics letters. [Part B]》1987,196(4):513-518
Classical SU(3) Yang-Mills-Higgs theory with the Higgs field in the adjoint representation is studies, when the SU(3) symmetry is broken down to U(3) and U(1)×U(1). Spherically symmetry equations of motion are solved for various boundary conditions. The finite-energy solutions correspond to magnetic monopoles and isopoles.  相似文献   

7.
The minimum SU(2)×U(1) electro-weak unified theory is described and several related problems including the connection between anomaly free and charge quantization, Kobayashi-Maskawa mixing and CP violation and Higgs sector are dis-cussed. The experimental verification minimum of SU(2)×U(1) model in low energy range is presented briefly. Physical conseguences concerning to free W and Z particles are discussed. The possibilities of the existence or gauge symmetry higher than SU(2)×U(1) for electro-weak interaction and with the minimum SU(2)×U(1) model as the first order of approximation in the low energy range are given. New phenomena involving Z Partice and their implication based on SU(2)×U(1) model are examined.  相似文献   

8.
We consider the possibilities for generating a baryon asymmetry in the early universe in a flipped SU(5) × U(1) model inspired by the superstring. Depending on the temperature of the radiation background after inflation we can distinguish between two scenarios for baryogenesis: (1) after reheating the original SU(5) × U(1) symmetry is restored, or there was no inflation at all; (2) reheating after inflation is rather weak and SU(5) × U(1) is broken. In either case the asymmetry is generated by the out-of-equilibrium decays of a massive SU(3) × SU(2) × U(1) singlet field φm. In the flipped SU(5) × U(1) model, gauge symmetry breaking is triggered by strong coupling phenomena, and is in general accompanied by the production of entropy. We examine constraints on the reheating temperature and the strong coupling scale in each of the scenarios.  相似文献   

9.
In the paper we discuss the role of the axial U(1)A symmetry in the chiral phase transition using the U(Nf)R×U(Nf)L linear sigma model with two massless quark flavors.It is expected that above a certain temperature the axial U(1)A symmetry will be restored.A string-like static solution,the η string can be formed and detected in the ultrarelativistic heavy-ion collision process.  相似文献   

10.
The extreme limits for 235U/238U % at ambiant temperature were determined experimentally with a long time band displacement process (almost 1 year) using the isotope exchange reaction between U(IV)resin and U(VI)solution. These limits are 0.738 and 0.712, considering 235U/238 = 0.725% for natural uranium. The redox reactions, allowing the band displacement were: 1) in front of the band is the reduction of U(VI) in solution by a cathionic resin in Ti(III)-form; 2) in the tail of the band is the oxydation of U(IV) in resin by a solution containing Fe(III) ions.  相似文献   

11.
A classical nonrelativistic U(1) × U(1) gauge field model for the electromagnetic interaction of composite particles is proposed and the quantum formalism is constructed. This gauge model containing a Chern–Simons U(1) field and the electromagnetic U(1) field can be coupled to both a bosonic or a fermionic matter field. We explicitly consider the second case, a composite fermion system in the presence of an electromagnetic field, and we carry out the canonical quantization by the Dirac method. The path integral approach is developed and the Feynman rules are established. A simplified model is considered. As an alternative path integral method, the BRST formalism for this gauge model is also treated.  相似文献   

12.
Bosonic part of SU(2)L U(1)Y effective chiral Lagrangian for electroweak symmetry breaking is derived from an underlying technicolor theory with no approximation. The underlying theory is assumed to be the most general gauge theory without fundamental scalars. A condensate is required to exist in the theory which breaks SU(2)L U(1)Y dynamically to U(1)em and the anomaly of the theory caused by gauge interaction must be cancelled. The formulation offers general definitions in terms of underlying theory for the low energy constants in effective chiral Lagrangian.``  相似文献   

13.
We present a new class of compactifying solutions for d = 11 supergravity. The internal 7-spaces are described by coset manifolds Npqr of the form SU(3) × U(1)/U(1) × U(1). The three integers p, q, r characterize the embedding of the stability subgroup U(1) × U(1) in SU(3) × U(1).Their supersymmetry content is quite remarkable. For a particular choice of p, q, r the isometry of Npqr is SU(3) × SU(2): in this case we find that N = 3 supersymmetry survives. For all the other values of p, q, r, supersymmetry is broken to N = 1, and the isometry group is SU(3) × U(1).We also find a class of solutions with internal photon curl Fαβγδ ≠ 0, breaking all supersymmetries.  相似文献   

14.
Monte Carlo results for the pure U(3) lattice gauge theory on a 64 lattice are reported. Wilson loops and the string tension are presented. The first-order phase transition in U(3) is reflected quite clearly in a discontinuity in the string tension at β = βc. The U(1) factor of U(3) is extracted using the determinant of the Wilson loops. As expected, the U(1) component appears to deconfine at the phase transition..  相似文献   

15.
Journal of High Energy Physics - The coset Sp(2, ℝ)/U(1) is parametrized by two real scalar fields. We generalize the formalism of auxiliary tensor (bispinor) fields in U(1) self-dual...  相似文献   

16.
We analyze U(1)H as a horizontal symmetry and its possibilities to explain the known elementary-fermion masses. We find that only two candidates, in the context of SU(3)c ? SU(2)L ? U(1)Y ? U(1)H nonsuper-symmetric, are able to fit the experimental result mb«mt. identity, but it is a common prejudice to assume that the appropriate family symmetry may explain this fact as a consequence of (i) and (ii). In what follows we will enlarge the SM gauge group with an extra U(1)H horizontal local gauge symmetry (the simplest multi-family continuous symmetry we can think of). We then show that the structure SU(3)c ? SU(2)L ? U(1)Y ? U(1)H by itself is able to explain (ii), and that the simplest supersymmetric (SUSY) extension of this model without a μ-term can not cope with (ii).  相似文献   

17.
We investigate the lattice gauge theory with a gauge group UxV(1) where U is a non-Abelian group and V(1) is a chiral Abelian group.In the strong coupling approximation for the U gauge field we find that the V(1) chiral symmetry is realized through parity doublets of composite fermions for strong V(1) coupling and that it is spontaneousely broken through a techni color-like mechanism for weak V(1) coupling.  相似文献   

18.
International Journal of Theoretical Physics - Quantum parity conservation is verified at all orders in perturbation theory for a massless parity-even U(1) × U(1) planar quantum...  相似文献   

19.
殷武  宋崇立 《发光学报》1991,12(4):325-333
本文用蒸发溶液法制备了Th(PO3)4、U(PO3)4及掺杂了U4+的Th(PO3)4:U4+单晶,确定了β-U(PO3)4属于正交晶系Cmca-D2h18点群,α-U(PO3)4和Th(PO3)4都为三斜晶系P1或P1点群,给出了它们的晶格参数.测量了U(PO3)4吸收谱,和Th(PO3)4基体中U4+的激发和荧光谱.在近紫外光激发下,Th(PO3)4:U4+产生一组荧光,对应于U4+离子的6d-5f电子跃迁.270和298nm的荧光寿命约10ns,对应于电偶极跃迁.在波长为553nm绿光激发下,Th(PO3)4:U4+中四价铀的电子产生上转换效应,释放出358和533nm窄带荧光、它们属于U4+的5f-5f电子跃迁,分别对应于3P2-3H4和1I5-3H4。给出了相应的荧光和上转换效应的跃迁能级图.  相似文献   

20.
The U(N) chiral model, when quenched using Parisi's rule, has a [U(1) × U(1)]N/U(1) global invariance. To determine whether this symmetry breaks spontaneously in weak coupling for N=∞, a one-loop calculation of the distribution of eigenvalues of the single U(N) matrix of the model is performed. This distribution is shown to be uniform on the unit circle and hence, no symmetry breaking occurs. Further, the order parameter | tr U|2/N2, which should be zero at N=∞ in the absence of spontaneous symmetry breaking, is evaluated in the weak coupling phase for one, two and three dimensions for N varying from 2 to 50 by Monte Carlo simulation of the quenched model. The data indicate that this parameter indeed goes to zero as N→∞ implying that the symmetry does not break.  相似文献   

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