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1.
We study flat directions and soft scalar masses using a Z3 orbifold model with SU(3) × SU(2) × U(1) gauge group and extra gauge symmetries including an anomalous U(1) symmetry. Soft scalar masses contain D-term contributions and particle mixing effects after symmetry breaking and they are parametrized by a few parameters. Some specific relations among scalar masses are obtained.  相似文献   

2.
The three-flavour Wess-Zumino model coupled to electromagnetism is treated as a constraint system using the Faddeev-Jackiw method. Expanding into series of powers of the Goldstone boson fields and keeping terms up to second and third order we obtain Coulomb-gauge hamiltonian densities.  相似文献   

3.
We show that gauge invariant definitions of thin, thick and hybrid center vortices, defined by Kovacs and Tomboulis on SO(3)×Z(2) configurations, can also be defined in SU(2). We make this connection using the freedom of choosing a particular SU(2) representative of SO(3). We further show that in another representative the Tomboulis σ–η thin vortices are P (projection) vortices. The projection approximation corresponds to dropping the perimeter factor of a Wilson loop after appropriate gauge fixing. We present results for static quark potentials based on these vortex counters and compare projection vortex counters with gauge invariant ones on the same configuration.  相似文献   

4.
The structure of differential forms on the bundle of connections p: C(P) → M of a principal SU (2)-bundle π : PM which are invariant under the natural representation of the gauge algebra of P on connections is determined. The invariance under the Lie algebra of all infinitesimal automorphisms of P is also analyzed.  相似文献   

5.
We derive a lower bound for the Wehrl entropy in the setting of SU(1, 1). For asymptotically high values of the quantum number k, this bound coincides with the analogue of the Lieb-Wehrl conjecture for SU(1, 1) coherent states. The bound on the entropy is proved via a sharp norm bound. The norm bound is deduced by using an interesting identity for Fisher information of SU(1, 1) coherent state transforms on the hyperbolic plane and a new family of sharp Sobolev inequalities on . To prove the sharpness of our Sobolev inequality, we need to first prove a uniqueness theorem for solutions of a semi-linear Poisson equation (which is actually the Euler-Lagrange equation for the variational problem associated with our sharp Sobolev inequality) on . Uniqueness theorems proved for similar semi-linear equations in the past do not apply here and the new features of our proof are of independent interest, as are some of the consequences we derive from the new family of Sobolev inequalities. Work partially supported by U.S. National Science Foundation grant DMS 06-00037.  相似文献   

6.
The four dimensional SU(2) WZW model coupled to electromagnetism is treated as a constraint system in the context of the Batalin-Fradkin-Vilkovisky formalism. Common features with the Faddeev-Jackiw approach are stressed and the same results are obtained. The Darboux’s transformations which are used to diagonalize the canonical one-form in the Faddeev-Jackiw formalism, are shown to transform the fields of the model into BRST and σ closed. The same analysis is also carried out in the case of spinor electrodynamics.  相似文献   

7.
We continue the investigation of Spin(7) holonomy metric of cohomogeneity one with the principal orbit SU(3)/U(1). A special choice of U(1) embedding in SU(3) allows more general metric ansatz with five metric functions. There are two possible singular orbits in the first-order system of Spin(7) instanton equation. One is the flag manifold SU(3)/T2 also known as the twistor space of CP(2) and the other is CP(2) itself. Imposing a set of algebraic constraints, we find a two-parameter family of exact solutions which have SU(4) holonomy and are asymptotically conical. There are two types of asymptotically locally conical (ALC) metrics in our model, which are distinguished by the choice of S1 circle whose radius stabilizes at infinity. We show that this choice of M theory circle selects one of the possible singular orbits mentioned above. Numerical analyses of solutions near the singular orbit and in the asymptotic region support the existence of two families of ALC Spin(7) metrics: one family consists of deformations of the Calabi hyper-Kähler metric, the other is a new family of metrics on a line bundle over the twistor space of CP(2).  相似文献   

8.
Using anomalous U(1) symmetry the quark mass texture is determined uniquely. We analyze squark mass spectrum based on the above mass matrices and discuss the possibility to solve the problems of FCNC and CP caused by complex phases of soft terms, including the viewpoint of M theory.  相似文献   

9.
O. Br 《Nuclear Physics B》2003,650(3):522-542
The spectral flow of the overlap operator is computed numerically along a particular path in gauge field space. The path connects two gauge equivalent configurations which differ by a gauge transformation in the non-trivial class of π4(SU(2)). The computation is done with the SU(2) gauge field in the fundamental, the 3/2, and the 5/2 representation. The number of eigenvalue pairs that change places along this path is established for these three representations and an even–odd pattern predicted by Witten is verified.  相似文献   

10.
童红  杨亚碧  石筑一  汪红 《物理学报》2013,62(13):132101-132101
基于联合实施微观相互作用玻色子模型的最大F旋方案 (sdIBM-Fmax)与γ射线能量-自旋曲线 (γ-ray energy over spin curves, E-GOS)方案, 成功描述了182Os核yrast带相继的SU(3)–U(5)–SU(3)结构相变, 由于缺少直观解释而显得抽象. 本文借助微观sdIBM-Fmax的微观参数与Bohr哈密顿量的势能曲面方程之间存在的泛函关系, 几何地给出了对这种相继相变途径的另外一种可能理解; 并阐述了在完全变形核的高角动量态中, 由于量子效应在高激发态与低激发态之间生成高简并的临界区, 提供了γ振动能量会变得低于转动能量的一个可能途径, 从而实现了SU(3)–U(5)的相变. 关键词: yrast带结构演化 势能曲面 相变临界区 182Os核')" href="#">182Os核  相似文献   

11.
唐美娟  王延申 《物理学报》2008,57(3):1360-1364
利用量子反散射方法研究了1+1维时空中具有非对角开边界条件下的SU(2)不变Thirring模型. 于辅助空间引入独立于谱参量的规范变换,找到了适当的Fock真空态. 通过Bethe Ansatz方法得到了系统相应转移矩阵的本征值和本征态,及其谱参数所满足的Bethe Ansatz方程,并讨论了体系的边界自由度. 关键词: SU(2)不变Thirring模型')" href="#">SU(2)不变Thirring模型 非对角开边界 量子反散射方法  相似文献   

12.
Starting with the quaternionic formulation of isospin SU(2) group, we have derived the relations for different components of isospin with quark states. Extending this formalism to the case of SU(3) group, we have considered the theory of octonion variables. Accordingly, the octonion splitting of SU(3) group have been reconsidered and various commutation relations for SU(3) group and its shift operators are also derived and verified for different isospin multiplets i.e. I, U and V-spins.  相似文献   

13.
We reconsider the Kaluza-Klein compactifications of D = 11 supergravity on AdS4 × (G/H)7 manifolds that were classified in the eighties, in the modern perspective of AdS4/CFT3 correspondence. We focus on one of the three N = 2 cases: (G/H)7 = M111 = SU(3) × SU(2) × U(1) /SU(2) × U(1)′ × U(1)′'. Relying on the systematic use of the harmonic analysis techniques developed in the eighties by one of us (P. Fré) with R. D'Auria, we derive the complete spectrum of long, short and massless Osp(2|4) × SU(3) × SU(2) unitary irreducible representations obtained in this compactification. Our result also provides a general scheme for the other N = 2 compactifications. Furthermore, it is a necessary comparison term in the AdS4/CFT3 correspondence: the complete AdS/CFT match of the spectra that we obtain will provide a much more stringent proof of the ACS/CFT correspondence than in the S7 case, since the structure of the superconformal field theory on the M2-brane world volume must be such as to reproduce, at the level of composite operators, the flavor group representations, the conformal dimensions and the hyperchanges that we obtain in the present article. The investigation of this match is left to future publications. Here we provide an exhaustive construction of the Kaluza-Klein side of our spectroscopy.  相似文献   

14.
A complete set of democratic quantum numbers is introduced to classify the states of an irreducible unitary representation (IUR) of the Poincaré group obtained from the decomposition of the direct product of three IUR. Such states are identified with the baryon states constituted of three free relativistic quarks. The transformation from current to constituent quarks is then easily reobtained. Moreover, the group SU(6) × SU(3) appears naturally as a collinear classification group for baryons. Results similar to those of the symmetric harmonic oscillator quark model are obtained.  相似文献   

15.
It is well known that the MIC–Kepler problem, an extension of the three-dimensional Kepler problems, admits the same dynamical and symmetry groups as the Kepler problem. This paper aims to study dynamical and symmetry groups of the SU(2) Kepler problem, where the SU(2) Kepler problem is defined to be the dynamical system reduced from the eight-dimensional conformal Kepler problem through an SU(2) symmetry and turns out to be an extension of the five-dimensional Kepler problem. It is shown that the SU(2) Kepler problem admits a dynamical group SO*(8) and that the phase space of the SU(2) Kepler problem is symplectomorphic with a co-adjoint orbit of SO*(8), on which the Kirillov–Kostant–Souriau form is defined. It is further shown that the subgroups, SU(4), SU*(4), and Sp(2)×SR5, of SO*(8) provide the symmetry groups, SU(4)/Z2SO(6), SU*(4)/Z2SO0(1,5), and (Sp(2)×SR5)/Z2SO(5)×SR5, of the SU(2) Kepler problem with negative, positive, and zero energies, respectively, where ×S denotes a semi-direct product. Furthermore, constants of motion for the SU(2) Kepler problem are found together with their Poisson brackets. The symmetry Lie algebra formed by constants of motion is shown to be isomorphic with so(6)su(4), so(1,5)su*(4), or so(5)SR5sp(2)SR5, depending on whether the energy is negative, positive, or zero, where S denotes a semi-direct sum. These Lie algebras are subalgebras of so*(8)so(2,6).  相似文献   

16.
A 5D SU(7) family unification model with two spinor representations of SO(14) is presented. The fifth dimension is compactified on S1/Z2×Z2′. The orbifolding is used to obtain 4D SO(10) chiral fermions. The 4D grand unification group is the flipped SU(5)×U(1). The doublet–triplet splitting through the missing partner mechanism is achieved. Also, fermion mass matrices are considered.  相似文献   

17.
All the connected components of the moduli space of flat connections on SU (2) and SO (3) (trivial and non-trivial) bundles over closed oriented surfaces are determined. The symplectic structure and volumes of the non-maximal strata of the moduli space are also determined.  相似文献   

18.
19.
The Schr?dinger equation for position-dependent mass singular oscillators is solved by means of the factorization method and point transformations. These systems share their spectrum with the conventional singular oscillator. Ladder operators are constructed to close the su(1,1) Lie algebra and the involved point transformations are shown to preserve the structure of the Barut-Girardello and Perelomov coherent states.  相似文献   

20.
We calculate numerically scattering phases for elastic meson-meson scattering processes in the strongly coupled massive Schwinger model with an SU(2) flavor symmetry. These calculations are based on Lüscher's method in which finite size effects in two-particle energies are exploited. The results from Monte Carlo simulations with staggered fermions for the lightest meson (“pion”) are in good agreement with the analytical strong-coupling prediction. Furthermore, the mass spectrum of low-lying mesonic states is investigated numerically. We find a surprisingly rich spectrum in the mass region [mπ, 4mπ].  相似文献   

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