Dirac quantization of open p-brane

We give the scheme of Dirac quantization of open p-brane in the D-brane background. Treating the mixed boundary conditions as primary constraints, we get a set of secondary constraints, then the constraints conditions are shown to be equivalent to orbifold conditions imposed on normal p-brane modes.     

Relatively and supersymmetries

We show how the supersymmetry transformations follow from the relativization of a pseudoclassical lagrangian describing particles with spin.     

T-duality and non-local supersymmetries

We study the non-localization of extended worldsheet supersymmetry under T-duality, when the associated complex structure depends on the coordinate with respect to which duality is performed. First, the canonical transformation which implements T-duality is generalized to the supersymmetric non-linear σ-models. Then, we obtain the non-local object which replaces the complex structure in the dual theory and write down the condition it should satisfy so that the dual action is invariant under the non-local supersymmetry. For the target space, this implies that the supersymmetry transformation parameter is a non-local spinor. The analogue of the Killing equation for this non-local spinor is obtained. It is argued that in the target space the supersymmetry is no longer realized in the standard way. The string theoretic origin of this phenomenon is briefly discussed.     

Superspaces and supersymmetries

A theory of graded Banach modules over a Banach-Grassmann algebra is developed and applied to differential geometry of super-manifolds. The explicit structure of superspaces carrying Poincaré supersymmetry and extended supersymmetry, including central charges, is described.     

First and second quantization theories of open p-brane and their spectra

Utilizing the free Polyakov action of open p-brane, we obtain the solution of satisfying the boundary conditions to Euler–Lagrange equation of the open p-brane, the first and second quantization theories of the p-brane are given. Further, we obtain a series of new multiple commutative relations between the different normal modes of the p  -brane, obtain the new lowering and raising multiple operators, and give a series of the new fundamental multiple commutative relations of the lowering and raising multiple operators in the state space. And then we mainly take p=3$p=3$ case for example to investigate the spectrum of the open 3-brane at different levels. Interestingly, we find three types of tachyon states including scalar states, vector states and 2-rank tensor states, respectively. Besides, the graviton fields, Kalb–Ramond fields, dilaton and photon states, 3-rank tensor states as well, appear at the same level in the open 3-brane model. For the spectrum of the p  -brane (p>3)$(p>3)$, one can do the whole analogous research on p=3$p=3$ except more complex.     

Fibre bundles and supersymmetries

By extending the frame bundle of a manifold admitting a spin structure to a principal fibre bundle with group the super-Poincaré group we are able to derive the supergravity Lagrangian and its invariances under supersymmetry and other transformations in a global form.     

Broken supersymmetries and shifted superpropagators

Superfield Feynman rules are derived for a general case where global supersymmetry is spontaneously broken by F-terms. The complete superspace dependence of the superpropagators is factored out and they are employed to discuss the corrections to the effective action and the non-renormalisation theorems. Their coupling to external gauge superfields is also contemplated and finite matter contributions to the gaugino mass and the Fayet-Iliopoulos term are considered.     

All possible generators of supersymmetries of the S-matrix

A generator of a symmetry or supersymmetry of the S-matrix has to have three simple properties (see sect. 2). Starting from these properties one can give a complete analysis of the possible structure of the pseudo Lie algebra of these generators. In a theory with non-vanishing masses one finds that the only extension of previously known relations is the possible appearance of “central charges” as anticommutators of Fermi charges. In the massless case (disregarding infrared problems and symmetry breaking) the Fermi charges may generate the conformal group together with a unitary internal symmetry group.     

Extended supersymmetries and the Dirac operator

We consider supersymmetric quantum mechanical systems in arbitrary dimensions on curved spaces with nontrivial gauge fields. The square of the Dirac operator serves as Hamiltonian. We derive a relation between the number of supercharges that exist and restrictions on the geometry of the underlying spaces as well as the admissible gauge field configurations. From the superalgebra with two or more real supercharges we infer the existence of integrability conditions and obtain a corresponding superpotential. This potential can be used to deform the supercharges and to determine zero modes of the Dirac operator. The general results are applied to the Kähler spaces CPⁿ.     

Role of heavy fermions and heavy Higgs scalars in the electroweak correction to the MW − MZ relation

The role of heavy fermions and heavy Higgs-scalars in the M_W ? M_Z relation resulting from the one-loop-corrected μ decay width Γ⁽¹⁾ and its experimental data Γ^exp is studied in the framework of the standard electroweak theory. Exact and approximate formulae are both given for these heavy particle effects. The quadratic dependence of Γ⁽¹⁾ on large fermion mass m_heavy gives a positive contribution to the calculation of M_W from Γ⁽¹⁾ = Γ^exp for a given M_Z, and cancels the light fermion contributions of the form ～ αln(m_light/M_W) at the value of m_heavy ～ 200 GeV. On the other hand, the Higgs mass dependence of the calculation is, at best, logarithmic, and does not produce visible effects. Applications for deriving constraints for the top-quark mass (or heavier fermion mass) are discussed, and a concrete example is given of the relation between experimental uncertainties in measurements of M_W,Z and the corresponding allowed region for m_t.     

Half-metallic properties in rocksalt and zinc-blende M N (M=Na, K): A first-principles study

Pseudopotentials and plane-wave basis set method is used to investigate the electronic structure and magnetic properties for state-of-the-art zinc-blende and rocksalt M N (M=K, Na) alloys. We find that these compounds exhibit half-metallic characters with an integer magnetic moment of 2.00μ_B. The half-metallic properties result from a fully spin-polarization of s and p states. The origin of energy gap mainly comes from the hybridization both s and p states. Total energies calculations indicate the rocksalt phase is lower in energy than the zinc-blende one. The difference of total energy are about 0.035 Ry per formula unit for KN and NaN, respectively. For these compounds, Slater-Pauling curve M_t=(Z_t−4) (in μ_B unit) is obeyed between valence electrons and total magnetic moment. Meanwhile, we also find the preservation of half metallic characters when the lattice parameter is moderate compressed.     

Fermonic zero-norm states and enlarged supersymmetries of Type II string

We calculate the NS–R fermionic zero-norm states of the type II string spectrum. The massless and some possible massive zero-norm states are seen to be responsible for the space-time supersymmetry. The existence of other fermionic massive zero-norm states with higher spinor–tensor indices correspond to new enlarged boson–fermion symmetries of the theory at high energy. We also discuss the R–R charges and R–R zero-norm states and justify the idea that the perturbative string does not carry the massless R–R charges. Received: 12 July 1999 / Revised version: 16 September 1999 / Published online: 17 March 2000     

On the Q(M) depolarization metric

In this work, we have derived a depolarization metric, named Q(M) here, from the nine bilinear constraints between the 16 Mueller-Jones matrix elements, reported previously by several authors following different approaches. This metric Q(M) is sensitive to the internal nature of the depolarization Mueller matrix and does not depend on the incident Stokes vector. Q(M) provides explicit information about the inner 3 × 3 internal matrix. Four bounds are associated to Q(M) for a totally depolarizing, partially depolarizing, non-depolarizing diattenuating or partially depolarizing, and non-depolarizing non-diattenuating optical system, respectively. To our best knowledge, Q(M) is the unique depolarization metric that provides such information in one single number.     

M(H) shape reconstruction using magnetic spectroscopy

Knowledge about the magnetization behavior M(H) is crucial for the use of magnetic materials in engineering applications. To date many systems exist that are able to measure the magnetization behavior, e.g. VSM, VCM, MOKE. In addition to their huge costs, complex and space-consuming measurement setup, large amount of preparatory work and restricted surface measurements are handicaps which restrict their field of application. Furthermore, the influence of additional physical quantities such as temperature, strain or pressure can only be investigated with great efforts. These influences are, however, of major importance in the development of magnetic sensor systems that are based on the change in magnetic properties.In this paper, a new measurement principle based on a frequency mixing technique is introduced for investigation of the shape of the magnetization curve of soft non-hysteretic magnetic materials. Based on the Taylor expansion of the magnetization curve and the spectral investigation of the inductively detected signal, a mathematical model for the reconstruction of M(H) is proposed. The model is both numerically and experimentally verified. It is shown that the magnetization curve of a nanocrystalline soft magnetic material used in this study can be reconstructed very accurately and the influence of an additional parameter, i.e. strain, can be investigated in detail as well.     

Synthesis and effect of Ce co-doping on photoluminescence characteristics of KZnSO4Cl: M (M=Dy or Mn) new phosphors

In the present paper KZnSO₄Cl:Ce³⁺, KZnSO₄Cl:Ce³⁺, Dy³⁺ and KZnSO₄Cl:Ce³⁺, Mn²⁺ new halosulfate phosphors were synthesized by wet chemical method. XRD and photoluminescence characterization of phosphors has been reported in this paper.     

Generalized M factor of hard-edged diffracted controllable dark-hollow beams

On the basis of the truncated second-order moments method on the cylindrical coordinate systems, an analytical expression of the generalized beam propagation factor ( factor) of hard-edged diffracted controllable dark-hollow beams is derived and illustrated numerically. It is shown that the factor of truncated controllable dark-hollow beams is dependent on the beam truncation parameter δ and the beam parameters N and ε. The result can be reduced to that for the non-truncated case as the truncation parameter approaches to be infinite. The power fraction is also discussed analytically and numerically.     

Singlet to triplet conversion of the M-center in KCl

Singlet to triplet conversion of the M center in KCl is produced by excitation in the F-band region through intermediate steps: the formation of metastable M′ or M⁺ centers. Evidence is obtained that, at 200°K and at low M center concentration, the M′ mechanism is predominant.