Sugawara-Type Constraints in Hyperbolic Coset Models

In the conjectured correspondence between supergravity and geodesic models on infinite-dimensional hyperbolic coset spaces, and E ₁₀/K(E ₁₀) in particular, the constraints play a central role. We present a Sugawara-type construction in terms of the E ₁₀ Noether charges that extends these constraints infinitely into the hyperbolic algebra, in contrast to the truncated expressions obtained in Damour et al. (Class. Quant. Grav. 24:6097, 2007) that involved only finitely many generators. Our extended constraints are associated to an infinite set of roots which are all imaginary, and in fact fill the closed past light-cone of the Lorentzian root lattice. The construction makes crucial use of the E ₁₀ Weyl group and of the fact that the E ₁₀ model contains both D = 11 supergravity and D = 10 IIB supergravity. Our extended constraints appear to unite in a remarkable manner the different canonical constraints of these two theories. This construction may also shed new light on the issue of ‘open constraint algebras’ in traditional canonical approaches to gravity.     

Chiral SU(4) × SU(4) breaking: masses and decay constants of charmed hadrons

The (4, 4*) ⊕ (4*, 4) model of broken chiral SU (4) × SU (4) symmetry has been used to calculate the third-order coupling constants involving charmed and ordinary pseudoscalar mesons. These coupling constants are exploited to derive some interesting new relations among the masses and decay constants of these charmed particles. Using the known masses and decay constants as inputs, we exploit these relations to predict:F _D = −1·41F _π ,F _F = −1·13F _π ,F _D/F_F = 1·25,m(D _s) = 1·43 GeV,m(F _s) = 1·39 GeV andm(K _s) = 1·02 GeV.     

Photoproduction of baryons decaying into Nπ and Nη

A combined analysis of photoproduction data on γp↦ πN, ηN was performed including the data on KΛ and KΣ. The data are interpreted in an isobar model with s-channel baryon resonances and π, ρ (ω), K, and K ^* exchange in the t-channel. Three baryon resonances have a substantial coupling to ηN, the well-known N(1535)S ₁₁, N(1720)P ₁₃, and N(2070)D ₁₅. The inclusion of data with open strangeness reveals evidence for further new resonances, N(1840)P ₁₁, N(1875)D ₁₃ and, with weaker evidence, for N(2170)D ₁₃.     

Structural state of Ge/Si heterosystems with (001), (111), and (7 7 10) interfaces

It is shown for (111) and (001) interfaces that at an identical degree of strain relaxation in semi-conductor epitaxial films, the ratio of distances D between neighboring dislocations is D ₍₁₁₁₎/D ₍₀₀₁₎ = 1.5. This allows us to establish that dislocation interface (7 7 10) contains partial 90° Shockley dislocations lying in three directions of 〈110〉.     

0-extended supergravity and Chern-Simons theories

We give generalizations of extended Poincaré supergravity with arbitrarily many supersymmetries in the absence of central charges in three dimensions by gauging its intrinsic global SO(N) symmetry. We call these ₀ (Aleph-null) supergravity theories. We further couple a non-Abelian supersymmetric Chern-Simons theory and an Abelian topological BF theory to ₀ supergravity. Our result overcomes the previous difficulty for supersymmetrization of Chern-Simons theories beyond N = 4. This feature is peculiar to the Chern-Simons and BF theories including supergravity in three dimensions. We also show that dimensional reduction schemes for four-dimensional theories such as N = 1 self-dual supersymmetric Yang-Mills theory or N = 1 supergravity theory that can generate ₀ globally and locally supersymmetric theories in three dimensions. As an interesting application, we present ₀ supergravity Liouville theory in two dimensions after appropriate dimensional reduction from three dimensions.     

Character of the N D -D h (0, d) phase transition in diskotic liquid crystals

The first experimental data on the orientational ordering of a diskotic reentrant nematic N _D are presented. The data show that the phase transition N _D -D _h (0, d) is a strong first-order transition with a large jump ΔS≃0.2 in the orientational order parameter S of the molecules. This indicates an anomalously strong coupling between the columnar and orientational ordering of the molecules and explains the absence of fluctuational divergence of the elastic moduli K ₁₁ and K ₂₂ in the nematic phase near this transition. Pis’ma Zh. éksp. Teor. Fiz. 63, No. 1, 29–32 (10 January 1996)     

ℵ0-extended supergravity and Chern-Simons theories

We give generalizations of extended Poincaré supergravity with arbitrarily many supersymmetries in the absence of central charges in three dimensions by gauging its intrinsic global SO(N) symmetry. We call these ℵ₀ (Aleph-null) supergravity theories. We further couple a non-Abelian supersymmetric Chern-Simons theory and an Abelian topological BF theory to ℵ₀ supergravity. Our result overcomes the previous difficulty for supersymmetrization of Chern-Simons theories beyond N = 4. This feature is peculiar to the Chern-Simons and BF theories including supergravity in three dimensions. We also show that dimensional reduction schemes for four-dimensional theories such as N = 1 self-dual supersymmetric Yang-Mills theory or N = 1 supergravity theory that can generate ℵ₀ globally and locally supersymmetric theories in three dimensions. As an interesting application, we present ℵ₀ supergravity Liouville theory in two dimensions after appropriate dimensional reduction from three dimensions.     

Wavelet analysis of learning and forgetting of photostimulation rhythms for a nonstationary electroencephalogram

Quantitative parameters characterizing transient processes of mastering and forgetting of photostimulation (PST) rhythms for a nonstationary electroencephalogram (EEG) are developed on the basis of a continuous wavelet transformation. Nonstationarity factor K _nst(μ), as well as rhythm mastering K _M (μ) and confinement K _C (μ) factors are calculated for various spectral ranges μ. Photoflash mastering time τ _M = τ _S + τ _I , which is the sum of latent silence period τ _S after PST actuation and the rhythm increasing period τ _I is calculated. In the case of PST, the EEG rhythm retardation time τ _R relative to the beginning of PST is calculated. Rhythm forgetting time τ _F = τ _P + τ _D after PST actuation is the sum of the preservation time τ _P of the corresponding rhythm over a certain time interval and its decay period τ _D . The lag time τ _L of the EEG signal relative to the PST signal after its removal is determined. The proposed method is used in quantitative analysis and classification of transient processes characterizing the properties of the central nervous system. Possible applications of the method in analysis of various nonstationary signals in physics are discussed.     

Radiative widths of neutral kaon excitations

We observe 147 events of the axial vector pairK ₁(1270)–K ₁(1400) produced in the Coulomb field of a Pb target and measure the radiative widths Γ(K ₁(1400)→K ⁰ + γ) = 280.8 ±23.2(stat.) ±40.4(syst.) keV and Γ(K ₁(1270) →K ⁰ + γ) = 73.2 ±6.1(stat.) ±28.3(syst.) keV. These first measurements are lower than the quark-model predictions. We also place upper limits on the radiative widths forK*(1410) andK ₂ ^* (1430) and find that the latter is very small in accord withSU(3)invariance in the naive quark model.     

Higher dimensional cosmologies

Einstein equations are derived for D-dimensional space-time that spontaneously compactify to the product M⁴ × Π_{i = 1}^α M^d_i in which the metric is taken to be of the generalized Robertson-Walker form. Cosmological solutions for these equations are studied with power law, oscillatory and exponential behaviour for the D-dimensional Einstein-Maxwell, N = 2, D = 10 and N = 1, D = 11 supergravity models. In the Einstein-Maxwell case the presence of a cosmological constant forces the extra dimensions to be static. Nevertheless, it is possible to find solutions with vanishing effective 4 dimensional cosmological constant with an expanding 4-dimensional space-time. In the supergravity models the requirement of having compact extra dimensions restricts the solutions to have expansion only in the 4-dimensional space-time. Matter contribution is added to the energy-momentum tensor in an attempt to find new solutions.     

Forward dispersion relations and Roy equations in <Emphasis Type="Italic">ππ</Emphasis> scattering

We first review the results of an analysis of ππ interactions in S, P and D waves for the two-pion effective mass from threshold to about 1.4GeV. In particular, we show a recent improvement of this analysis above the Kˉ threshold using more data for phase shifts and including the S0-wave inelasticity from ππ→Kˉ. In addition, we have improved the fit to the f ₂(1270)-resonance and used a more flexible P-wave parametrization above the Kˉ threshold and included an estimation of the D2-wave inelasticity. The better accuracy thus achieved also required a refinement of the Regge analysis above 1.42GeV. Finally, in this work we check that the ππ scattering amplitudes obtained in this approach satisfy remarkably well forward dispersion relations and Roy's equations.     

The hyperfine splittings in heavy-light mesons and quarkonia

Hyperfine splittings (HFS) are calculated within the Field Correlator Method, taking into account relativistic corrections. The HFS in bottomonium and the B _q (q = n, s) mesons are shown to be in full agreement with experiment if a universal coupling α _HF = 0.310 is taken in perturbative spinspin potential. It gives M(B*) −M(B) = 45.7(3) MeV, M(B _s ^* ) − M(B _s ) = 46.7(3) MeV (n _f = 4), while in bottomonium Δ_HF(b $ \bar b $ \bar b ) = M(Υ(9460)) − M(η _b (1S)) = 63.4 MeV for n _f = 4 and 71.1 MeV for n _f = 5 are obtained; just the latter agrees with recent BaBar data. For unobserved excited states we predict M(Υ(2S))−M(η _b (2S)) = 36(2)MeV,M(Υ(3S))−M(η _b (3S)) = 28(2)MeV, and also M(B _c ^*) = 6334(4) MeV, M(B _c (2S)) = 6868(4) MeV, M(B _c ^* (2S)) = 6905(4) MeV. The mass splittings between D(2³ S ₁) − D(2¹ S ₀), D _s (2³ S ₁) − D _s (2¹ S ₀) are predicted to be ∼75 MeV, which are significantly smaller than in several other studies but agree with the mass splitting between recently observed D(2533) and D*(2610).     

The newly observed open-charm states in quark model

Comparing the measured properties of the newly observed open-charm states D(2550), D(2600), D(2750), D(2760), D _s1(2710), D _sJ (2860), and D _sJ (3040) with our predicted spectroscopy and strong decays in a constituent quark model, we find that (1) the D(2 ¹ S ₀) assignment to D(2550) remains open for its too broad width determined by experiment; (2) the D(2600) and D _s1(2710) can be identified as the 2 ³ S ₁–1 ³ D ₁ mixtures; (3) if the D(2760) and D(2750) are indeed the same resonance, they would be the D(1 ³ D ₃); otherwise, they could be assigned as the D(1 ³ D ₃) and D^￠₂(1D)D^{\prime}_{2}(1D), respectively; (4) the D _sJ (2860) could be either the D _s1(2710)’s partner or the D _s (1 ³ D ₃); and (5) both the D _s1(2P) and D^￠_s1(2P)D^{\prime}_{s1}(2P) interpretations for the D _sJ (3040) seem likely. The E1 and M1 radiative decays of these sates are also studied. Further experimental efforts are needed to test the present quarkonium assignments for these new open-charm states.     

D<Subscript>sJ</Subscript>(2860) and D<Subscript>sJ</Subscript>(2715)

Recently the Babar Collaboration reported a new cs̄ state, D_sJ(2860), and the Belle Collaboration observed D_sJ(2715). We investigate the strong decays of the excited cs̄ states using the ³ P ₀ model. After comparing the theoretical decay widths and decay patterns with the available experimental data, we are inclined to conclude that: (1) D_sJ(2715) is probably the 1^-(1³ D ₁) cs̄ state, although the 1^-(2³ S ₁) assignment is not completely excluded; (2) D_sJ(2860) seems unlikely to be the 1^-(2³ S ₁) and 1^-(1³ D ₁) candidate; (3) to consider D_sJ(2860) either as a 0⁺(2³ P ₀) or as a 3^-(1³ D ₃) cs̄ state is consistent with the experimental data; (4) the experimental search of D_sJ(2860) in the channels D_sη, DK^*, D^*K and D_s ^*η will be crucial to distinguish the above two possibilities. PACS 13.25.Ft; 12.39.-x     

The heterotic string and the geometry of the supersymmetric Einstein-Yang-Mills background

It is shown that the Wess-Zumino term of a heterotic superstring in aN = 1,D = 10 supergravity background can be given in terms of the torsion of the background in both versions (IA and IB) of theN = 1,D = 10 supergravity theory. The gauge degrees of freedom of the background are included according to the ideas of Kaluza and Klein. Explicit expressions for the vielbein, connection, torsion, and curvature of a space with 506 bosonic and 16 fermionic coordinates are given.     

On the Dirac eigenvalues as observables of the on-shell <Emphasis Type="Italic">N</Emphasis> = 2<Emphasis Type="Italic">D</Emphasis> = 4 Euclidean supergravity

We generalize previous works on the Dirac eigenvalues as dynamical variables of Euclidean gravity and N =1 D = 4 supergravity to on-shell N = 2 D = 4 Euclidean supergravity. The covariant phase space of the theory is defined as the space of the solutions of the equations of motion modulo the on-shell gauge transformations. In this space we define the Poisson brackets and compute their value for the Dirac eigenvalues.      

The S-D mixing and dielectron widths of higher charmonium 1−− states

The dielectron widths of ψ(4040), ψ(4160), and ψ(4415), and their ratios are shown to be in good agreement with experiment, if in all cases the S-D mixing with a large mixing angle θ ≅ 34° is taken. Arguments are presented why continuum states give small contributions to the wave functions at the origin. We find that the Y (4360) resonance, considered as a pure 3 ³ D ₁ state, would have very small dielectron width, Γ _ee (Y (4360)) = 0.060 keV. On the contrary, for large mixing between the 4 ³ S ₁ and 3 ³ D ₁ states with the mixing angle θ = 34.8°, Γ _ee (ψ(4415)) = 0.57 keV coincides with the experimental number, while a second physical resonance, probably Y (4360), has also a rather large Γ _ee (Y (∼4400)) = 0.61 keV. For the higher Y (4660) resonance, considered as a pure 5 ³ S ₁ state, we predict the dielectron width Γ _ee (Y (4660)) = 0.70 keV, but it becomes significantly smaller, namely 0.31 keV, if the mixing angle between the 5 ³ S ₁ and 4 ³ D ₁ states has the characteristic value θ = 34°. The mass and dielectron width of the 6 ³ S ₁ charmonium state are calculated. The text was submitted by the authors in English.     

Manifestly supersymmetric extensions of (curvature)2-terms in six-dimensional N = 2 supergravity

A systematic and manifestly supersymmetric procedure for supersymmetrization of general (curvature)²-terms in N = 2 supergravity in six dimensions (D = 6) is presented in superspace. The general form of new terms for the supersymmetrization in supertranslation rules is given. As a by-product, the superspace structure of quaternionic Kähler manifolds is elucidated. Our method is the D = 6 application of our previously established formulation for the D = 10, N = 1 supergravity with the O(α′) superstring corrections.     

The kappa in J/Ψ↦K<Superscript>+</Superscript>π

BES II data for J/Ψ↦K ^*(890)Kπ reveal a strong κ peak in the Kπ S-wave near threshold. Both magnitude and phase are determined in slices of Kπ mass by interferences with strong K ₀(1430), K ₁(1270) and K ₁(1400) signals. The phase variation with mass agrees within errors with LASS data for Kπ elastic scattering. A combined fit is presented to both BES and LASS data. The fit uses a Breit-Wigner amplitude with an s-dependent width containing an Adler zero. The κ pole is at (760±20(stat)±40(syst)) - i(420±45(stat)±60(syst)) MeV. The S-wave I = 0 scattering length a ₀ = 0.23±0.04 m _π ^-1 is close to the prediction 0.19±0.02 m _π ^-1 of Chiral Perturbation Theory at O(p ⁴). An erratum to this article can be found at .