On the large order behavior of Φ 4 4

We continue the rigorous study of the large order behavior of the perturbation series for the ⁴ model in 4 dimensions started in [1]. In this paper we prove a result announced in [1]. We show that the exact radius of convergence of the Borel transform of the renormalized perturbation series for ₄ ⁴ is greater than or equal to the expected value given by the position of the first renormalon [2]. This result holds for any vector (²)² model withN components, and makes use of the Lipatov bound of [1]. This result is based on a partial resummation of counterterms similar to the one of [3], but in a phase-space analysis of the renormalized series.     

Anisotropy Spectra of the Solvent-Sensitive Fluorophore 4-Dimethylamino-4′-Cyanostilbene in the Presence of Light Quenching

We examined the emission wavelength-dependent anisotropies of the solvent-sensitive fluorophore 4-dimethylamino-4-cyanostilbene (DCS) under conditions of light quenching by polarized time-delayed quenching pulses. Illumination on the long-wavelength side of the emission spectrum with time-delayed light pulses resulted in a progressive decrease in the emission anisotropy as the observation wavelength increased toward the stimulating wavelength. The anisotropy changes of DCS were most wavelength dependent when spectral relaxation occurred during the excited-state lifetime. Light quenching of DCS in a low-viscosity solvent revealed no wavelength-dependent anisotropies. Control measurements using a solvent-insensitive fluorophore did not show any wavelength-dependent anisotropy with light quenching. The data for DCS can be explained by a model which allows wavelength-selective quenching of the long-wavelength emission formed by time-dependent spectral relaxation. These results indicate that polarized light quenching can be used to study systems which display multiple emissions and/or time-dependent spectral shifts.     

Construction of the Hierarchical φ4-Trajectory

We study the invariant unstable manifold of the trivial renormalization-group fixed point tangent to the ⁴-vertex in the hierarchical approximation. We parametrize it by a running ⁴-coupling with linear step -function. The manifold is studied as a fixed point of the renormalization group composed with a flow of the running coupling. We present a rigorous construction of it beyond perturbation theory by means of a contraction mapping. Starting from a perturbative approximant of order seven, we obtain a convergent representation in dimensions 2 < D < 28/9 with certain restrictions. The perturbative approximant is logarithmically divergent in D = 3 dimensions.     

Determination of the Dipole Moments of the Molecules of 4′-Substituted 3-Hydroxyflavones Using the Electrooptic Absorption Method

The dipole moments in the equilibrium ground ( _g) and excited Franck–Condon states ( _e ^FC) of the molecules of 4-(methoxy)-3-hydroxyflavone (FOM), 4-(dimethylamino)-3-hydroxyflavone (FME), and 4-N-(15-azacrown-5(-3-hydroxyflavone (FCR) in 1,4-dioxane were measured. Characteristic of these probes is excited-state intramolecular proton transfer. For comparison, the dipole moments of the molecules of 4-(dimethylamino)-3-methoxyflavone (FME3ME) were measured, for which the excited-state intramolecular proton transfer is lacking. It is established that in the case of FME, FCR, and FME3ME the dipole moments _g and _e ^FC are parallel to the absorption transition dipole moment m _a responsible for absorption. Among the compounds studied, FOM has the least values of _g and _e ^FC, only 9.4·10^–30 and 26.3·10^–30 C·m, respectively. The dipole moments _g, _e ^FC and m _a are not parallel to one another, and the angles between them lie in the range 4–55°. This effect is due to FOM not having a strong electron-donating group, such as an amino group.     

Local existence of the Borel transform in Euclidean φ 4 4

We bound rigorously the large order behaviour of ₄ ⁴ euclidean perturbative quantum field theory, as the simplest example of renormalizable, but non-super-renormalizable theory. The needed methods are developed to take into account the structure of renormalization, which plays a crucial role in the estimates. As a main thorem, it is shown that the Schwinger functions at ordern are bounded byK ⁿ n!, which implies a finite radius of convergence for the Borel transform of the perturbation series.     

Analyticity of scattering for the ϕ4 theory

We consider scattering for the equation (+m ²)+³=0 on four-dimensional Minkowski space. Form>0, one-to-one and onto wave operatorsW _± :HH are known to exist for all 0, whereH denotes the Hilbert space of finite-energy Cauchy data. We prove that the maps (,u)W _± (u) and (,u)(W _± )^–1 (u) are continuous from [0, )×H toH, and extend to real-analytic functions from an open neighborhood of {0}×H×{0}×H to the Hilbert spaceH _–1 of Cauchy data with Poincaré-invariant norm. Form=0, wave operatorsW _± are known to exist as diffeomorphisms ofH for all 0, where hereH denotes the Hilbert space of finite Einstein energy Cauchy data. In this case we prove that the maps (,u)(W _± ) (u) and (,u)(W _± )^–1 (u) extend to real-analytic functions from a neighborhood of [0, )×H×H toH.     

Semileptonic decays of the hypernucleus4HΛ

Two-channel type semileptonic decays of the hypernucleus⁴H are considered:⁴H_A ³H+p+^–+ and⁴H³He+n+^–+ . The particle energy spectra are computed taking into account the presence of strong interaction in the final state and the Pauli principle both in the direct and in the charge-exchange decay channels.The importance of the role played by interactions in forming the spectra of particles created in decays, is noted. Characteristic features of energy spectra and angular correlations of particles in the charge-exchange decay channel are discussed. The importance of such effects is noted for the dynamics of multichannel mesonless hypernuclear decays with similar energy release values.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 42–45, July, 1990.     

Light-scattering studies of the dynamical behaviour of liquid 4He close to the λ-line

The paper begins with a review of experiments carried out by the present authors and their collaborators to determine by light scattering the dynamic structure factor of liquid ⁴He at temperatures close to the superfluid transition. This review includes details of the experimental techniques and reports a number of new sets of experimental results ; it concentrates particularly on the low-frequency part of the dynamic structure factor (the second-sound Brillouin doublet and the Rayleigh line), and the results cover both the hydrodynamic and the critical regimes for one particular value of the wave-vector. A comparison is made with the results of other authors, particularly those of Greytak and his collaborators. Following this presentation of the experimental data, an attempt is made to describe the dynamical behaviour of helium near the superfluid transition in terms of simple physical pictures, and then to use these pictures as the basis of simple calculations. The results often seem to agree surprisingly well with experiment, although the agreement may well be fortuitous; this part of the paper is frankly speculative and ought not to be taken too seriously. Comparison is made with the results of rigorous theoretical work, including recent attempts to apply the techniques of the renormalization group ; although these latter attempts have led to a degree of success, some of the results obtained seem to be in serious disagreement with experiment.     

The spectrum of the 4-generation Dirac–Kähler extension of the SM

We compute the mass spectrum of the fermionic sector of the Dirac–Kähler extension of the SM (DK-SM) by showing that there exists a Bogoliubov transformation that transforms the DK-SM into a flavor U(4)$U(4)$ extension of the SM (SM-4) with a particular choice of masses and mixing textures. Mass relations of the model allow determination of masses of the 4th generation. Tree level prediction for the mass of the 4th charged lepton is 370 GeV. The model selects the normal hierarchy for neutrino masses and reproduces naturally the near tri-bimaximal and quark mixing textures. The electron neutrino and the 4th neutrino masses are related via a see-saw-like mechanism.     

Local existence of the Borel transform in euclidean massless Φ 4 4

We extend the methods of [1] to prove large order estimates on the renormalized Feynman amplitudes of massless ₄ ⁴ euclidean field theory, at non-exceptional momenta. The Borel transform of the perturbative series is analytic in a disk centered at the origin of the complex plane. This result is a step towards the rigorous investigation of the infra-red singularities in the Borel plane, for theories containing massless particles, like the gauge theories.     

A new proof of the existence and nontriviality of the continuum ϕ 2 4 and ϕ 3 4 quantum field theories

We use Schwinger-Dyson equations combined with rigorous “perturbation-theoretic” correlation inequalities to give a new and extremely simple proof of the existence and nontriviality of the weakly-coupled continuum ? ₂ ⁴ and ? ₃ ⁴ quantum field theories, constructed as subsequence limits of lattice theories. We prove an asymptotic expansion to order λ or λ² for the correlation functions and for the mass gap. All Osterwalder-Schrader axioms are satisfied except perhaps Euclidean (rotation) invariance.     

Direct determination of the transition energy of NH4I at the transition I⇆II

The energy and temperature of the transition I?II of NH₄I were measured by using a direct differential calorimetric method. This method was now for the first time applied to a transition below room temperature. The results 809 cal/mole for the transition energy and the temperature interval from ?17.4°C to ?14.4°C for the transition temperature were obtained. The value of the transition energy is somewhat greater than the earlier result ofBridgman determined by means of an indirect method.     

Influence of the annealing atmosphere on the properties of LiCoPO4–graphitic carbon foams composites

The investigation on the properties of LiCoPO₄–graphitic carbon foams (LCP-GCF) composites is reported in this work. The diffraction analysis (XRD) on powders confirmed the presence of LiCoPO₄ as major crystalline phase and Li₄P₂O₇ and Co₂P as secondary phases. The morphological investigation of the composites shows a layer of crystalline spongy-like material on the surface of the GCF for t?=?0 h and of acicular crystallites with different dimensions (5–50 μm) for t?≥?0.1 h. The voltammetric curves (cyclic voltammogramms) show mean values of reduction potential above 5.0 V independently of the annealing time. The LCP-GCF composites deliver a discharge-specific capacity of 76mAh g^?1 (t?=?0 h) and of 102mAh g^?1 (t?=?0.1 h) at a discharge rate of C/10 and room temperature. The electrochemical impedance spectroscopy data reveal a decrease of the electrical resistance and the improvement of the Li-ion conductivity as a function of the annealing time.     

Simultaneous analysis of the ν2 and ν4 bands of methane

Vibration-rotation spectra of the ν₂ and ν₄ bands of CH₄ have been analysed by a simultaneous diagonalization of the hamiltonian matrices for the v ₂=1 and v ₄=1 states coupled by the Bξ_2,4 Coriolis interaction term. The effective hamiltonians used extend to sextic centrifugal distortion terms. The results are a significant improvement on any previous analysis; 438 assigned transitions up to J′=16 have been fitted with an overall standard deviation of 0·016 cm^-1. The method used is compared with an alternative theoretical approach given by Berger.     

On the Experimental Determination of 4f–4f Intensity Parameters from the Emission Spectra of Europium (III) Compounds

Optics and Spectroscopy - Eu3+ complexes and specially β-diketonate compounds are well known and studied in several areas due to their luminescence properties, such as sensors and lightning...     

Ground state of the 4α + Λ nucleus within the 4α+Λ cluster model

The s-wave bound state of the 4α+Λ system is investigated. The relevant solution to the Schrödinger equation is expanded in the basis formed by the eigenfunctions of Hamiltonian for the 4α subsystem. Differential equations for Yakubovsky components are employed to calculate basis functions. Phenomenological potentials for αα and αΛ interactions are used. In the 4α system, additional three-particle potentials for the interaction between α clusters are introduced in such a way as to reproduce the experimental data on the binding energies, the root-mean-square radii, and the charge form factors for the ¹²C and the ¹⁶O nucleus. The binding energy, the root-mean-square radius, and the hyperon distribution in the ground state of the _Λ ¹⁷ O nucleus are calculated. The results of the calculations are in good agreement with those obtained on the basis of the ¹⁶O+Λ two-particle model with the phenomenological Woods-Saxon potential.     

Properties of the decay H→γγ using the approximate α_s~4 corrections and the principle of maximum conformality

The decay channel H→γγ is an important channel for probing the properties of the Higgs boson.In this paper,we analyze its decay width by using the perturbative QCD corrections up to the α_s~4 order with the help of the principle of maximum conformality(PMC).PMC has been suggested in literature for eliminating the conventional renormalization scheme-and-scale ambiguities.After applying PMC,we observe that an accurate renormalization scale independent decay width Γ(H→γγ) up to the N~4 LO level can be achieved.Taking the Higgs mass,M_H = 125.09±0.21 ±0.11 GeV,given by the ATLAS and CMS collaborations,we obtain Γ(H→γγ)|LHC = 9.364_(0.075)~(0.076) KeV.     

Challenge to the suppression of tumor growth by the β4-galactosyltransferase genes

It has been well established that structural changes in glycans attached to proteins and lipids are associated with malignant transformation of cells. We focused on galactose residues among the sugars since they are involved in the galectin-mediated biology, and many carbohydrate antigens are frequently expressed on this sugar. We found changes in the expression of the β4-galactosyltransferase (β4GalT) 2 and 5 genes in cancer cells: decreased expression of the β4GalT2 gene and increased expression of the β4GalT5 gene. The growth of mouse melanoma cells showing enhanced expression of the β4GalT2 gene or reduced expression of the β4GalT5 gene is inhibited remarkably in syngeneic mice. Tumor growth inhibition is probably caused by the induction of apoptosis, inhibition of angiogenesis, and/or reduced MAPK signals. Direct transduction of human β4GalT2 cDNA together with the adenovirus vector into human hepatocellular carcinoma cells grown in SCID mice results in marked growth retardation of the tumors. β4GalT gene-transfer appears to be a potential tool for cancer therapy.