Novel sets of coupling expansion parameters for low-energy pQCD

In quantum theory, physical amplitudes are usually presented in the form of a Feynman perturbation series in powers of coupling constant α. However, it is known that these amplitudes are not regular functions at α = 0. For QCD, we propose new sets of expansion parameters w _k (α _s ) that reflect singularity at α _s = 0 and should be used instead of powers α _s ^k . Their explicit form is motivated by the so-called Analytic Perturbation Theory. These parameters reveal saturation in a strong coupling case at the level α _s ^eff (α _s 1) = w ₁(α _s 1) ∼ 0.5. They can be used for the quantitative analysis of divers low-energy amplitudes. We argue that this new picture with non-power sets of perturbation expansion parameters, as well as the saturation feature, is of a rather general nature. The text was submitted by the author in English. A preliminary version with the main results was published in [1].     

Beam-energy and system-size dependence of the CME

The energy dependence of the local and violation in Au + Au and Cu + Cu collisions in a large energy range is estimated within a simple phenomenological model. It is expected that at LHC the Chiral Magnetic effect (CME) will be about 20 times weaker than at RHIC. In the lower energy range this effect should vanish sharply at energy somewhere above the top SPS one. To elucidate CME background effects a transport model including magnetic field evolution is put forward.     

Soft topological objects in topological media

Topological invariants in terms of the Green’s function in momentum and real space determine properties of smooth textures within topological media. In space dimension d = 1 the topological invariant N ₃ in terms of the Green’s function (ω, k _x , x) determines the fermion number of the kink, while in space dimension d = 3 the topological invariant N ₅ in terms of the Green’s function (ω, k _x , k _y , k _z , z) determines quantization of Hall conductivity in the soliton plane within the topological insulators.     

Finitary Topos for Locally Finite,Causal and Quantal Vacuum Einstein Gravity

The pentalogy (Mallios, A. and Raptis, I. (2001). International Journal of Theoretical Physics 40, 1885; Mallios, A. and Raptis, I. (2002). International Journal of Theoretical Physics 41, 1857; Mallios, A. and Raptis, I. (2003).International Journal of Theoretical Physics 42, 1479; Mallios, A. and Raptis, I. (2004). ‘paper-book’/research monograph); I. Raptis (2005). International Journal of Theoretical Physics (to appear)is brought to its categorical climax by organizing the curved finitary spacetime sheaves of quantumcausal sets involved therein, on which a finitary (:locally finite), singularity-free, background manifold independent and geometrically prequantized version of the gravitational vacuum Einstein field equations were seen to hold, into a topos structure . We show that the category of finitary differential triads is a finitary instance of an elementary topos proper in the original sense dueto Lawvere and Tierney. We present in the light of Abstract Differential Geometry (ADG) a Grothendieck-type of generalization of Sorkin’s finitary substitutes of continuous spacetime manifoldtopologies, the latter’s topological refinement inverse systems of locally finite coverings and their associated coarse graining sieves, the upshot being that is also a finitary example of a Grothendieck topos. In the process, we discover that the subobject classifier Ω _fcq of is a Heyting algebra type of object, thus we infer that the internal logic of our finitary topos is intuitionistic, as expected. We also introduce the new notion of ‘finitary differential geometric morphism’ which, as befits ADG, gives a differential geometric slant to Sorkin’s purely topological acts of refinement (:coarse graining). Based on finitary differential geometric morphisms regarded as natural transformations of the relevant sheaf categories, we observe that the functorial ADG-theoretic version of the principle of general covariance of GeneralRelativity is preserved under topological refinement. The paper closes with a thorough discussion of four future routes we could take in order to further develop our topos-theoretic perspective on ADG-gravity along certain categorical trends in current quantum gravity research. PACS numbers: 04.60.-m, 04.20.Gz, 04.20.-q Posted at the General Relativity and Quantum Cosmology (gr-qc) electronic archive (www.arXiv.org), as: gr-qc/0507100.     

Fourier-Mukai Transform and Adiabatic Curvature of Spectral Bundles for Landau Hamiltonians on Riemann Surfaces

We study the family of Landau Hamiltonians on a Riemann surface S by means of a Nahm transform and an integral functor related to the Fourier-Mukai transform associated to its jacobian variety J(S). This approach allows us to explicitly determine the spectral bundles associated to the holomorphic Landau levels. As a first main result we prove that these spectral bundles are holomorphic stable bundles with respect to the canonical polarization of J(S) determined by the theta divisor .The spectral bundles are endowed with a natural connection and the adiabatic charge transport properties of the corresponding Landau levels are determined by the adiabatic curvature of , which coincides with the curvature of the determinant bundle det . By means of the theory of analytic torsion and determinant bundles developed by Bismut, Gillet and Soulé we compute the adiabatic curvature of the spectral bundles on an arbitrary Riemann surface. We prove that all the holomorphic Landau levels have the same charge transport coefficients but their adiabatic curvatures differ by a term which involves the relative analytic torsion of different powers of the canonical bundle of S twisted by a fixed line bundle.     

On pair production of scalar top quarks in <Emphasis Type="Italic">e</Emphasis><Superscript>+</Superscript><Emphasis Type="Italic">e</Emphasis><Superscript>−</Superscript> collisions at ILC and a possibility of their mass reconstruction

We study pair production of scalar top quarks (stop, ) in e ⁺ e ⁻ collisions with the subsequent decay of the top squarks into b quarks and charginos . We simulate this process by using PYTHIA6.4 for the beam energy 2E _b = = 350, 400, 500, 800, 1000 GeV. A set of criteria for physical variables is proposed, which provides good separation of stop signal events from top quark pair production being the main background. These criteria allow us to reconstruct the mass of the top squark with an integrated luminosity of 1000 fb⁻¹ provided that the neutralino mass is known. The article is published in the original.     

On the corrections to the Casimir effect depending on the resolution of measurement

The Casimir force      

On the leptonic decay of a heavy quarkonium with a Higgs-boson emission

The leptonic () decay of a heavy quark-antiquark bound state T( Q) with a Higgs-boson H emission is investigated. Applying the low-energy theorem to meson-Higgs coupling allows one to estimate the probability of the decay T( Q) → H. Only the simple version of the Standard Model extension containing two-Higgs doublet is considered. The text was submitted by the author in English.     

Proximity-induced superconductivity in graphene

We propose a way of making graphene superconductive by putting on it small superconductive islands which cover a tiny fraction of graphene area. We show that the critical temperature, T _c , can reach several Kelvins at the experimentally accessible range of parameters. At low temperatures, T T _c , and zero magnetic field, the density of states is characterized by a small gap E _g ≤ T _c resulting from the collective proximity effect. Transverse magnetic field H _g (T) ∝ E _g is expected to destroy the spectral gap driving graphene layer to a kind of a superconductive glass state. Melting of the glass state into a metal occurs at a higher field H _g2(T). The article is published in the original.     

Leptoquark pair production in hadronic interactions

The scalar and vector leptoquark pair production cross sections in hadronic collisions are calculated. In a model independent analysis we consider the most general C and P conserving couplings of gluons to both scalar and vector leptoquarks described by an effective low-energy Lagangian which obeys SU(3)_c invariance. Analytical expressions are derived for the differential and integral scattering cross sections including the case of anomalous vector leptoquark couplings, K _G and Λ_G, to the gluon field. Numerical predictions are given for the kinematic range of the TEVATRON and LHC. The pair production cross sections are also calculated for the resolved photon contributions to at HERA and LEP ? LHC, and for the process at possible future e ^{+ e ?} linear colliders and γγ colliders. Estimates of the search potential for scalar and vector leptoquarks at present and future high energy colliders are given.     

Measurement of B d 0 - oscillations

B _d ⁰ meson oscillations are measured in hadronic Z⁰ decays using the charge of a lepton or the mean charge of an event hemisphere to sign the presence of a b or a b? quark when it is produced, and using the charge of a lepton emitted at large pt or of a D*^± to sign the presence of a B or a B? meson when it decays. With 3.2 million hadronic Z⁰ decays registered by DELPHI between 1991 and 1994, the mass difference Δm _d between the two physical B _d ⁰ states is measured in four channels: Taking into account the statistical overlap between these measurements and the common systematic uncertainties, the combined result is:      

Heavy baryons in the relativistic quark model

In the framework of the relativistic quasipotential quark model the mass spectrum of baryons with two heavy quarks is calculated. The quasipotentials for interactions of two quarks and of a quark with a scalar and axial vector diquark are evaluated. The bound state masses of baryons with are computed.     

Separated cross-sections in \pi^{0}_{} electroproduction at threshold at Q2 = 0.05GeV2/c2

The differential cross-sections σ₀ = σ_T + εσ_L , σ_LT , and σ_TT of electroproduction from the proton were measured from threshold up to an additional center-of-mass energy of 40MeV, at a value of the photon four-momentum transfer of Q ² = 0.05 GeV²/c² and a center-of-mass angle of θ = 90^° . By an additional out-of-plane measurement with polarized electrons σ_LT' was determined. This showed for the first time the presence of an imaginary part of the s -wave above the threshold, which is usually interpreted as a unitary cusp. The predictions of the Heavy Baryon Chiral Perturbation Theory (HBChPT) are in disagreement with these data. On the other hand, the data are somewhat better predicted by the MAID phenomenological model and are in good agreement with the dynamical model DMT.     

High-temperature heat capacity of the Al<Subscript>63</Subscript>Cu<Subscript>25</Subscript>Fe<Subscript>12</Subscript> quasicrystal

The mechanisms of energy absorption by metallic alloys with long-range aperiodic lattice order and electronic properties of marginal metals are studied. The heat capacity and linear expansion coefficient of the Al₆₃Cu₂₅Fe₁₂ icosahedral phase in the temperature range 300–1000 K are measured for the first time. Disagreement between the measured heat capacity and predictions made from the Debye model is found and analyzed. It is shown that the excess heat capacity observed at the temperatures of the experiment is fitted by Einstein’s function in the approximation T

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Θ_E.

     

g-factors of rotational states in 176Hf, 177Hf,and 180Hf

g-factors of rotational states in ¹⁷⁶Hf and ¹⁸⁰Hf were measured with the twelve detector IPAC-apparatus of our laboratory [1]. The natural radioactivity 3.78 · 10¹⁰y ¹⁷⁶Lu and the 5.5 h isomer ^180mHf were used which populate the ground-state rotational bands of ¹⁷⁶Hf and ¹⁸⁰Hf. The integral rotations of γ-γ directional correlations in strong external magnetic fields and in static hyperfine fields of (Lu → Hf)Fe₂ and HfFe₂ were observed. The following results were obtained: The hyperfine field in (Lu → Hf)Fe₂ was calibrated by observing the integral rotation of the 9/2^? first excited state of ¹⁷⁷Hf populated in the decay of 6.7d ¹⁷⁷Lu. The g-factor of this state was redetermined in an external magnetic field as Finally the g-factor of the 2 ₁ ⁺ state of ¹⁷⁶Hf was derived from the measured g(2 ₁ ⁺ ) of ¹⁸⁰Hf by use of the precisely known ratio g(2 ₁ ⁺ , ¹⁷⁶Hf)/g(2₁ ⁺, ¹⁸⁰Hf) [2] as      

Particle-quadrupole and particle-octupole coupled states in 145Sm

In the present paper we present part of the results obtained in the study of above-yrast states in ¹⁴⁵Sm using the ¹⁴²Nd(α,Xnγ) reaction. γ-γ, angular distribution, polarization, and excitation function measurements were performed. All multiplet members of the and the multiplets have been observed. The unperturbed energies for the multiplet have been estimated using the extensive information existing on one neutron transfer reactions. The results are compared with the ¹⁴³Nd case. The similarity is remarkable.     

Electromagnetic effects and scattering lengths extraction from experimental data on K → 3π decays

The final state interactions in K ^± → π^±π⁰π⁰ decays are considered using the methods of nonrelativistic quantum mechanics. It is shown how to take into account the largest electromagnetic effect in the analysis of experimental data using the amplitudes calculated earlier. The relevant expressions for amplitude corrections valid both above and below the two charged pions production threshold , including the average effect for the threshold bin, are proposed. These formulae can be used in the procedure of pion scattering lengths measurement from spectrum. The text was submitted by the authors in English.     

Coupled Lugiato-Lefever equation for nonlinear frequency comb generation at an avoided crossing of a microresonator

Guided-mode coupling in a microresonator generally manifests itself through avoided crossings of the corresponding resonances. This coupling can strongly modify the resonator local effective dispersion by creating two branches that have dispersions of opposite sign in spectral regions that would otherwise be characterized by either positive (normal) or negative (anomalous) dispersion. In this paper, we study, both analytically and computationally, the general properties of nonlinear frequency comb generation at an avoided crossing using the coupled Lugiato-Lefever equation. In particular, we find that bright solitons and broadband frequency combs can be excited when both branches are pumped for a suitable choice of the pump powers and the detuning parameters. A deterministic path for soliton generation is found.

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A multiple production study of neutral strange particles in νμ CC interactions in the NOMAD experiment

A multiple production study of neutral strange particles in ν_μ charged current interactions has been performed using the full data sample from the NOMAD experiment. This analysis allows one to investigate the mechanisms of strange particle production in neutrino interactions. In this study we have tried to build a model for the production of strange particles, which would allow us to describe our measured rates of neutral strange particles, as well as the rates of the single-, double-and triple-V ⁰ production: Λ, K ⁰, , K ⁰ K ⁰, ΛK ⁰, Λ , K ⁰ , ΛΛ, and K ⁰ K ⁰ K ⁰. The text was submitted by the authors in English.     

Identified hadron production at high transverse momenta in p+ p collisions at $\sqrt{s_{NN}}=200$ GeV in STAR

We report the transverse momentum (p _T ) distributions for identified charged pions, protons and anti-protons using events triggered by high deposit energy in the Barrel Electro-Magnetic Calorimeter (BEMC) from p+p collisions at  GeV. The spectra are measured around mid-rapidity (|y|<0.5) over the range of 3<p _T <15 GeV/c with particle identification (PID) by the relativistic ionization energy loss (rdE/dx) in the Time Projection Chamber (TPC) of the Solenoidal Tracker at RHIC (STAR). The charged pion, proton and anti-proton spectra at high p _T are compared with published results from minimum bias triggered events and the Next-Leading-Order perturbative quantum chromodynamic (NLO pQCD) calculations (DSS, KKP and AKK 2008). In addition, we present the particle ratios of π ⁻/π ⁺, , p/π ⁺ and in p+p collisions.