Aspects of effective action for super Chern-Simons-Matter models

We develop the superfield background field method and study the effective action in the N = 2, d3 supersymmetric Chern-Simons-matter systems. The one-loop low-energy effective action for non-Abelian supersymmetric Chern-Simons theory is computed to order F ⁴ by use of N = 2 superfield heat kernel techniques.     

Abelian Chern-Simons term in superfluid 3He-A

We show in this paper that an Abelian Chern-Simons term is induced in (2 + 1)- and (3 + 1)-dimensional rotating superfluid ³He-A and that it plays an important role in its dynamics. Because U(1) symmetry is spontaneously broken in ³He-A, a Goldstone mode appears and contributes to the induced Chern-Simons term. We found that the coefficient of the Chern-Simons term, which is equivalent to Hall conductance, depends on an infra-red cut-off of the Goldstone mode, and that the orbital angular momentum of ³He-A in a cylinder geometry is derived from the Chern-Simons term.     

Kauffman knot polynomials in classical abelian Chern-Simons field theory

Kauffman knot polynomial invariants are discovered in classical abelian Chern-Simons field theory. A topological invariant t^I(L) is constructed for a link L, where I is the abelian Chern-Simons action and t a formal constant. For oriented knotted vortex lines, t^I satisfies the skein relations of the Kauffman R-polynomial; for un-oriented knotted lines, t^I satisfies the skein relations of the Kauffman bracket polynomial. As an example the bracket polynomials of trefoil knots are computed, and the Jones polynomial is constructed from the bracket polynomial.     

How to measure the charm density in the proton

We study two experimental ways to measure the heavy-quark content of the proton: using the Callan-Gross ratio R(x, Q ²) = F _L /F _T and/or the azimuthal cos(2φ) asymmetry in DIS. Our approach is based on the following observations. First, the ratio R(x, Q ²) = F _L /F _T and azimuthal cos(2φ) asymmetry in heavy-quark leptoproduction are stable, both parametrically and perturbatively, within pQCD. Second, both these quantities are sensitive to resummation of the mass logarithms of the type α_sln(Q ²/m ²). We conclude that the heavy-quark densities in the nucleon can, in principle, be determined from high-Q ² data on the Callan-Gross ratio and/or the azimuthal asymmetry. In particular, the charm content of the proton can be measured in future studies at the proposed Large Hadron-Electron (LHeC) and Electron-Ion (EIC) Colliders.     

Can recently measured moments of F3vN discriminate between field theories of strong interactions?

It is demonstrated that moments of the flavor non-singlet structure function F₃^vN cannot discriminate, contrary to recent claims, between QCD and other nontrivial fixed point theories of strong interactions, even by taking into account the CDHS precision measurements. Only quantities, such as F₂(x, Q²), which receive also flavor singlet contributions (dominant at small x) can provide us with discriminative tests of strong interaction theories using present experiments; it is not sufficient to study just moments (n > 2) of F₂, since these are sensitive mainly to the non-singlet (large-x) contribution.     

Sum rules and the pion form factor in QCD

We propose a new approach to the investigation of the pion electromagnetic form factor in QCD based on the systematic use of the QCD sum rule technique. The theoretical curve obtained for F_π(Q²) is in good agreement with existing experimental data.     

Star products from commutative string theory

A boundary-state computation is performed to obtain derivative corrections to the Chern-Simons coupling between a p-brane and the RR gauge potential C ^p −3. We work to quadratic order in the gauge field strength F, but all orders in derivatives. In a certain limit, which requires the presence of a constant B-field background, it is found that these corrections neatly sum up into the *₂ product of (commutative) gauge fields. The result is in agreement with a recent prediction using noncommutativity.     

Axions from chiral family symmetry

We investigate the possibility that family symmetry, G_F, is spontaneously broken chiral global symmetry. We classify the interesting cases when family symmetry can result in an automatic Peccei-Quinn symmetry U(1)_PQ and thus provide a solution to the strong CP problem. The result disfavors having two or four families. For more than four families, U(1)_PQ is in general automatic. In the case of three families, a unique Higgs sector allows U(1)_PQ in the simplest case of G_F = [SU(3)]³. Cosmological consideration also puts strong constraint on the number of families. For G_F = [SU(N)]³ cosmology singles out the three-family (N = 3) case as a unique solution if there are three light neutrinos. Possible implication of decoupling theorem as applied to family symmetry breaking is also discussed.     

Fitting models to correlated data III: A comparison between residual analysis and other methods

Applications of the χ² test, the F test, the Durbin-Watson d test, and the f (or Sign) test, to examples of correlated data treatment, show important drawbacks with the d test and (apparently) with the f test. An analytical approach based on residual analysis suggests an improvement in their use that leads to better results at lowest order; it also points out a distinction between goodness-of-fit tests, as the f test, and goodness-of-modeling tests, as the χ² and F tests. The residual analysis method is applied to the same examples; it looks faster, simpler, and often more accurate than the classical ones.     

A theoretical study of F centres in BaClF and SrClF

We present point-ion calculations of the electronic structure of F centres in BaClF and SrClF. The relative positions of the singlet and doublet absorption bands of the F centres at F^? and Cl^? sites suggest a new assignment of the bands to the F centre sites. The F(F^?) has the singlet below the doublet, the F(Cl^?) the reverse order. Comparison of calculated spin resonance parameters with experiment supports this suggestion.     

The hypothesis of statistical jet evolution confronted withe + e − annihilation data

We describe the processe ⁺ e ^?→ hadrons in a “dynamical” phase space, where energy and momentum are quantised in a volume, which expands with velocity of light in a sequence of discrete time steps. Our hypothesis of statistical evolution which is based on an appropriate application of the equipartition principle, determines uniquely the distribution over the resolvable states in this dynamical phase space and leads to a branching process. Neglecting all degrees of freedom except energy and momentum, and restricting to final state pions we arrive at a minimal model with no other parameters thanh, c andm _π. We compare this model in detail with data on multiplicities, inclusive spectra and energy-energy correlations; new energy flow measurements will be proposed. The low energy region (1<W<5 GeV) may provide a clue on the role of color as a new degree of freedom.     

Development of a 2D dosimetry system based on the optically stimulated luminescence of Al2O3

A laser-scanning 2D dosimetry system based on the Optically Stimulated Luminescence (OSL) signal from Al₂O₃ films was built and demonstrated. The main challenge of using the OSL from Al₂O₃ for 2D dosimetry by laser scanning is the long lifetime (∼35 ms) of the main luminescence centers in this material (F-centers). In this work, we demonstrated the possibility of performing 2D dosimetry by laser scanning using a combination of the fast UV emission of F⁺-centers (lifetime <7 ns) and the slow F-center emission of Al₂O₃:C, and an algorithm to correct for the slow F-center luminescence lifetime. We also investigated the possibility of using Al₂O₃:C,Mg, to take advantage of its greater F⁺-center emission compared to Al₂O₃:C. Results from 6 MV photon beam irradiations from a clinical linear accelerator were compared to radiographic and radiochromic film profiles showing a good qualitative agreement.     

Quantum Hypothesis Testing for Gaussian States: Quantum Analogues of χ2, t-, and F-Tests

We consider quantum counterparts of testing problems for which the optimal tests are the χ², t-, and F-tests. These quantum counterparts are formulated as quantum hypothesis testing problems concerning Gaussian state families, and they contain nuisance parameters, which have group symmetry. The quantum Hunt-Stein theorem removes some of these nuisance parameters, but other difficulties remain. In order to remove them, we combine the quantum Hunt-Stein theorem and other reduction methods to establish a general reduction theorem that reduces a complicated quantum hypothesis testing problem to a fundamental quantum hypothesis testing problem. Using these methods, we derive quantum counterparts of the χ², t-, and F-tests as optimal tests in the respective settings.     

A self-consistent test of the rescaling model of the EMC effect

We examine predictions of the dynamical rescaling model for the dueteron. An alternate expression for F₂^D is derived by explicitly including the six-quark state. This lead to a new self-consistence test for dynamical rescaling which is well established. However, discrepancies remain between the experimental F₂^D and the predictions of the model.     

Intensities of inter-Stark transitions in activated crystals

A scheme of calculation of line strengths for indirect electric dipole transitions between Stark states of impurity ions in dielectric crystals is proposed. It is shown that knowledge of the three semiphenomenological Judd-Ofelt parameters of a crystalline system is sufficient for quantitative calculations. The formulas obtained were approved for YAG:Nd³⁺ crystals based on calculation of the spectroscopic characteristics of the lines of the inter-Stark transitions ⁴ F _3/2 → ⁴ I _9/2 and ⁴ F _3/2 → ⁴ I _11/2.     

Les systèmes hétérogènes « eau–zéolithe hydrophobe »: de nouveaux ressorts moléculaires

Pressure–volume isotherms have been determined for three heterogeneous ‘water–zeolite’ systems. The first two concern hydrophobic purely siliceous zeolites: silicalite-1 (F⁻) and zeolite β (F⁻); the third comprises a more hydrophilic commercial zeolite of the type ZSM-5. The P–V diagram for the water–silicalite-1 (F⁻) system is characterized by a plateau corresponding to the intrusion of water inside the pores of the solid. During the release the phenomenon is reversible. This system, which is able to accumulate and restore superficial energy, constitutes a molecular spring. For zeolite β, the P–V curve displays a plateau during the compression, but during the release, the phenomenon is not reversible. In that case, the system absorbs mechanical energy and acts as a bumper. The third system, based on the more hydrophilic ZSM-5 zeolite shows a linear isotherm without any plateau. These results open new applications perspectives in the field of the energetics for hydrophobic zeolites in contact with water. To cite this article: V. Eroshenko et al., C. R. Physique 3 (2002) 111–119     

Guidelines for efficient direct ablation of dielectrics with single femtosecond pulses

We provide guidelines to femtosecond laser users to select ad hoc laser parameters, namely the fluence and pulse duration, in the context of the development of ablation processes at the surface of dielectrics using single femtosecond pulses. Our results and discussion are based on a comprehensive experimental and theoretical analysis of the energy deposition process at the surface of fused silica samples and of their postmortem ablation characteristics, in the range of intensities from 10¹³ to 10¹⁵ W/cm². We show experimentally and numerically that self-induced plasma transient properties at the pulse timescale dramatically determine the efficiency of energy deposition and affect the resulting ablation morphology. In practice, we determine that the precise measurement of two characteristic fluence values, namely the laser-induced ablation threshold F _th,LIAT and the fluence F _opt for maximum ablation efficiency, are only required to qualify the outcomes of laser ablation at the surface of a dielectric in an extended range of applied fluence.     

DSE Perspective on QCD Modeling,Distribution Amplitudes,and Form Factors

We describe results for the pion distribution amplitude (PDA) at the non-perturbative scale μ = 2 GeV by projecting the Poincaré-covariant Bethe–Salpeter wave-function onto the light-front and use it to investigate the ultraviolet behavior of the electromagnetic form factor, F _π (Q ²), on the entire domain of spacelike Q ². The significant dilation of this PDA compared to the known asymptotic PDA is a signature of dynamical chiral symmetry breaking on the light front. We investigate the transition region of Q ² where non-perturbative behavior of constituent-like quarks gives way to the partonic-like behavior of quantum chromodynamics (QCD). The non-perturbative approach is based on the Dyson–Schwinger equation (DSE) framework for continuum investigations in QCD. The leading-order, leading-twist perturbative QCD result for Q ² F _π (Q ²) underestimates the new DSE computation by just 15 % on \({Q^2\gtrsim 8\,}\) GeV², in stark contrast with the result obtained using the asymptotic PDA.     

Isospin projected FBCS wavefunction for light nuclei

Two equivalent isospin projection methods are proposed and applied to a conventional FBCS wavefunction, thus obtaining a F _NT BCS one. To test the effect of the projection the FBCS and F _NT BCS wavefunctions are compared with an exact shell model one. Practical calculations are carried out for He⁶ using the Volkov's semi-realistic potential and the first 3 major shells. Results of the calculations show that a) the F _NT BCS with 5 free parameters is capable of approximating the shell model wavefunction with 87 parameters and b) the FBCS results differ little from the F _NT BCS ones in this special case, what should be caused by the Pauli principle and the large energy spacing ?ω.