Stochastic perturbative derivation of the axial anomaly

The axial anomaly is calculated as the infinite Langevin time limit of stochastic triangle diagrams. Their regularization is insured with the help of an analytic stochastic regulator. The usual axial anomaly is recovered only when the Langevin equations used to generate the perturbative expansion are gauge covariant.     

Testing the nature of the electroweak breaking from polarized e+e- beams

We present a quite general expression of the longitudinal $\text{A}{}_{\mathrm{|}}$ and the transverse $\text{A}{}_{\mathrm{\cap }}$ asymmetries for the single and pair production electroweak (pseudo) scalars (Higgs, $\text{π}$, $\text{σ}$, S_μ …) from polarized e⁺e^- colliding beams via annihilation mechanism. We suggest that the measurements of $\text{A}{}_{\mathrm{|}}$ and $\text{A}{}_{\mathrm{\cap }}$ can reveal the nature of such spinless bosons and, then, the nature of the electroweak breaking, if these spinless bosons are produced at LEP and SLC energies.     

7-Hydroxy-2-(2,3,4-trimethoxyphenyl)-4H-1-benzopyran-4-one: (7-hydroxy-2′,3′,4′-trimethoxyflavone)

7-Hydroxy-2,3,4-trimethoxyflavone, (C₁₈H₁₆O₆),M _r =328.32 crystallizes in the orthorhombic system, space groupPbna, with the following crystal data:a=8.853(2),b=12.870(2),c=26.293(3)Å,V=2996(1)ų,Z=8, MoK, =0.67 cm^–1,D _c =1.454 g·cm^–3,F(000)=1376,T=294K. The structure was solved by direct-methods and has been refined by full-matrix least-squares methods to a finalR value (F>(F)) of 0.0496. The molecule is not planar, the dihedral angle between the phenyl ring and the fused ring system is 27.3°. There are no intramolecular hydrogen bonds, but intermolecular short hydrogen contacts exist between hydroxyl hydrogen and carbonyl oxygen atoms.     

Precise mass measurement of a double-stranded 500 base-pair (309 kDa) polymerase chain reaction product by negative ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) has been used to determine the mass of a double-stranded 500 base-pair (bp) polymerase chain reaction (PCR) product with an average theoretical mass of the blunt-ended (i.e. unadenylated) species of 308 859.35 Da. The PCR product was generated from the linearized bacteriophage Lambda genome which is a double-stranded template. Utilization of ethanol precipitation in tandem with a rapid microdialysis step to purify and desalt the PCR product was crucial to obtain a precise mass measurement. The PCR product (0.8 pmol/μL) was electrosprayed from a solution containing 75% acetonitrile, 25 mM piperidine, and 25 mM imidazole and was infused at a rate of 200 nL/min. The average molecular mass and the corresponding precision were determined using the charge-states ranging from 172 to 235 net negative charges. The experimental mass and corresponding precision (reported as the 95% confidence interval of the mean) was 309 406 +/- 27 Da (87 ppm). The mass accuracy was compromised due to the fact that the PCR generates multiple products when using Taq polymerase due to the non-template directed 3'-adenylation. This results in a mixture of three PCR products with nearly identical mass (i.e. blunt-ended, mono-adenylated and di-adenylated) with unknown relative abundances that were not resolved in the spectrum. Thus, the experimental mass will be a weighted average of the three species which, under our experimental conditions, reflects a nearly equal concentration of the mono- and di-adenylated species. This report demonstrates that precise mass measurements of PCR products up to 309 kDa (500 bp) can be routinely obtained by ESI-FTICR requiring low femtomole amounts. Copyright 1999 John Wiley & Sons, Ltd.     

1:1 Crystal Complexes of 2',6'‐Dimethoxyflavone with 3‐Bromo and 3‐Chloro‐2,6‐dimethoxybenzoic Acid

The structures of two solid inclusion compounds with the 2',6'‐dimethoxyflavone host molecule, 1, were investigated by single‐crystal X‐ray analysis. Both compounds, 1�3‐bromo‐2,6‐dimethoxybenzoic acid (1:1) and 1�3‐chloro‐2,6‐dimethoxybenzoic acid (1:1) crystallize in the centrosymmetric group P‐1. The complexation involves an intermolecular hydrogen bond between the carbonyl group of the flavone and the acidic hydrogen of the acid.     

Quantum hall conductivity in a Landau type model with a realistic geometry II

We use a mathematical framework that we introduced in a previous paper to study geometrical and quantum mechanical aspects of a Hall system with finite size and general boundary conditions. Geometrical structures control possibly the integral or fractional quantization of the Hall conductivity depending on the value of NB/2π (N is the number of charge carriers and B is the magnetic field). When NB/2π is irrational, we show that monovaluated wave functions can be constructed only on the graph of a free group with two generators. When NB/2π is rational, the relevant space becomes a punctured Riemann surface. We finally discuss our results from a phenomenological viewpoint.