The Jülich-Bonn group aims at an extensive study of the baryonbaryon ( BB ) interaction involving strange baryons (Λ, Σ, Ξ) within SU(3) chiral effective field theory. An overview achievements and new developments over past few years is provided. topics covered are: 1) Derivation leading charge-symmetry breaking (CSB) for Λ N system its application in a CSB effects A =4 Λ-hypernuclei. 2) Update...

Field theoretic models possessing a global internal fermionic shift symmetry are considered. When such a symmetry is realized locally, spin 3/2 fields appear naturally as gauge fields. Implementation of the gauging procedure requires not only the usual replacement of ordinary derivatives by covariant derivatives containing the spin 3/2 fields, but also the inclusion of additional monomials. The...

The discussion of the 70-plet of negative parity baryons illustrates the large Nc QCD approach to orbitally excited baryons. In the case of the ` = 1 baryons the existing data allows to make numerous predictions to first order in the SU(3) symmetry breaking. New relations between splittings are found that follow from the spin-flavor symmetry breaking. The Λ(1405) is well described as a three-qu...

The hierarchy in the Yukawa couplings may be the result of a gauged horizontal U(1)H symmetry. If the mixed anomalies of the Standard Model gauge group with U(1)H are cancelled by a Green-Schwarz mechanism, a relation between the gauge couplings, the Yukawa couplings and the μ-term arises. Assuming that at a high energy scale g 3 = g 2 2 = 5 3g 2 1 and (memμmτ )/(mdmsmb) ∼ λ (where λ is of the ...

Second solution: For any λ > 0, the map (x,y) 7→ (λx,λ−1y) preserves both areas and the hyperbola xy = 1. We may thus rescale the picture so that A,B are symmetric across the line y = x, with A above the line. As P moves from A to B, the area of APB increases until P passes through the point (1,1), then decreases. Consequently, P = (1,1) achieves the maximum area, and the desired equality is ob...

Second solution: For any λ > 0, the map (x,y) 7→ (λx,λ−1y) preserves both areas and the hyperbola xy = 1. We may thus rescale the picture so that A,B are symmetric across the line y = x, with A above the line. As P moves from A to B, the area of APB increases until P passes through the point (1,1), then decreases. Consequently, P = (1,1) achieves the maximum area, and the desired equality is ob...

The problem of weakly correlated electrons on a square lattice is formulated in terms of one-loop renormalization group. Starting from the action for the entire Brillouin zone (and not with a low-energy effective action) we reduce successively the cutoff Λ about the Fermi surface and follow the renormalization of the coupling U as a function of three energy-momenta. We calculate the intrinsic s...

We propose a new symmetry reduction method for (1+1)-dimensional differential-difference equations (DDEs), namely, the λ -symmetry of solving ordinary differential is generalized to DDEs. Order-reduction processes are consequence invariance given DDE under vector fields class. These satisfy prolongation formula. A simple example order-reduction provided illustrate application.

Superconducting cosmic strings may be viewed as wires of thickness 1/Λ with Λ = 1016 TeV. We show that the weak interactions will spread out the current to distances r = (1/MZ) ln(I/MZ), where I is the magnitude of the current in the string. Consequences for the scattering of light by these strings is presented. Symmetry breaking at scales of Λ = 10 TeV, or higher, may induce strings that behav...