[en] In this paper, the authors derive the current algebra of principal chiral models with a Wess-Zumino term. At the critical coupling where the model becomes conformally invariant (Wess-Zumino-Novikov-Witten theory), this algebra reduces to two commuting Kac-Moody algebras, while in the limit where the coupling constant is taken to zero (ordinary chiral model), we recover the current algebra of that model. In this way, the latter is explicitly realized as a deformation of the former, with the coupling constant as the deformation parameter

[en] We review the attempts to construct black hole/string solutions in asymptotically plane wave spacetimes. First, we demonstrate that geometries admitting a covariantly constant null Killing vector cannot admit event horizons, which implies that pp-waves can't describe black holes. However, relaxing the symmetry requirements allows us to generate solutions which do possess regular event horizons while retaining the requisite asymptotic properties. In particular, we present two solution generating techniques and use them to construct asymptotically plane wave black string/brane geometries

[en] In this paper, states in the absolute (semi-relative) cohomology but not in the relative cohomology are examined through the component decomposition of the string field theory action for the 2D string. It is found that they are auxiliary fields without kinetic terms, but are important for instance in the master equation for the Ward-Takahashi identities. The ghost structure is analyzed in the Siegel gauge, but it is noted that the absolute (semi-relative) cohomology states are lost

[en] In this paper, the β functions and the c-functions are calculated in a two-dimensional field theory where the coupling parameters are functions of fields. The action of the theory is given by a combination of the Polyakov action for string theory and the Zamoldchikov action for the deformation of conformal field theory. The c-function is written as the Landau-Ginzburg type action in terms of the coupling parameter functions. The linear β-functions near fixed points are given by the Klein-Gordon equation. The corresponding well-defined masses are calculated

[en] This paper presents an alternative approach to the method of partial algebraization. This approach does not make any use of Lie symmetries. All Quasi-Exactly-Solvable (QES) problems, can also be constructed in this approach

[en] In this paper following the generalization of the Grassmann Algebra provided by Quantum Groups, the authors introduce an extension of fermionic coordinates and an action for the classical point particle mechanics which has a symmetry that resembles a supersymmetric transformation

[en] In this paper, a new ansatz for quark and lepton mass matrices is proposed in the context of supersymmetric grand unified theories. The 13 parameters describing fermion masses and mixings are determined in terms of only 6 free parameters, allowing 7 testable predictions. The values of V_us, V_cb, V_ub, m_u, m_d, m_s and m_b are then predicted as a function of the 3 charged lepton masses, m_c, m_t and tam β, the ratio of Higgs vacuum expectation values. In particular, the Cabibbo angle and m_s/m_d are determined in terms of only lepton masses. All predictions are in very good agreement with experiments

[en] The authors show that the strong coupling limit of d-dimensional quantum electrodynamics with 2^d/2^[d/2] flavors of fermions can be mapped onto the s = 1/2 quantum Heisenberg antiferromagnet in d - 1 space dimensions. In this paper, the authors use this mapping to prove that the strong coupling limit of QED breaks chiral symmetry. The staggered Neel order parameter of the antiferromagnet is the expectation value of a mass operator in QED and the spin-waves are pions. The authors speculate that the chiral symmetry breaking phase transition corresponds to a transition between the flux phase and the conventional Neel ordered phase of an antiferromagnetic t-J model

[en] In this paper the results of new particle searches conducted by the CDF collaboration at the Fermilab bar pp Collider are given

[en] In this paper, the authors study the ground state of a particle moving on an even-dimensional Riemannian manifold (M,g_μν under the action of a nondegenerate magnetic field B_μ,ν in the hypothesis that the metric and the symplectic two-form provided by B, define a conformal Kahler structure on M. On a Riemannian surface the Hamiltonian always has a degenerate ground state and in the compact case its degeneration is equal to the volume of the surface in h units minus one half of the Euler-Poincare characteristic