Showing papers in "Nuclear Physics in 1990"

TL;DR: In this article, the authors define the continuum limit and compute the partition function for closed surfaces of any genus, and discuss the appropriate way to define continuum string perturbation theory in these systems and show that the coefficients (as well as critical exponents) are universal.

TL;DR: In this paper, the correlation functions of the naturally occuring operators in the minimal topological model are computed, using topological methods, in genus zero and genus one, suggesting that the two approaches to two-dimensional gravity are equivalent.

TL;DR: In this article, a systematic method for the calculation of amplitudes in hot gauge theories is developed, which is necessary to distinguish between hard momenta (of order T ) and soft momenta(of order gT ) over soft momentsa, effective propagators and vertices are required.

TL;DR: In this article, two integrable 2D relativistic field theory models are studied by the thermodynamic Bethe ansatz method and the finite volume ground state energy of these two theories is calculated numerically using the integral equations of the temperature Bethe- ansatz approach.

TL;DR: In this paper, a theory of representations of U q [SU( n + 1)] for q a root of unity is given, and a discrete analog of the Feigin-Fuchs construction with corresponding concepts of null vectors or unitarity.

TL;DR: In this article, the authors define a new representation for quantum general relativity, in which exact solutions of the quantum constraints may be obtained, by means of a noncanonical graded Poisson algebra of classical observables, defined in terms of Ashtekar's new variables.

TL;DR: In this paper, a duality in the moduli space of string vacua which pairs topologically distinct Calabi-Yau manifolds and shows that the yield isomorphic conformal theories is described.

TL;DR: In this paper, the Ricci-flat Kahler metric is calculated in the vicinity of the nodes for the conifold, the resolution and the deformation, and it is shown that, owing to a topological obstruction, the manifold obtained as the result of independently resolving and deforming the nodes of a conifolds in general cannot be Kahler.

TL;DR: In this paper, a method to calculate the elastic scattering amplitude at low energies in two-dimensional quantum field theories is proposed and tested in a numerical simulation of the O(3) non-linear σ-model on a simple square lattice.

TL;DR: In this article, the experimentally determined properties of energy levels of A = 21−44 nuclei are compiled and evaluated with emphasis on nuclear spectroscopy, and the available information on excitation energies, spins, parities, isospins, lifetimes or widths and observed decay is summarized in a master table.

TL;DR: In this paper, it was shown that the anomalous (gluonic) U (1) A current, K μ, is not in general to be identified with the gluon spin.

TL;DR: In this paper, the energy levels of A = 11 and 12 nuclei with emphasis on material leading to information about the structure of the A =11 and 12 systems were analyzed.

TL;DR: In this paper, the authors determine all solutions to the consistency equations which have to be satisfied by anomalies in gravitational theories with a Poincare-invariant ground state, i.e.

TL;DR: In this article, a complete calculation of leading and next-to-leading QCD corrections to the QCD factors η2K and η ¯ 2 B, relevant for the CP-violating ǫ-parameter and B 0 − B ¯ 0 mixing in the presence of a heavy top quark, is presented.

TL;DR: In this article, the authors describe string vacuum configurations for which the radii (moduli) of the internal compact space vary in four-dimensional space-time, focusing on configurations which have the interpretation of cosmic strings.

TL;DR: In this article, the moduli fields are accompanied by (Ramond-Ramond) scalar superpartners and the low-energy effective mutual interaction of these excitations is described by a quaternionic σ-model in target space.

TL;DR: In this paper, a low-energy analysis of macroscopic superstrings is presented and various analogies between these superstrings and solitons in supersymmetric theories are discussed.

TL;DR: In this article, a dual σ-model with coordinates y α ( α = 1, α, n ) for which the roles of field equations and Bianchi identities are interchanged is introduced, and the hidden symmetries are made manifest by considering a target space of double the dimension with coordinates Z M = ( x μ, y α ).

TL;DR: In this article, a Born and one-loop approximation was used to extract quark and gluon distributions from a source consisting of a nucleus of heavy quarkonium bound states, states well understood in QCD.

TL;DR: In this article, Ciafaloni et al. analyzed the asymptotic behaviour of deep inelastic processes in the semi-hard region x→0, where the angles between incoming and outgoing partons are ordered.

TL;DR: In this paper, a nonperturbative definition of two-dimensional quantum gravity, based on a double scaling limit of the random matrix model, was proposed, and an operator formalism for utilizing the method of orthogonal polynomials that allows us to solve the matrix models to all orders in the genus expansion was developed.

TL;DR: In this paper, the authors argue that a lot of insight is to be gained by insisting that black holes and strings should be unified, and they stress that the two pictures really are complementary.

TL;DR: In this paper, a detailed description of the method used and the results obtained for measuring various decay widths of the B-mesons into baryon-antibaryon pairs are presented.

TL;DR: In this article, the authors calculate the leading q2-dependence of the form factor of a heavey quark in the limit of a very large heavy quark mass.

TL;DR: In this article, the genus zero correlation functions of an arbitrary topological field theory coupled to two-dimensional topological gravity are determined by an appropriate Landau-Ginzburg potential.

TL;DR: In this article, it was shown that moduli space is a direct product of two Kahler manifolds of restricted type, spanned by the moduli related respectively to 27 and 27 matter fields.

TL;DR: In this paper, the authors studied the high-temperature behavior of the n-point function to one-loop order in thermal QCD and employed an analytic continuation of the imaginary-time formalism.

TL;DR: In this paper, the masses and three-point couplings for all affine Toda theories are calculated and the exact factorisable S-matrices are conjectured on the basis of the classical masses and couplings.

TL;DR: In this article, the authors derived the subleading terms of an eikonal function up to two loops and for D = 4, they found a finite and positive classical correction to the Einstein deflection, implying a deviation from the external metric picture.

TL;DR: In this article, the existence and properties of non-perturbative vacua for the open bosonic string were investigated using successive orders in a level-truncation method, and numerical values for nonzero expectation values of all fields to level two were obtained.