Showing papers in "Physics Letters B in 1990"

TL;DR: In this paper, the authors examined the possibility of the existence of a large internal dimension at relatively low energies of the order of a few TeV, which is a general prediction of perturbative string theories, which relate its size to the supersymmetry breaking scale.

TL;DR: In this paper, the consequences of spontaneously broken chiral symmetry for the forces among two or more nucleons were derived using phenomenological lagrangians, and the results were used to derive the consequences for the chiral forces among nucleons.

TL;DR: In this article, it was shown that the two-point function χ(λ,N), in which λ is the cosmological constant and N−1 is the string coupling constant, obeys a scaling law χ (λ, N=N −(m+1 2 ) ⨍((λ c −λ)N m/(m+ 1 2 ) ) in the limit in which n−1 goes to zero and λ goes to a critical value λc; this transition is a "condensation of handles" on the world sheet

TL;DR: In this paper, the authors present an extension of their earlier observations on symmetries in operation in the weak decays of heavy mesons containing a single heavy quark, which allow them to obtain absolutely normalized model-independent predictions in the heavy quarks limit of all of the form factors for the Q1 → Q2 induced weak pseudoscalar and pseudoscalar to vector transitions in terms of a single universal function ξ(t) with ξ (0) = 1.

TL;DR: In this article, a Lorentz invariant effective field theory description of QCD in the presence of heavy quarks at energies large compared to QCD scale and small compared to the heavy quark mass is presented.

TL;DR: In this paper, consistent equations of motion of interacting gauge fields of all spins in 3+1 dimensions are formulated in a closed form, which are explicitly general coordinate invariant, possess all necessary higher spin gauge symmetries and reduce to the usual equations of free massless fields at the linearized level.

TL;DR: In this article, a possible definition of path integrals for string theory is studied, based on a discretized version of Polyakov's generating functional, and the finite resolution of string theory, as opposed to the infinite resolution in particle theory, clearly emerges from a renormalization group type analysis.

TL;DR: In this paper, the dependence on the heavy quark mass was extracted analytically and the resulting continuum effective field theory action was illustrated by calculating the one-loop renormalization of an arbitrary heavy-light bilinear.

TL;DR: In this article, the role of the fusion algebra in determining the interactions and the Chan-Paton symmetry of open-string models is clarified, and the internal symmetry of fusion algebra is adapted for symmetry breaking.

TL;DR: In this paper, the quenching of hard jets in ultrarelativistic nuclear collisions is estimated emphasizing its sensitivity to possible changes in the energy loss mechanism in a quark-gluon plasma.

TL;DR: In this paper, the exact specific heat for a series of models of matter coupled to 2D gravity, indexed by positive integers p and q, was found, and it was shown that they are the c < 1 minimal models with diagonal modular invariants.

TL;DR: In this paper, the duality symmetry of torus compactifications can be realized as a symmetry of a world sheet action and the corresponding double volume factor is duality symmetric.

TL;DR: In this paper, it was shown that the large QCD corrections to heavy flavour production due to small χ logarithms can be evaluated and resummed in closed form, including the coefficient factor, based on a k ⊥ -dependent factorization of the Born and structure function terms.

TL;DR: In this paper, a systematic analysis of B meson decays into pions has been performed for decay modes with 2−7 pions in the final state, and the upper limits obtained on various branching ratios are consistent with the current model predictions.

TL;DR: In this article, a unified method to analyze the structure of QCD coherence in a hard process with incoming hadrons is presented, in particular the regimes of x→0 and x→1 where x is the Bjorken variable.

TL;DR: In this article, a quantum analogue of Bose and Fermi oscillators is used for the realization of quantum slq(n|m) generators, where the q-oscillators are obtained from the quantum algebra itself by the contraction method.

TL;DR: In this paper, a simple representation of Friedman cosmological models in terms of a pressure-density relationship which allows the Einstein equations to be solved exactly is presented. And the resulting 1-parameter set of inflationary models includes the well-known power-law and exponential inflationary universes together with new types of intermediate inflationary behaviour in which the scale factor expands as an exponential of an arbitrary power of the time.

TL;DR: In this paper, the authors use the techniques of an effective field theory for heavy quark systems to calculate lepton energy distributions in heavy meson decays, and show that there are no nonperturbative corrections of order mbΛQCD to the average invariant mass-squared of the final hadronic state.

TL;DR: In this article, the authors conjecture the existence of a new discrete symmetry of the modular type relating weak and strong coupling in string theory, which would strongly constrain the nonperturbative behaviour in string partition functions and introduce the notion of a maximal (minimal) coupling constant.

TL;DR: In this paper, the quantum Drinfeld-Sokolov reduction of the affine Kac-Moody algebra sl( n ) Λ gives the W n -algebra of Fateev-Zamolodchikov-Lukyanov.

TL;DR: In this paper, the authors investigated the leading order effects of the finite charm quark mass on semileptonic B decays and c c c production and found that the matrix elements of dimension-four operators suppressed by one power of Λ QCD m c in the weak hadronic current may be parameterized by a single new non-perturbative function and one unknown dimensionful constant.

TL;DR: In this article, the authors find explicit functionals that map SU(2) algebra generators to those of several quantum deformations of that algebra, as well as their SU(1, 1) analogs.

TL;DR: The effect of electroweak fermion number violation in the early universe is to distribute a fermanion number excess over all the electroweak doublets as discussed by the authors, which can result in the production of heavy stable particles in numbers comparable to the number of baryons.

TL;DR: In this article, it was shown that any hamiltonian system admits a Lax representation, at least locally at generic points in phase space, and introduced the most general Poisson bracket ensuring the involution property of the integrals of motion and existence of a lax pair.

TL;DR: In this paper, the scaling limit for the corresponding macroscopic loop correlators is constructed and agrees with the one of the hermitean model to all orders in 1 N 2, in particular the double scaling limits of the two models will lead to identical string equations.

TL;DR: In this article, the precision of sin 2 θ MS w (m z ) extracted from LEP data (0.233±0.001) confirms the prediction of minimal supersymmetric GUTs within the errors of about 2%.

TL;DR: In this article, the leading radiative corrections to various weak interaction parameters due to new heavy particles were studied, using an effective chiral lagrangian and input from low energy QCD to confirm the large size of these effects in technicolor theories.

TL;DR: In this paper, a four-dimensional string model whose effective field theory has an O(6)×O(4) gauge symmetry was presented, which is broken to the standard model at a very high scale.

TL;DR: In this paper, a global analysis of eight SLAC deep inelastic experiments on e-p and e-d scattering performed between 1970 and 1985 is presented, showing that R p = R d and R d − R p are larger than predictions based on perturbative QCD and on QCD with the inclusion of kinematic targets.