Canonical description of T-duality with NSNS background

Journal of High Energy Physics - The analyticity properties of the scattering amplitude in the nonforward direction are investigated for a field theory in the manifold R3,1 ⨂ S1. The theory...     

Closed-string tachyon condensation and the worldsheet super-higgs effect

Alternative gauge choices for worldsheet supersymmetry can elucidate dynamical phenomena obscured in the usual superconformal gauge. In the particular example of the tachyonic E8 heterotic string, we use a judicious gauge choice to show that the process of closed-string tachyon condensation can be understood in terms of a worldsheet super-Higgs effect. The worldsheet gravitino assimilates the goldstino and becomes a dynamical propagating field. Conformal, but not superconformal, invariance is maintained throughout.     

Comments on the computation of quantum fluctuations of gluons in a multi-instanton background

Relying on previous results, the computation of quantum fluctuations of gluons in a Yang-Mills multi-instanton background field is explained. For the present most comprehensive formula due to Jack the integration constant is determined. The formulae are evaluated in more detail for the special case of the 't Hooft solutions.     

p-adic string theories provide lattice Discretization to the ordinary string worldsheet

A class of models called p-adic strings is useful in understanding the tachyonic instability of string theory. These are found to be empirically related to the ordinary strings in the p-->1 limit. We propose that these models provide discretization for the string worldsheet and argue that the limit is naturally thought of as a continuum limit in the sense of the renormalization group.     

Position-space description of the cosmic microwave background and its temperature correlation function

We suggest that the cosmic microwave background (CMB) temperature correlation function C(theta) as a function of angle provides a direct connection between experimental data and the fundamental cosmological quantities. The evolution of inhomogeneities in the prerecombination universe is studied using Green's functions in position space. We find that a primordial adiabatic point perturbation propagates as a sharp-edged spherical acoustic wave. Density singularities at its wave fronts create a feature in the CMB correlation function distinguished by a dip at theta approximately 1.2 degrees. Characteristics of the feature are sensitive to the values of cosmological parameters, in particular to the total and the baryon densities.     

Observation of an excited charm baryon Omega c* decaying to Omega c0gamma

We report the first observation of an excited singly charmed baryon Omega c* (css) in the radiative decay Omega c0gamma, where the Omega c0 baryon is reconstructed in the decays to the final states Omega(-)pi+, Omega(-)pi+pi0, Omega(-)pi+pi(-)pi+, and Xi(-)K(-)pi+pi+. This analysis is performed using a data set of 230.7 fb(-1) collected by the BABAR detector at the PEP-II asymmetric-energy B factory at the Stanford Linear Accelerator Center. The mass difference between the Omega c* and the Omega c0 baryons is measured to be 70.8+/-1.0(stat)+/-1.1(syst) MeV/c2. We also measure the ratio of inclusive production cross sections of Omega c* and Omega c0 in e+e(-) annihilation.     

Observation of the decay Omega(0)(c)-->Omega(-)e(+)nu(e)

Using the CLEO detector at the Cornell Electron Storage Ring we have observed the Omega(0)(c) (css ground state) in the decay Omega(0)(c)-->Omega(-)e(+)nu(e). We find a signal of 11.4+/-3.8(stat) events. The probability that we have observed a background fluctuation is 7.6x10(-5). We measure B(Omega(0)(c)-->Omega(-)e(+)nu(e)).sigma(e(+)e(-)-->Omega(0)(c)X)=(42.2+/-14.1(stat)+/-5.7(syst)) fb and R=[Gamma(Omega(0)(c)-->Omega(-)pi(+))]/[Gamma(Omega(0)(c)-->Omega(-)enu(e))]=00.41+/-0.19(stat)+/-0.04(syst). This is the first statistically significant observation of an individual decay mode of the Omega(0)(c) in e(+)e(-) annihilation and the first example of a baryon decaying via beta emission, where no quarks from the first generation participate in the reaction.     

Comments on the dimensionality of time

Some brief remarks are made on the relation between the ordering and dimensionality properties of time and the laws of physics. Time is defined as the ordinal of the set of photographs describing the configuration of the Universe associated with each collision of a test particle. This set of pictures is ordered by a parameter which appears in simple physical laws, and it is these laws which determine the ordering. Time is one-dimensional because these snapshots can be ordered with a single parameter. The signature of space-time appears to be related to the measurement process. If there were no time dimension, there would probably be no physical laws, because there would seem to be nothing to predict: while if there were more than one timelike dimension, then the extra dimensions may be unobservable and so physically nonexistent.Work supported by a grant from Long Island University.     

Comments on the Debije-Brinkman equation

We present a macroscopic derivation of the Debije-Brinkman equation for the flow of a fluid through a polymer coil. By using an exact relation between the sedimentation coefficient and the permeability it is found that the permeability of the coil is strongly dependent on the nature of the fluid, due to local clustering of the polymer segments.     

Comments on the scalar-tensor theory

Scalar-tensor theories are discussed as encompassing three classical long-range fields, including the electromagnetic field. In order to shed additional light on the restrictive assumptions made by Dicke concerning the coupling of the scalar field with matter, the ponderomotive laws of a scalar-tensor theory are constructed free of approximations in the form of integral laws. The integrals are extended over two- and three-dimensional domains that lie entirely in empty space but surround the regions containing matter; as for the latter, the vacuum field equations are not required to hold, but no further assumptions are made. It turns out that the gradient of the incident scalar field will contribute to the rate of change of the mass and linear momentum of a particle an amount proportional to that particle's scalar-field source strength, which in turn is an arbitrary function of time, unless Dicke's special restriction is imposed. To this extent the motion of a test particle is indeterminate, contrary to experience.A preliminary version of this paper was presented at the colloquium on relativistic fluids and fields under the auspices of the Centre National de la Recherche Scientifique in Paris in June 1967. Support by Aerospace Research Laboratories and by the Air Force Office of Scientific Research, both agencies of the United States Air Force, is gratefully acknowledged, as is a travel grant by the CNRS.     

Comments on the Morita equivalence

It is known that the noncommutative Yang-Mills (YM) theory with periodical boundary conditions on a torus at a rational noncommutativity parameter value is Morita equivalent to the ordinary YM theory with twisted boundary conditions on a dual torus. We give a simple derivation of this fact. We describe the one-to-one correspondence between these two theories and the corresponding gauge invariant observables. In particular, we show that under the Morita map, the Polyakov loops in the ordinary YM theory are converted to the open noncommutative Wilson loops discovered by Ishibashi, Iso, Kawai, and Kitazawa.