Showing papers in "Modern Physics Letters A in 1994"
TL;DR: In this paper, a hierarchy of possible sum rules for quantum probability additivity is presented, each of which implies its successor, and a series of natural generalizations of the quantum formalism is delineated.
Abstract: The additivity of classical probabilities is only the first in a hierarchy of possible sum rules, each of which implies its successor. The first and most restrictive sum rule of the hierarchy yields measure theory in the Kolmogorov sense, which is appropriate physically for the description of stochastic processes such as Brownian motion. The next weaker sum rule defines a generalized measure theory which includes quantum mechanics as a special case. The fact that quantum probabilities can be expressed "as the squares of quantum amplitudes" is thus derived in a natural manner, and a series of natural generalizations of the quantum formalism is delineated. Conversely, the mathematical sense in which classical physics is a special case of quantum physics is clarified. The present paper presents these relationships in the context of a "realistic" interpretation of quantum mechanics.
435 citations
TL;DR: In this article, a class of two-dimensional field theories, based on (generically degenerate) Poisson structures and generalizing gravity-Yang-Mills systems, is presented.
Abstract: A class of two-dimensional field theories, based on (generically degenerate) Poisson structures and generalizing gravity-Yang–Mills systems, is presented. Locally, the solutions of the classical equations of motions are given. A general scheme for the quantization of the models in a Hamiltonian formulation is found. A BRS-formulation is outlined briefly.
433 citations
TL;DR: In this paper, a CP-asymmetry is found in the reflection coefficients of quarks hitting the phase boundary created during the electroweak transition and a regular GIM behavior is found as intuitively expected.
Abstract: In CP arguments, we argue against a Standard Model explanation of the baryon asymmetry of the universe in the presence of a first order phase transition. A CP-asymmetry is found in the reflection coefficients of quarks hitting the phase boundary created during the electroweak transition. The problem is analyzed both in an academic zero temperature case and in the realistic finite temperature one. The building blocks are similar in both cases: Kobayashi-Maskawa CP-violation, CP-even phases in the reflection coefficients of quarks, and physical transitions due to fermion self-energies. In both cases an effect is present at order $\alpha_W^2 $ in rate. A regular GIM behavior is found as intuitively expected. In the finite temperature case, a crucial role is played by the damping rate of quasiparticles in a hot plasma, which is a relevant scale together with MW and the temperature. The effect is many orders of magnitude below what observation requires, and indicates that non-standard physics is indeed needed ...
430 citations
TL;DR: In this article, the authors apply simultaneously the principles of quantum mechanics and general relativity to find an intrinsic limitation to quantum measurements of space-time distances and show that the intrinsic uncertainty of a length is proportional to the one third power of the length itself.
Abstract: Applying simultaneously the principles of quantum mechanics and general relativity we find an intrinsic limitation to quantum measurements of space-time distances. The intrinsic uncertainty of a length is shown to be proportional to the one third power of the length itself. This uncertainty in space-time measurements implies an intrinsic uncertainty of the space-time metric and yields quantum decoherence for particles heavier than the Planck mass.
227 citations
TL;DR: In this paper, the authors generalize the connection between the off-shell Bethe ansatz equation and the solutions of the SU(2) Knizhnik-Zamolodchikov equations to the case of simple Lie algebras of higher rank.
Abstract: We generalize the previously established connection between the off-shell Bethe ansatz equation for inhomogeneous SU(2) lattice vertex models in the quasiclassical limit and the solutions of the SU(2) Knizhnik-Zamolodchikov equations to the case of simple Lie algebras of higher rank.
156 citations
TL;DR: In this article, a large-N matrix model was constructed for the topological CP1 model, which consists of the holomorphic maps from Riemann surfaces onto CP1, and the action of the matrix model has the form where M is an N × N Hermitian matrix and tn,P(tn,Q), (n = 0, 1, 2, 3, 4, 5), are the coupling constants of the nth descendant of the puncture (Kahler) operator.
Abstract: We discuss the topological CP1 model which consists of the holomorphic maps from Riemann surfaces onto CP1. We construct a large-N matrix model which reproduces precisely the partition function of the CP1 model at all genera of Riemann surfaces. The action of our matrix model has the form where M is an N × N Hermitian matrix and tn,P(tn,Q), (n = 0, 1, 2, …) are the coupling constants of the nth descendant of the puncture (Kahler) operator.
144 citations
TL;DR: By taking into account both quantum mechanical and general relativistic effects, an equation that describes some limitations on the measurability of space-time distances can be derived as mentioned in this paper, and possible features of quantum gravity which are suggested by this equation.
Abstract: By taking into account both quantum mechanical and general relativistic effects, an equation that describes some limitations on the measurability of space-time distances can be derived. We then discuss possible features of quantum gravity which are suggested by this equation.
141 citations
TL;DR: In this article, the Penrose diagram is constructed by enforcing time-reversal symmetry. But the line element continues smoothly through the horizon; by exploiting this feature, they are able to give a very simple and physically transparent derivation of the Hawking radiance.
Abstract: Guided by a Hamiltonian treatment of spherically symmetric geometry, we are led to a remarkably simple—stationary, but not static—form for the line element of Schwarzschild (and Reissner-Nordstrom) geometry. The line element continues smoothly through the horizon; by exploiting this feature we are able to give a very simple and physically transparent derivation of the Hawking radiance. We construct the complete Penrose diagram by enforcing time-reversal symmetry. Finally we outline how an improved treatment of the radiance, including effects of self-gravitation, can be obtained.
125 citations
TL;DR: In this article, it was shown that bosonic strings may be viewed as a particular class of vacua for N = 1 superstrings, and N=1 superstrings may be a special class of vacuum selection for N=2 strings.
Abstract: We show that bosonic strings may be viewed as a particular class of vacua for N=1 superstrings, and N=1 superstrings may be viewed as a particular class of vacua for N=2 strings. Continuing this line of string hierarchies, we are led to search for a universal string theory which includes all the rest as a special vacuum selection.
93 citations
TL;DR: In this paper, the cyclic quantum dilogarithm is interpreted as a cyclic 6j-symbol of the Weyl algebra, considered as a Borel subalgebra BUq(sl(2)).
Abstract: The cyclic quantum dilogarithm is interpreted as a cyclic 6j-symbol of the Weyl algebra, considered as a Borel subalgebra BUq(sl(2)). Using modified 6j-symbols, an invariant of triangulated links in triangulated three-manifolds is constructed. Apparently, it is an ambient isotopy invariant of links.
80 citations
TL;DR: In this paper, the decay width of process in the region 60 GeV
Abstract: We consider in detail various theoretical uncertainties of the perturbative predictions for the decay width of process in the region 60 GeV
TL;DR: For a heavy Higgs boson (mH≫mt), the QCD corrections become very large (50-100%), while for a lighter one, the corrections are negligible.
Abstract: Two-photon decay of the Higgs boson H→γγ and its reverse process γγ→H are important processes in detecting Higgs boson which plays a fundamental role in the Standard Model of electroweak interaction. We calculate the QCD corrections to these processes for all mass ranges of the Higgs boson without any constraint for the top quark mass. For a heavy Higgs boson (mH≫mt), the QCD corrections become very large (50–100%), while for a lighter one (mH≤mt), the corrections are negligible.
TL;DR: In this article, the authors present a detailed numerical analysis of a fully-fledged computation of one-loop supersymmetric quantum effects on the mass of the weak gauge boson W± in the standard on-shell renormalization scheme based on the input parameters.
Abstract: We present a detailed numerical analysis of a fully-fledged computation of one-loop supersymmetric quantum effects on the mass of the weak gauge boson W± in the standard on-shell renormalization scheme based on the input parameters (GF, α, MZ). The importance of the process-dependent contributions as compared to the universal effects is assessed. The final numerical results show that in large regions of parameter space the potential radiative shifts could be within the level of precision expected at LEP II, depending on the model considered. A comparison is made with other renormalization frameworks.
TL;DR: In this article, an explicit expression for all the quantum integrals of motion for the isotropic Heisenberg s = 1/2 spin chain is presented, expressed in terms of a sum over simple polynomials in spin variables.
Abstract: An explicit expression for all the quantum integrals of motion for the isotropic Heisenberg s=1/2 spin chain is presented. The conserved quantities are expressed in terms of a sum over simple polynomials in spin variables. This construction is direct and independent of the transfer matrix formalism. Continuum limits of these integrals in both ferromagnetic and antiferromagnetic sectors are briefly discussed.
TL;DR: In this article, the authors calculate the valence distribution of down quarks and up quarks in the proton and the neutron, taking into account the major sources of charge symmetry violation, including the effect of the mass difference of u and d quarks on the bag wave function, and the masses of the intermediate diquark states.
Abstract: We calculate the valence distribution of down quarks in the proton and up quarks in the neutron (the ‘minority’ quark distributions), taking into consideration the major sources of charge symmetry violation, including the effect of the mass difference of the u and d quarks on the bag wave function, and the masses of the intermediate diquark states. The relative difference of the distributions can be as large as 10% for intermediate values of Bjorken x.
TL;DR: In this paper, it was shown that neutrino mixing in exact parity models is a general phenomenon, provided that the neutrinos mass matrix is real, such that the probability of a given weak eigenstate remaining in that eigen state averages to less than half when averaged over many oscillations.
Abstract: We re-examine neutrino oscillations in exact parity models. Previously it was shown in a specific model that large neutrino mixing angles result. We show here that this is a general result of neutrino mixing in exact parity models provided that the neutrino mass matrix is real. In this case, the effects of neutrino mixing in exact parity models is such that the probability of a given weak eigenstate remaining in that eigenstate averages to less than half when averaged over many oscillations. This result is interesting in view of the accumulating evidence for a significant deficit in the number of solar neutrinos. It may also be of relevance to the atmospheric neutrino anomaly.
TL;DR: Realistic quantum mechanics based on complex probability theory is shown to have a frequency interpretation, to coexist with Bell's theorem, to be linear, to include wavefunctions which are expansions in eigenfunctions of Hermitian operators and to describe both pure and mixed systems.
Abstract: As a possible alternative to conventional quantum mechanics, the Bayesian version of probability theory is extended to include complex probabilities. An additional assumption of realism restores a frequency interpretation while coexisting with Bell’s theorem. Such complex probabilities are shown to have a superposition principle, to include wave functions which are expansions in eigenfunctions of Hermitian operators, to have a path-integral representation and to describe both pure and mixed systems. A scalar particle in Rd is shown to obey the Schrodinger equation with mass, vector potential and metric appearing as moments of a fundamental probability. Illustrative examples are given. The quantum version of Bayesian inference is discussed.
TL;DR: In this paper, a class of Calabi-Yau compactifications which are constructed as complete intersection in weighted projective space is considered and the instanton sum is calculated for manifolds with one Kahler modulus.
Abstract: We consider a class of Calabi-Yau compactifications which are constructed as a complete intersection in weighted projective space. For manifolds with one Kahler modulus we construct the mirror manifolds and calculate the instanton sum.
TL;DR: In this article, it was shown that the generalized knot invariants, obtained through SU(2) Chern-Simons topological field theory, which give the known polynomials as special cases, are indeed sensitive to the chirality of these knots.
Abstract: Up to 10 crossing numbers, there are two knots, 942 and 1071 whose chirality is not detected by any of the known polynomials, namely, Jones invariants and their two variable generalizations, HOMFLY and Kauffman invariants. We show that the generalized knot invariants, obtained through SU(2) Chern-Simons topological field theory, which give the known polynomials as special cases, are indeed sensitive to the chirality of these knots.
TL;DR: In this article, a maximum cavity size is suggested by the inverse critical frequency of such emission/absorption rates at a given temperature, or a maximum temperature at a certain frequency.
Abstract: Bosonic q-oscillators commute with themselves and so their free distribution is Planckian. In a cavity, their emission and absorption rates may grow or shrink – and even diverge – but they nevertheless balance to yield the Planck distribution via Einstein’s equilibrium method, (a careless application of which might produce spurious q-dependent distribution functions). This drives home the point that the black-body energy distribution is not a handle for distinguishing q-excitations from plain oscillators. A maximum cavity size is suggested by the inverse critical frequency of such emission/absorption rates at a given temperature, or a maximum temperature at a given frequency. To remedy fragmentation of opinion on the subject, we provide some discussion, context, and references.
TL;DR: In this article, a new class of topological conformal field theories (TCFTs) characterized by a rational W potential is presented, which includes the minimal models of A and D types as its subclasses.
Abstract: We present a new class of topological conformal field theories (TCFTs) characterized by a rational W potential, which includes the minimal models of A and D types as its subclasses. An explicit form of the W potential is found by solving the underlying dispersionless KP hierarchy in a particular small phase space. We also discuss the dispersionless KP hierarchy in large phase spaces by reformulating the hierarchy, and show that the W potential takes a universal form, which does not depend on a specific form of the solution in a large space.
TL;DR: In this paper, the authors considered flavor changing neutral current effects coming from the Z′ exchange in 3-3-1 models and showed that the mass of this extra neutral vector boson may be less than 2 TeV and discussed the problem of quark family discrimination.
Abstract: We consider flavor changing neutral current effects coming from the Z′ exchange in 3–3–1 models. We show that the mass of this extra neutral vector boson may be less than 2 TeV and discuss the problem of quark family discrimination.
TL;DR: In this paper, it was shown that the β-function of the gauge coupling in 2+1 dimensions gauge theory coupled to any renormalizable system of spinor and scalar fields is zero.
Abstract: We prove that the β-function of the gauge coupling in 2+1 dimensions gauge theory coupled to any renormalizable system of spinor and scalar fields is zero. This result holds both when the gauge field action is the Chern-Simons action and when it is the topologically massive action.
TL;DR: In this paper, the anomalous dimension has been calculated to get energy dependence of mean multiplicities in higher order QCDs and it has been used to obtain energy dependence on the mean of the average multiplicity of the gluon and quark jets.
Abstract: The ratio of average multiplicities in gluon and quark jets is shown to become noticeably smaller in higher order QCD compared to its lowest order value which improves agreement with experiment. QCD anomalous dimension has been calculated. It has been used to get energy dependence of mean multiplicities.
TL;DR: In this paper, it is suggested that both the Peccei-Quinn symmetry and the spontaneously broken R symmetry may be the sources of the needed μ term in the minimal supersymmetric standard model provided that they are spontaneously broken at a scale 1010-1012GeV.
Abstract: We stress that a natural solution of the μ problem requires two ingredients: a symmetry that would enforce μ=0 as well as the occurrence of a small breaking parameter that generates a nonzero μ. It is suggested that both the Peccei-Quinn symmetry and the spontaneously broken R symmetry may be the sources of the needed μ term in the minimal supersymmetric standard model provided that they are spontaneously broken at a scale 1010–1012GeV. To solve the strong CP problem with a hidden sector confining group, both of these symmetries are needed in superstring models with an anomalous U(1)A.
TL;DR: In this paper, the nested Bethe ansatz is generalized to open and independent boundary conditions depending on two continuous and two discrete free parameters, which are used to find the exact eigenvectors and eigenvalues of the An−1 vertex models and spin chains with such boundary conditions.
Abstract: The nested Bethe ansatz is generalized to open and independent boundary conditions depending on two continuous and two discrete free parameters. This is used to find the exact eigenvectors and eigenvalues of the An−1 vertex models and SU(n) spin chains with such boundary conditions. The solution is found for all diagonal families of solutions to the reflection equations in all possible combinations. The Bethe ansatz equations are used to find the first order finite size correction.
TL;DR: In this article, a list of Calabi-Yau manifolds realized as complete intersections of polynomials in Cartesian products of complex projective spaces is presented, containing 97,360 configurations with Euler numbers ranging from 0 to −200.
Abstract: We have obtained a new list of Calabi-Yau manifolds realized as complete intersections of polynomials in Cartesian products of complex projective spaces. It contains 97,360 configurations with Euler numbers ranging from 0 to −200. A remarkable structure emerges from this compilation.
TL;DR: In this article generalized quons interpolating between Bose, Fermi, para-Bose, and anyonic statistics are proposed, which follow from the R-matrix approach to deformed associative algebras.
Abstract: Generalized quons interpolating between Bose, Fermi, para-Bose, para-Fermi and anyonic statistics are proposed. They follow from the R-matrix approach to deformed associative algebras. It is proved that generalized quons have the same main properties as quons. A new result for the number operator is presented and some physical features of generalized quons are discussed in the limit .
TL;DR: In this paper, an exact solution to the Einstein field equations is found, which represents the gravitational collapse of a thick domain wall, which can be measured as a gravitational wave at the spacelike infinity.
Abstract: An exact solution to the Einstein field equations is found, which represents the gravitational collapse of a thick domain wall. During the collapse, the wall emits gravitational radiation, which can be measured as a gravitational pp wave at the spacelike infinity. The time-reversed solution represents an expanding universe, in which a domain wall resides. It is shown explicitly that such a wall can be inflated away.
TL;DR: In this paper, a model of discretized 2D gravity interacting with Ising spins where the phase boundaries are restricted to have minimal length is considered and it is shown analytically that the critical exponent, γ, is 1/3 at the spin transition point.
Abstract: We consider a model of discretized 2D gravity interacting with Ising spins where the phase boundaries are restricted to have minimal length and show analytically that the critical exponent, γ, is 1/3 at the spin transition point. The model captures the numerically observed behavior of standard multiple Ising spins coupled to 2D gravity.