Higher Dimensional SUSY Quantum Mechanics

Higher dimensional supersymmetric quantum mechanics is studied. General properties of the two dimensional case are presented. For three spatial dimesions or higher, a spin structure is shown to arise naturally from the nonrelativistic supersymmetry algebra.Comment: 8 pages, Late

Multiple-q states and skyrmion lattice of the triangular-lattice Heisenberg antiferromagnet under magnetic fields

Ordering of the frustrated classical Heisenberg model on the triangular-lattice with an incommensurate spiral spin structure is studied under magnetic fields by means of a mean-field analysis and a Monte Carlo simulation. Several types of multiple-q states including the "skyrmion-lattice" state is observed in addition to the standard single-q state. In contrast to the Dzyaloshinskii-Moriya interaction driven system, the present model allows both skyrmions and anti-skyrmions, together with a new thermodynamic phase where skyrmion and anti-skyrmion lattices form a domain state.Comment: 5 pages, 4 figures, accepted for publication in Phys. Rev. Let

One-Nucleon Effective Generators of the Poincare Group derived from a Field Theory: Mass Renormalization

We start from a Lagrangian describing scalar "nucleons" and mesons which interact through a simple vertex. Okubo's method of unitary transformation is used to describe a single nucleon dressed by its meson cloud. We find an expression for the physical mass of the nucleon being correct up to second order in the coupling constant. It is then verified that this result is the same as the corresponding expression found by Feynman techniques. Finally we also express the three boost operators in terms of the physical nucleon mass. Doing so we find expressions for all the ten generators of Poincar\'e transformations for the system of one single dressed nucleon.Comment: 19 pages, no figure

Is the anomalous decay ratio of D_{sJ}(2632) due to isospin breaking?

Quark pair annihilation into gluons is suppressed at large momenta due to the asymptotic freedom. As a consequence, mass eigenvalues of heavy states should be almost diagonal with respect to up and down quark masses, thereby breaking isospin. We suggest the particle observed by the SELEX Collaboration, D_{sJ}(2632) to be to a good extent a [cd][dbar sbar] state, which would explain why its D^0 K^+ mode is anomalously suppressed with respect to D_s eta. Predictions for the rates of the yet unobserved modes D_s pi^0 and D^+ K^0 are given.Comment: 3 pages, 1 figur

A new look at scalar mesons

Light scalar mesons are found to fit rather well a diquark-antidiquark description. The resulting nonet obeys mass formulae which respect, to a good extent, the OZI rule. OZI allowed strong decays are reasonably reproduced by a single amplitude describing the switch of a qbar-q pair, which transforms the state into two colourless pseudoscalar mesons. Predicted heavy states with one or more quarks replaced by charm or beauty are briefly described; they should give rise to narrow states with exotic quantum numbers.Comment: 4 pages, 1 figure, misprints corrected, references added, accepted for publication in Phys. Rev. Let

Comment on "Valence QCD: Connecting QCD to the Quark Model"

I criticize certain conclusions about the physics of hadrons drawn from a "valence QCD" approximation to QCD.Comment: 12 pages, 8 figures; some minor improvements made to the tex

Integrating Industry and National Economic Accounts: First Steps and Future Improvements

The integration of the annual I-O accounts with the GDP-by-industry accounts is the most recent in a series of improvements to the industry accounts provided by the BEA in recent years. BEA prepares two sets of national industry accounts: The I-O accounts, which consist of the benchmark I-O accounts and the annual I-O accounts, and the GDPby- industry accounts. Both the I-O accounts and the GDP-by-industry accounts present measures of gross output, intermediate inputs, and value added by industry. However, in the past, they were inconsistent because of the use of different methodologies, classification frameworks, and source data. The integration of these accounts eliminated these inconsistencies and improved the accuracy of both sets of accounts. The integration of the annual industry accounts represents a major advance in the timeliness, accuracy, and consistency of these accounts, and is a result of significant improvements in BEA's estimating methods. The paper describes the new methodology, and the future steps required to integrate the industry accounts with the NIPAs. The new methodology combines source data between the two industry accounts to improve accuracy; it prepares the newly integrated accounts within an I-O framework that balances and reconciles industry production with commodity usage. Moreover, the new methodology allows the acceleration of the release of the annual I-O accounts by 2 years and for the first time, provides a consistent time series of annual I-O accounts. Three appendices are provided: A description of the probability-based method to rank source data by quality; a description of the new balancing produced for producing the annual I-O accounts; and a description of the computation method used to estimate chaintype price and quantity indexes in the GDP-by-industry accounts.

Noise and Inertia-Induced Inhomogeneity in the Distribution of Small Particles in Fluid Flows

The dynamics of small spherical neutrally buoyant particulate impurities immersed in a two-dimensional fluid flow are known to lead to particle accumulation in the regions of the flow in which rotation dominates over shear, provided that the Stokes number of the particles is sufficiently small. If the flow is viewed as a Hamiltonian dynamical system, it can be seen that the accumulations occur in the nonchaotic parts of the phase space: the Kolmogorov--Arnold--Moser tori. This has suggested a generalization of these dynamics to Hamiltonian maps, dubbed a bailout embedding. In this paper we use a bailout embedding of the standard map to mimic the dynamics of impurities subject not only to drag but also to fluctuating forces modelled as white noise. We find that the generation of inhomogeneities associated with the separation of particle from fluid trajectories is enhanced by the presence of noise, so that they appear in much broader ranges of the Stokes number than those allowing spontaneous separation

Rational Terms in Theories with Matter

We study rational remainders associated with gluon amplitudes in gauge theories coupled to matter in arbitrary representations. We find that these terms depend on only a small number of invariants of the matter-representation called indices. In particular, rational remainders can depend on the second and fourth order indices only. Using this, we find an infinite class of non-supersymmetric theories in which rational remainders vanish for gluon amplitudes. This class includes all the "next-to-simplest" quantum field theories of arXiv:0910.0930. This provides new examples of amplitudes in which rational remainders vanish even though naive power counting would suggest their presence.Comment: 10+4 pages. (v2) typos corrected, references adde