Model-independent analysis for determining mass splittings of heavy baryons

We study the hyperfine mass differences of heavy hadrons in the heavy quark effect theory (HQET). The effects of one-gluon exchange interaction are considered for the heavy mesons and baryons. Base on the known experimental data, we predict the masses of some heavy baryons in a model-independent way.Comment: 14 pages, 1 figur

Phases and geometry of the N=1 A_2 quiver gauge theory and matrix models

We study the phases and geometry of the N=1 A_2 quiver gauge theory using matrix models and a generalized Konishi anomaly. We consider the theory both in the Coulomb and Higgs phases. Solving the anomaly equations, we find that a meromorphic one-form sigma(z)dz is naturally defined on the curve Sigma associated to the theory. Using the Dijkgraaf-Vafa conjecture, we evaluate the effective low-energy superpotential and demonstrate that its equations of motion can be translated into a geometric property of Sigma: sigma(z)dz has integer periods around all compact cycles. This ensures that there exists on Sigma a meromorphic function whose logarithm sigma(z)dz is the differential. We argue that the surface determined by this function is the N=2 Seiberg-Witten curve of the theory.Comment: 41 pages, 2 figures, JHEP style. v2: references adde

Specific protein content of pools of plasma for fractionation from different sources: impact of frequency of donations

Background and Objectives Plasma pools for the production of human plasma medicinal products are distinguished according to the collection method (recovered or apheresis plasma) and the donor remuneration status. National regulations and the physical status of the donor determine the donation frequency and plasma volume per session. Relevant protein contents of different types of pools have not fully been compared. Materials and Methods We compared the levels of total protein, 15 main relevant plasma protein markers, and anti-B19 and anti-Streptococcus pneumoniae IgG in single-type pools of donations from different countries (Belgium, Finland, France, the Netherlands, Germany, United States). Both recovered plasma from non-remunerated donors and apheresis plasma from remunerated and non-remunerated donors were studied. Results Pools from paid US high-frequency, high-volume plasmapheresis donors showed significantly lower total protein ()9%), albumin ()15%), total IgG ()24%), IgM ()28%), hemopexin ()11%) and retinol-binding protein ()10%) but higher C1inhibitor, pre-albumin and C-reactive protein contents than pools from unpaid European Union (EU) or US whole-blood or plasmapheresis donors. In contrast to pools from compensated EU plasmapheresis donors, pools from unpaid whole-blood or plasmapheresis donors showed no significant differences, whatever the collection method or country. Reductions in specific protein contents correlated well with protein half-life. Conclusion These results should be taken into account with regard to donor health management and protein recovery. Key words: albumin, donor remuneration, immunoglobulin, plasma donors, plasma fractionation, proteins

Resonances for "large" ergodic systems in one dimension: a review

The present note reviews recent results on resonances for one-dimensional quantum ergodic systems constrained to a large box. We restrict ourselves to one dimensional models in the discrete case. We consider two type of ergodic potentials on the half-axis, periodic potentials and random potentials. For both models, we describe the behavior of the resonances near the real axis for a large typical sample of the potential. In both cases, the linear density of their real parts is given by the density of states of the full ergodic system. While in the periodic case, the resonances distribute on a nice analytic curve (once their imaginary parts are suitably renormalized), In the random case, the resonances (again after suitable renormalization of both the real and imaginary parts) form a two dimensional Poisson cloud

Fractional Cauchy problems on bounded domains: survey of recent results

In a fractional Cauchy problem, the usual first order time derivative is replaced by a fractional derivative. This problem was first considered by \citet{nigmatullin}, and \citet{zaslavsky} in $\mathbb R^d$ for modeling some physical phenomena. The fractional derivative models time delays in a diffusion process. We will give a survey of the recent results on the fractional Cauchy problem and its generalizations on bounded domains D\subset \rd obtained in \citet{m-n-v-aop, mnv-2}. We also study the solutions of fractional Cauchy problem where the first time derivative is replaced with an infinite sum of fractional derivatives. We point out a connection to eigenvalue problems for the fractional time operators considered. The solutions to the eigenvalue problems are expressed by Mittag-Leffler functions and its generalized versions. The stochastic solution of the eigenvalue problems for the fractional derivatives are given by inverse subordinators

pi and rho loop corrections to omega photoproduction in the resonance region

One-loop corrections due to the intermediate $\pi N$ and $\rho N$ states are studied in $\omega$ photoproduction near threshold. Our results show that the coupled-channel effects should be taken into account in extracting reliable nucleon resonance parameters from the forthcoming vector meson photoproduction data in the resonance region.Comment: 4 pages, to be published in the proceedings of XVI International Conference on Particles and Nuclei (PANIC'02), Osaka, Japan, Sep. 30 - Oct. 4, 200

Low-Energy Brane-World Effective Actions and Partial Supersymmetry Breaking

As part of a programme for the general study of the low-energy implications of supersymmetry breaking in brane-world scenarios, we study the nonlinear realization of supersymmetry which occurs when breaking N=2 to N=1 supergravity. We consider three explicit realizations of this supersymmetry breaking pattern, which correspond to breaking by one brane, by one antibrane or by two (or more) parallel branes. We derive the minimal field content, the effective action and supersymmetry transformation rules for the resulting N=1 theory perturbatively in powers of kappa = 1/M_{Planck}. We show that the way the massive gravitino and spin-1 fields assemble into N=1 multiplets implies the existence of direct brane-brane contact interactions at order O(kappa). This result is contrary to the O(kappa^2) predicted by the sequestering scenario but in agreement with recent work of Anisimov et al. Our low-energy approach is model independent and is a first step towards determining the low-energy implications of more realistic brane models which completely break all supersymmetries.Comment: Latex, 29 Page

Tachyon-Dilaton-induced Inflation as an alpha'-resummed String Background

Within the framework of a novel functional method on the world-sheet of the string, we discuss simple but re-summed (in the Regge slope) inflationary scenarios in the context of closed Bosonic strings, living in four target-space dimensions, in the presence of non-trivial tachyon, dilaton and graviton cosmological backgrounds. The inflationary solutions are argued to guarantee the vanishing of the corresponding Weyl anomaly coefficients in a given world-sheet renormalization scheme, thereby ensuring conformal invariance of the corresponding sigma-model to all orders in the Regge slope. The key property is the requirement of "homogeneity" of the corresponding Weyl anomaly coefficients. Inflation entails appropriate relations between the dilaton and tachyon field configurations, whose form can lead to either a de Sitter vacuum, incompatible though (due to the cosmic horizons) with the perturbative string scattering amplitudes, or to cosmic space-times involving brief inflationary periods, interpolating smoothly between power-law and/or Minkowski Universes. The latter situation is characterized by well-defined scattering amplitudes, and is thus compatible with a perturbative string framework. It is this scenario that we consider a self-consistent ground state in our framework, which is based on local field redefinitions of background fields.Comment: 35 pages Latex, three eps figures incorporate