Isospin-violating nucleon-nucleon forces using the method of unitary transformation

Recently, we have derived the leading and subleading isospin-breaking three-nucleon forces using the method of unitary transformation. In the present work we extend this analysis and consider the corresponding two-nucleon forces using the same approach. Certain contributions to the isospin-violating one- and two-pion-exchange potential have already been discussed by various groups within the effective field theory framework. Our findings agree with the previously obtained results. In addition, we present the expressions for the subleading charge-symmetry-breaking two-pion exchange potential which were not considered before. These corrections turn out to be numerically important. Together with the three-nucleon force results presented in our previous work, the results of the present study specify completely isospin-violating nuclear forces up to the order $q^5/\Lambda^5$, where $q$ ($\Lambda$) denotes the soft (hard) scale.Comment: 25 pages, 12 figure

Triple Products and Yang-Baxter Equation (II): Orthogonal and Symplectic Ternary Systems

We generalize the result of the preceeding paper and solve the Yang-Baxter equation in terms of triple systems called orthogonal and symplectic ternary systems. In this way, we found several other new solutions.Comment: 38 page

Macroscopic description of particle systems with non-local density-dependent diffusivity

In this paper we study macroscopic density equations in which the diffusion coefficient depends on a weighted spatial average of the density itself. We show that large differences (not present in the local density-dependence case) appear between the density equations that are derived from different representations of the Langevin equation describing a system of interacting Brownian particles. Linear stability analysis demonstrates that under some circumstances the density equation interpreted like Ito has pattern solutions, which never appear for the Hanggi-Klimontovich interpretation, which is the other one typically appearing in the context of nonlinear diffusion processes. We also introduce a discrete-time microscopic model of particles that confirms the results obtained at the macroscopic density level.Comment: 4 pages, 3 figure

Production of f0(1710)f_0(1710), f0(1500)f_0(1500), and f0(1370)f_0(1370) in J/ψJ/\psi hadronic decays

A coherent study of the production of $f_0^i$ ($i=1$, 2, 3 corresponding to $f_0(1710)$, $f_0(1500)$, and $f_0(1370)$) in $J/\psi\to V f_0 \to V PP$ is reported based on a previously proposed glueball and $Q\bar{Q}$ nonet mixing scheme, and a factorization for the decay of $J/\psi\to V f_0^i$, where $V$ denotes the isoscalar vector mesons $\phi$ and $\omega$, and $P$ denotes pseudoscalar mesons. The results show that the $J/\psi$ decays are very sensitive to the structure of those scalar mesons, and suggest a glueball in the $1.5-1.7$ GeV region, in line with Lattice QCD. The presence of significant glueball mixings in the scalar wavefunctions produces peculiar patterns in the branching ratios for $J/\psi\to V f_0^i\to VPP$, which are in good agreement with the recently published experimental data from the BES collaboration.Comment: Version accepted by PRD; Numerical results in Tab IV and VI changed due to correction of an error in quoting an experimental datum; Conclusion is not change

Low-momentum effective theory for nucleons

Starting from a precise two-nucleon potential, we use the method of unitary transformations to construct an effective potential that involves only momenta less than a given maximal value. We describe this method for an S-wave potential of the Malfliet-Tjon type. It is demonstrated that the bound and scattering state spectrum calculated within the effective theory agrees exactly with the one based on the original potential. This might open an avenue for the construction of effective chiral few-nucleon forces and for a systematic treatment of relativistic effects in few-body systems.Comment: 10 pp, LaTeX file, 4 figures (uses epsf), extended version, accepted for publiaction in Phys.Lett.

Low-momentum Hyperon-Nucleon Interactions

We present a first exploratory study for hyperon-nucleon interactions using renormalization group techniques. The effective two-body low-momentum potential V_low-k is obtained by integrating out the high-momentum components from realistic Nijmegen YN potentials. A T-matrix equivalence approach is employed, so that the low-energy phase shifts are reproduced by V_low-k up to a momentum scale Lambda ~ 500 MeV. Although the various bare Nijmegen models differ somewhat from each other, the corresponding V_low-k interactions show convergence in some channels, suggesting a possible unique YN interaction at low momenta.Comment: 4 pages, 6 figure

Weak Wave Turbulence Scaling Theory for Diffusion and Relative Diffusion in Turbulent Surface Waves

We examine the applicability of the weak wave turbulence theory in explaining experimental scaling results obtained for the diffusion and relative diffusion of particles moving on turbulent surface waves. For capillary waves our theoretical results are shown to be in good agreement with experimental results, where a distinct crossover in diffusive behavior is observed at the driving frequency. For gravity waves our results are discussed in the light of ocean wave studies.Comment: 5 pages; for related work visit http://www.imedea.uib.es/~victo

Detecting barriers to transport: A review of different techniques

We review and discuss some different techniques for describing local dispersion properties in fluids. A recent Lagrangian diagnostics, based on the Finite Scale Lyapunov Exponent (FSLE), is presented and compared to the Finite Time Lyapunov Exponent (FTLE), and to the Okubo-Weiss (OW) and Hua-Klein (HK) criteria. We show that the OW and HK are a limiting case of the FTLE, and that the FSLE is the most efficient method for detecting the presence of cross-stream barriers. We illustrate our findings by considering two examples of geophysical interest: a kinematic meandering jet model, and Lagrangian tracers advected by stratospheric circulation.Comment: 15 pages, 9 figures, submitted to Physica

Development and mechanical testing of a short intramedullary nail for fixation of femoral rotational osteotomy in cerebral palsy patients

<p>Abstract</p> <p>Background</p> <p>Rotational osteotomy is frequently indicated to correct excessive femoral anteversion in cerebral palsy patients. Angled blade plate is the standard fixation device used when performed in the proximal femur, but extensile exposure is required for plate accommodation. The authors developed a short locked intramedullary nail to be applied percutaneously in the fixation of femoral rotational osteotomies in children with cerebral palsy and evaluated its mechanical properties.</p> <p>Methods</p> <p>The study was divided into three stages. In the first part, a prototype was designed and made based on radiographic measurements of the femoral medullary canal of ten-year-old patients. In the second, synthetic femoral models based on rapid-prototyping of 3D reconstructed images of patients with cerebral palsy were obtained and were employed to adjust the nail prototype to the morphological changes observed in this disease. In the third, rotational osteotomies were simulated using synthetic femoral models stabilized by the nail and by the AO-ASIF fixed-angle blade plate. Mechanical testing was done comparing both devices in bending-compression and torsion.</p> <p>Results</p> <p>The authors observed proper adaptation of the nail to normal and morphologically altered femoral models, and during the simulated osteotomies. Stiffness in bending-compression was significantly higher in the group fixed by the plate (388.97 ± 57.25 N/mm) than in that fixed by the nail (268.26 ± 38.51 N/mm) as torsional relative stiffness was significantly higher in the group fixed by the plate (1.07 ± 0.36 Nm/°) than by the nail (0.35 ± 0.13 Nm/°).</p> <p>Conclusions</p> <p>Although the device presented adequate design and dimension to fit into the pediatric femur, mechanical tests indicated that the nail was less stable than the blade plate in bending-compression and torsion. This may be a beneficial property, and it can be attributed to the more flexible fixation found in intramedullary devices.</p

Processed meat consumption and Lung function: modification by antioxidants and smoking

This article has supplementary material available from www.erj.ersjournals.com: This study was supported by the Medical Research Council, UK. H. Okubo was supported in part by fellowship of the Astellas Foundation for Research on Metabolic Disorders, Japan and the Naito Memorial Grant for Research Abroad from the Naito Foundation, Japan