Photonic SUSY Two-Loop Corrections to the Muon Magnetic Moment

Photonic SUSY two-loop corrections to the muon magnetic moment are contributions from diagrams where an additional photon loop is attached to a SUSY one-loop diagram. These photonic corrections are evaluated exactly, extending a leading-log calculation by Degrassi and Giudice. Compact analytical expressions are provided and the numerical behaviour is discussed. The photonic corrections reduce the SUSY one-loop result by 7...9%. The new terms are typically around ten times smaller than the leading logarithms, but they can be larger and have either sign in cases with large SUSY mass splittings. We also provide details on renormalization and regularization and on how to incorporate the photonic corrections into a full SUSY two-loop calculation.Comment: 25 page

Isospin Breaking in the Relation Between the tau-->nu_tau pi pi and e^+e^- -->pi^+ pi^- Versions of |F_\pi (s)|^2$ and Implications for (g-2)_mu

We investigate two points related to existing treatments of isospin-breaking corrections to the CVC relation between the e^+e^- --> pi^+ pi^- cross-section and dGamma[tau^- --> nu_tau pi^- pi^0]/ds. Implications for the value of the hadronic contribution to a_mu =(g-2)_mu /2 based on those analyses incorporating hadronic tau decay data are also considered. We conclude that the uncertainty on the isospin-breaking correction which must be applied to the tau decay data should be significantly increased, and that the central value of the rho-omega ``mixing'' contribution to this correction may be significantly smaller than indicated by the present standard determination. Such a shift would contribute to reducing the discrepancy between the tau- and electroproduction-based determinations of the leading order hadronic contribution to a_mu.Comment: 15 pages, 1 figur

An extended-phase-space dynamics for the generalized nonextensive thermostatistics

We apply a variant of the Nose-Hoover thermostat to derive the Hamiltonian of a nonextensive system that is compatible with the canonical ensemble of the generalized thermostatistics of Tsallis. This microdynamical approach provides a deterministic connection between the generalized nonextensive entropy and power law behavior. For the case of a simple one-dimensional harmonic oscillator, we confirm by numerical simulation of the dynamics that the distribution of energy H follows precisely the canonical q-statistics for different values of the parameter q. The approach is further tested for classical many-particle systems by means of molecular dynamics simulations. The results indicate that the intrinsic nonlinear features of the nonextensive formalism are capable to generate energy fluctuations that obey anomalous probability laws. For q<1 a broad distribution of energy is observed, while for q>1 the resulting distribution is confined to a compact support.Comment: 4 pages, 5 figure

R-values in Low Energy e^+e^- Annihilation

This presentation briefly summarizes the recent measurements of R-values in low energy e^+e^- annihilation. The new experiments aimed at reducing the uncertainties in R-values and performed with the upgraded Beijing Spectrometer (BESII) at Beijing Electron Positron Collider (BEPC) in Beijing and with CMD-2 and SND at VEEP-2M in Novosibirsk are reviewed and discussed.Comment: 17 pages, 10 figures, invited presentation at the XIX International Symposium on Lepton and Photon Interactions at High Energy, Stanford University, August 199

SP-0489: HPV-transformation in the cervix and at non-cervical sites

Pla general d'un dels panells horitzontals sobre espais verds de Barcelona a l'exposició Ciutat. Barcelona projecta a l'Edifici Fòrum. Exposició sobre la planificació urbanística i arquitectònica de Barcelon

A Dynamic Approach to the Thermodynamics of Superdiffusion

We address the problem of relating thermodynamics to mechanics in the case of microscopic dynamics without a finite time scale. The solution is obtained by expressing the Tsallis entropic index q as a function of the Levy index alpha, and using dynamical rather than probabilistic arguments.Comment: 4 pages, new revised version resubmitted to Phys. Rev. Let

Main Field Tracking Measurement in the LHC Superconducting Dipole and Quadrupole Magnets

One of the most stringent requirements during the energy ramp of the Large Hadron Collider (LHC) is to have a constant ratio between dipole-quadrupole and dipole-dipole field so as to control the variation of the betatron tune and of the beam orbit throughout the acceleration phase, hence avoiding particle loss. To achieve the nominal performance of the LHC, a maximum variation of ±0.003 tune units can be tolerated. For the commissioning with low intensity beams, acceptable bounds are up to 30 times higher. For the quadrupole-dipole integrated field ratio, the above requirements translate in the tight windows of 6 ppm and 180 ppm, while for dipole differences between sectors the acceptable error is of the order of 10^-4. Measurement and control at this level are challenging. For this reason we have launched a dedicated measurement R&amp;D to demonstrate that these ratios can be measured and controlled within the limits for machine operation. In this paper we present the techniques developed to power the magnets during the current ramps, the instrumentation and data acquisition setup used to perform the tracking experiments, the calibration procedure and the data reduction employed

A Demonstration Experiment for the Main Field Tracking and the Sextupole and Decapole Compensation in the LHC Main Magnets

A dedicated measurement campaign was set up to test the FiDeL concept and its LSA implementation. The test was performed by demonstrating the tracking of B1 and B2 for two LHC main dipoles and one LHC main quadrupole. It also included the compensation of the b3 and b5 harmonics in the dipole magnets using the sextupole and decapole corrector magnets. In this report we present the techniques developed to power the magnets for these tests during the current ramps; the instrumentation and data acquisition setup used to perform the tracking experiments; the calibration procedure and data corrections employed; and finally the main results obtained

Complete Exact Solution of Diffusion-Limited Coalescence, A + A -> A

Some models of diffusion-limited reaction processes in one dimension lend themselves to exact analysis. The known approaches yield exact expressions for a limited number of quantities of interest, such as the particle concentration, or the distribution of distances between nearest particles. However, a full characterization of a particle system is only provided by the infinite hierarchy of multiple-point density correlation functions. We derive an exact description of the full hierarchy of correlation functions for the diffusion-limited irreversible coalescence process A + A -> A.Comment: 4 pages, 2 figures (postscript). Typeset with Revte

The vector form factor of the pion from unitarity and analyticity: a model-independent approach

We study a model-independent parameterization of the vector pion form factor that arises from the constraints of analyticity and unitarity. Our description should be suitable up to sqrt(s) ~ 1.2 GeV and allows a model-independent determination of the mass of the rho(770) resonance, M(rho) = (775.1 +- 0.5) MeV. We analyse the experimental data on tau(-) -> pion(-) pion(0) neutrino(tau), in this framework, and its consequences on the low-energy observables worked out by chiral perturbation theory. An evaluation of the two-pion contribution to the anomalous magnetic moment of the muon, a_muon, and to the fine structure constant, alpha(M(Z)^2), is also performed.Comment: 1+15 pages, 2 figure