Measured optical absorption coefficients for uranium plasmas

Absolute emissivities of uranium plasmas in gas driven shock tub

MC generator TAUOLA: implementation of Resonance Chiral Theory for two and three meson modes. Comparison with experiment

We present a partial upgrade of the Monte Carlo event generator TAUOLA with the two and three hadron decay modes using the theoretical models based on Resonance Chiral Theory. These modes account for 88% of total hadronic width of the tau meson. First results of the model parameters have been obtained using BaBar data for three pion mode.Comment: 5 pages, 1 figure, contribution to the Proceedings of the QCD@Work12 Conferenc

Theoretical inputs and errors in the new hadronic currents in TAUOLA

The new hadronic currents implemented in the TAUOLA library are obtained in the unified and consistent framework of Resonance Chiral Theory: a Lagrangian approach in which the resonances exchanged in the hadronic tau decays are active degrees of freedom included in a way that reproduces the low-energy results of Chiral Perturbation Theory. The short-distance QCD constraints on the imaginary part of the spin-one correlators yield relations among the couplings that render the theory predictive. In this communication, the obtaining of the two- and three-meson form factors is sketched. One of the criticisms to our framework is that the error may be as large as 1/3, since it is a realization of the large-N_C limit of QCD in a meson theory. A number of arguments are given which disfavor that claim pointing to smaller errors, which would explain the phenomenological success of our description in these decays. Finally, other minor sources of error and current improvements of the code are discussed.Comment: 5 pages, no figures, contribution to the Proceedings of the QCD@Work12 Conferenc

Hadron structure in tau -> KKpi nu_tau decays

We analyse the hadronization structure of both vector and axial-vector currents leading to tau -> KKpi nu_tau decays. At leading order in the 1/Nc expansion, and considering only the contribution of the lightest resonances, we work out, within the framework of the resonance chiral Lagrangian, the structure of the local vertices involved in those processes. The couplings in the resonance theory are constrained by imposing the asymptotic behaviour of vector and axial-vector spectral functions ruled by QCD. In this way we predict the hadron spectra and conclude that, contrarily to previous assertions, the vector contribution dominates by far over the axial-vector one in all KKpi charge channels.Comment: 32 pages, 7 figure

Occurrence of Banded Chlorosis of Sugarcane in Puerto Rico

Chlorotic banding was first observed in Puerto Rico on the leaves of sugarcane P.R. 1059 at Central Aguirre. Since P.R. 1059 is a promising sugarcane variety, the trouble has caused considerable concern. A survey showed that the extent of chlorotic bandings varied with localities. A study of the records of the temperature patterns during the summer of 1964 showed that an outbreak of banding occurred mostly where high air temperatures had prevailed. As the cool season advanced, the symptom of chlorotic banding disappeared from the leaves of P.R. 1059. Since the symptoms are similar to those described for banded chlorosis of sugarcane, but no causal agent has been identified, the malady has been tentatively identified as banded chlorosis caused by high air temperatures

τ−→ηπ−π0ντ\tau^-\to\eta\pi^-\pi^0\nu_\tau and σ(e+e−→ηπ+π−)\sigma(e^+e^-\to \eta\pi^+\pi^-) at low energies

We analyze the hadronization structure of $\tau \to \eta \pi^- \pi^0 \nu_\tau$ decays. In the isospin limit only the vector current contributes to this process. We compute the relevant form factor within Resonance Chiral Theory, at leading order in the $1/N_C$ expansion, and considering only the contribution of the lightest vector resonances. The couplings in the resonance theory are constrained by imposing the asymptotic behaviour of vector spectral functions ruled by $QCD$. We reproduce the branching ratio of this mode and predict the low-energy behaviour of $\sigma\left(e^+e^-\to\eta\pi^+\pi^-\right)$ using isospin symmetry.Comment: 4 pages, 3 figures. To appear in the Proceedings of the QCD10 (25th anniversary) 15th International QCD Conference. 28th June - 3rd July 2010 Montpellier (France) (Nucl. Phys. Proc. Suppl.

Resonance Chiral Lagrangian Currents and Experimental Data for τ−→π−π−π+ντ\tau^-\to\pi^{-}\pi^{-}\pi^{+}\nu_{\tau}

In this paper we document the modifications introduced to the previous version of the Resonance Chiral Lagrangian current ({\it Phys.Rev.} {\bf D86} (2012) 113008) of the $\tau^\pm \to \pi^\pm \pi^\pm \pi^\mp \nu_\tau$ decay which enable the one dimensional distributions measured by the BaBar collaboration to be well modeled. The main change required to model the data is the addition of the $\sigma$ resonance. Systematic errors, theoretical and experimental ones, limitations due to fits of one dimensional distributions only, and resulting difficulties and statistical/systematic errors for fitted parameters are addressed. The current and fitting environment is ready for comparisons with the fully exclusive experimental data. The present result for $\tau^\pm \to \pi^\pm \pi^\pm \pi^\mp \nu_\tau$ is encouraging for work on other $\tau$ decay modes and Resonance Chiral Lagrangian based currents.Comment: 16 pages, 2 figure

Improving the Hadronization of QCD currents in TAUOLA and PHOKHARA

We present our study of the hadronization structure of both vector and axial-vector currents leading to decays of the tau into two kaons and a pion. The cornerstones of our framework are the large-N_C limit of QCD, the chiral structure exhibited at low energies and the proper asymptotic behaviour, ruled by QCD, that is demanded to the associated form factors. The couplings of the theory are mostly constrained by this procedure and upon the analysis of BaBar data on e^+e^- -> KK pi we are able to predict the hadronic spectra.Comment: 4 pages, 1 figure. To appear in the Proceedings of QCD 08: 14th International QCD Conference, 7-12th July 2008 Montpellier (France). To be published by Elsevier in Nuclear Physics B (Proceedings Supplement