Analysis of BaBar data for three meson tau decay modes using the Tauola generator

The hadronic current for the $\tau^- \to \pi^-\pi^+\pi^-\nu_\tau$ decay calculated in the framework of the Resonance Chiral Theory with an additional modification to include the $\sigma$ meson is described. Implementation into the Monte Carlo generator Tauola and fitting strategy to get the model parameters using the one-dimensional distributions are discussed. The results of the fit to one-dimensional mass invariant spectrum of the BaBar data are presented.Comment: 5 pages, 1 figure. Proceedings of the 7th Edition of the International Workshop on Quantum Chromodynamics -QCD@Work: Interantional Workshop on QCD, Theory and Experiment- (16-19 June 2014, Giovinazzo, Italy

Two-photon form factors of the pi0, eta and eta-prime mesons in the chiral theory with resonances

We have developed a phenomenological approach which describes very well the pi0, eta and eta-prime meson production in the two-photon interactions. The simultaneous description of the pi0, eta and eta-prime meson two-photon form factors is consistent with data in the space-like region. The obtained form factors are implemented in the event generator EKHARA and the simulated cross sections are presented. Uncertainties in the measured form factors coming from the model dependence in Monte Carlo simulations are studied. The model predictions for the form factor slopes at the origin are given and the high-Q2 limit is also discussed.Comment: 11 pages, 7 figures, 3 tables; two-column revtex4 styl

Refining the scalar and tensor contributions in τ → πππντ decays

In this article we analyze the contribution from intermediate spin-0 and spin-2 resonances to the τ → νπππ decay by means of a chiral invariant Lagrangian incorporating these mesons. In particular, we study the corresponding axial-vector form-factors. The advantage of this procedure with respect to previous analyses is that it incorporates chiral (and isospin) invariance and, hence, the partial conservation of the axial-vector current. This ensures the recovery of the right low-energy limit, described by chiral perturbation theory, and the transversality of the current in the chiral limit at all energies. Furthermore, the meson form-factors are further improved by requiring appropriate QCD high-energy conditions. We end up with a brief discussion on its implementation in the Tauola Monte Carlo and the prospects for future analyses of Belle’s data

Refining the scalar and tensor contributions in τ→πππντ\tau\to \pi\pi\pi\nu_\tau decays

In this article we analyze the contribution from intermediate spin-0 and spin-2 resonances to the $\tau\to\nu \pi\pi\pi$ decay by means of a chiral invariant Lagrangian incorporating these mesons. In particular, we study the corresponding axial-vector form-factors. The advantage of this procedure with respect to previous analyses is that it incorporates chiral (and isospin) invariance and, hence, the partial conservation of the axial-vector current. This ensures the recovery of the right low-energy limit, described by chiral perturbation theory, and the transversality of the current in the chiral limit at all energies. Furthermore, the meson form-factors are further improved by requiring appropriate QCD high-energy conditions. We end up with a brief discussion on its implementation in the Tauola Monte Carlo and the prospects for future analyses of Belle's data.Comment: 32 pages, 13 figures. Extended discussion on the numerical importance of the tensor and scalar resonances and the parametrization of the scalar propagator. Version published in JHE

Total and inelastic cross-sections at LHC at CM energy of 7 TeV and beyond

We discuss expectations for the total and inelastic cross-sections at LHC CM energies $\sqrt{s}\ =\ 7\ TeV$ {and $14\ TeV$} obtained in an eikonal minijet model augmented by soft gluon $k_t$-resummation, which we describe in some detail. We present a band of predictions which encompass recent LHC data and suggest that the inelastic cross-section described by two channel eikonal models include only uncorrelated processes. We show that this interpretation of the model is supported by the LHC data.Comment: 32 pages, 6 figures, Version to appear in Physical Review

Confronting theoretical predictions with experimental data; fitting strategy for multi-dimensional distributions

After developing a Resonance Chiral Lagrangian (RχL) model to describe hadronic τ lepton decays [18], the model was confronted with experimental data. This was accomplished using a fitting framework which was developed to take into account the complexity of the model and to ensure the numerical stability for the algorithms used in the fitting. Since the model used in the fit contained 15 parameters and there were only three 1-dimensional distributions available, we could expect multiple local minima or even whole regions of equal potential to appear. Our methods had to thoroughly explore the whole parameter space and ensure, as well as possible, that the result is a global minimum. This paper is focused on the technical aspects of the fitting strategy used. The first approach was based on re-weighting algorithm published in [17] and produced results in around two weeks. Later approach, with improved theoretical model and simple parallelization algorithm based on Inter-Process Communication (IPC) methods of UNIX system, reduced computation time down to 2-3 days. Additional approximations were introduced to the model decreasing time to obtain the preliminary results down to 8 hours. This allowed to better validate the results leading to a more robust analysis published in [12]

Review of e

In this talk we review the current experimental status of electron-positron annihilation into π+π-η as well as the theoretical models to describe the data. Application of the CVC hypothesis to get the τ- decay to π-π0η branching fraction is discussed and its values from the different experiments is listed

p – air production cross-section and uncorrelated mini-jets processes in pp-scattering

For the p – air production cross-section, we use a Glauber formalism which inputs the pp inelastic cross-section from a mini-jet model embedded in a single-channel eikonal expression, that provides the needed contribution of uncorrelated processes. It is then shown that current LO parton density functions for the pp mini-jet cross-sections, with a rise tempered by acollinearity induced by soft gluon re-summation, are well suited to reproduce recent cosmic ray results. By comparing results for GRV, MRST72 and MSTW parametrizations, we estimate the uncertainty related to the low-x behavior of these densities.(FQM 6552, FQM 101). D.A.F. acknowledges the São Paulo Research Foundation (FAPESP) and the Coordination for the Improvement of Higher Education Personnel (CAPES) for financial support (contract: 2014/00337-8). O.S. acknowledges partial support from funds of Foundation of Polish Science grant POMOST/2013-7/12, that is co-financed from European Union, Regional Development Fund