0000000001151548
AUTHOR
Jorge Portolés Ibáñez
D-0-(D-0)over-bar mixing in the weak-gauged U(4)(L)circle times U(4)(R) chiral Lagrangian model
The D-0- mixing is analyzed in a weak gauged U(4)(L) x U(4)(R) chiral lagrangian model where the electroweak interaction is introduced as a gauge theory over the meson degrees of freedom. This model allows a particular realization of the G.I.M. mechanism and then could be useful in the study of processes where G.I.M. suppression is effective. As a test of the model we have also analyzed the K-0- mixing. We find am, in good agreement with the experimental result and we show that the D-0- mixing is very much suppressed in agreement with previous estimates in the Heavy Quark expansion framework.
Spectral distribution for the decay tau -> v(tau)K pi
With the newly available data sets on hadronic tau decays from the B-factories BaBar and BELLE, and future data from BESIII, precise information on the decay distributions will soon become available. This calls for an improvement of the decay spectra also on the theoretical side. In this work, the distribution function for the decay tau -> v(tau)K pi will be presented with the relevant K pi vector and scalar forth factors being calculated in the framework of the resonance chiral theory, also taking into account additional constraints from dispersion relations and short-distances. As a by-product the slope and curvature of the vector form factor F-+(K pi)(s) are determined to be lambda'(+) =…
Green function in the resonance region
11 páginas, 2 figuras.-- arXiv:hep-ph/0404004v2
Hadron structure in tau -> KK pi nu_tau decays
We analyze the hadronization structure of both vector and axial-vector currents leading to tau -> KK pi nu(tau) decays. At leading order in the 1/N-C 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 behavior of vector and axial-vector spectral functions ruled by QCD. In this way we predict the hadron spectra and conclude that, contrary to previous assertions, the vector contribution dominates by far over the axial-vector one in all KK pi charge channe…
tau ->pi pi pi nu(tau) decays in the resonance effective theory
tau-->pipipinu(tau) decays are analyzed within the framework of the resonance effective theory of QCD. We work out the relevant Lagrangian that describes the axial-vector current hadronization contributing to these processes, in particular the local a(1)(1260)-rho(770)-Goldstone interactions. The new coupling constants are constrained by imposing the asymptotic behavior of the corresponding spectral function within QCD. Hence we compare the theoretical framework with the experimental data, obtaining a good quality fit from the ALEPH spectral function and branching ratio. We also get values for the mass and on-shell width of the a(1)(1260) resonance. In this way we are able to provide the st…
What can be learned from the Belle spectrum for the decay tau(-) -> nu(t)K(S)pi(-)
A theoretical description of the differential decay spectrum for the decay tau(-) -> nu(tau)K(S)pi(-), which is based on the contributing K pi vector and scalar form factors F(+)(K pi)(s) and F(0)(K pi)(s) being calculated in the framework of resonance chiral theory (R chi T), additionally imposing constraints from dispersion relations as well as short distance QCD, provides a good representation of a recent measurement of the spectrum by the Belle Collaboration. Our fit allows to deduce the total branching fraction B[tau(-) -> v(tau)K(S)pi(-)] = 0.427 +/- 0.024% by integrating the spectrum, as well as the K* resonance parameters M(K)* = 895.3 +/- 0.2 MeV and Gamma(K)* = 47.5 +/- 0.4 MeV, w…