74 research outputs found
Three pseudoscalar meson production in annihilation
We study, at leading order in the large number of colours expansion and
within the Resonance Chiral Theory framework, the odd-intrinsic-parity cross-sections in the energy regime
populated by hadron resonances, namely 3 \, m_{\pi} \lsim E \lsim 2 \,
\mbox{GeV}. In addition we implement our results in the Monte Carlo generator
PHOKHARA 7.0 and we simulate hadron production through the radiative return
method.Comment: 39 pages, 5 figure
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
- …