11 research outputs found
Dispersive representation of the K pi vector form factor and fits to tau -> K pi nu(tau) and Ke3 data
Recently, we introduced several dispersive representations for the vector
form factor and fitted them to the Belle spectrum of . Here, we briefly present the model and discuss the results for the
slope and curvature of arising from the best fit. Furthermore, we
compare the pole position of the charged computed from our model
with other results in the literature. Finally, we discuss the prospects of a
simultaneous fit to and spectra.Comment: Talk given at "International Workshop on Effective Field Theories:
from the pion to the upsilon", February 2009, Valencia, Spain. 7 pages, 2
figures. PoS style. Minor correction in figure
Improving the Kpi vector form factor through Kl3 constraints
The vector form factor, , used to reproduce the Belle
spectrum of \tauKpi decays is described by means of a three-times subtracted
dispersion relation also incorporating constraints from decays. The
slope and curvature of are fitted to the data yielding
and . The pole parameters of the are found to be
MeV and
MeV. The phase-space integrals relevant for analyses and the -wave
isospin-1/2 phase-shift threshold parameters are also calculated.Comment: 3 pages, uses aipproc style. Talk presented by R. Escribano at the IX
International Conference on Quark Confinement and Hadron Spectrum (QCHS09),
Madrid, Spain, 30.8-3.9.201
Constraining the Kpi vector form factor by tau---> K pi nu_tau and K_l3 decay data
A subtracted dispersive representation of the vector form factor,
, is used to fit the Belle spectrum of \tauKpi decays
incorporating constraints from results on decays. Through the use of
three subtractions, the slope and curvature of are obtained
directly from the data yielding
and . The phase-space integrals
relevant for analyses are calculated. Additionally, from the pole
position on the second Riemann sheet the mass and width of the
are found to be MeV and
MeV. Finally, we study the -wave
isospin-1/2 phase-shift and its threshold parameters.Comment: Talk presented at 15th International QCD Conference, Montpellier,
France. Submitted to Nuc. Phys. (Proc. Suppl.), 4 pages, 1 figur
K pi vector form factor, dispersive constraints and tau -> nu_tau K pi decays
Recent experimental data for the differential decay distribution of the decay
by the Belle collaboration are described by a
theoretical model which is composed of the contributing vector and scalar form
factors and . Both form factors are constructed
such that they fulfil constraints posed by analyticity and unitarity. A good
description of the experimental measurement is achieved by incorporating two
vector resonances and working with a three-times subtracted dispersion relation
in order to suppress higher-energy contributions. The resonance parameters of
the charged meson, defined as the pole of in the
complex -plane, can be extracted, with the result MeV and MeV. Finally, employing the
three-subtracted dispersion relation allows to determine the slope and
curvature parameters and
of the vector form factor
directly from the data.Comment: 16 pages, 1 figure, version to appear in Eur. Phys. J.
Kπ form factors, final state interactions and D+ -> π+π+ decays
Altres ajuts: this work has been supported in part under the EU Contract No. MRTN-CT-2006-035482 "FLAVIAnet"Contribution to International Conference on Hadron Spectroscopy (HADRON09), Florida State University (Tallahassee), USA, 29.11-4.12.2009We present a model for the decay D+ → K−π+π+. The weak interaction part of this reaction is described using the effective weak Hamiltonian in the factorisation approach. Hadronic final state interactions are taken into account through the Kπ scalar and vector form factors fulfilling analyticity, unitarity and chiral symmetry constraints. Allowing for a global phase difference between the S and P waves of −65◦, the Dalitz plot of the D+ → K−π+π+ decay, the Kπ invariant mass spectra and the total branching ratio due to S-wave interactions are well reproduced