121 research outputs found
Radiative two-pion decay of the tau lepton
We consider the bremsstrahlung and model-dependent contributions to the
radiative decay in the context of a
meson dominance model. We focus on several observables related to this decay,
including the branching ratio and the photon and di-pion spectra. Particular
attention is paid to the sensitivity of different observables upon the effects
of model-dependent contributions and of the magnetic dipole moment of the
vector meson. Important numerical differences are found with
respect to results obtained in the framework of chiral perturbation theory.Comment: 14 pages, 8 figures, submitted for publicatio
Recent progress on isospin breaking corrections and their impact on the muon g-2 value
We describe some recent results on isospin breaking corrections which are of
relevance for predictions of the leading order hadronic contribution to the
muon anomalous magnetic moment (amuhadLO) when using tau lepton data. When
these corrections are applied to the new combined data on the pi^+pi^0 spectral
function, the prediction for amuhadLO based on tau lepton data gets closer to
the one obtained using e^+e^- data.Comment: 6 pages, 3 figures, Proceedings of the PhiPsi09 Workshop, Oct. 13-16,
2009, Beijing, China. Some typos corrected, and the FSR correction used in a
previous work is added to Table
Arte, arquitectura y emblemática en tres certámenes poéticos zaragozanos del Siglo de Oro
Por su propia naturaleza, el certamen poético presenta un marcado carácter literario que, sin embargo, no excluye su dimensión artística, sobre todo en la categoría dedicada a la compo-sición de jeroglíficos. Así queda de manifiesto en sendos certámenes zaragozanos celebrados en 1614 y 1628 en honor a la beata Teresa de Jesús y a la Virgen del Pilar, que contaron con la participación del tracista descalzo fray Alberto de la Madre de Dios y del pintor Jusepe Martínez respectivamente. A ello se suma el ejemplo de la arquitectura al servicio del jeroglífico, con la Cruz del Coso como protagonista de una empresa para el recién nombrado inquisidor general fray Luis Aliaga en el certamen poético organizado en su honor en 1619. Este trabajo propone la reconstrucción material de los jeroglíficos zaragozanos, a través de los cuales estableceremos las conexiones entre arte, poesía y emblemática tan frecuentes en el marco de la fiesta barroca del Siglo de Oro.By its very nature, the poetic contest presents a marked literary character which, however, does not exclude its atistic dimension, mainly in the category of hieroglyphs. We can verify this in both Zaragoza contests held in 1614 and 1628 in honor of Blessed Teresa de Jesus and Virgin of Pilar, which counted with the participation of the Barefoot Carmelite architect fray Alberto de la Madre de Dios and the painter Jusepe Martinez respectively. To this we can add the example of architecture in the service of the hieroglyphic, as shows the Cross of the Coso, protagonist of an imprese for the newly appointed General Inquisitor fray Luis Aliaga in the poetic contest organized in his honor in 1619. This paper proposes the material reconstruction of the Zaragoza hieroglyphs, through which we’ll establish the relationship among Art, Poetry and Emblematic Literature, so frequent in the context of Spanish Golden Age festivities
Coexistence of Two Rare Sarcomas: Primary Leiomyosarcoma of Bone and Epithelioid Hemangioendothelioma of the Liver
A 33-year-old woman sought medical attention for a painful swelling of the left
ankle. Plain radiographs revealed an osteolytic lesion involving the left distal tibia.
An excisional biopsy provided the diagnosis of leiomyosarcoma in the tibia. A
staging work-up was performed and an abdominal CT showed 4 liver hypodense
lesions in both lobes with peripheral contrast enhancement. A liver biopsy
confirmed the diagnosis of epithelioid hemangioendothelioma of the liver. No
association between these two entities has been described before. This case
introduces the importance of the pathological confirmation of apparent metastatic
lesions in low grade sarcomas and provides a review of the literature of both
tumours
Gauge invariance and finite width effects in radiative two-pion tau lepton decay
The contribution of the rho^{\pm} vector meson to the tau -> pi pi nu gamma
decay is considered as a potential source for the determination of the magnetic
dipole moment of this light vector meson. In order to keep gauge-invariance of
the whole decay amplitude, a procedure similar to the fermion loop-scheme for
charged gauge bosons is implemented to incorporate the finite width effects of
the rho^{\pm} vector meson. The absorptive pieces of the one-loop corrections
to the propagators and electromagnetic vertices of the rho^{\pm} meson and
W^{\pm} gauge boson have identical forms in the limit of massless particles in
the loops, suggesting this to be a universal feature of spin-one unstable
particles. Model-dependent contributions to the tau -> pi pi nu gamma decay are
suppressed by fixing the two-pion invariant mass distribution at the rho meson
mass value. The resulting photon energy and angular distribution is relatively
sensitive to the effects of the rho magnetic dipole moment.Comment: 22 pages, 4 postscript figures, references and comments on relevance
of perturbative treatment of rho electromagnetic vertex are added, accepted
for pub. in Phys. Rev.
New results on the hadronic vacuum polarization to the muon g-2
Results on the lowest-order hadronic vacuum polarization contribution to the
muon magnetic anomaly are presented. They are based on the latest published
experimental data used as input to the dispersion integral. Thus recent results
on tau to nutau pi pi0 decays from Belle and on e+ e- annihilation to pi+ pi-
from BABAR and KLOE are included. The new data, together with improved
isospin-breaking corrections for tau decays, result into a much better
consistency among the different results. A discrepancy between the Standard
Model prediction and the direct g-2 measurement is found at the level of 3
sigma.Comment: proceedings of the PhiPsi09 conference, Oct. 13-16, 2009, Beijing,
Chin
The Discrepancy Between tau and e+e- Spectral Functions Revisited and the Consequences for the Muon Magnetic Anomaly
We revisit the procedure for comparing the pi pi spectral function measured
in tau decays to that obtained in e+e- annihilation. We re-examine the
isospin-breaking corrections using new experimental and theoretical input, and
find improved agreement between the tau- --> pi- pi0 nu_tau branching fraction
measurement and its prediction using the isospin-breaking-corrected e+e- -->
pi+pi- spectral function, though not resolving all discrepancies. We recompute
the lowest order hadronic contributions to the muon g-2 using e+e- and tau data
with the new corrections, and find a reduced difference between the two
evaluations. The new tau-based estimate of the muon magnetic anomaly is found
to be 1.9 standard deviations lower than the direct measurement.Comment: 10 pages, 6 figures, submitted to Eur. Phys. J. C; (v2): Revised
version with improved and uniform treatment of tau and e+e- data with
HVPTools and a few minor bug fixes; (v3): Final version accepted for
publicatio
The RADMED monitoring program as a tool for MSFD implementation: toward an ecosystem based approach
In the western Mediterranean Sea, the RADMED
monitoring programme is already conducting several of the
evaluations required under the Marine Strategy Framework
Directive (MFSD) along the Spanish Mediterranean coast.
The different aspects of the ecosystem that are regularly sampled
under this monitoring programme are the physical environment
and the chemical and biological variables of the
water column, together with the planktonic communities,
biomass and structure. Moreover, determinations of some
anthropogenic stressors on the marine environment, such as
contaminants and microplastics, are under development.
Data are managed and stored at the Instituto Español de
Oceanografía (IEO) Data Centre that works under the Sea-
DataNet infrastructure, and are also stored in the IBAMar
database. In combination with remote sensing data, they are
used to address open questions on the ecosystems in the western
Mediterranean Sea.Postprint2,293
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