On the massless contributions to the vacuum polarization of heavy quarks

Recently Groote and Pivovarov have given notice of a possible fault in the use of sum rules involving two-point correlation functions to extract information on heavy quark parameters, due to the presence of massless contributions that invalidate the construction of moments of the spectral densities. Here we show how to circumvent this problem through a new definition of the moments, providing an infrared safe and consistent procedure.Comment: 1+9 pages, 3 figures. Discussion on QCD sum rules applications added. Conclusions unchanged. Version to be published in Journal of Physics

Lepton Flavour Violation in charged leptons within SUSY-seesaw

In this paper we review our main results for Lepton Flavour Violating (LFV) semileptonic tau decays and muon-electron conversion in nuclei within the context of two Constrained SUSY-Seesaw Models, the CMSSM and the NUHM. The relevant spectrum is that of the Minimal Supersymmetric Standard Model extended by three right handed neutrinos, $\nu_{R_i}$ and their corresponding SUSY partners, ${\tilde \nu}_{R_i}$, ($i=1,2,3$). We use the seesaw mechanism for neutrino mass generation and choose a parameterisation of this mechanism that allows us to incorporate the neutrino data in our analysis of LFV processes. In addition to the full one-loop results for the rates of these processes, we will also review the set of simple formulas, valid at large $\tan \beta$, which are very useful to compare with present experimental bounds. The sensitivity to SUSY and Higgs sectors in these processes will also be discussed. This is a very short summary of the works in Refs. \cite{Arganda:2008jj} and \cite{Arganda:2007jw} to which we refer the reader for more details.Comment: 6 pages, 6 figures. To be published in the proceedings of the Tau08 Conference, Novosibirsk, Russia, 22-25 September 200

Hadron structure in tau -> KKpi nu_tau decays

We analyse the hadronization structure of both vector and axial-vector currents leading to tau -> KKpi nu_tau decays. At leading order in the 1/Nc 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 behaviour of vector and axial-vector spectral functions ruled by QCD. In this way we predict the hadron spectra and conclude that, contrarily to previous assertions, the vector contribution dominates by far over the axial-vector one in all KKpi charge channels.Comment: 32 pages, 7 figure

Supersymmetric contributions to direct CP violation in K -> pi pi gamma decays

We analyze the supersymmetric contributions to direct-CP-violating observables in $K \to \pi\pi\gamma$ decays induced by gluino-mediated magnetic-penguin operators. We find that \epsp_{+-\gamma} and the differential width asymmetry of $K^\pm \to \pi^\pm \pi^0 \gamma$ decays could be substantially enhanced with respect to their Standard Model values, especially in the scenario where \epsp/\eps is dominated by supersymmetric contributions. These observables could therefore provide a useful tool to search for New Physics effects in $|\Delta S|=1$ transitions, complementary to \epsp/\eps and rare decays.Comment: 14 pages, Latex. Numerical error in Eq.(36) corrected, conclusions unchanged; version to appear in Phys. Lett.

Nombre y propialidad

El nombre común y el nombre propio tienen un modo de significar diferente. El de los nombres comunes es semántico (o léxico) —poseen intensión—; el de los nombres propios es onímico (o propial). La propialidad consiste en dar al interlocutor la instrucción de identificar al particular que lleva ese nombre. Pese a que todos los nombres propios tienen el modo de significar propial, solo algunos refieren. Existen nombres propios modificados que, si bien su sentido solo se explica por la identificación de un particular (v.gr. Miley Cyrus en X hace un Miley Cyrus), no son expresiones referenciales; a ello se suma que existen verbos con propialidad (v.gr. madrileñear) que carecen, evidentemente, de referencialidad. En suma, los nombres con propialidad identifican, pero no necesariamente refieren.Common nouns and proper nouns have different ways of signifying. Common nouns signify semantically –they have intension–, while proper nouns signify onymically. Properhood consists of identifying for the interlocutor an entity that bears a certain name. Even though all proper nouns have this onymic way of signifying, only some of them refer. There are modified proper nouns that, while their meaning may be explained only by the identification of one particular entity (for example, Miley Cyrus in X does a Miley Cyrus), they are not expressions that refer. In addition, there are verbs with properhood (for example, madrileñear –‘to do the special thing the people of Madrid do’–) which obviously lack reference. In short, nouns with properhood identify, but they do not necessarily refer

Estudio exploratorio de las Preferencias de Metodología de Enseñanza de las Ciencias en Estudiantes de Secundaria: El caso de un Centro de Educación Secundaria

This study aims to carry out an initial approach to the secondary education students' preferences regarding science teaching methods. The study also analyses the influence of academic level and gender on these preferences. Two hundred and forty spanish secondary education students (112 women and 128 men) at different educational levels (but they are all from the same high school) have participated in this research. All of them have been administered a multiple choice test of 6 items each with four options. In these items each option offers a way of teaching. The statistical analysis of the results obtained allow us to conclude that: a) Students show a significant predilection for student-centered teaching methods; and b) Academic level has a significant effect on teaching method preferences among students, but gender does not

"Problemas de norma: el ejemplo de por contra"

En ocasiones se ha mantenido que el marcador del discurso "por contra" deberla desaparecer del español actual porque se trata de un galicismo innecesario. En este artículo se prende mostrar que esta opinión está equivocada por dos razones: la primera, su significado no es igual al de “par contre” en francés; y la segunda, los marcadores del discurso españoles "por el contrario” “en cambio”, que se presentan como posibles sustitutos, no poseen el mismo significado. It has been argued sometimes that discourse marker "por contra" should not have a place in current Spanish because of its being an unnecessary gallicism. In this paper we aim to show that this view is wrong on two bases: first, its meaning does not equal that of "par contre" in French; and second, discourse markers in Spanish such as "por el contrario" and “en cambio” which are claimed to be suitable substitutes, do not convey the same meaning

Phenomenology of the <VVP> Green's function within the Resonance Chiral Theory

We analyse the odd-intrinsic-parity effective Lagrangian of QCD valid for processes involving one pseudoscalar with two vector mesons described in terms of antisymmetric tensor fields. Substantial information on the odd-intrinsic-parity couplings is obtained by constructing the vector-vector-pseudoscalar Green's three-point function, at leading order in 1/N_C, and demanding that its short-distance behaviour matches the corresponding OPE result. The QCD constraints thus enforced allow us to predict the decay amplitude omega -> pi gamma, the O(p^6) corrections to pi -> gamma gamma and the slope parameter in pi -> gamma gamma^*.Comment: 4 pages, 1 figure. Talk given at QCD 03: High-Energy Physics International Conference in Quantum Chromodynamics, Montpellier, France, 2-8 Jul 200

Quality classification of Spanish olive oils by untargeted gas chromatography coupled to hybrid quadrupole–time of flight mass spectrometry with atmospheric pressure chemical ionization and metabolomics-based statistical approach

The novel atmospheric pressure chemical ionization (APCI) source has been used in combination with gas chromatography (GC) coupled to hybrid quadrupole time-of-flight (QTOF) mass spectrometry (MS) for determination of volatile components of olive oil, enhancing its potential for classification of olive oil samples according to their quality using a metabolomics-based approach. The full-spectrum acquisition has allowed the detection of volatile organic compounds (VOCs) in olive oil samples, including extra virgin, virgin and lampante qualities. A dynamic headspace extraction with cartridge solvent elution was applied. The metabolomics strategy consisted of three different steps: a full mass spectral alignment of GC-MS data using MzMine 2.0, a multivariate analysis using Ez-Info and the creation of the statistical model with combinations of responses for molecular fragments. The model was finally validated using blind samples, obtaining an accuracy in oil classification of 70 % taking the official established method, “PANEL TEST” as reference.The authors acknowledge the financial support of Generalitat Valenciana, as research group of excellence (PROMETEO II/2014/023) and Collaborative Research on Environment and Food-Safety (ISIC/2012/016). This work and C. Sales grant has been supported by Universitat Jaume I research promotion plans (P1-1B2013-70

Form Factors in the radiative pion decay

We perform an analysis of the form factors that rule the structure-dependent amplitude in the radiative pion decay. The resonance contributions to pion -> e nu_e gamma decays are computed through the proper construction of the vector and axial-vector form factors by setting the QCD driven asymptotic properties of the three-point Green functions VVP and VAP, and by demanding the smoothing of the form factors at high transfer of momentum. A comparison between theoretical and experimental determinations of the form factors is also carried out. We also consider and evaluate the role played by a non-standard tensor form factor. We conclude that, at present and due to the hadronic incertitudes, the search for New Physics in this process is not feasible.Comment: 14 pages, no figures. Typos corrected. Accepted for publication in The European Physical Journal