Axial Anomaly and Polarized Radiative Decays

We extend the approach of Dolgov and Zakharov to the axial anomaly to study polarized radiative decays. We analyse the pattern of mass singularity cancellation in the corresponding decay rates. We compare polarized and unpolarized cases. The cancellation of the infrared and collinear singularities is verified to all powers of the lepton mass for the $\pi^+$ and $Z^0$ polarized radiative decays.Comment: 18 pages, LaTeX, 4 PostScript figure

Speech Rhythm in English and Italian: an Experimental Study on Early Sequential Bilingualism

The study investigates the dynamics of speech rhythm in early sequential bilingual children who have access to Italian-English immersion programs. The research focused on the Italian and English semi-spontaneous narrative productions of 9 students, aged between 6;7 and 10;11 and distributed across three different classes (Year 1, Year 3, Year 5). Their speech was recorded and subject to an interval-based analysis via computation of %V/ΔC, PVI and Varco metrics. The retrieved metrics underwent within-group and between-group one-way ANOVAs in order to identify valuable cross-linguistic variations among children of the same age and statistically significant differences between different age groups (Y1, Y3, Y5). The results appear to support a stress-centered interpretation of speech rhythm: according to this view, all languages could be arranged on a stress-timed continuum in which “syllable-timing” is marked by sparser occurrences of (regular) prominence due to the relative absence of vocalic elision and consonantal complexity. Indeed, the comparative analysis drawn between the normalized vocalic indexes of Y1, Y3 and Y5 students revealed a statistically relevant increase in vocalic variation phenomena both in Italian and in English. Moreover, Y1 and Y3 consonantal scores were comparatively higher in the Italian sample: it will be discussed how unpredictable stress-timed patterns can arise as a function of proficiency, speech-rate and age-related disfluencies

Valence Instability of YbCu2_2Si2_2 through its quantum critical point

We report Resonant inelastic x-ray scattering measurements (RIXS) in YbCu$_2$Si$_2$ at the Yb L$_{3}$ edge under high pressure (up to 22 GPa) and at low temperatures (down to 7 K) with emphasis on the vicinity of the transition to a magnetic ordered state. We find a continuous valence change towards the trivalent state with increasing pressure but with a pronounced change of slope close to the critical pressure. Even at 22 GPa the Yb$^{+3}$ state is not fully achieved. The pressure where this feature is observed decreases as the temperature is reduced to 9 GPa at 7K, a value close to the critical pressure (\itshape{p\normalfont{$_c$}}\normalfont $\approx$ 7.5 GPa) where magnetic order occurs. The decrease in the valence with decreasing temperature previously reported at ambient pressure is confirmed and is found to be enhanced at higher pressures. We also compare the f electron occupancy between YbCu$_2$Si$_2$ and its Ce-counterpart, CeCu$_2$Si$_2$

Meson-Baryon Effective Chiral Lagrangian at O(q3)O(q^3) Revisited

After our work [1] was published, Frink and Meissner [2] pointed out that the O(q^3) three-flavour meson-baryon chiral Lagrangian presented there was not minimal. Here, we critically review their paper and revise ours. Remarkably, we find that the effective meson-baryon chiral Lagrangian at O(q^3) contains 76 monomials, i.e. eight less than in [1] and two less than in [2]

Meson-Baryon Effective Chiral Lagrangians at O(q^3) Revisited

After our work was published, Frink and Mei{\ss}ner \cite{FM06} pointed out that our {\cal O}(q^3) three-flavour meson-baryon chiral Lagrangian was not minimal. Here, we discuss their findings and revise ours accordingly. We find that eight monomials in our ${\cal O}(q^3)$ Lagrangian are not independent, but in addition, two monomials were wrongly discarded, which, as a result, makes the agreement in the number of independent monomials with \cite{FM06} complete.Comment: 7 pages, 1 table. A mistake was corrected. Our Lagrangian and that of [2] contain the same number of monomial

New developments in fabrication of high-energy-resolution analyzers for inelastic X-ray spectroscopy

New improvements related to the fabrication of spherical bent analyzers for 1 meV energy-resolution inelastic X-ray scattering spectroscopy are presented