Measurement of the CKM angles alpha and gamma at the BaBar experiment

We present recent measurements of the CKM angles alpha and gamma using data collected by the BaBar detector at the PEP-II asymmetric-energy e+ e- collider at the Stanford Linear Accelerator Center. In addition to constraints on alpha from the decays B0 -> pi+ pi-, B0 -> rho+ pi- and B0 -> rho+ rho-, we also report the first measurement of time-dependent CP asymmetries in the decay B0 -> a1+(1260) pi-. We present measurements of gamma in B+ -> D(*)0 K+ decays using a Dalitz analysis in the modes D^0 -> Ks pi+ pi- and D^0 -> pi+ pi- pi0.Comment: 5 pages, contributed to the Proceedings of Lake Louise Winter Institute 2007: Fundamental Interactions, Lake Louise, Alberta, Canada 19-24 Feb 200

On the Classification of Automorphic Lie Algebras

It is shown that the problem of reduction can be formulated in a uniform way using the theory of invariants. This provides a powerful tool of analysis and it opens the road to new applications of these algebras, beyond the context of integrable systems. Moreover, it is proven that sl2-Automorphic Lie Algebras associated to the icosahedral group I, the octahedral group O, the tetrahedral group T, and the dihedral group Dn are isomorphic. The proof is based on techniques from classical invariant theory and makes use of Clebsch-Gordan decomposition and transvectants, Molien functions and the trace-form. This result provides a complete classification of sl2-Automorphic Lie Algebras associated to finite groups when the group representations are chosen to be the same and it is a crucial step towards the complete classification of Automorphic Lie Algebras.Comment: 29 pages, 1 diagram, 9 tables, standard LaTeX2e, submitted for publicatio

Persistence of poor sleep predicts the severity of the clinical condition after 6months of standard treatment in patients with eating disorders

Clinical evidence suggests that eating disorder (ED) patients experience poor sleep even if they rarely complain of it. However, direct empirical evidence supporting this relationship is still sparse. In order to provide direct evidence, poor sleep, severity of the ED symptoms and depression were obtained in 562 ED patients at treatment admission (T0). For 271 patients out of them, data were also available after 6 months of standard treatment (T1). Results evidence that at T0 poor sleep predicts severity of ED symptoms through the mediation of depression. Persistence of poor sleep at T1 directly predicts the severity of the ED symptoms both directly and through the mediation of depression. These findings suggest that the treatment of ED may benefit from addressing poor sleep since its presence and persistence increase comorbidity and attrition to the standard treatment

Turing pattern formation in the Brusselator system with nonlinear diffusion

In this work we investigate the effect of density dependent nonlinear diffusion on pattern formation in the Brusselator system. Through linear stability analysis of the basic solution we determine the Turing and the oscillatory instability boundaries. A comparison with the classical linear diffusion shows how nonlinear diffusion favors the occurrence of Turing pattern formation. We study the process of pattern formation both in 1D and 2D spatial domains. Through a weakly nonlinear multiple scales analysis we derive the equations for the amplitude of the stationary patterns. The analysis of the amplitude equations shows the occurrence of a number of different phenomena, including stable supercritical and subcritical Turing patterns with multiple branches of stable solutions leading to hysteresis. Moreover we consider traveling patterning waves: when the domain size is large, the pattern forms sequentially and traveling wavefronts are the precursors to patterning. We derive the Ginzburg-Landau equation and describe the traveling front enveloping a pattern which invades the domain. We show the emergence of radially symmetric target patterns, and through a matching procedure we construct the outer amplitude equation and the inner core solution.Comment: Physical Review E, 201

B→a1(1260)a1(1260)B \to a_1(1260) a_1(1260) and b1(1235)b1(1235)b_1(1235) b_1(1235) decays in the perturbative QCD approach

In this work, we study six tree-dominated $B \to a_1(1260) a_1(1260)$ and $b_1(1235) b_1(1235)$ decays in the perturbative QCD(pQCD) approach, where $a_1$($b_1$) is a $^3P_1$($^1P_1$) axial-vector meson. Based on the perturbative calculations and phenomenological analysis, we find that: (a) the CP-averaged branching ratio of $B^0 \to a_1^+ a_1^-$ decay in the pQCD approach is $54.7 \times 10^{-6}$, which agrees well with the current data and the predictions given in the QCD factorization approach within errors; (b) the numerical results for the decay rates of other five channels are found to be in the order of $10^{-6} \sim 10^{-5}$, which could be accessed at B factories and Large Hadron Collider(LHC) experiments; (c) other physical observables such as polarization fractions and direct CP-violating asymmetries are also investigated with the pQCD approach in the present work and the predictions can be confronted with the relevant experiments in the near future; (d) the different phenomenologies shown between $B \to a_1 a_1$ and $B \to b_1 b_1$ decays are expected to be tested by the ongoing LHC and forthcoming Super-B experiments, which could shed light on the typical QCD dynamics involved in these decay modes, as well as in $^3P_1$ meson $a_1$ and $^1P_1$ meson $b_1$.Comment: 1 figure, 27 pages, references added, improved version. Accepted for publication in Phys. Rev.

REALIZZAZIONE DI UN PACCHETTO SOFTWARE MIRATO ALLA ELABORAZIONE DEI DATI MULTISPETTRALI ACQUISITI ATTRAVERSO L'IMPIEGO DEL SENSORE MIVIS

Come previsto dal contratto CNR/ASI n. ARS 99-15, riguardante la Valutazione dei nuovi sensori aerospaziali per il telerilevamento nell’area mediterranea, e’ stata portata a termine la realizzazione di un pacchetto software mirato alla elaborazione dei dati multispettrali acquisiti attraverso l’impiego del sensore MIVIS [Bugliolo et al.1996; Bugliolo et al.1999; Buongiorno et al.1999; Teggi et al.1999] . Tale software permette di calibrare i dati digitalizzati adeguandoli alle caratteristiche proprie del sensore, operando nel campo del visibile, dell’infrarosso vicino (VIR) e nel campo dell’infrarosso termico(TIR). Allo scopo di implementare le funzioni analitiche necessarie alla calibrazione del dato si è ricorsi alla programmazione in linguaggio ANSI-C ed in linguaggio IDL. Il motivo di tale duplice scelta risiede nel fatto che questi linguaggi presentano rispettivamente vantaggi diversi per ciò che riguarda le prestazioni in esecuzione e la versatilità d’elaborazione. In particolare lo standard ANSI-C garantisce buona compatibilità tra sistemi diversi ed una eccellente rapidità di elaborazione tenuto conto della mole dei dati usualmente trattata; il software realizzato attraverso IDL presenta invece una interfaccia grafica assente nel programma C ed una gestione delle routine maggiormente ‘friendly’

Preliminary analysis of the potential of LANDSAT imagery to study desertification

The use of LANDSAT imagery to define and delimit areas under process of desertification was investigated. Imagery for two different years (1973 and 1978) and two different seasons (dry and rainy seasons in 1976), were used to identify terrain morphology and vegetation cover. The analysis of LANDSAT interpretation, combined with geological and soil information obtained from published literature, allowed the identification of eleven ecological units which were classified corresponding to the degree of the Xique Xique region of Rio Sao Francisco