4,708 research outputs found
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
and decays in the perturbative QCD approach
In this work, we study six tree-dominated and
decays in the perturbative QCD(pQCD) approach, where
() is a () axial-vector meson. Based on the
perturbative calculations and phenomenological analysis, we find that: (a) the
CP-averaged branching ratio of decay in the pQCD approach
is , 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 , 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 and
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 meson and meson .Comment: 1 figure, 27 pages, references added, improved version. Accepted for
publication in Phys. Rev.
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
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 nellâarea mediterranea, eâ stata portata a termine la realizzazione di un pacchetto software mirato alla elaborazione dei dati multispettrali acquisiti attraverso lâimpiego 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, dellâinfrarosso vicino (VIR) e nel campo dellâinfrarosso termico(TIR). Allo scopo di implementare le funzioni analitiche necessarie alla calibrazione del dato si Ăš 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 ciĂČ che riguarda le prestazioni in esecuzione e la versatilitĂ dâelaborazione. In particolare lo standard ANSI-C garantisce buona compatibilitĂ tra sistemi diversi ed una eccellente rapiditĂ 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 âfriendlyâ
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