Physics Results from RICH Detectors

RICH detectors have become extraordinarily useful. Results include measurement of solar neutrino rates, evidence for neutrino oscillations, measurement of TeV gamma-rays from gravitational sources, properties of QCD, charm production and decay, and measurement of the CKM matrix elements Vcs, Vcb and Vub. A new value |Vub/Vcb|=0.087+/-0.012 is determined.Comment: Invited talk at ``The 3rd International Workshop on Ring Imaging Cherenkov Detectors," Ein-Gedi, Dead-Sea, Israel, Nov. 15-20, 1998, 21 pages, 22 fig

3-3-1 Models at Electroweak Scale

We show that in 3-3-1 models there exist a natural relation among the $SU(3)_L$ coupling constant $g$, the electroweak mixing angle $\theta_W$, the mass of the $W$, and one of the vacuum expectation values, which implies that those models can be realized at low energy scales and, in particular, even at the electroweak scale. So that, being that symmetries realized in Nature, new physics may be really just around the corner.Comment: 10 pages, version to be published in Physics Letters

Apoio institucional para incubação de Empreendimentos Econômicos Solidários: proposta metodológica com base na experiência do IFSC

This paper presents research results from an incubation experience on the Florianópolis-Continente Campus of the Federal Institute of Santa Catarina (IFSC), carried out between 2010 and 2013, and a brief history of incubation in the institution. The experience was examined in the light of methodological processes of Technological Incubators of Popular Cooperatives (ITCPs) of the South and Southeast of Brazil. The results point to the need for a methodological redefinition of institutional support to Solidarity Economy Enterprises (ESS) at IFSC. Based on the unsustainable situation of the EES at the stage of post-incubation, it proposes an alternative to the incubation processes, to ensure a systematic training and advice through a pedagogical project for a theoretical and practical course.Keywords: associated work, solidarity economy, incubation.O trabalho apresenta resultados de pesquisa sobre uma experiência de incubação no Campus Florianópolis– Continente do Instituto Federal de Santa Catarina (IFSC), realizada entre 2010 e 2013, bem como faz um breve histórico da incubação na instituição. A experiência foi analisada à luz de processos metodológicos de Incubadoras Tecnológicas de Cooperativas Populares (ITCPs) das regiões Sul e Sudeste do Brasil. Os resultados obtidos apontam para a necessidade de redefinição metodológica para o apoio institucional a Empreendimentos Econômicos Solidários (EES) no IFSC. Fundamentando-se na situação de insustentabilidade dos EES na fase de pós-incubação, propõe uma alternativa aos processos de incubação de forma a garantir a formação e a assessoria sistemáticas por meio de um projeto pedagógico de curso teórico-prático.Palavras-chave: trabalho associado, economia solidária, incubação

Anomalous heavy-fermion and ordered states in the filled skutterudite PrFe4P12

Specific heat and magnetization measurements have been performed on high-quality single crystals of filled-skutterudite PrFe_4P_{12} in order to study the high-field heavy-fermion state (HFS) and low-field ordered state (ODS). From a broad hump observed in C/T vs T in HFS for magnetic fields applied along the direction, the Kondo temperature of ~ 9 K and the existence of ferromagnetic Pr-Pr interactions are deduced. The {141}-Pr nuclear Schottky contribution, which works as a highly-sensitive on-site probe for the Pr magnetic moment, sets an upper bound for the ordered moment as ~ 0.03 \mu_B/Pr-ion. This fact strongly indicates that the primary order parameter in the ODS is nonmagnetic and most probably of quadrupolar origin, combined with other experimental facts. Significantly suppressed heavy-fermion behavior in the ODS suggests a possibility that the quadrupolar degrees of freedom is essential for the heavy quasiparticle band formation in the HFS. Possible crystalline-electric-field level schemes estimated from the anisotropy in the magnetization are consistent with this conjecture.Comment: 7 pages and 7 figures. Accepted for publication in Phys. Rev.

Fibrillin-1 and -2 differentially modulate endogenous TGF-β and BMP bioavailability during bone formation

Extracellular microfibrils composed of fibrillin-1 and -2 regulate bone formation through modulation of TGF-β and BMP signaling

Charm System Tests of CPT and Lorentz Invariance with FOCUS

We have performed a search for CPT violation in neutral charm meson oscillations. While flavor mixing in the charm sector is predicted to be small by the Standard Model, it is still possible to investigate CPT violation through a study of the proper time dependence of a CPT asymmetry in right-sign decay rates for $D^0\to K^-\pi^+$ and \d0b\to K^+\pi^-. This asymmetry is related to the CPT violating complex parameter $\xi$ and the mixing parameters $x$ and $y$: $A_{CPT}\propto{\rm Re} \xi y-{\rm Im} \xi x$ . Our 95% confidence level limit is $-0.0068<{\rm Re} \xi y-{\rm Im} \xi x<0.0234$. Within the framework of the Standard Model Extension incorporating general CPT violation, we also find 95% confidence level limits for the expressions involving coefficients of Lorentz violation of $(-2.8<N(x,y,\delta)(\Delta a_0 + 0.6 \Delta a_Z)<4.8)\times 10^{-16}$ GeV, $(-7.0<N(x,y,\delta)\Delta a_X<3.8)\times 10^{-16}$ GeV, and $(-7.0<N(x,y,\delta)\Delta a_Y<3.8)\times 10^{-16}$ GeV, where $N(x,y,\delta)$ is the factor which incorporates mixing parameters $x$, $y$ and the doubly Cabibbo suppressed to Cabibbo favored relative strong phase $\delta$.Comment: 12 pages 5 figure

Measurements of Ξc+\Xi_c^{+} Branching Ratios

Using data collected by the fixed target Fermilab experiment FOCUS, we measure the branching ratios of the Cabibbo favored decays $\Xi_c^+ \to \Sigma^+K^-\pi^+$, $\Xi_c^+ \to \Sigma^+ \bar{K}^{*}(892)^0$, and $\Xi_c^+ \to \Lambda^0K^-\pi^+\pi^+$ relative to $\Xi_c^+ \to \Xi^-\pi^+\pi^+$ to be $0.91\pm0.11\pm0.04$, $0.78\pm0.16\pm0.06$, and $0.28\pm0.06\pm0.06$, respectively. We report the first observation of the Cabibbo suppressed decay $\Xi_c^+ \to \Sigma^+K^+K^-$ and we measure the branching ratio relative to $\Xi_c^+ \to \Sigma^+K^-\pi^+$ to be $0.16\pm0.06\pm0.01$. We also set 90% confidence level upper limits for $\Xi_c^+ \to \Sigma^+ \phi$ and $\Xi_c^+ \to \Xi^*(1690)^0(\Sigma^+ K^-) K^+$ relative to $\Xi_c^+ \to \Sigma^+K^-\pi^+$ to be 0.12 and 0.05, respectively. We find an indication of the decays $\Xi_c^+ \to \Omega^-K^{+}\pi^+$ and $\Xi_c^+ \to \Sigma^{*}(1385)^+ \bar{K}^0$ and set 90% confidence level upper limits for the branching ratios with respect to $\Xi_c^+ \to \Xi^-\pi^+\pi^+$ to be 0.12 and 1.72, respectively. Finally, we determine the 90% C.L. upper limit for the resonant contribution $\Xi_c^+ \to \Xi^{*}(1530)^0 \pi^+$ relative to $\Xi_c^+ \to \Xi^-\pi^+\pi^+$ to be 0.10.Comment: 14 pages, 8 figure

Measurement of Masses and Widths of Excited Charm Mesons D2∗D_2^* and Evidence for Broad States

Using data from the FOCUS experiment we analyze the $D^+\pi^-$ and $D^0\pi^+$ invariant mass distributions. We measure the $D_2^{*0}$ mass M_{D_2^{*0}} = (2464.5 \pm 1.1 \pm 1.9) \mev and width \Gamma_{D_2^{*0}} = (38.7 \pm 5.3 \pm 2.9) \mev, and the $D_2^{*+}$ mass M_{D_2^{*+}} = (2467.6 \pm 1.5 \pm 0.76) \mev and width \Gamma_{D_2^{*+}} = (34.1 \pm 6.5 \pm 4.2) \mev. We find evidence for broad structures over background in both the neutral and charged final state. If each is interpreted as evidence for a single L=1, $j_q=1/2$ excited charm meson resonance, the masses and widths are M_{1/2}^0 =(2407 \pm 21 \pm 35) \mev, \Gamma_{1/2}^0 = (240 \pm 55 \pm 59) \mev, and M_{1/2}^+ = (2403 \pm 14 \pm 35) \mev \Gamma_{1/2}^+ = (283 \pm 24 \pm 34) \mev, respectively.Comment: 15 pages, 4 figures. Submitted to Phys. Lett. B. Added preprint number

Study of Lambda/c+ Cabibbo Favored Decays Containing a Lambda Baryon in the Final State

Using data from the FOCUS experiment (FNAL-E831), we study the decay of $\Lambda^+_c$ baryons into final states containing a $\Lambda$ hyperon. The branching fractions of $\Lambda^+_c$ into $\Lambda \pi^+$, $\Lambda \pi^+ \pi^+ \pi^-$ and $\Lambda \bar{K} ^0 K^+$ relative to that into $pK^-\pi^+$ are measured to be $0.217 \pm 0.013 \pm 0.020$, $0.508 \pm 0.024 \pm 0.024$ and $0.142 \pm 0.018 \pm 0.022$, respectively. We also report new measurements of $\frac{\Gamma(\Lambda^+_c \to \Sigma^0 \pi^+)}{\Gamma(\Lambda^+_c \to \Lambda \pi^+)} = 1.09 \pm 0.11 \pm 0.19$, $\frac{\Gamma(\Lambda^+_c \to \Sigma^0 \pi^+\pi^+ \pi^-)}{\Gamma(\Lambda^+_c \to \Lambda \pi^+ \pi^+ \pi^-)} = 0.26 \pm 0.06 \pm 0.09$ and $\frac{\Gamma(\Lambda^+_c \to \Xi(1690)^0(\Lambda \bar{K} ^0) K^+)}{\Gamma(\Lambda^+_c \to \Lambda \bar{K} ^0 K^+)} = 0.33 \pm 0.10 \pm 0.04$. Further, an analysis of the subresonant structure for the $\Lambda^+_c \to \Lambda \pi^+\pi^+\pi^-$ decay mode is presented.Comment: 14 pages, 6 figures, 3 tables, Submitted to Physics Letter