Determination of the Form Factors for the Decay B0 --> D*-l+nu_l and of the CKM Matrix Element |Vcb|

We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ and of the parameters $\rho^2$, $R_1$, and $R_2$, which fully characterize the form factors of the $B^0 \to D^{*-}\ell^{+}\nu_\ell$ decay in the framework of HQET, based on a sample of about 52,800 $B^0 \to D^{*-}\ell^{+}\nu_\ell$ decays recorded by the BABAR detector. The kinematical information of the fully reconstructed decay is used to extract the following values for the parameters (where the first errors are statistical and the second systematic): $\rho^2 = 1.156 \pm 0.094 \pm 0.028$, $R_1 = 1.329 \pm 0.131 \pm 0.044$, $R_2 = 0.859 \pm 0.077 \pm 0.022$, $\mathcal{F}(1)|V_{cb}| = (35.03 \pm 0.39 \pm 1.15) \times 10^{-3}$. By combining these measurements with the previous BABAR measurements of the form factors which employs a different technique on a partial sample of the data, we improve the statistical accuracy of the measurement, obtaining: $\rho^2 = 1.179 \pm 0.048 \pm 0.028, R_1 = 1.417 \pm 0.061 \pm 0.044, R_2 = 0.836 \pm 0.037 \pm 0.022,$ and $\mathcal{F}(1)|V_{cb}| = (34.68 \pm 0.32 \pm 1.15) \times 10^{-3}.$ Using the lattice calculations for the axial form factor $\mathcal{F}(1)$, we extract $|V_{cb}| =(37.74 \pm 0.35 \pm 1.25 \pm ^{1.23}_{1.44}) \times 10^{-3}$, where the third error is due to the uncertainty in $\mathcal{F}(1)$

Study of the Exclusive Initial-State Radiation Production of the DDˉD \bar D System

A study of exclusive production of the $D \bar D$ system through initial-state r adiation is performed in a search for charmonium states, where $D=D^0$ or $D^+$. The $D^0$ mesons are reconstructed in the $D^0 \to K^- \pi^+$, $D^0 \to K^- \pi^+ \pi^0$, and $D^0 \to K^- \pi^+ \pi^+ \pi^-$ decay modes. The $D^+$ is reconstructed through the $D^+ \to K^- \pi^+ \pi^+$ decay mode. The analysis makes use of an integrated luminosity of 288.5 fb$^{-1}$ collected by the BaBar experiment. The $D \bar D$ mass spectrum shows a clear $\psi(3770)$ signal. Further structures appear in the 3.9 and 4.1 GeV/$c^2$ regions. No evidence is found for Y(4260) decays to $D \bar D$, implying an up per limit \frac{\BR(Y(4260)\to D \bar D)}{\BR(Y(4260)\to J/\psi \pi^+ \pi^-)} < 7.6 (95 % confidence level)

Measurements of Branching Fractions, Polarizations, and Direct CP-Violation Asymmetries in B→ρK∗ and B→f0(980)K∗ Decays

We report searches for B -meson decays to the charmless final states ρ K ∗ and f 0 ( 980 ) K ∗ with a sample of 232 × 10 6 B ¯¯¯ B pairs collected with the BABAR detector at the PEP-II e + e − collider. We measure in units of 10 − 6 the following branching fractions, where the first error quoted is statistical and the second systematic, or upper limits are given at the 90% confidence level : B ( B + → ρ 0 K * + ) < 6.1 , B ( B + → ρ + K * 0 ) = 9.6 ± 1.7 ± 1.5 , B ( B 0 → ρ − K * + ) < 12.0 , B ( B 0 → ρ 0 K * 0 ) = 5.6 ± 0.9 ± 1.3 , B ( B + → f 0 ( 980 ) K * + ) = 5.2 ± 1.2 ± 0.5 , and B ( B 0 → f 0 ( 980 ) K * 0 ) < 4.3 . For the significant modes, we also measure the fraction of longitudinal polarization and the charge asymmetry: f L ( B + → ρ + K * 0 ) = 0.52 ± 0.10 ± 0.04 , f L ( B 0 → ρ 0 K * 0 ) = 0.57 ± 0.09 ± 0.08 , A C P ( B + → ρ + K * 0 ) = − 0.01 ± 0.16 ± 0.02 , A C P ( B 0 → ρ 0 K * 0 ) = 0.09 ± 0.19 ± 0.02 , and A C P ( B + → f 0 ( 980 ) K * + ) = − 0.34 ± 0.21 ± 0.03

Integração de técnicas de solo, plantas e animais para recuperar áreas degradadas Integration of techniques of soil, plants and animals for restoration of degraded areas

Este trabalho trata da recuperação de áreas degradadas pela mineração da fração argila em Doutor Pedrinho-SC. O estudo utilizou técnicas para integrar o solo, as plantas e os animais. Testaram-se dois níveis de topografia, regular e irregular, dois níveis de adubação, orgânica e química, e dois níveis de serapilheira, com e sem. A espécie arbórea selecionada foi a leguminosa Mimosa scabrella (bracatinga). Poleiros artificiais foram instalados na área a fim de incrementar o número de sementes provenientes de áreas vizinhas pelos devidos dispersores. Aos nove meses de avaliação, a partir das análises químicas de solo, não foram verificados incrementos nutricionais. A bracatinga apresentou índice de sobrevivência superior a 92%, enquanto que a cobertura do solo pela copa das árvores foi significativamente superior para os tratamentos que receberam serapilheira, com valores maiores de 67%. Apesar de a cobertura do solo pela revegetação natural não apresentar diferença, em geral, houve tendência da mesma ser maior nos tratamentos com topografia regular. Os poleiros artificiais foram responsáveis pela vinda de vinte e uma sementes pertencentes a seis morfoespécies distintas. Entre as doze famílias botânicas de plantas espontâneas identificadas, a maior parte apresentou síndrome de polinização zoofilica, dispersão de sementes anemocórica e hábito herbáceo. Conclui-se que a bracatinga, a abubação orgânica e/ou química, a serapilheira e os poleiros artificiais são indicados para utilização em programas de recuperação de áreas degradadas semelhantes ao deste estudo. Estudos complementares são necessários para avaliar a pertinência ou não do uso da topografia irregular em programas de recuperação de áreas degradadas.<br>This paper is about the restoration of areas degraded by clay mining in Doutor Pedrinho/ Brasil, state of Santa Catarina. The study employs techniques that integrate soil, plants and animals. Two types of surface preparation (regular and irregular), two types of fertilizer (organic and chemical), and two conditions of litter (present and absent) were tested. The species selected for the experiment was the legume Mimosa scabrella (bracatinga). Artificial perches were installed in the area in order to increase the amount of seeds from neighborhood areas. Chemical analysis of the soil, nine months after the initiation of the experiment, did not show any nutritional potential increase. The bracatinga showed a survival rate over 92%, whereas the soil cover by bracatinga canopies was significantly larger in the treatments where litter was added, with values over 67%. Although the soil cover by natural revegetation did not show any significant differences, it was in general larger in regular surface treatments. The artificial perches were responsible for bringing twenty one seeds from six distinct morpho species. Among the 12 identified botanical families, the larger part of them showed insect pollination, wind-dispersed seed and herbaceous habit. The conclusion is that the integrated use of bracatinga, organic and/or chemical fertilizer, litter and artificial perches are indicated for restoration programs in degraded areas similar to the one presented in this study. Further investigation is required to evaluate the relevance of the use of irregular surface in the restoration of degraded areas

The BaBar detector: Upgrades, operation and performance

Contains fulltext : 121729.pdf (preprint version ) (Open Access

Measurement of the Decay B−→D∗0e−νˉB^- \to D^{*0} e^- \bar{\nu}

8 pages, 2 postscript figures, submitted to EPS2007 (2007 Europhysics Conference on High Energy Physics, Manchester, England)Using 226 million $B\bar{B}$ events recorded on the $\Upsilon(4S)$ resonance with the BABAR detector at the SLAC $e^+e^-$ storage rings PEPII, we reconstruct $B^-\to D^{*0} e^-\bar\nu_e$ decays using the decay chain $D^{*0}\to{}D^0{}\pi^0$ and $D^{0}\to{}K^-\pi^+$. From the dependence of their differential rate on $w$, the product of the four-velocities of $B^-${} and $D^{*0}$, and using the description of the form factor $F(w)$ by Caprini et al., we obtain the preliminary results $\rho^2_{A_1} = 1.15\pm 0.06 \pm 0.08$, $F(1)\cdot|V_{cb}| = (36.3\pm 0.6 \pm 1.4)\cdot 10^{-3}$, and ${\cal B}(B^-\to D^{*0} e^-\bar\nu_e) = (5.71\pm 0.08\pm 0.41)$. The first errors are statistical and the second ones are systematic. \

Observation of the semileptonic decays B -> D-*tau(-)(nu)over-bar(tau) and evidence for B -> D tau(-)(nu)over-bar(tau)

We present measurements of the semileptonic decays B--> D-0 tau(-)(nu) over bar (tau), B--> D-*0 tau(-)(nu) over bar (tau), (B) over bar (0)-> D+tau(-)(nu) over bar (tau), and (B) over bar (0)-> D*+tau(-)(nu) over bar (tau), which are potentially sensitive to non-standard model amplitudes. The data sample comprises 232x10(6) Upsilon(4S)-> B (B) over bar decays collected with the BABAR detector. From a combined fit to B- and (B) over bar (0) channels, we obtain the branching fractions B(B -> D tau(-)(nu) over bar (tau))=(0.86 +/- 0.24 +/- 0.11 +/- 0.06)% and B(B -> D-*tau(-)(nu) over bar (tau))=(1.62 +/- 0.31 +/- 0.10 +/- 0.05)% (normalized for the (B) over bar (0)), where the uncertainties are statistical, systematic, and normalization-mode-related

Search for the radiative leptonic decay B+→γell+νB^+ \to \gamma ell^+ \nu

7 pages, 1 postscript figure, submitted to Phys.Rev.LettWe present the results of a search for $B^{+}\to\gamma \ell^{+}\nu_{\ell}$, where $\ell = e, \mu$. We use a sample of 232 million $B\bar{B}$ pairs recorded at the $\Upsilon(4S)$ with the BaBar detector at the PEP-II $B$ Factory. We measure a partial branching fraction $\Delta\mathcal{B}$ in a restricted region of phase space that reduces the effect of theoretical uncertainties, requiring the lepton energy to be between 1.875 and 2.850GeV, the photon energy to be between 0.45 and 2.35GeV, and the cosine of the angle between the lepton and photon momenta to be less than -0.36, with all quantities computed in the $\Upsilon(4S)$ center-of-mass frame. We find $\Delta\mathcal{B}(B^{+}\to\gamma \ell^{+}\nu_{\ell}) = (-0.3^{+1.3}_{-1.5} ({stat}) \pm 0.6 ({syst}) \pm 0.1 ({th})) \times 10^{-6}$, assuming lepton universality. Interpreted as a 90% C.L. Bayesian upper limit, the result corresponds to $1.7\times10^{-6}$ for a prior flat in amplitude, and $2.3\times10^{-6}$ for a prior flat in branching fraction

Search for the decays B-0 -> e(+)e(-)gamma and B-0 ->mu(+)mu(-)gamma

We present results of a search for the decays B-0 -> l(+)l(-)gamma (l=e or mu). The search is performed using 320x10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II B Factory at SLAC. We find no significant signal and set the following branching fraction upper limits at the 90% confidence level: B(B-0 -> e(+)e(-)gamma)mu(+)mu(-)gamma)< 1.6x10(-7)