Search for rare quark-annihilation decays, B --> Ds(*) Phi

We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and u-bar quarks in the B- meson. Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions BF(B- --> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid Communications

A Precision Measurement of the Lambda_c Baryon Mass

The $\Lambda_c^+$ baryon mass is measured using $\Lambda_c^+\to\Lambda K^0_S K^+$ and $\Lambda_c^+\to\Sigma^0 K^0_S K^+$ decays reconstructed in 232 fb$^{-1}$ of data collected with the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ storage ring. The $\Lambda_c^+$ mass is measured to be $2286.46\pm0.14\mathrm{MeV}/c^2$. The dominant systematic uncertainties arise from the amount of material in the tracking volume and from the magnetic field strength.Comment: 14 pages, 8 postscript figures, submitted to Phys. Rev.

Longitudinal study of the associations between change in sedentary behavior and change in adiposity during childhood and adolescence:Gateshead Millennium Study

BACKGROUND: Sedentary time (ST) has been reported to have a range of negative health effects in adults, however, the evidence for such effects among children and adolescents is sparse. The primary aim of the study was to examine associations between changes in sedentary behavior (time and fragmentation) and changes in adiposity across childhood and adolescence. METHODS: Participants were recruited as part of the Gateshead Millennium Study. Measures were taken at age 7y (n=502), 9y (n=506), 12y (n=420) and 15y (n=306). Participants wore an ActiGraph GT1M and accelerometer epochs were 'sedentary' when recorded counts were ⩽25 counts/15 s. ST was calculated and fragmentation (SF) was assessed by calculating the number of sedentary bouts per sedentary hour. Associations of changes in ST and SF with changes in adiposity (Body Mass Index (BMI), and Fat Mass Index (FMI)) were examined using bivariate linear spline models. RESULTS: Increasing ST by 1% per year was associated with an increase in BMI of 0.08 kg/m(2)/year (95%CI: 0.06-0.10; P<0.001) and FMI of 0.15 kg/m(2)/year (0.11-0.19; P<0.001). Change in SF was associated with BMI and FMI (P<0.001). An increase of 1 bout per sedentary hour per year (i.e. sedentary time becoming more fragmented) was associated with an increase in BMI of 0.07 kg/m(2)/year (0.06-0.09; P<0.001) and an increase in FMI of 0.14 kg/m(2)/year (0.10-0.18; P<0.001) over the 8y period. However, an increase in SF between 9y-12y was associated with a 0.09 kg/m(2)/year decrease in BMI (-0.18-0.00; p=0.046) and 0.11 kg/m(2)/year decrease in FMI (-0.22-0.00; P=0.049). CONCLUSIONS: Increased ST and increased SF from 7y to 15y were associated with increased adiposity. This is the first study to show age-specific associations between change in objectively measured sedentary behaviour and adiposity after adjustment of MVPA in children and adolescents.. The study suggests that, targeting sedentary behaviour for obesity prevention may be most effective during periods in which we see large increases in ST.International Journal of Obesity accepted article preview online, 15 March 2017. doi:10.1038/ijo.2017.69

Measurement of the branching fraction ratios and CP asymmetries in B-→ D0 CP K-decays

We present a preliminary study of $B^- \to D^0_{CP} \pi^-$ and $B^- \to D^0_{CP} K^-$ decays, with the $D^0_{CP}$ reconstructed in the CP-odd eigenstates $K_s \pi^0$, $K_s \omega$, in the CP-even eigenstates $K^+ K^-$, $\pi^+ \pi^-$, and in the (non-CP) flavor eigenstate $K^\mp \pi^\pm$. Using a sample of about 382 million Y(4S) decays into BBbar pairs, collected with the BABAR detector operating at the PEP-II asymmetric-energy B Factory at SLAC, we measure the ratios of the branching fractions R_CP+- and the direct CP asymmetries A_CP+-. The results are: R_CP- = 0.81 \pm 0.10 (stat) \pm 0.05 (syst) R_CP+ = 1.07 \pm 0.10 (stat) \pm 0.04 (syst) A_CP- = -0.19 \pm 0.12 (stat) \pm 0.02 (syst) A_CP+ = 0.35 \pm 0.09 (stat) \pm 0.05 (syst