In a sample of 467 million $B\overline B$ pairs collected with the BABAR detector at the PEP-II collider at SLAC we have observed the decay $\overline{B}^0\rightarrow\Lambda_c^+{\overline p} \pi^0$ ...and measured the branching fraction to be $(1.94\pm0.17 \pm 0.14 \pm 0.50)\times 10^{-4}$, where the uncertainties are statistical, systematic, and the uncertainty on the $\Lambda_c^+\rightarrow p {K^-} \pi^+$ branching fraction, respectively. We determine an upper limit of $1.5\times 10^{-6}$ at $90\%$ C.L. for the product branching fraction ${\cal B} (\overline{B}^0\rightarrow \Sigma_c^+(2455)\overline p)\times{\cal B} (\Lambda_c^+\rightarrow p K^- \pi^+)$. Furthermore, we observe an enhancement at the threshold of the invariant mass of the baryon-antibaryon pair.
An R&D program on monolithic CMOS pixel sensors for application at the ILC has been started at LBNL. This program profits of significant synergies with other R&D activities on CMOS pixel sensors. The ...project activities after the first semester of the R&D program are reviewed.
We observe the decays $ $D^*_{s1}(2710)^+ \to D^*K$ and $D^*_{sJ}(2860)^+ \to D^*K$ and measure their branching fractions relative to the $D K$ final state. We also observe, in the $D^*K$ mass ...spectrum, a new broad structure at a mass of $(3044 \pm 8_{stat} (^{+30}_{-5})_{syst})$ $MeV/c^2$ having a width $\Gamma=(239 \pm 35_{stat} (^{+46}_{-42})_{syst})$ $MeV$. To obtain this result we use 470 ${\rm fb}^{-1}$ of data recorded by the BaBar detector at the PEPII asymmetric-energy $e^+e^-$ storage rings at the Stanford Linear Accelerator Center running at center-of-mass energies near 10.6 GeV.
Search for B-meson decays to b1rho and b1K Aubert, B.; Karyotakis, Y.; Lees, J.P. ...
Physical review. D, Particles, fields, gravitation, and cosmology,
2009, Letnik:
80
Journal Article
We present a search for decays of $B$ mesons to final states with a $b\_1$ meson and a $\rho$ or $K^*(892)$ meson. The search is based on a data sample consisting of 465 million $B\kern 0.18em{\kern ...-0.18em B}{}$ pairs collected by the {\slshape B\kern-0.1em{\smaller A}\kern-0.1em B\kern-0.1em{\smaller A\kern-0.2em R}} detector at the SLAC National Accelerator Laboratory. We do not observe any statistically significant signal. The upper limits we set on the branching fractions range from 1.4 to $8.0 \times 10^{-6}$ at the 90% confidence level (C.L.), including systematic uncertainties.
We measure the rate of D0-D0bar mixing with the observable yCP=(tauKpi/tauKK)-1, where tauKK and tauKpi are respectively the mean lifetimes of CP-even D0->K+K- and CP-mixed D0->K-pi+ decays, using a ...data sample of 384/fb collected by the Babar detector at the SLAC PEP-II asymmetric-energy B Factory. From a sample of D0 and D0bar decays where the inital flavor of the decaying meson is not determined, we obtain yCP = 1.12 +/- 0.26 (stat) +/- 0.22 (sys)%, which excludes the no-mixing hypothesis at 3.3 sigma, including both statistical and systematic uncertainties. This result is in good agreement with a previous Babar measurement of yCP obtained from a sample of D*+->D0pi+ events, where the D0 decays to K-pi+, K+K-, and pi+pi-, which is disjoint with the untagged D0 events used here. Combining the two results taking into account statistical and systematic uncertainties, where the systematic uncertainties are assumed to be 100% correlated, we find yCP = 1.16 +/- 0.22 (stat) +/- 0.18 (sys)%, which excludes the no-mixing hypothesis at 4.1 sigma.
Four aliphatic epoxides, 1-naphthyl glycidyl ether (NGE), 1-naphthylpropylene oxide (NPO), 4-nitrophenyl glycidyl ether (NPGE), 3,3,3-trichloropropylene oxide (TCPO) and two of their precursors, ...1-allylnaphthalene (AN) and 3,3,3-trichloropropylene (TCP), were selected for DNA strand-break analysis in liver in vivo with mice. The four epoxides selected were among the most mutagenic aliphatic epoxides in our previous structure-mutagenicity studies with the Ames test and had been evaluated for their in vivo genotoxicity as measured by sister-chromatid exchange (SCE) and chromosome aberrations (CA). A significant increase in the percentage of unwound DNA was observed at a 4-h exposure time for all the compounds at high doses except for AN. TCPO, the least genotoxic compound in bone marrow, had the greatest liver toxicity after 1-h exposure while NGE showed the most toxicity after 6 h. As might be expected from their corresponding epoxides, AN but not TCP exhibited significant SCE activity in the bone marrow of mice. This study reemphasizes the importance of evaluating the stability of direct-acting alkylating agents in comparing test results and in establishing the relative order of genotoxicity for such compounds.
Abstract
The semiconductor tracker (SCT) is one of the tracking systems for charged particles in the ATLAS detector. It consists of 4088 silicon strip sensor modules.
During Run 2 (2015–2018) the ...Large Hadron Collider delivered an integrated luminosity of 156 fb
-1
to the ATLAS experiment at a centre-of-mass proton-proton collision energy of 13 TeV. The instantaneous luminosity and pile-up conditions were far in excess of those assumed in the original design of the SCT detector.
Due to improvements to the data acquisition system, the SCT operated stably throughout Run 2.
It was available for 99.9% of the integrated luminosity and achieved a data-quality efficiency of 99.85%.
Detailed studies have been made of the leakage current in SCT modules and the evolution of the full depletion voltage, which are used to study the impact of radiation damage to the modules.
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