Silica-scaled Chrysophytes of cold region

This first survey in 2009 and 2010 on silica-scaled Chrysophytes in Zhenbao Island Wetland Preserve, Northeast China, recorded 32 taxa (5 in Chrysophyceae and 27 in Synurophyceae), of which 29 were previously found in other parts of China, three species, Spiniferomonas serrata, Mallomonas transsylvanica and Synura punctulosa are new records to China. In terms of biogeography, 1 taxon is endemic, 2 bipolar, 1 northern temperate, 9 cosmopolitan, and 18 of wide distribution. The endemism of Synura punctulosa, appears due to its poor dispersal ability; lack of sampling data may also contribute its known distribution range. Spiniferomonas serrata and Mallomonas transsylvanica, two bipolar taxa, are the first report in China. More research efforts are needed for adequately understanding the distributions of this group of algae. © (2012) Trans Tech Publications, Switzerland

Chemical composition, sources, and deposition fluxes of water-soluble inorganic ions obtained from precipitation chemistry measurements collected at an urban site in northwest China

Precipitation samples were collected at an urban site in Xi&#39;an, northwest China during March to November in 2009 and were then analyzed to determine the pH and concentrations of water-soluble inorganic ions (Na(+), NH(4)(+), K(+), Mg(2+), Ca(2+), SO(4)(2-), NO(3)(-), Cl(-), and F(-)) in precipitation. The pH of precipitation ranged from 4.1 to 7.6 for all of the samples with an annual volume-weighted mean of 6.4. While a large portion of the precipitation events were weakly acidic or alkaline, around 30% of the precipitation events in the autumn were strongly acidic. Precipitation events with air masses from the northeast and the southeast were weakly acidic while those with air masses from the northwest and the southwest were alkaline. SO(4)(2-), Ca(2+), NH(4)(+), and NO(3)(-) were dominant ions in the precipitation, accounting for 37%, 25%, 18%, and 9%, respectively, of the total analyzed ions. Ca(2+) and NH(4)(+) were found to be the major neutralizers of precipitation acidity; however, the contribution of Mg(2+), although much lower than those of Ca(2+) and NH(4)(+), was important, in many cases, in changing the precipitation from weakly acidic to weakly alkaline. Enrichment factor analysis confirmed that SO(4)(2-) and NO(3)(-) were produced from anthropogenic sources, Ca(2+), K(+), and 80% Mg(2+) were from crustal sources, and Na(+), Cl(-), and &sim;20% of Mg(2+) were from marine sources. The annual wet depositions were estimated to be 3.5 t km(-2) per year for sulfur; 2.3 t km(-2) per year for nitrogen, of which 0.8 t km(-2) per year was oxidized nitrogen and 1.5 t km(-2) per year was reduced nitrogen; and 3.0 t km(-2) per year for Ca(2+).</p

Evidence for the decay X(3872) -> psi(2S)gamma

Evidence for the decay mode X(3872) -> psi(2S)gamma in B+ -> X(3872)K+ decays is found with a significance of 4.4 standard deviations. The analysis is based on a data sample of proton proton collisions, corresponding to an integrated luminosity of 3 fb(-1), collected with the LHCb detector, at centre-of-mass energies of 7 and 8 TeV. The ratio of the branching fraction of the X(3872) -> psi(2S)gamma decay to that of the X(3872) -> J/psi gamma decay is measured to be B(X(3872) -> psi(2S)gamma)/B(X(3872) -> J/psi gamma) = 2.46 +/- 0.64 +/- 0.29, where the first uncertainty is statistical and the second is systematic. The measured value does not support a pure D (D) over bar* molecular interpretation of the X(3872) state. (C) 2014 CERN for the benefit of the LHCb Collaboration. Published by Elsevier B.V

Measurement of the (B)over-bar(0)-B-0 and (B)over-bars(0)-B-s(0) production asymmetries in pp collisions at root s=7 TeV

The (B) over bar (0)-B-0 and (B) over bar (0)(s)-B-s(0) production asymmetries, A(P)(B-0) and A(P)(B-s(0)), are measured by means of a time-dependent analysis of B-0 -> J/Psi K-*0, B-0 -> D-pi(+) and B-s(0) -> D-s(-)pi(+) decays, using a data sample corresponding to an integrated luminosity of 1.0 fb(-1), collected by LHCb in pp collisions at a centre-of-mass energy of 7 TeV. The measurements are performed as a function of transverse momentum and pseudorapidity of the B-0 and B-s(0) mesons within the LHCb acceptance. The production asymmetries, integrated over p(T) and eta in the range 4 < p(T) < 30 GeV/c and 2.5 < eta < 4.5, are determined to be A(P)(B-0) = (-0.35 +/- 0.76 +/- 0.28)% and A(P)(B-s(0)) = (1.09 +/- 2.61 +/- 0.66)%, where the first uncertainties are statistical and the second systematic. (C) 2014 The Authors. Published by Elsevier B.V

Identification of beauty and charm quark jets at LHCb

Identification of jets originating from beauty and charm quarks is important for measuring Standard Model processes and for searching for new physics. The performance of algorithms developed to select b- and c-quark jets is measured using data recorded by LHCb from proton-proton collisions at root s = 7TeV in 2011 and at root s = 8TeV in 2012. The efficiency for identifying a b (c) jet is about 65%(25%) with a probability for misidentifying a light-parton jet of 0.3% for jets with transverse momentum pT > 20GeV and pseudorapidity 2 : 2 < eta < 4.2. The dependence of the performance on the pT and eta of the jet is also measured

B flavour tagging using charm decays at the LHCb experiment

An algorithm is described for tagging the flavour content at production of neutral B mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a B meson with the charge of a reconstructed secondary charm hadron from the decay of the other b hadron produced in the proton-proton collision. Charm hadron candidates are identified in a number of fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is calibrated on the self-tagged decay modes B+ -> J/psi K+ and B-0 -> J/psi K*(0) using 3.0fb(-1) of data collected by the LHCb experiment at pp centre-of-mass energies of 7TeV and 8TeV. Its tagging power on these samples of B -> J/psi X decays is (0.30 +/- 0.01 +/- 0.01) %