Search results for "BT"
showing 10 items of 1498 documents
Neutrinoless Double-Electron Capture
2020
Double-beta processes play a key role in the exploration of neutrino and weak interaction properties, and in the searches for effects beyond the Standard Model. During the last half century many attempts were undertaken to search for double-beta decay with emission of two electrons, especially for its neutrinoless mode ($0\nu2\beta^-$), the latter being still not observed. Double-electron capture (2EC) was not in focus so far because of its in general lower transition probability. However, the rate of neutrinoless double-electron capture ($0\nu2$EC) can experience a resonance enhancement by many orders of magnitude in case the initial and final states are energetically degenerate. In the re…
First observation of the doubly charmed baryon decay Ξcc++→Ξc+π+
2018
The doubly charmed baryon decay Ξcc++→Ξc+π+ is observed for the first time, with a statistical significance of 5.9σ, confirming a recent observation of the baryon in the Λc+K−π+π+ final state. The data sample used corresponds to an integrated luminosity of 1.7 fb−1, collected by the LHCb experiment in pp collisions at a center-of-mass energy of 13 TeV. The Ξcc++ mass is measured to be 3620.6±1.5(stat)±0.4(syst)±0.3(Ξc+) MeV/c2 and is consistent with the previous result. The ratio of branching fractions between the decay modes is measured to be [B(Ξcc++→Ξc+π+)×B(Ξc+→pK−π+)]/[B(Ξcc++→Λc+K−π+π+)×B(Λc+→pK−π+)]=0.035±0.009(stat)±0.003(syst).
Measurement of the c0 Baryon Lifetime
2018
We report a measurement of the lifetime of the $��_c^0$ baryon using proton-proton collision data at center-of-mass energies of 7 and 8~TeV, corresponding to an integrated luminosity of 3.0 fb$^{-1}$ collected by the LHCb experiment. The sample consists of about 1000 $��_b^-\to��_c^0��^-\bar��_�� X$ signal decays, where the $��_c^0$ baryon is detected in the $pK^-K^-��^+$ final state and $X$ represents possible additional undetected particles in the decay. The $��_c^0$ lifetime is measured to be $��_{��_c^0} = 268\pm24\pm10\pm2$ fs, where the uncertainties are statistical, systematic, and from the uncertainty in the $D^+$ lifetime, respectively. This value is nearly four times larger than, …
Study of W Boson Production in Association with Beauty and Charm
2015
The associated production of a W boson with a jet originating from either a light parton or heavy-flavor quark is studied in the forward region using proton-proton collisions. The analysis uses data corresponding to integrated luminosities of 1.0 and 2.0 fb[superscript -1] collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, respectively. The W bosons are reconstructed using the W → μν decay and muons with a transverse momentum, p[subscript T], larger than 20 GeV in the pseudorapidity range 2.0 20 GeV and 2.2 20 GeV. The fraction of W + jet events that originate from beauty and charm quarks is measured, along with the charge asymmetries of the W + b and W + c produ…
Classification of Renal Cell Carcinoma Based on Morphologic and Cytogenetic Correlations
1995
Typing or classification of renal cell carcinomas — a term introduced by Murphy and Mostofi in 1965 (1) — has been a debatable field since Grawitz (2) introduced the term hypernephroma in 1883. Grawitz postulated a hypernephrogenic origin of renal cancers, whose cells exhibit a light cytoplasm. During recent decades it has become customary to view renal cell carcinoma as a complex entity. Despite support for this idea by the World Health Organization (3) a morphological subtyping of renal cell carcinoma has not been recognized until recently. In 1986 Thoenes et al. (4) proposed a new pathomorphological subtyping of epithelial renal cell tumors, renal cell carcinoma (RCC) and adenoma (RCA), …
[Regular Paper] Detection of H. pylori Induced Gastric Inflammation by Diffuse Reflectance Analysis
2018
Spectral acquisitions contain rich information and thus, are promising modalities for early detection of gastric diseases. In this study, we analyze the diffuse reflectance of the gastric inflammatory lesions induced by the bacterium H. pylori in the mouse stomach. A pipeline has been designed to characterize and classify spectra acquired on mice. The pipeline is based on a band clustering algorithm followed by the computation of meaningful division and subtraction features and by classification with a linear SVM classifier. Currently, the pipeline is able to recognize inflamed stomach's spectra with an accuracy of 98%. These results are promising and the same pipeline could be adapted for …
Half-width plots, a simple tool to predict peak shape, reveal column kinetics and characterise chromatographic columns in liquid chromatography: Stat…
2013
Peak profiles in chromatography are characterised by their height, position, width and asymmetry; the two latter depend on the values of the left and right peak half-widths. Simple correlations have been found between the peak half-widths and the retention times. The representation of such correlations has been called half-width plots. For isocratic elution, the plots are parabolic, although often, the parabolas can be approximated to straight-lines. The plots can be obtained with the half-widths/retention time data for a set of solutes experiencing the same kinetics, eluted with a mobile phase at fixed or varying composition. When the analysed solutes experience different resistance to mas…
The forgotten mathematical legacy of Peano
2019
International audience; The formulations that Peano gave to many mathematical notions at the end of the 19th century were so perfect and modern that they have become standard today. A formal language of logic that he created, enabled him to perceive mathematics with great precision and depth. He described mathematics axiomatically basing the reasoning exclusively on logical and set-theoretical primitive terms and properties, which was revolutionary at that time. Yet, numerous Peano’s contributions remain either unremembered or underestimated.
Video materiāli ar subtitriem angļu valodā lasīšanas ātruma un izpratnes paaugstināšanai 11. klasē
2020
Mūsdienās ir nepieciešama efektīva lasīšanas izpratne un ātrums, lai atrastu atbilstošu un patiesu informāciju, piemēram, laikrakstos, transporta grafikos un citos rakstveida avotos. Diplomdarba mērķis bija izpētīt, kā video materiālu ar angļu subtitriem pielietošana var palielināt lasīšanas ātrumu un izpratni 11. klasē. Pētījuma metode bija gadījuma pētījums ar 12 skolēnu izlasi. Datu vākšanas gaitā tika veikti skolēnu lasīšanas ātruma un izpratnes mērījumi, ievāktas atgriezeniskās saites anketas un veiktas daļēji strukturētas intervijas ar divām skolotājām. Pētījuma rezultātā tika atklāts, ka nedaudz paaugstinājās lasīšanas ātrums, bet pazeminājās teksta izpratne. Šajā gadījumā video mate…
Epidemiology of stroke and transient ischemic attacks: Current knowledge and perspectives
2015
International audience; Because of the growing size and aging of the world's population, the global burden of stroke is increasing dramatically. Current epidemiological data indicate that 16.9 million people suffer a stroke each year, which represents a global incidence of 258/100,000 year, with marked differences between high- and low-income countries, and an age-adjusted incidence 1.5 times higher in men than in women. Although primary prevention has contributed to a decrease in stroke incidence in high-income countries, the so-called 'epidemiological transition' has led to an increase in incidence in middle-to-low-income countries as well. In addition, the incidence of ischemic stroke in…