82 research outputs found
Model-independent extraction of {pipe}Vtq{pipe} matrix elements from top-quark measurements at hadron colliders
No full textCurrent methods to extract the quark-mixing matrix element {pipe}Vtb{pipe} from single-top-production measurements assume that {pipe}Vtb{pipe}>>{pipe}Vtd{pipe},{pipe}Vts{pipe}: top quarks decay into b quarks with 100 % branching fraction, s-channel single-top production is always accompanied by a b quark and initial-state contributions from d and s quarks in the t-channel production of single top quarks are neglected. Triggered by a recent measurement of the ratio, 0. 90 ±0. 04 performed by the D0 collaboration, we consider a {pipe}Vtb{pipe} extraction method that takes into account non zero d- and s-quark contributions both in production and decay. We propose a strategy that allows to extract consistently and in a model-independent way the quark-mixing matrix elements {pipe}Vtd{pipe}, {pipe}Vts{pipe}, and {pipe}Vtb{pipe} from the measurement of R and from single-top measured event yields. As an illustration, we apply our method to the Tevatron data using a CDF analysis of the measured single-top event yield with two jets in the final state, one of which is identified as a b-quark jet. We constrain the {pipe}Vtq{pipe} matrix elements within a four-generation scenario by combining the results with those obtained from direct measurements in flavor physics and determine the preferred range for the top-quark decay width within different scenarios. © 2012 Springer-Verlag / Società Italiana di Fisica
The solubility and oxidation state of nickel in silicate melt at low oxygen fugacities: Results using a mechanically assisted equilibration technique
No full textThe solubility of Ni in a silicate melt has been measured using a new, mechanically assisted equilibration technique over a wide range of controlled ƒO2 values. The melt composition corresponds to the 1 atm eutectic in the system CaAl2Si2O8-CaMgSi2O6 + 10 wt% CaO. The experiments were performed at 1300°C and over an ƒO2 range of 10−8.5 to 10−13.75, and over a temperature range of 1270 to 1390°C at a constant gas mixing ratio ( ). The experiment consists of a sample of melt contained within a crucible of Ni metal and held in a 1 atm gas mixing furnace. A Ni spindle is entered into the sample from above and continuously rotated at a constant angular velocity using a viscometer head. The stirring of the sample serves to accelerate the approach to equilibrium between the liquid sample and the metal crucible (and spindle). This arrangement allows relatively rapid equilibration of Ni content following changes to higher or lower ƒO2 values. Samples of the melt may be taken at any time for analysis and thus the equilibrium solubility of Ni in the silicate melt may be determined from unambiguous experimental reversals. The Ni contents of samples, analysed both by INAA and by ICP-AES, range from 25 to 5300 ppm.
The data presented in this paper indicate that the oxidation state of Ni in the investigated melt is Ni2+ over the entire range of ƒO2 investigated. This conclusion contrasts with recent reports in the literature of an inflection in the ƒO2 dependence of Ni solubility, which has been interpreted as solution of neutral Ni at low ƒO2 (Morse et al., 1991; Colson, 1992; Ehlers et al., 1992). We also present data for the temperature dependence of Ni solubility in the investigated melt. The solubility decreases with increasing temperature at constant ƒO2. The present results are in good agreement with the metal-loop-equilibration experiments reported by Holzheid et al. (1994)
Rapport I.13 Comparaison de résultats théoriques et expérimentaux pour une roue de pompe hélico-centrifuge
No full textThe paper gives the comparison between experimental measurements and theoretical flow calculations in an open mixed flow impeller.
Various measurements from nominal flow Qn to partial flow .5 Qn show the velocity distribution in the impeller channels and boundary unsteady pressures around the impeller on the casing inner surface.
Flow calculations from a quasi-tridimensional flow model are compared to measured values. The deviation may be considered as acceptable. The front casing unsteady pressure leads to an estimate of the energy exchange between the impeller main flow and the boundary flow initiated in the gap between the impeller blades and the front casing.L'étude présentée est une analyse comparée de résultats théoriques et expérimentaux obtenus pour une roue ouverte de pompe hélico-centrifuge.
Les diverses mesures menées depuis le débit nominal Qn jusqu'à un débit partiel de 0,5 Qn mettent en évidence l'évolution du champ des vitesses et des pressions pariétales instationnaires en ceinture, ainsi que l'apparition des recirculations. La comparaison de ces mesures à des données théoriques, obtenues à partir d'un programme de calcul quasi-tridimensionnel montre une concordance acceptable.
De même, l'analyse des pressions pariétales instationnaires donne une image des échanges d'énergie roue-fluide en ceinture.Huang X., Rieutord Émile, Spettel F., Lapray Jean-François. Rapport I.13 Comparaison de résultats théoriques et expérimentaux pour une roue de pompe hélico-centrifuge. In: Machines hydrauliques. Conception et exploitation. Développements récents et Applications aux différents secteurs industriels. Vingtièmes journées de l'hydraulique. Lyon, 4-6 avril 1989. Tome 1, 1989
Model-independent extraction of |V_{tq}| matrix elements from top-quark measurements at hadron colliders
No full textCurrent methods to extract the quark-mixing matrix element from single-top production measurements assume that : top quarks decay into quarks with 100% branching fraction, s-channel single-top production is always accompanied by a quark and initial-state contributions from and quarks in the -channel production of single top quarks are neglected. Triggered by a recent measurement of the ratio performed by the D0 collaboration, we consider a extraction method that takes into account non zero d- and s-quark contributions both in production and decay. We propose a strategy that allows to extract consistently and in a model-independent way the quark mixing matrix elements , , and from the measurement of and from single-top measured event yields. As an illustration, we apply our method to the Tevatron data using a CDF analysis of the measured single-top event yield with two jets in the final state one of which is identified as a -quark jet. We constrain the matrix elements within a four-generation scenario by combining the results with those obtained from direct measurements in flavor physics and determine the preferred range for the top-quark decay width within different scenarios
Spettel, Emma C. (Birth, 1900-10-04)
No full textAddress: 2270 Loth St.4277/Pg.37/1900/F W/Cinti, Ohio/Cinti, Ohio/Dr. P.W. GoodOriginal record filed in drawer labeled 'SPANCE-STAHEL'
Spettel, Bertha E. (Death, 1874-07-24)
No full textAddress: 55 Liberty St.Age at death: 4moPg.122/484/1874/F W S/City/Dr. G. Richard/Hust/Walnut HillsOriginal record filed in drawer labeled 'SPANCE-STAHEL'
Spettel, Ida (Birth, 1900-02-05)
No full textAddress: 1407 Clay St.643/Pg.146/1900/F W/US/U S./C. Buecker, Mid.Original record filed in drawer labeled 'SPANCE-STAHEL'
Search for a CP-odd Higgs boson decaying to Zh in pp collisions at root s=8 TeV with the ATLAS detector
No full textSee paper for full list of authors – 13 pages plus author list + cover pages (30 pages total), 5 figures, 2 tables, submitted to Phys. Lett. B, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2013-06/International audienceA search for a heavy, CP-odd Higgs boson, , decaying into a boson and a 125 GeV Higgs boson, , with the ATLAS detector at the LHC is presented. The search uses proton--proton collision data at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 20.3 fb. Decays of CP-even bosons to or pairs with the boson decaying to electron or muon pairs are considered, as well as decays with the boson decaying to neutrinos. No evidence for the production of an boson in these channels is found and the 95% confidence level upper limits derived for \sigma (gg\rightarrow A) \times \mbox{BR}(A \rightarrow Zh) \times \mbox{BR}(h \rightarrow f\bar{f}) are 0.098--0.013 pb for and 0.57--0.014 pb for in a range of 220--1000 GeV. The results are combined and interpreted in the context of two-Higgs doublet models
Bulk chemistry and mineralogy of a new "Unique" metal-rich chondritic breccia, Hamadah Al Hamra 237
No full textBulk chemistry and mineralogy of a new "Unique" metal-rich chondritic breccia, Hamadah Al Hamra 237
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