Measurement of the W boson mass with the D0 detector Acharya, B. S.; Augsten, K.; Bagby, L. ...
Physical review. D, Particles, fields, gravitation, and cosmology,
2014, Letnik:
89, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We give a detailed description of the measurement of the W boson mass, MW, performed on an integrated luminosity of 4.3 fb super(-1), which is based on similar techniques as used for our previous ...measurement done on an independent data set of 1 fb super(-1) of data. The data were collected using the DO detector at the Fermilab Tevatron Collider. This data set yields 1.68 x 10 super(6) W arrow right ev candidate events. We measure the mass using the transverse mass, electron transverse momentum, and missing transverse energy distributions. The MW measurements using the transverse mass and the electron transverse momentum distributions are the most precise of these three and are combined to give MW = 80.367 + or - 0.013(stat) + or - 0.022(syst) GeV = 80. 367 + or - 0.026 GeV. When combined with our earlier measurement on 1 fb super(-1) of data, we obtain MW = 80.375 + or - 0.023 GeV.
We present various properties of the production of the X ( 3872 ) and ψ ( 2S ) states based on 10.4 fb-1 collected by the D0 experiment in Tevatron p p ¯ collisions at s=1.96 TeV . For both states, ...we measure the nonprompt fraction fNP of the inclusive production rate due to decays of b -flavored hadrons. We find the fNP values systematically below those obtained at the LHC. The fNP fraction for ψ ( 2S ) increases with transverse momentum, whereas for the X ( 3872 ) it is constant within large uncertainties, in agreement with the LHC results. The ratio of prompt to nonprompt ψ ( 2S ) production, ( 1-fNP ) / fNP , decreases only slightly going from the Tevatron to the LHC, but for the X ( 3872 ) , this ratio decreases by a factor of about 3. We test the soft-pion signature of the X ( 3872 ) modeled as a weakly bound charm-meson pair by studying the production of the X ( 3872 ) as a function of the kinetic energy of the X ( 3872 ) and the pion in the X ( 3872 ) π center-of-mass frame. For a subsample consistent with prompt production, the results are incompatible with a strong enhancement in the production of the X ( 3872 ) at the small kinetic energy of the X ( 3872 ) and the π in the X ( 3872 ) π center-of-mass frame expected for the X+soft -pion production mechanism. For events consistent with being due to decays of b hadrons, there is no significant evidence for the soft-pion effect, but its presence at the level expected for the binding energy of 0.17 MeV and the momentum scale Λ =M ( π ) is not ruled out.
This paper is describing an investigation of sodium lingo-sulfonate and sodium dodecyl-sulfate mixtures influence on zinc concentrates high temperature oxidative pressure leaching and zinc ...electro-winning. For this purpose, surfactants concentration at leaching tests was varied from 200 to 800 mg∙l-1. It was established that the maximum zinc extraction (99 %) at leaching was achieved in the presence of mixture containing 800 mg∙l-1 lignosulfonate and 200 mg∙l-1 sodium dodecyl-sulfate. Therefore, this mixture can be recommended for high temperature oxidative pressure leaching of zinc concentrates. Sulfur-sulfide pellets formation also was observed at a low lingo-sulfonate concentration (200 mg∙l-1) in a mixture with sodium dodecyl-sulfate. This phenomenon can lead to emergency shut down of autoclave. It was observed that the mixture usage of 800 mg∙l-1 lignosulfonate and 200 mg∙l-1 sodium dodecyl-sulfate had no significant impact on zinc current efficiency, it was in the rage of 92-93 %. The mixture usage of 200 mg∙l-1 lignosulfonate and 600 mg∙l-1 sodium dodecyl-sulfate allowed to increase current efficiency up to 95 %. Increasing sodium dodecyl-sulfate concentration in mixtures with lignosulfonates leads to decrease of current efficiency, to formation of deep pores and defects on cathode zinc surface.
The Friedländer condensation was employed to synthesize two series of 3,3‘-polymethylene bridged ligands, L, based on 2-(2‘-pyridyl)-benzohquinoline and 2,2‘-bibenzohquinoline (BHQ) along with the ...fully aromatic naphtho1,2-b-1,10-phenanthroline. Complexes Cu(L)2+ were prepared as their perchlorate or hexafluorophosphate salts. The solution state structures were analyzed by NMR and shielding effects reflected significant interligand π-stacking interaction in the complexes. Solid-state structures of the complexes where L = 3,3‘-tetramethylene-2,2‘-bibenzohquinoline or naphtho1,2-b-1,10-phenanthroline were determined by X-ray analysis. The tetramethylene bridged complex showed a highly distorted coordination geometry with the BHQ rings of opposing ligands π-stacked at a interplanar distance of about 3.37 Å. Complexes of the BHQ series showed a pronounced MLCT absorption maximum which shifted bathochromically from 496 to 610 nm as the 3,3‘-bridge decreased from 4 to 2 carbons. The BHQ complexes luminesced strongly in CH2Cl2 solution and the tetramethylene-bridged system showed the longest yet recorded excited-state lifetime for a copper MLCT excited state, τ = 5.3 μs and Φ = 0.10.
We study the production of the exotic charged charmonium-like state $Z_c^{\pm}(3900)$ in $p \bar p$ collisions through the sequential process $\psi(4260) \rightarrow Z_c^{\pm}(3900) \pi^{\mp}$, ...$Z_c^{\pm}(3900) \rightarrow J/\psi \pi^{\pm}$. Using the subsample of candidates originating from semi-inclusive weak decays of $b$-flavored hadrons, we measure the invariant mass and natural width to be $M=3902.6^{+5.2}_{-5.0}{\rm \thinspace (stat)}^{+3.3}_{-1.4}{\rm \thinspace (syst)}$ MeV and $\Gamma=32 ^{+28}_{-21}{\rm \thinspace (stat)} ^{+26}_{-7}{\rm \thinspace (syst)}$ MeV, respectively. We search for prompt production of the $Z_c^{\pm}(3900)$ through the same sequential process. No significant signal is observed, and we set an upper limit of 0.66 at the 95\% credibility level on the ratio of prompt production to the production via $b$-hadron decays. The study is based on $10.4~\rm{fb^{-1}}$ of $p \overline p $ collision data collected by the D0 experiment at the Fermilab Tevatron collider.
Research subject
. Fluid inclusions in quartz of three vein systems associated with tectonic cracks occurred during the development of thrust and shear deformations of the Western Transbaikalia. Vein ...systems localized in volcanic, terrigenous and granite rocks.
Methods
. The composition of fluid inclusions was studied by microthermometry, Raman spectroscopy and gas chromatography-mass spectrometry.
Results
. The quartz under study was formed by high-density medium-temperature NaCl-KCl and a low- and medium-salinity water-carbon dioxide fluid (2-5 wt % NaCl eq.). A distinctive feature of quartz of different vein systems was found to be the gas phase composition of inclusions associated with the composition of host rocks. The minimum temperatures of vein quartz formation were determined to range from 180 to 450°C under the minimum fluid pressure values of 0.7-2.9 kbar.
Conclusions
. Complex vein systems of the junction zone of the Baikal-Muiskaya and Barguzino-Vitimskay SFZ, confined to different host rocks and having different structural positions, are characterized by a similar fluid composition and a common thermodynamic history reflecting the change of deformation aggregates. The metamorphogenic-hydrothermal nature of the fluid involved in the formation of quartz vein systems was established. The development of the hydrothermal system was accompanied by its influence on the host rocks, which was manifested in the variations of fluid composition. The evolution of a single hydrothermal system is associated with tectonic deformation processes, which can be described by three dynamic stages corresponding to three quartz generations.
Here, we present a measurement of the effective weak mixing angle parameter sin2θℓeff in $p\bar{p}$ → Z/γ* → μ+μ– events at a center-of-mass energy of 1.96 TeV, collected by the D0 detector at the ...Fermilab Tevatron Collider and corresponding to 8.6 fb–1 of integrated luminosity. The measured value of sin2θℓeffμμ = 0.23016 ± 0.00064 is further combined with the result from the D0 measurement in $p\bar{p}$ → Z/γ* → e+e– events, resulting in sin2θℓeffcomb = 0.23095 ± 0.00040. This combined result is the most precise measurement from a single experiment at a hadron collider and is the most precise determination using the coupling of the Z/γ* to light quarks.
PDF
