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Showing papers by "Jun Lu published in 1994"


Journal ArticleDOI
F. Abe1, M. G. Albrow1, S. R. Amendolia1, D. Amidei1  +394 moreInstitutions (1)
TL;DR: In this paper, a search for the top quark with the Collider Detector at Fermilab (CDF) in a sample of pp collisions at √s=1.8 TeV with an integrated luminosity of 19.3±0.7 pb−1 is summarized.
Abstract: A search[1] for the top quark with the Collider Detector at Fermilab (CDF) in a sample of pp collisions at √s=1.8 TeV with an integrated luminosity of 19.3±0.7 pb−1 is summarized. We find 12 events consistent with either two W bosons, or a W boson and at least one b jet. The probability that the measured yield is consistent with the background is 0.26%. Though the statistics are too limited to establish firmly the existence of the top quark, a natural interpretation of the excess is that it is due to tt production. Under this assumption, constrained fits to individual events yield a top quark mass of 174±10+13−12 GeV/c2. The tt production cross section is measured to be 13.9+6.1−4.8 pb. Some implications of the measured value of the top mass are discussed.

276 citations


Journal ArticleDOI
F. Abe1, M. G. Albrow1, S. R. Amendolia1, D. Amidei1  +394 moreInstitutions (1)
TL;DR: In this article, the authors presented the results of a search for the top quark in 19.3 pb[sup [minus]1] of [ital [bar p]p] collisions at [radical][ital s] = 1.8 TeV.
Abstract: We present the results of a search for the top quark in 19.3 pb[sup [minus]1] of [ital [bar p]p] collisions at [radical][ital s] =1.8 TeV. The data were collected at the Fermilab Tevatron collider using the Collider Detector at Fermilab (CDF). The search includes standard model [ital t[bar t]] decays to final states [ital ee][nu][bar [nu]], [ital e][mu][nu][bar [nu]], and [mu][mu][nu][bar [nu]] as well as [ital e]+[nu]+jets or [mu]+[nu]+jets. In the ([ital e],[mu])+[nu]+jets channel we search for [ital b] quarks from [ital t] decays via secondary vertex identification and via semileptonic decays of the [ital b] and cascade [ital c] quarks. In the dilepton final states we find two events with a background of 0.56[sub [minus]0.13][sup +0.25] events. In the [ital e],[mu]+[nu]+jets channel with a [ital b] identified via a secondary vertex, we find six events with a background of 2.3[plus minus]0.3. With a [ital b] identified via a semileptonic decay, we find seven events with a background of 3.1[plus minus]0.3. The secondary vertex and semileptonic-decay samples have three events in common. The probability that the observed yield is consistent with the background is estimated to be 0.26%. The statistics are too limited to firmly establish the existence of the more » top quark; however, a natural interpretation of the excess is that it is due to [ital t[bar t]] production. We present several cross-checks. Some support this hypothesis; others do not. Under the assumption that the excess yield over background is due to [ital t[bar t]], constrained fitting on a subset of the events yields a mass of 174[plus minus]10[sub [minus]12][sup +13] GeV/[ital c][sup 2] for the top quark. The [ital t[bar t]] cross section, using this top quark mass to compute the acceptance, is measured to be 13.9[sub [minus]4.8][sup +6.1] pb. « less

227 citations


Journal ArticleDOI
Fumio Abe, M. G. Albrow1, D. Amidei2, J. Antos3  +395 moreInstitutions (30)
TL;DR: In this article, a photon cross section measurement from the Collider Detector at Fermilab experiment is presented, where the detector and trigger upgrades, as well as six times the integrated luminosity compared with their previous publication, have contributed to a much more precise measurement and extended [ital P][sub [ital T]] range.
Abstract: A prompt photon cross section measurement from the Collider Detector at Fermilab experiment is presented. Detector and trigger upgrades, as well as six times the integrated luminosity compared with our previous publication, have contributed to a much more precise measurement and extended [ital P][sub [ital T]] range. As before, QCD calculations agree qualitatively with the measured cross section, but the data has a steeper slope than the calculations.

66 citations


Journal ArticleDOI
Xintao Wu1, Pengcheng Chen1, Shaowu Du1, Nianyong Zhu1, Jun Lu1 
TL;DR: In this paper, the synthesis of transition metal clusters involving bridging sulfido ligands is discussed. And the potential application of the "unit construction" schemes in synthesis of other bridging ligands are presented.
Abstract: Designed synthesis for some transition metal clusters involving bridging-sulfido ligands is reviewed. The basic concept with the use of reactive fragments as building blocks is described. It is shown that the sulfido ligands with lone-pair electrons and the unsaturated coordination sites play important roles in this rational synthesis. The relationship between the metallic coordination types of the sulfido ligands and their assembling activity in the compounds is summarized. Examples of the six kinds of “unit construction” with reactive fragments as building blocks are shown, indicating clearly that the “unit construction” is a reasonable way in the synthesis of transition metal clusters involving bridging sulfido ligands. Finally, the potential application of the “unit construction” schemes in the synthesis of transition metal clusters involving other bridging ligands is presented.

42 citations


Journal ArticleDOI
TL;DR: In this paper, two different polymeric solids have been obtained by the reaction of Rh 2 (O 2 CCH 3 ) 4 with TCNE (tetracyanoethylene).

36 citations


Journal ArticleDOI
TL;DR: In this article, graphite films have been characterized with respect to surface morphology and microstructure using transmission electron microscopy and a smooth interface between the graphite and the Ni was observed.

31 citations


Journal ArticleDOI
Fumio Abe, M. G. Albrow1, D. Amidei2, C. Anway-Wiese3  +388 moreInstitutions (31)
TL;DR: In this article, the authors measured the branching ratio of the collision data from the 1992-1993 run of the Collider Detector at Fermilab and derived a branching ratio for the top quark mass.
Abstract: We present a measurement of the ratio $\frac{\ensuremath{\sigma}B(W\ensuremath{\rightarrow}e\ensuremath{ u})}{\ensuremath{\sigma}B({Z}^{0}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}})}$ in $\overline{p}p$ collisions at $\sqrt{s}=1.8$ TeV The data represent an integrated luminosity of 21.7 ${\mathrm{pb}}^{\ensuremath{-}1}$ from the 1992-1993 run of the Collider Detector at Fermilab. We find $\frac{\ensuremath{\sigma}B(W\ensuremath{\rightarrow}e\ensuremath{ u})}{\ensuremath{\sigma}B({Z}^{0}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}})}=10.90\ifmmode\pm\else\textpm\fi{}0.32(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.29(\mathrm{syst})$. From this value, we extract a value for the $W$ width, $\ensuremath{\Gamma}(W)=2.064\ifmmode\pm\else\textpm\fi{}0.061(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.059(\mathrm{syst})$ GeV, and the branching ratio, $\frac{\ensuremath{\Gamma}(W\ensuremath{\rightarrow}e\ensuremath{ u})}{\ensuremath{\Gamma}(W)=0.1094\ifmmode\pm\else\textpm\fi{}0.0033(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.0031(\mathrm{syst})}$, and we set a decay-mode-independent limit on the top quark mass ${m}_{\mathrm{top}}g62$ GeV/${\mathit{c}}^{2}$ at the 95% C.L.

16 citations


Journal ArticleDOI
TL;DR: The cubane-like complexes {WAg3Se3I}(Se)(Ph3P)3 (I) and {MoAg3 Se3I](Se), Ph3P3 (II) have been synthesized by the reaction of [Et4N]2[MSe4] (M = W or Mo) and Ag(Ph 3P) 3I in CH3CN/CH2Cl2 solvent and characterized by X-ray crystallography as mentioned in this paper.

11 citations


Journal ArticleDOI
TL;DR: In this paper, the initial stages of chemical vapor deposition of TiSi2 from TiCl4, H2, and Si(100) have been investigated with respect to the phase formation sequence.
Abstract: The initial stages of chemical vapor deposition of TiSi2 from TiCl4, H2, and Si(100) have been investigated with respect to the phase formation sequence. The result showed that the metastable C49 TiSi2 phase was formed prior to the equilibrium C54 TiSi2 phase. As the growth continued, the C49 phase was transformed to the C54 phase. X‐ray diffraction analyses showed that both TiSi2 phases exhibited an epitaxial‐like growth with respect to the substrate. Moreover, the transformation from the C49 phase to the C54 phase was favored by increased film thickness rather than high‐temperature annealing. The results could be explained by an interfacial stabilization effect where the metastable C49 phase is stabilized by epitaxy. In addition, the influence of oxygen and carbon on the process was investigated by adding O2and C2H4 to the reaction gas mixture. Oxygen had no effect while a minor stabilization of the C49 phase was observed when carbon was introduced during deposition.

10 citations


Journal ArticleDOI
Fumio Abe, M. G. Albrow1, D. Amidei2, J. Antos3  +406 moreInstitutions (32)
TL;DR: In this article, the results of a search in [ital [bar p] [ital p] collisions at [radical][ital s] = 1.8 TeV for the top quark decaying to a charged Higgs bosson ([ital H][sup [plus minus]]).
Abstract: We present the results of a search in [ital [bar p]] [ital p] collisions at [radical][ital s] =1.8 TeV for the top quark decaying to a charged Higgs bosson ([ital H][sup [plus minus]]). We search for dilepton final states from the decay chain [ital t] [ital [bar t]][r arrow][ital HH] (or [ital HW], or [ital WW])+[ital b] [ital [bar b]][r arrow][ital ll]+[ital X]. In a sample of 19.3 pb[sup [minus]1] collected during 1992--93 with the Collider Detector at Fermilab, we observe 2 events with a background estimation of 3.0[plus minus]1.0 events. Limits at 95% C.L. in the (M[sub top],M[sub [ital H][sup [plus minus]]]) plane are presented. For the case [ital M][sub top][lt][ital M][sub [ital W]]+[ital M][sub [ital b]], we exclude at 95% C.L. the entire ([ital M][sub top],[ital M][sub H[plus minus]]) plane for the branching ratio [ital B]([ital H][r arrow][tau][nu]) larger than 75%. We also interpret the results in terms of the parameter tan[beta] of two-Higgs-doublet models.

9 citations


Journal ArticleDOI
TL;DR: In this paper, the reflection and transmission coefficients of ballistic two-dimensional electrons by a potential barrier, induced via a surface gate, reveal that both coefficients vary gradually with the barrier height when it is less then the electron Fermi energy.
Abstract: Measurements of the reflection and transmission coefficients of ballistic two‐dimensional electrons by a potential barrier, induced via a surface gate, reveal that both coefficients vary gradually with the barrier height when it is less then the electron Fermi energy. Superimposed on the gradual variation, oscillatory structure which are consistent with interference resonances are also observed. The data imply that the potential barrier seen by the two‐dimensional electrons is sharp compared to the electron wavelength.


Journal ArticleDOI
Fumio Abe, M. G. Albrow1, D. Amidei2, J. Antos3  +408 moreInstitutions (32)
TL;DR: In this article, the authors measured the angular distribution of the [ital W]+jet angular distribution using the Collider Detector at Fermilab (CDF) during 1988--89 and 1992--93 Tevatron runs.
Abstract: The [ital W]+jet angular distribution is measured using [ital W][minus][gt][ital e][nu] events recorded with the Collider Detector at Fermilab (CDF) during 1988--89 and 1992--93 Tevatron runs. The data agree well with both a leading order and a next-to-leading order theoretical prediction. The shape of the angular distribution is similar to that observed in photon+jet data, and significantly different from that observed in dijet data.


Journal ArticleDOI
TL;DR: The cubane-like complexes {WAg3Se3I}(Se)(Ph3P)3 (I) and {MoAg3 Se3I](Se), Ph3P3 (II) have been synthesized by the reaction of [Et4N]2[MSe4] (M = W or Mo) and Ag(Ph 3P) 3I in CH3CN/CH2Cl2 solvent and characterized by X-ray crystallography as discussed by the authors.
Abstract: The novel cubane-like complexes {WAg3Se3I}(Se)(Ph3P)3 (I) and {MoAg3Se3I}(Se)(Ph3P)3 (II) have been synthesized by the reaction of [Et4N]2[MSe4] (M = W or Mo) and Ag(Ph3P)3I in CH3CN/CH2Cl2 solvent and characterized by X-ray crystallography. In the structures of the title compounds, W(Mo) and Ag atoms are distorted tetrahedrally coordinated and one corner of the cubane-like cluster core is completed by an iodine atom which connects three Ag atoms with the average bond lengths 3.064(3.066)A.