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排序方式: 共有310条查询结果,搜索用时 641 毫秒
91.
Abe F Akimoto H Akopian A Albrow MG Amendolia SR Amidei D Antos J Aota S Apollinari G Arisawa T Asakawa T Ashmanskas W Atac M Azzi-Bacchetta P Bacchetta N Bagdasarov S Bailey MW de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Barone M Bauer G Bedeschi F Behrends S Belforte S Bellettini G Bellinger J Benjamin D Bensinger J Beretvas A Berge JP Berryhill J Bertolucci S Bettelli S Bevensee B Bhatti A Biery K Bigongiari C Binkley M Bisello D Blair RE Blocker C Bloom K Blusk S Bodek A Bokhari W 《Physical review letters》2000,84(25):5716-5721
We report the results of a search for a W' boson produced in pp collisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample recorded by the Collider Detector at Fermilab. We consider the decay channel W'-->&munumu and search for anomalous production of high transverse mass munumu lepton pairs. We observe no excess of events above background and set limits on the rate of W' boson production and decay relative to standard model W boson production and decay using a fit of the transverse mass distribution observed. If we assume standard model strength couplings of the W' boson to quark and lepton pairs, we exclude a W' boson with invariant mass less than 660 GeV/c2 at 95% confidence level. 相似文献
92.
Graphite-furnace atomic absorption spectrometry is used to analyze sodium metal after conversion to sodium nitrate. Chromium, Ni, Co, Cd and Pb have detection limits in sodium of 0.18, 0.48, 0.11, 0.02 and 0.48 μg g-1; these are similar to the concentrations in nuclear-grade sodium, except for lead, which is below the detection limit. The behaviour of sodium nitrate, chloride and sulphate as matrices is compared. 相似文献
93.
Affolder T Akimoto H Akopian A Albrow MG Amaral P Amendolia SR Amidei D Anikeev K Antos J Apollinari G Arisawa T Asakawa T Ashmanskas W Azfar F Azzi-Bacchetta P Bacchetta N Bailey MW Bailey S de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Belforte S Bell WH Bellettini G Bellinger J Benjamin D Bensinger J Beretvas A Berge JP Berryhill J Bevensee B Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Blusk SR Bocci A Bodek A 《Physical review letters》2001,86(20):4472-4478
We present the results of a search for neutral Higgs bosons produced in association with b quarks in pp-->bb(phi)-->bbb final states with 91+/-7 pb(-1) of pp collisions at sqrt[s] = 1.8 TeV recorded by the Collider Detector at Fermilab. We find no evidence of such a signal and the data are interpreted in the context of the neutral Higgs sector of the minimal supersymmetric extension of the standard model. With basic parameter choices for the supersymmetric scale and the stop-quark mixing, we derive 95% C.L. lower mass limits for neutral Higgs bosons for tan(beta) values in excess of 35. 相似文献
94.
Affolder T Akimoto H Akopian A Albrow MG Amaral P Amidei D Anikeev K Antos J Apollinari G Arisawa T Artikov A Asakawa T Ashmanskas W Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Bailey S de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Belforte S Bell WH Bellettini G Bellinger J Benjamin D Bensinger J Beretvas A Berge JP Berryhill J Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Blusk SR Bocci A Bodek A Bokhari W 《Physical review letters》2002,88(7):071801
We report a study of the decays B0 --> J/psiK(*)0pi(+)pi(-), which involve the creation of a uu or dd quark pair in addition to a b -->c(cs) decay. The data sample consists of 110 pb(-1) of pp collisions at square root[s] = 1.8 TeV collected by the CDF detector at the Fermilab Tevatron collider during 1992-1995. We measure the branching fractions to be B(B0 --> J/psiK(*0)pi(+)pi(-)) = (6.6 +/- 1.9 +/- 1.1)x10(-4) and B(B0 --> J/psiK0pi(+)pi(-)) = (10.3 +/- 3.3 +/- 1.5)x10(-4). Evidence is seen for contributions from psi(2S)K(*)0, J/psiK0rho(0), J/psiK(*+)pi(-), and J/psiK1(1270). 相似文献
95.
Affolder T Akimoto H Akopian A Albrow MG Amaral P Amidei D Anikeev K Antos J Apollinari G Arisawa T Asakawa T Ashmanskas W Azfar F Azzi-Bacchetta P Bacchetta N Bailey MW Bailey S de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Belforte S Bell WH Bellettini G Bellinger J Benjamin D Bensinger J Beretvas A Berge JP Berryhill J Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Blusk SR Bocci A Bodek A Bokhari W Bolla G 《Physical review letters》2001,87(14):141802
We present results from a measurement of double diffraction dissociation in pp collisions at the Fermilab Tevatron collider. The production cross section for events with a central pseudorapidity gap of width Deltaeta(0)>3 (overlapping eta = 0) is found to be 4.43+/-0.02(stat)+/-1.18(syst) mb [ 3.42+/-0.01(stat)+/-1.09(syst) mb] at square root of (s) = 1800[630] GeV. Our results are compared with previous measurements and with predictions based on Regge theory and factorization. 相似文献
96.
97.
We report a novel type of anchoring transition (ANT) in a liquid crystal driven by the physical gelation of the system. The ANT manifests as anomaly in the thermal behaviour of the dielectric permittivity. Data from X‐ray studies suggest that ANT is caused by the ability of the gel fibres to compete with the substrate‐driven orientation conditions. It is further found that the molecular reorientation is possible only in cases where the gel is weak, the difference between weak and strong gels being established by rheological measurements. 相似文献
98.
Geetha Thiagarajan Effendi Widjaja Jun Hyuk Heo Jason K. Cheung Busolo Wabuyele Xiaodun Mou Mohammed Shameem 《Journal of Raman spectroscopy : JRS》2015,46(6):531-536
Structural complexity of biological drug products presents an analytical challenge in terms of early detection of aggregation and/or degradation. In the present study, Raman and Raman optical activity (ROA) were evaluated for their sensitivity to detect heat‐induced molecular instability in an Immunoglobulin G4 subclass therapeutic monoclonal antibody present in its formulation matrix. The therapeutic antibody was subjected to heat stress at 50 °C and was analyzed at various time points up to 1 month. The current results suggest that Raman and ROA are sensitive to early‐stage detection of heat‐induced instability of the antibody, in which significant changes could be observed at 1 week of stress. ROA could provide early detection of the subtle differences at the tertiary structure level in a heat‐stressed monoclonal antibody and Raman/ROA spectra could provide early detection in secondary structural changes as well. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
99.
Freestanding conducting polyaniline film for the control of electromagnetic radiations 总被引:2,自引:0,他引:2
Electromagnetic interference is pollution generated due to dense nature of circuitry in electronic devices and is required to be control at its source. Polyaniline is an environmentally stable conducting polymer which can be cast as thin film, which can replace the corrosive metals as a shield for the control of electromagnetic radiations. In this communication we discuss our results on the preparation of flexible freestanding conducting polyaniline film of varied thickness using either p-toluenesulphonic acid (PTSA) or camphor-10-sulphonic acid as a primary dopant and 4-chloro-3-methyl phenol (CMC) as a secondary dopant. The resulting films were characterized by conductivity, scanning electron micrograph and shielding effectiveness measurements (SE). The SE measurements were carried out using co-axial transmission line method in the frequency range of 0.1–1000 MHz. We noticed that only the change of 2% in the shielding effectiveness of these films over the period of 3 years indicating the environmental stability of polyaniline films. 相似文献
100.