36,441 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
Letter from Carl Hayden to L. B. Williams
No full textLetter from Carl Hayden to L. B. Williams concerning the proposed township in the Grand Canyon
Many-electron theory of resonant charge transfer: Role of surface states in He and He+ scattering off Si(100)
No full textA many-electron theory of resonant charge transfer, originally formulated for the scattering of an atom with an empty valence orbital from a surface, is extended to treat the case where the valence orbital is initially occupied by one or two electrons. The scattering of He and He+ from the Si(001) surface is investigated. The interaction is assumed to be with the narrow band of surface states, and not the much wider bulk band. As a result, considerable oscillations are found in the ionization and/or neutralization probabilities as a function of the incident energy.PT: J; CR: AMOS AT, 1989, ADV CHEM PHYS, V76, P335 AMOS AT, 1989, SOLID STATE COMMUN, V71, P449 BLOSS W, 1978, SURF SCI, V72, P277 BRAKO R, 1981, SURF SCI, V108, P253 BURROWS BL, 1984, Q APPL MATH, V42, P73 BURROWS BL, 1990, J PHYS A-MATH GEN, V23, P1101 BURROWS BL, 1991, SURF SCI, V253, P365 CHADI DJ, 1975, PHYS STATUS SOLIDI B, V68, P405 HAGSTRUM HD, 1954, PHYS REV, V96, P336 HAGSTRUM HD, 1961, PHYS REV, V122, P83 HERMAN F, 1963, ATOMIC STRUCTURE CAL IHM J, 1980, PHYS REV B, V21, P4592 MUDA Y, 1980, SURF SCI, V97, P283 MUDA Y, 1988, NUCL INSTRUM METH B, V33, P388 MUDA Y, 1988, PHYS REV B, V37, P7048 PAULING L, 1935, INTRO QUANTUM MECHAN ROBERTS N, 1990, SURF SCI, V236, P112 SOUDA R, 1985, SURF SCI, V150, L59 SOUDA R, 1986, NUCL INSTRUM METH B, V15, P114 SOUDA R, 1986, NUCL INSTRUM METH B, V15, P138 SOUDA R, 1986, SURF SCI, V176, P657 SULSTON KW, 1988, PHYS REV B, V37, P9121 SULSTON KW, 1988, SURF SCI, V197, P555 SULSTON KW, 1989, SURF SCI, V244, P543 WEAKLIEM PC, 1990, SURF SCI, V232, L219 WEISENDANGER R, 1990, SURF SCI, V232, P1; NR: 26; TC: 4; J9: PHYS REV B; PG: 11; GA: HZ245Source type: Electronic(1
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
Measurement of b-hadron masses
No full textMeasurements of b-hadron masses are performed with the exclusive decay modes B +→J/ψK +, B 0→J/ψK +, B0→J/ψKS0, Bs0→J/ψφ and Λb0→J/ψΛ using an integrated luminosity of 35pb -1 collected in pp collisions at a centre-of-mass energy of 7 TeV by the LHCb experiment. The momentum scale is calibrated with J/ψ→μ +μ - decays and verified to be known to a relative precision of 2 ×10 -4 using other two-body decays. The results are more precise than previous measurements, particularly in the case of the Bs0 and Λb0 masses
Measurement of the ZZ production cross section and Z -> l(+)l(-)l '(+)l '(-) branching fraction in pp collisions at root s=13TeV
No full textFour-lepton production in proton-proton collisions, pp -> (Z/gamma*)(Z/gamma*)-> l(+)l(-)l '(+)l '(-), where l,l '(-) = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.6fb(-1). The ZZ production cross section, sigma(pp -> ZZ) = 14.6(-1.8)(+1.9)(stat)(-0.3)(+0.5) (syst) +/-0.2 (theo) +/-0.4 (lumi) pb, is measured for events with two opposite-sign, sameflavor lepton pairs produced in the mass region 60 < m(l+l-) m (l'+l'-) < 120GeV. The Z boson branching fraction to four leptons is measured to be B(Z -> l(+)l(-)l '(+)l '(-)) = 4.9(-0.7)(+0.8)(stat)(-0.2)(+0.3)(syst)(-0.1)(+0.2)(theo) +/- 0.1 (lumi) x10(-6) for the four-lepton invariant mass in the range 80 < m(l+)l-l'+l' < 100GeVand dilepton mass m(l+l-) > 4GeVfor all opposite-sign, same-flavor lepton pairs. The results are in agreement with standard model predictions. (C) 2016 The Author. Published by Elsevier B. V. This is an open access article under the CC BY licens
Shake table test response of large-scale bridge columns supported on rocking shallow foundations
No full textThis paper presents the results of a series of large-scale shake table tests of bridge columns supported on rocking foundations. The tests took place at the NEES@UCSD facility in May 2013. Two one-third scale specimens of bridge piers were built and tested; one was aligned with the uniaxial direction of shaking and the other was placed on a skew configuration. They were placed inside a large confining soil box with 3.4 m height of well compacted clean sand at 90% relative density which weighed 2.5 MN. The columns were designed to remain elastic and support a weight of 235 kN each. Three series of tests were performed; (a) one with no underground water, (b) a second with the water level 1.2 m below the footings, and (c) a third with the water level 0.6 m below the footing. The test protocol included up to six historical near fault ground motions of increasing intensity which resulted in drift ratios of the columns up to 13.8%. The specimens sustained drift ratios up to 6.9%, corresponding to the level of demand expected for the Maximum Considered Earthquake, with small residual drifts and no structural damage. Key experimental responses are presented
Angular distributions in the decay B -> K*l(+)l(-)
No full textWe use a sample of 384 X 10(6) B (B) over bar events collected with the BABAR detector at the PEP-II e(+)e(-) collider to study angular distributions in the rare decays B -> K(*)l(+)l(-), where l(+)l(-) is either e(+)e(-) or mu(+)mu(-). For low dilepton invariant masses, m(ee) 3.2 GeV/c(2), we measure A(FB) = 0.76(-0.32)(+0.52) +/- 0.07 F-L = 0.71(-0.22)(+0.20) +/- 0.04
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