1,575 research outputs found
The role of -induced reactions on lead and iron in neutrino detectors
We have calculated cross sections and branching ratios for neutrino induced
reactions on ^{208}Pb and ^{56}Fe for various supernova and
accelerator-relevant neutrino spectra. This was motivated by the facts that
lead and iron will be used on one hand as target materials in future neutrino
detectors, on the other hand have been and are still used as shielding
materials in accelerator-based experiments. In particular we study the
inclusive ^{56}^{56}Co and ^{208}^{208}Bi cross
sections and calculate the neutron energy spectra following the decay of the
daughter nuclei. These reactions give a potential background signal in the
KARMEN and LSND experiment and are discussed as a detection scheme for
supernova neutrinos in the proposed OMNIS and LAND detectors. We also study the
neutron-emission following the neutrino-induced neutral-current excitation of
^{56}Fe and ^{208}Pb.Comment: 23 pages (including 7 figures
Muon capture on nuclei with N > Z, random phase approximation, and in-medium renormalization of the axial-vector coupling constant
We use the random phase approximation to describe the muon capture rate on
Ca,Ca, Fe, Zr, and Pb. With
Ca as a test case, we show that the Continuum Random Phase
Approximation (CRPA) and the standard RPA give essentially equivalent
descriptions of the muon capture process. Using the standard RPA with the free
nucleon weak form factors we reproduce the experimental total capture rates on
these nuclei quite well. Confirming our previous CRPA result for the
nuclei, we find that the calculated rates would be significantly lower than the
data if the in-medium quenching of the axial-vector coupling constant were
employed.Comment: submitted to Phys. Rev.
The role of market orientation and innovation capability in export performance of small-and medium-sized enterprises: a Latin American perspective
Purpose - This study aims to extend the existing base of knowledge of proactive and reactive market orientation and innovation capability by testing their impact on the export performance of emerging-market small- and medium-sized enterprises (SMEs) in a Latin American context. Design/methodology/approach - This paper is a replication study, and its data were collected through a survey answered by general, marketing, sales or export managers at 155 Mexican SMEs. The research model was tested using partial least squares. Findings - The study results indicate that innovation capability and reactive market orientation are drivers of export performance in Latin American SMEs. Moreover, proactive market orientation has been found to have an indirect effect on export results. Practical implications - This study highlights to managers of Latin American SMEs the importance of capability development and deployment to improve export performance. Social implications - SMEs enabled by strategic and technological innovation based on current and latent customer needs can advantageously perform in foreign markets and can drive economic growth and social and human development in Latin America. Originality/value - Recent studies have focused on emerging-market enterprises and the necessity of developing dynamic capabilities to achieve internationalisation. This study extends previous research by assessing the robustness and generalizability of drivers in export performance for manufacturing SMEs in Latin America. In particular, it provides empirical insights on the capabilities to develop by Latin American SMEs to achieve better export performance
Signal for supernova and neutrinos in water \v{C}erenkov detectors
We suggest that photons with energies between 5 and 10 MeV, generated by the
() and () reactions on O, constitute a
signal which allows a unique identification of supernova and
neutrinos in water \v{C}erenkov detectors. We calculate the yield of
such events and estimate that a few hundred of them would be detected
in Superkamiokande for a supernova at 10 kpc distance.Comment: 8 pages, RevTex 3.0, figures and text available at
http://www.krl.caltech.edu/preprints/MAP.htm
Neutrino induced transitions between the ground states of the A=12 triad
Neutrino induced reactions on C, an ingredient of liquid
scintillators, have been studied in several experiments. We show that for
currently available neutrino energies, 300 MeV, calculated
exclusive cross sections CN for both muon
and electron neutrinos are essentially model independent, provided the
calculations simultaneously describe the rates of several other reactions
involving the same states or their isobar analogs. The calculations agree well
with the measured cross sections, which can be therefore used to check the
normalization of the incident neutrino spectrum and the efficiency of the
detector.Comment: 9 pages REVTEX, 2 postscript figures, text and figures available at
http://www.krl.caltech.edu/preprints/MAP.htm
Monitoring surface resonances on Co2MnSi(100) by spin-resolved photoelectron spectroscopy
The magnitude of the spin polarization at the Fermi level of ferromagnetic
materials at room temperature is a key property for spintronics. Investigating
the Heusler compound CoMnSi a value of 93 for the spin polarization has
been observed at room temperature, where the high spin polarization is related
to a stable surface resonance in the majority band extending deep into the
bulk. In particular, we identified in our spectroscopical analysis that this
surface resonance is embedded in the bulk continuum with a strong coupling to
the majority bulk states. The resonance behaves very bulk-like, as it extends
over the first six atomic layers of the corresponding (001)-surface. Our study
includes experimental investigations, where the bulk electronic structure as
well as surface-related features have been investigated using spin-resolved
photoelectron spectroscopy (SR-UPS) and for a larger probing depth
spin-integrated high energy x-ray photoemission spectroscopy (HAXPES). The
results are interpreted in comparison with first-principles band structure and
photoemission calculations which consider all relativistic, surface and
high-energy effects properly.Comment: 9 pages, 8 figures, Heusler alloy, electronic structure and
photoemissio
Meta‐analytic structural equation modeling made easy: A tutorial and web application for one‐stage MASEM
Meta‐analytic structural equation modeling (MASEM) refers to fitting structural equation models (SEMs) (such as path models or factor models) to meta‐analytic data. Currently, fitting MASEMs may be challenging for researchers that are not accustomed to working with R software and packages. Therefore, we developed webMASEM; a web application for MASEM. This app implements the one‐stage MASEM approach, and allows users to apply MASEM in a user‐friendly way. The aim of this article is to provide a tutorial on one‐stage MASEM and a practical guide to webMASEM. We will pay specific attention to how the data should be structured and prepared for webMASEM, because mistakes in this step may lead to faulty results without receiving an error message. The use of webMASEM is illustrated with an analysis of a meta‐analytic path model in which the path coefficients are moderated by a study‐level variable, a meta‐analytic factor model in which the factor loadings are moderated by a study‐level variable, and a meta‐analytic panel model in which the effects are moderated by a study‐level variable. All used datafiles and R scripts are available online
Political Reality: Attack Ads are Here to Stay
The primary research questions of this study center on two largely overlooked areas in negative political advertising: (1) Would the sponsor of the attack ad message be better off with a positive message? (2) When one is targeted by an attack ad, how should the attacked candidate respond? M-Turk subjects (n = 1,380) were used to conduct a multi-stage experimental design to capture the dynamic aspects of how subjects react to the use of attack ads in a hypothetical political campaign. In general, subjects did not respond favorably to attack ads, as these negative political messages caused damage to the image of both the attacker and the attacked. However, it was found that attack ads did cause greater harm to the evaluations of the attacked candidate than to the attacker. Positive ads offered in response to an attack ad helped the attacked candidate recover, whereas negative counter ads, when executed in response to an attack ad, inflicted greater damage to the attacked than the attacker. Suggestions for future research are offered in this highly relevant area of political campaigning
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