5,928 research outputs found

    First in-beam studies of a Resistive-Plate WELL gaseous multiplier

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    We present the results of the first in-beam studies of a medium size (10×\times10 cm2^2) Resistive-Plate WELL (RPWELL): a single-sided THGEM coupled to a pad anode through a resistive layer of high bulk resistivity (∌\sim109Ω^9 \Omegacm). The 6.2~mm thick (excluding readout electronics) single-stage detector was studied with 150~GeV muons and pions. Signals were recorded from 1×\times1 cm2^2 square copper pads with APV25-SRS readout electronics. The single-element detector was operated in Ne\(5% CH4\mathrm{CH_{4}}) at a gas gain of a few times 104^4, reaching 99%\% detection efficiency at average pad multiplicity of ∌\sim1.2. Operation at particle fluxes up to ∌\sim104^4 Hz/cm2^2 resulted in ∌\sim23%\% gain drop leading to ∌\sim5%\% efficiency loss. The striking feature was the discharge-free operation, also in intense pion beams. These results pave the way towards robust, efficient large-scale detectors for applications requiring economic solutions at moderate spatial and energy resolutions.Comment: Accepted by JINS

    Measurement of the Proton's Neutral Weak Magnetic Form Factor

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    We report the first measurement of the parity-violating asymmetry in elastic electron scattering from the proton. The asymmetry depends on the neutral weak magnetic form factor of the proton which contains new information on the contribution of strange quark-antiquark pairs to the magnetic moment of the proton. We obtain the value GMZ=0.34±0.09±0.04±0.05G_M^Z= 0.34 \pm 0.09 \pm 0.04 \pm 0.05 n.m. at Q2=0.1Q^2=0.1 (GeV/c)2{}^2.Comment: 4 pages TEX, text available at http://www.krl.caltech.edu/preprints/OAP.htm

    Measurement of the vector analyzing power in elastic electron-proton scattering as a probe of double photon exchange amplitudes

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    We report the first measurement of the vector analyzing power in inclusive transversely polarized elastic electron-proton scattering at Q^2 = 0.1 (GeV/c)^2 and large scattering angles. This quantity should vanish in the single virtual photon exchange, plane wave impulse approximation for this reaction, and can therefore provide information on double photon exchange amplitudes for electromagnetic interactions with hadronic systems. We find a non-zero value of A=-15.4+/-5.4 ppm. No calculations of this observable for nuclei other than spin 0 have been carried out in these kinematics, and the calculation using the spin orbit interaction from a charged point nucleus of spin 0 cannot describe these data.Comment: 4 pages, 2 figures, submitted to Phys. Rev. Let

    Going places

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    Journeys. We all make them. Often they take us to exotic places. Sometimes they take us even further. They might take us through time. Or they might take us into a new way of life. There are times too, when we go all over the world and back again only to find that home is, after all, where it’s all happening. This book contains stories about many different types of journey. We hope you will enjoy travelling into it and finding a world that suits you

    Dual Routes from Social Identity to Collective Opposition against Criminal Organisations: Intracultural Appropriation Theory and the roles of Honour Codes and Social Change Beliefs

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    Italian criminal organisations (COs) are a serious global threat. Intracultural Appropriation Theory (ICAT) holds that such groups exploit cultural codes of masculinity and honour to legitimise and lower resistance to their actions. Such codes are an important feature of Southern Italian group membership. A large survey (N = 1173) investigated the role of two previously under-examined facets of honour cultures – personal concerns for reputation, and female honour ideology. In addition, drawing on social identity theory, and testing a dual route hypothesis, this research investigated the role of beliefs about the necessity of social change in the articulation between identification, honour, and collective action intentions. Consistent with ICAT, and with previous research, male-honour related values uniquely predicted collective action intentions against criminal organisations. In addition, consistent with the dual route hypothesis: a) regional identification positively predicted social change beliefs which in turn explained stronger intentions to oppose COs collectively, and, b) regional identification was also positively associated with masculine honour which in turn predicted weaker intentions to oppose COs. The evidence supports the idea that social identity can have opposing effects on collective action in the same context, depending on which beliefs are mobilised

    Lexicality and frequency in specific language impairment: accuracy and error data from two nonword repetition tests

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    Purpose: Deficits in phonological working memory and deficits in phonological processing have both been considered potential explanatory factors in Specific Language Impairment (SLI). Manipulations of the lexicality and phonotactic frequency of nonwords enable contrasting predictions to be derived from these hypotheses. Method: 18 typically developing (TD) children and 18 children with SLI completed an assessment battery that included tests of language ability, non-verbal intelligence, and two nonword repetition tests that varied in lexicality and frequency. Results: Repetition accuracy showed that children with SLI were unimpaired for short and simple high lexicality nonwords, whereas clear impairments were shown for all low lexicality nonwords. For low lexicality nonwords, greater repetition accuracy was seen for nonwords constructed from high over low frequency phoneme sequences. Children with SLI made the same proportion of errors that substituted a nonsense syllable for a lexical item as TD children, and this was stable across nonword length. Conclusions: The data show support for a phonological processing deficit in children with SLI, where long-term lexical and sub-lexical phonological knowledge mediate the interpretation of nonwords. However, the data also suggest that while phonological processing may provide a key explanation of SLI, a full account is likely to be multi-faceted
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