28 research outputs found

    New Constraints (and Motivations) for Abelian Gauge Bosons in the MeV-TeV Mass Range

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    We survey the phenomenological constraints on abelian gauge bosons having masses in the MeV to multi-GeV mass range (using precision electroweak measurements, neutrino-electron and neutrino-nucleon scattering, electron and muon anomalous magnetic moments, upsilon decay, beam dump experiments, atomic parity violation, low-energy neutron scattering and primordial nucleosynthesis). We compute their implications for the three parameters that in general describe the low-energy properties of such bosons: their mass and their two possible types of dimensionless couplings (direct couplings to ordinary fermions and kinetic mixing with Standard Model hypercharge). We argue that gauge bosons with very small couplings to ordinary fermions in this mass range are natural in string compactifications and are likely to be generic in theories for which the gravity scale is systematically smaller than the Planck mass - such as in extra-dimensional models - because of the necessity to suppress proton decay. Furthermore, because its couplings are weak, in the low-energy theory relevant to experiments at and below TeV scales the charge gauged by the new boson can appear to be broken, both by classical effects and by anomalies. In particular, if the new gauge charge appears to be anomalous, anomaly cancellation does not also require the introduction of new light fermions in the low-energy theory. Furthermore, the charge can appear to be conserved in the low-energy theory, despite the corresponding gauge boson having a mass. Our results reduce to those of other authors in the special cases where there is no kinetic mixing or there is no direct coupling to ordinary fermions, such as for recently proposed dark-matter scenarios.Comment: 49 pages + appendix, 21 figures. This is the final version which appears in JHE

    Two-Body B Meson Decays to η\eta and η\eta^{'} -- Observation of BηB\to \eta{'}K$

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    In a sample of 6.6 million produced B mesons we have observed decays B -> eta' K, with branching fractions BR(B+ -> eta' K+ = 6.5 +1.5 -1.4 +- 0.9) x 10510^{-5} and BR(B0 -> eta' K0 = 4.7 +2.7 -2.0 +- 0.9) x 10510^{-5}. We have searched with comparable sensitivity for 17 related decays to final states containing an eta or eta' meson accompanied by a single particle or low-lying resonance. Our upper limits for these constrain theoretical interpretations of the B -> eta' K signal.Comment: 12 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

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    Attorneys' Questions and Children's Productivity in Child Sexual Abuse Criminal Trials

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    Summary: We investigated the links between questions child witnesses are asked in court, children’s answers, and case outcome. Samples of acquittals and convictions were matched on child age, victim–defendant relationship, and allegation count and severity. Transcripts were coded for question types, including a previously under-examined type of potentially suggestive question, declarative questions. Children’s productivity was conceptualized in a novel way by separating new from repeated content and by adjusting the definition based on the linguistic demands of the questions. Attorneys frequently used declarative questions, and disconcertingly, attorneys who used these and other suggestive questions more frequently were more likely to win their case. Open-ended and closed-ended questions elicited similar levels of productivity from children, and both elicited more productivity compared with suggestive questions. Results highlight how conceptualization of questions and answers can influence conclusions, and demonstrate the important real-world implications of attorney questioning strategies on legal cases with child witnesses Copyright © 2014 John Wiley & Sons, Ltd. Legal cases involving alleged child sexual abuse have received massive media coverage in the USA and abroad over the last several decades (see, e.g., Britton, 2004; Commonwealth v. Sandusky in Drape, 2012; Levs & Dolan, 2012; Paulson, 2002; State v. Buckey, 1990). This attentio
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