25 research outputs found

    Penguins leaving the pole: bound-state effects in B decaying to K* + photon

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    Applying perturbative QCD methods recently seen to give a good description of the two body hadronic decays of the B meson, we address the question of bound-state effects on the decay B into K* + gamma. Consistent with most analyses, we demonstrate that gluonic penguins, with photonic bremsstrahlung off a quark, change the decay rate by only a few percent. However, explicit off-shell b-quark effects normally discarded are found to be large in amplitude, although in the standard model accidents of phase minimize the effect on the rate. Using an asymptotic distribution amplitude for the K* and just the standard model, we can obtain a branching ratio of a few times 10^{-5}, consistent with the observed rate.Comment: 12 pages. U. of MD PP \#94-129; DOE/ER/40762-033; WM-94-104. LaTeX, One figure, available by fax or pos

    Exact Theorems Concerning CP and CPT Violations in C=-1 Entangled State of Pseudoscalar Neutral Mesons

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    Neutral pseudoscalar mesons in an entangled or Einstein-Podolsky-Rosen state are routinely produced in phi and B factories. Based on the peculiar properties of an entangled state, we present some general exact theorems about parameters characterizing CP and CPT violations, by using various asymmetries defined for the correlated decays of the two entangled mesons, which are rigorously calculated.Comment: 10 pages, published versio

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
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