28 research outputs found
A Parton Model for Inclusive Semileptonic B Meson Decays
The parton model for semileptonic B meson decays is studied with special
attention to the decay distributions. We find that the spectra show dramatic
variations when we introduce cuts on the hadronic energy or invariant mass of
hadrons. Results for both and decays are
presented. The detailed spectra may help to separate the two types of decays.Comment: 9 pages, DO-TH 93/29, OHSTPY-HEP-T-93-011, September 199
Probing for the Charm Content of and Mesons
A slow bump exists in the inclusive spectrum,
while the softness of spectrum in decay
is in strong contrast with expectations from color octet mechanism. We propose
{\it intrinsic} charm as the explanation:the former is due to ,with three charm quarks in the final state; the latter is just a small
fraction of "jet" events, where the
slow moving system evolves into pairs. Experimental search
for these phenomena at B Factories and the Tevatron is strongly urged, as the
implications go beyond QCD.Comment: 4 pages, REVTEX, 10 eps figures included. Major revision with more
discussions on the rescattering background, and a reappraisal of the
Upsilon(1S) decay in the presence of intrinsic charm, leading to a change in
Titl
Integrating sequence and array data to create an improved 1000 Genomes Project haplotype reference panel
A major use of the 1000 Genomes Project (1000GP) data is genotype imputation in genome-wide association studies (GWAS). Here we develop a method to estimate haplotypes from low-coverage sequencing data that can take advantage of single-nucleotide polymorphism (SNP) microarray genotypes on the same samples. First the SNP array data are phased to build a backbone (or 'scaffold') of haplotypes across each chromosome. We then phase the sequence data 'onto' this haplotype scaffold. This approach can take advantage of relatedness between sequenced and non-sequenced samples to improve accuracy. We use this method to create a new 1000GP haplotype reference set for use by the human genetic community. Using a set of validation genotypes at SNP and bi-allelic indels we show that these haplotypes have lower genotype discordance and improved imputation performance into downstream GWAS samples, especially at low-frequency variants. © 2014 Macmillan Publishers Limited. All rights reserved