Search For Exotic Tau-decays

The Crystal Ball detector at the Doris II storage ring at DESY was used to search for the exotic decay processes tau -> e gamma, tau -> e pi0, tau -> e eta. No signal was observed. We obtained the following 90% CL upper limits on the branching fractions:B(tau -> e gamma)< 2.0x10^(-4),B(tau -> e pi0) < 1.4x10^(-4),B(tau -> e eta) < 2.4x10^(-4)

*Measurement of the Branching Ratios for the Decays Tau->Hadron Pi-0-Nu and Tau->Hadron Pi-0-Pi-0-Nu

Contains fulltext : 29793.pdf (publisher's version ) (Open Access

Data from: High nucleotide diversity and limited linkage disequilibrium in Helicoverpa armigera facilitates the detection of a selective sweep

Insecticides impose extreme selective pressures on populations of target pests and so insecticide resistance loci of these species may provide the footprints of ‘selective sweeps’. To lay the foundation for future genome-wide scans for selective sweeps and inform genome-wide association study designs, we set out to characterize some of the baseline population genomic parameters of one of the most damaging insect pests in agriculture worldwide, Helicoverpa armigera. To this end, we surveyed nine Z-linked loci in three Australian H. armigera populations. We find that estimates of π are in the higher range among other insects and linkage disequilibrium decays over short distances. One of the surveyed loci, a cytochrome P450, shows an unusual haplotype configuration with a divergent allele at high frequency that led us to investigate the possibility of an adaptive introgression around this locus

The Electron Spectrum From B-meson Decays

The Crystal Ball Collaboration has measured the energy spectrum of electrons from semileptonic B meson decays at the e+ e– storage ring DORIS II. Branching ratios and weak mixing angles of the Kobayashi-Maskawa matrix are determined using several models for the hadronic matrix elements. We obtain the branching ratio for semileptonic B decays to charmed states BR(B -> e nu Xc )=(11.7+-0.4+-1.0)%. Our result for the corresponding Kobayashi-Maskawa matrix element is |Vcb |=0.052+-0.006. The model dependence of both results is included in the error. We have not observed semileptonic B decays to non-charmed mesons. Analyzing the measured electron spectrum above 2.4 GeV, where no b->c decays contribute, we find BR(B -> e nu Xu )/BR(B -> e nu Xc )<6.5% at the 90% confidence level.this corresponds to an upper limit |V ub /V cb |