Observation of the Bc+ → J/ψπ+π0 decay

The first observation of the Bc+→J/ψπ+π0 decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of 9 fb−1, collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV. The ratio of its branching fraction relative to the Bc+→J/ψπ+ channel is measured to beBBc+→J/ψπ+π0BBc+→J/ψπ+=2.80±0.15±0.11±0.16, where the first uncertainty is statistical, the second systematic and the third related to imprecise knowledge of the branching fractions for B+ → J/ψK*+ and Bc+→J/ψπ+ decays, which are used to determine the π0 detection efficiency. The π+π0 mass spectrum is found to be consistent with the dominance of an intermediate ρ+ contribution in accordance with a model based on QCD factorisation

Cosmid contig and cDNA map of the human chromosome 13q14 region frequently lost in B-cell chronic lymphocytic leukemia

We constructed a fine physical map of human chromosome 13q14 region between D13S1168 and D13S25 loci consisting of cosmid and cDNA clones. This interval had been shown to be in the center of the genome region frequently lost in a human blood malignancy known as B-cell chronic lymphocytic leukemia (BCLL), Mapping of the genome region is a step in searching for a putative tumor suppressor gene for BCLL. A chr13-specific cosmid library (LA13NC01) was screened with four YAC and seven WI-STS markers belonging to the above 13q14 interval, yielding a cosmid subset of more than 400 clones representing the region. Cosmids between D13S1168 and D13S25 loci were arranged in contigs. Seven different clones were found in cDNA libraries by hybridization screening with YAC ICRF66c1 and two cosmids covering the D13S319 locus, which is the central point for BCLL-associated deletions, The cDNA clones were mapped against the contigous cosmids