Download or read book A Measurement of the B0 --] J/psi Pi+pi- Branching Fraction written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the branching fraction for the decay of the neutral B meson into the final state J/???−. The data set contains approximately 56 million B{bar B} pairs produced at the?(4S) resonance and recorded with the BABAR detector at the PEP-II asymmetric-energy e+e− storage ring. The result of this analysis is?(B ° → J/??+?−) = (4.6 ± 0.7 ± 0.6) x 10−5, where the first error is statistical and the second is systematic. In addition we measure?(B° → J???°) = (1.6 ± 0.6 ± 0.4) x 10−5.