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 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/[psi][pi][sup+][pi][sup -]. The data set contains approximately 56 million B[bar B] pairs produced at the[Upsilon](4S) resonance and recorded with the BABAR detector at the PEP-II asymmetric-energy e[sup+]e[sup -] storage ring. The result of this analysis is[Beta](B[sup 0][yields] J/[psi][pi][sup+][pi][sup -])= (4.6[+-] 0.7[+-] 0.6) x 10[sup -5], where the first error is statistical and the second is systematic. In addition we measure[Beta](B[sup 0][yields] J?[psi][rho][sup 0])= (1.6[+-] 0.6[+-] 0.4) x 10[sup -5].