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].

The authors study the decays B° → J/???− and B+ → J/??+?°, including intermediate resonances, using a sample of 382 million B{bar B} pairs recorded by the BABAR detector at the PEP-II e+e− B factory. They measure the branching fractions?(B° → J/??°) = (2.7 ± 0.3 ± 0.17) x 10−5 and?(B+ → J/??+) = (5.0 ± 0.7 ± 0.31) x 10−5. The authors also set the following upper limits at the 90% confidence level:?(B° → J/??+?− non-resonant)

The authors study the decay B[sup -] [yields] J/[psi]K[sup -][pi][sup +][pi][sup -] using 117 million B[bar B] events collected at the [Upsilon](4S) resonance with the BaBar detector at the PEP-II e[sup +]e[sup -] asymmetric-energy storage ring. They measure the branching fractions [Beta](B[sup -] [yields] J/[psi]K[sup -] [pi][sup +][pi][sup -]) = (116 [+-] 7(stat.) [+-] 9(syst.)) x 10[sup -5] and [Beta](B[sup -] [yields] X(3872)K[sup -]) x [Beta](X(3872) [yields] J/[psi][pi][sup +][pi][sup -]) = (1.28 [+-] 0.41) x 10[sup -5] and find the mass of the X(3872) to be 3873.4 [+-] 1.4MeV/c[sup 2]. They search for the h[sub c] narrow state in the decay B[sup -] [yields] h[sub c] K[sup -], h[sub c] [yields] J/[psi][pi][sup +][pi][sup -] and for the decay B[sup -] [yields] J/[psi]D[sup 0][pi][sup -], with D[sup 0] [yields] K[sup -][pi][sup +]. They set the 90% C.L. limits [Beta](B[sup -] [yields] h[sub c]K[sup -]) x [Beta](h[sub c] [yields] J/[psi][pi][sup +][pi][sup -])

This thesis reports on a measurement of the branching ratio of the Cabibbo-suppressed decay B$+\atop{u}$ 2!J/[Psi][pi]+, where J/[Psi] 2![mu]+[mu]-

The authors measure the branching fractions of the [psi](2S) meson to the leptonic final states e[sup +]e[sup -] and [mu][sup +][mu][sup -] relative to that for [psi](2S) [yields] J/[psi] [pi][sup +][pi][sup -]. The method uses [psi](2S) mesons produced in the decay of B mesons at the [Upsilon](4S) resonance in a data sample collected with the BABAR detector at the Stanford Linear Accelerator Center. Using previous measurements for the [psi](2S) [yields] J/[psi] [pi][sup +][pi][sup -] branching fraction, they determine the e[sup +]e[sup -] and [mu][sup +][mu][sup -] branching fractions to be 0.0078 [+-] 0.0009 [+-] 0.0008 and 0.0067 [+-] 0.0008 [+-] 0.0007 respectively.

We present measurements of the branching fraction and time-dependent CP asymmetries in B{sup 0} {yields} J/{psi}{pi}{sup 0} decays based on (231.8 {+-} 2.6) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. We obtain a branching fraction {Beta}(B{sup 0} {yields} J/{psi}{pi}{sup 0}) = (1.94 {+-} 0.22 (stat) {+-} 0.17 (syst)) x 10{sup -5}. We also measure the CP asymmetry parameters C = -0.21 {+-} 0.26 (stat) {+-} 0.06 (syst) and S = -0.68 {+-} 0.30 (stat) {+-} 0.04 (syst).