Branching Fractions and CP Asymmetries in B ---] H+ Hh'-


Book Description

Relative branching fractions of B{sub d, s} {yields} h{sup +}h'{sup -} decays (where h, h' = K or {pi}) and direct CP asymmetry in B{sub d} {yields} K{sup +}{pi}{sup -} have been measured with 180 pb{sup -1} of data collected by the CDFII detector at the Tevatron collider. This includes the first BR measurement of a charmless B{sub s} {yields} PP decay (B{sub s} {yields} K{sup +}K{sup -}).



















Measurement of Branching Fractions and CP-Violating Asymmetries in B0 {u2192} K0$\bar{K}$0 and B+ to $\bar{K}$0K+ Decays at the BaBar Experiment


Book Description

Over the last few years, the B factories have established the Cabbibo-Kobayashi-Maskawa mechanism of CP violation in the Standard Model through the study of the decays of B mesons. The focus of Belle and BaBar has now expanded to the search for signatures of new physics beyond the Standard Model, particularly through examination of flavor-changing neutral-current transitions, which proceed through diagrams involving virtual loops. These decays are suppressed in the Standard Model, increasing sensitivity to new-physics effects but decreasing branching fractions. Exploiting large and growing datasets, BaBar and Belle have made many measurements in loop decays where a b quark transitions to an s quark, observing hints of possible deviations from Standard Model expectations in CP-violating measurements.




Measurement of CP Asymmetries and Branching Fractions in B0 -] Pi+ Pi-, B0 -] K+ Pi-, B0 -] Pi0 Pi0, B0 -] K0 Pi0 and Isospin Analysis of B -] Pi Pi Decays


Book Description

The authors present preliminary results of improved measurements of the CP-violating asymmetries and branching fractions in the decays B° →??−, B° → K+?−, B° →?°?°, and B° → K°?°. This update includes all data taken at the?(4S) resonance by the BABAR experiment at the asymmetric PEP-II B-meson factory at SLAC, corresponding to 467 ± 5 million B{bar B} pairs. They find S{sub??} = -0.68 ± 0.10 ± 0.03, C{sub??} = -0.25 ± 0.08 ± 0.02,?{sub K{sub?}} = -0.107 ± 0.016{sub -0.004}, {sup +0.006}, C{sub?°?°} = -0.43 ± 0.26 ± 0.05,?(B° →?°?°) = (1.83 ± 0.21 ± 0.13) x 10−6,?(B° → K°?°) = (10.1 ± 0.6 ± 0.4) x 10−6, where the first error is statistical and the second is systematic. They observe CP violation with a significance of 6.7? in B° → {pi}− and 6.1? in B° → K+{pi}−. Constraints on the Unitarity Triangle angle? are determined from the isospin relation between all B → {pi}{pi} rates and asymmetries.




Measurement of CP Asymmetries and Branching Fractions in Charmless Two-Body B-Meson Decays to Pions and Kaons


Book Description

We present improved measurements of CP-violation parameters in the decays B° →??−, B° → K+?−, and B° →?°?°, and of the branching fractions for B° →?°?° and B° → K°?°. The results are obtained with the full data set collected at the?(4S) resonance by the BABAR experiment at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory, corresponding to 467 ± 5 million B{bar B} pairs. We find the CP-violation parameter values and branching fractions S{sub?+?−} = -0.68 ± 0.10 ± 0.03, C{sub?+?−} = -0.25 ± 0.08 ± 0.02,?{sub K−?+} = -0.107 ± 0.016{sub -0.004}{sup +0.006}, C{sub?°?°} = -0.43 ± 0.26 ± 0.05,?(B° →?°?°) = (1.83 ± 0.21 ± 0.13) x 10−6,?(B° → K0?°) = (10.1 ± 0.6 ± 0.4) x 10−6, where in each case, the first uncertainties are statistical and the second are systematic. We observe CP violation with a significance of 6.7 standard deviations for B° →?+?− and 6.1 standard deviations for B° → K+{pi}{sup -}, including systematic uncertainties. Constraints on the Unitarity Triangle angle? are determined from the isospin relations among the B → {pi}{pi} rates and asymmetries. Considering only the solution preferred by the Standard Model, we find? to be in the range [71{sup o}, 109{sup o}] at the 68% confidence level.