5 research outputs found
Measurements of b → sγ Decays at BABAR
Get PDFWe present measurements of the Branching Fraction and photon energy spectrum in
b → X_sγ decays in a sample of 89 million BB[overbar] pairs collected at the BABAR detector at Stanford
Linear Accelerator Center's PEP-II asymmetric B-factory. Results from a fully-inclusive and a sum
of 38 exclusive final states techniques are presented and found to be consistent with the Standard
Model calculations, as well as experimental results obtained from semileptonic b → X_clv decays
Search for B → (ρ/ω)γ decays at BABAR
Get PDFWe present the results of the search for the decays ß(0/±) ? ?(0/±)? (previously observed) and ß0 ? ?? (for which currently only an upper limit exists). Together with ß ? K*? decays, B ? (?/?)? allow us to measure the ratio of CKM-matrix elements |Vtd/Vts|. The analysis is based on the full BaBar dataset of 424.35 fb-1, corresponding to 465 million BB pairs, and makes heavy use of multivariate classification techniques based on decision trees. We find ßR(B ? ?±? ) = (1.20+0.42-0.38±0.20)×10-6, ßR(B ? ?0?)= (0.95+0.23-0.21 ±0.06)×10-6, and ßR(B ? ??)=(0.51+0.27-0.24±0.10)×10-6, where the first error is statistical and the second is systematic. We do not observe a statistically significant signal in the latter channel and set an upper limit at ßR(B ? ??) < 0.9 × 10-6 (90% C.L.). We also measure the isospin and SU(3)F violating quantities ?(B+ ? ?+?)/2?(B0 ? ?0?) - 1 = -0.43+0.25-0.22±0.10 and ?(B ? ??)/?(B0 ? ?0?) - 1 = -0.49+0.30-0.27±0.10.</p
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Search for B to rho/omega gamma decays at BaBar
No full textThe authors present the results of the search for the decays B{sup 0/{+-}} {yields} {rho}{sup 0/{+-}}{gamma} (previously observed) and B{sup 0} {yields} {omega}{gamma} (for which currently only an upper limit exists). Together with B {yields} K*{gamma} decays, B {yields} ({rho}/{omega}){gamma} allow us to measure the ratio of CKM-matrix elements |V{sub td}/V{sub ts}|. The analysis is based on the full BABAR dataset of 424.35 fb{sup -1} corresponding to 465 million B{bar B} pairs, and makes heavy use of multivariate classification techniques based on decision trees. They find {Beta}(B{sup {+-}} {yields} {rho}{sup {+-}}{gamma}) = (1.20{sub -0.38}{sup +0.42} {+-} 0.20) x 10{sup -6}, {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) = (0.95{sub -0.21}{sup +0.23} {+-} 0.06) x 10{sup -6}, {Beta}(B{sup 0} {yields} {omega}{gamma}) = (0.51{sub -0.24}{sup +0.27} {+-} 0.10) x 10{sup -6}, where the first error is statistical and the second is systematic. They do not observe a statistically significant signal in the latter channel and set an upper limit at {Beta}(B{sup 0} {yields} {omega}{gamma}) < 0.9 x 10{sup -6} (90% C.L.). They also measure the isospin and SU(3){sub F} violating quantities {Lambda}(B{sup +} {yields} {rho}{sup +}{gamma})/2{Lambda}(B{sup 0} {yields} {rho}{sup 0}{gamma})-1 = -0.43{sub -0.22}{sup +0.25} {+-} 0.10 and {Lambda}(B{sup 0} {yields} {omega}{gamma})/{Lambda}(B{sup 0} {yields} {rho}{sup 0}{gamma})-1 = -0.49{sub -0.27}{sup +0.30} {+-} 0.10
Measurement of Time-dependent CP-Violating Asymmetries in Decays
No full text15 pages, 4 postscript figures. Submitted to International Europhysics Conference On High-Energy Physics (HEP 2005), Lisbon, Portugal Added one author, added references, changed two plotsWe present preliminary measurements of the CP asymmetry parameters in B^0 -> K^0_S K^0_S K^0_S decays, reconstructing two of the K^0_S into pi^+pi^- and one into pi^0pi^0. In a sample of 227M pairs collected by the BABAR detector at the PEP-II B-Factory at SLAC, we find the CP parameters to be S = -0.25^{+0.68}_{-0.61} (stat) +/- 0.05 (syst) and C = 0.56^{+0.34}_{-0.43} (stat) +/- 0.04 (syst). Combining this result with the previous BABAR measurement, obtained from events with three K^0_S decaying into pi^+pi^-, we get S = -0.63^{+0.32}_{-0.28} (stat) +/- 0.04(syst) C = -0.10 +/- 0.25 (stat) +/- 0.05 (syst
