205 research outputs found
Measurement of the branching fraction for
We present a measurement of the branching fraction for the decay B- --> D0 K*- using a sample of approximately 86 million BBbar pairs collected by the BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the K*- through its decay to K0S pi-. We measure the branching fraction to be B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}
Observation of a significant excess of events in B meson decays
We present an observation of the decay based on a sample of 124 million pairs recorded by the BABAR detector at the PEP-II asymmetric-energy Factory at SLAC. We observe events, where the first error is statistical and the second is systematic, corresponding to a significance of 4.2 standard deviations including systematic uncertainties. We measure the branching fraction \BR(B^{0} \to \pi^{0} \pi^{0}) = (2.1 \pm 0.6 \pm 0.3) \times 10^{-6}, averaged over and decays
Observation of the Decay B=> J/psi eta K and Search for X(3872)=> J/psi eta
We report the observation of the meson decay
and evidence for the decay , using {90} million
events collected at the \ensuremath{\Upsilon{(4S)}}\xspace resonance
with the detector at the PEP-II asymmetric-energy storage
ring. We obtain branching fractions of )= and
)=. We search for the new narrow mass state, the
X(3872), recently reported by the Belle Collaboration, in the decay B^\pm\to
X(3872)K^\pm, X(3872)\to \jpsi \eta and determine an upper limit of
(B^\pm \to X(3872) K^\pm \to \jpsi \eta K^\pm)
at 90% C.L.Comment: 7 pages and two figures, submitted to Phys. Rev. Lett
Measurement of B-0 -> D-s(*)D+*(-) branching fractions and B-0 -> D-s*D+*(-) polarization with a partial reconstruction technique
We present a study of the decays B-0 --> D-s((*)) D*-, using 20.8 fb(-1) of e(+)e(-) annihilation data recorded with the BABAR detector. The analysis is conducted with a partial reconstruction technique, in which only the D-s((*)+) and the soft pion from the D*- decay are reconstructed. We measure the branching fractions B(B-0 --> Ds+D*-) = (1.03 +/- 0.14 +/- 0.13 +/- 0.26)% and B(B-0 --> D-s(*+) D*-) = (1.97 +/- 0.15 +/- 0.30+/- 0.49)%, where the first error is statistical, the second is systematic, and the third is the error due to the D-s(+) --> phipi(+) branching fraction uncertainty. From the B-0 --> D-s(*+) D*- angular distributions, we measure the fraction of longitudinal polarization Gamma(L)/Gamma = (51.9 +/- 5.0 +/- 2.8)%, which is consistent with theoretical predictions based on factorization
Search for the radiative decays B ->rho gamma and B-0 ->omega gamma
A search of the exclusive radiative decays B-->rho(770)gamma and B-0-->omega(782)gamma is performed on a sample of about 84x10(6) B (B) over bar events collected by the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) storage ring. No significant signal is seen in any of the channels. We set upper limits on the branching fractions B of B(B-0-->rho(0)gamma)rho(+)gamma)omegagamma)rhogamma)=Gamma(B+-->rho(+)gamma)=2xGamma(B-0-->rho(0)gamma), we find the combined limit B(B-->rhogamma)rhogamma)/B(B-->K(*)gamma)<0.047 at 90% C.L
Search for D-0-(D)over-bar(0) mixing and a measurement of the doubly Cabibbo-suppressed decay rate in D-0 -> K pi decays
We present results of a search for D-0-(D) over bar (0) mixing and a measurement of R-D, the ratio of doubly Cabibbo-suppressed decays to Cabibbo-favored decays, using D-0-->K(+)pi(-) decays from 57.1 fb(-1) of data collected near roots=10.6 GeV with the BABAR detector at the PEP-II collider. At the 95% confidence level, allowing for CP violation, we find the mixing parameters x('2)<0.0022 and -0.056<y(')<0.039, and the mixing rate R-M<0.16%. In the limit of no mixing, R-D=[0.357+/-0.022(stat)+/-0.027(syst)]% and the CP-violating asymmetry A(D)=0.095+/-0.061(stat)+/-0.083(syst)
Measurement of the branching fraction for B±→χc0K±
We present preliminary results for the measurement of the branching fraction of the decay B+- -> chi_c0 K+- from a sample of 75 million BB pairs collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The chi_c0 meson is reconstructed through its two-body decays to pi+ pi- and K+ K-. We measure BR(B+- -> chi_c0 K+-) * BR(chi_c0 -> pi+ pi-) = (1.08 +- 0.35 (stat) +- 0.10 (syst))*10^-6 and BR(B+- -> chi_c0 K+-) * BR(chi_c0 -> K+ K-) = (1.48 +- 0.44 (stat) +- 0.17 (syst)) * 10^-6. Using the known values for the chi_c0 decays branching fractions, we combined these results to obtain BR(B+- -> chi_c0 K+-) = (2.4 +- 0.7) * 10^-4
Measurement of time-dependent CP asymmetries and constraints on sin(2 beta+gamma) with partial reconstruction of B-0 -> D-*-/+pi(+/-) decays
We present a measurement of time-dependent CP-violating asymmetries in decays of neutral B mesons to the final states D(*-/+)pi(+/-), using approximately 82x10(6) B (B) over bar events recorded by the BABAR experiment at the PEP-II e(+)e(-) storage ring. Events containing these decays are selected with a partial reconstruction technique, in which only the high-momentum pi(+/-) from the B decay and the low-momentum pi(-/+) from the D*-/+ decay are used. We measure the amplitude of the asymmetry to be -0.063+/-0.024(stat)+/-0.014(syst) and compute bounds on \sin(2beta+gamma)\
Measurement of the branching fractions and CP asymmetry of B- -> (D(CP)K-)-K-0 decays with the BaBar detector
We present a study of B--->(DCPK-)-K-0 decays, where D-CP(0) is reconstructed in CP-even channels, based on a sample of 88.8x10(6) Y(4S)-->B (B) over bar decays collected with the BABAR detector at the PEP-II e(+)e(-) storage ring. We measure the ratio of Cabibbo-suppressed to Cabibbo-favored branching fractions B(B--->(DCPK-)-K-0)/B(B--->D(CP)(0)pi(-))=[8.8+/-1.6(stat)+/-0.5(syst)]x10(-2) and the CP asymmetry A(CP)=0.07+/-0.17(stat)+/-0.06(syst). We also measure B(B--->(DK-)-K-0)/B(B--->D(0)pi(-))=[8.31+/-0.35(stat)+/-0.20(syst)]x10(-2) using a sample of 61.0x10(6) B (B) over bar pairs
Measurements of branching fractions and dalitz distributions for B-0 ->(DK0)-K-(*)+/-pi(-/+) decays
We present measurments of the branching fractions for the three-body decays B-0 -> D((*) -/+)K(0)pi(+/-) and their resonant submodes B0 -> D(*)K-/+*(+/-) usinga sample of approximately 88 x 10(6) B (B) over bar pairs collected by the BABER detector at the SLAC PEP-II assymetric energy storage ring. We measure: B(B-0-> D(-/+)K(0)pi(+/-)) = (4.9 +/- 0.7(stat) +/- 0.5(syst)) x 10(-4), B(B-0 -> D*(-/+)K(0)pi(+/-)) = (3.0 +/- 0.7(stat) +/- 0.3(syst)) x 10(-4), B(B-0 -> D-/+K*(+/-)) = (4.6 +/- 0.6(stat) +/- 0.5(syst)) x 10(-4), B(B-0 -> D*K-/+*(+/-) = (3.2 +/- 0.6(stat) +/- 0.3(syst)) x 10(-4). From these measurements we determine the fractions of resonant events to be f(B0 -> D+/-K*(-/+)) = 0.63 +/- 0.08(stat) +/- 0.04(syst) and f(B-0 -> D*K-/+*(+/-)) = 0.72 +/- 0.14(stat) +/- 0.05(syst)
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