Bound on the ratio of decay amplitudes for -B0-->J/psiK*0 and B0-->J/psiK*0.

We have measured the time-dependent decay rate for the process B-->J/psiK(*0) (892) in a sample of about 88x10(6) Upsilon(4S)-->B(-)B decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. In this sample we study flavor-tagged events in which one neutral B meson is reconstructed in the J/psiK(*0) or J/psi(-)K(*0) final state. We measure the coefficients of the cosine and sine terms in the time-dependent asymmetries for J/psiK(*0) and J/psi(-)K(*0), find them to be consistent with the standard model expectations, and set upper limits at 90% confidence level (C.

Search for B0 decays to invisible final states and to nunugamma.

We establish upper limits on branching fractions for B0 decays to final states where the decay products are purely invisible (i.e., no observable final state particles) and for B0 decays to nunugamma.

Measurement of the time-dependent CP asymmetry in the B0-->phiK0 decay.

We present a measurement of the time-dependent CP asymmetry for the neutral B-meson decay B0-->phiK0. We use a sample of approximately 114 x 10(6) B-meson pairs taken at the Upsilon(4S) resonance with the BABAR detector at the PEP-II B-meson factory at SLAC. We reconstruct the CP eigenstates phiK0S and phiK0L, where phi-->K+K-, K0S-->pi+pi-, and K0L is observed via its hadronic interactions.

Measurement of the direct CP asymmetry in b-->s gamma Decays.

We describe a measurement of the direct CP asymmetry between inclusive b-->s gamma and b-->s gamma decays. This asymmetry is expected to be less than 0.01 in the standard model, but could be enhanced up to about 0.

Observation of the decay B-->J/psietaK and search for X(3872)-->J/psieta.

We report the observation of the B meson decay B+/- -->J/psietaK+/- and evidence for the decay B0-->J/psietaK0S, using 90 x 10(6) BB; events collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC PEP-II e+e- asymmetric-energy storage ring. We obtain branching fractions of B(B+/- -->J/psietaK+/-) = [10.8 +/- 2.

Measurement of branching fractions and charge asymmetries in B+/--->rho+/-pi0 and B+/--->rho0pi+/- decays, and search for B0-->rho0pi0.

We present measurements of branching fractions and charge asymmetries in B-meson decays to rho(+)pi(0), rho(0)pi(+), and rho(0)pi(0). The data sample comprises 89x10(6) Upsilon(4S)-->BBmacr; decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find the charge-averaged branching fractions B(B+-->rho(+)pi(0))=[10.

Study of high momentum eta' production in B --> eta'Xs.

We measure the branching fraction for the charmless semi-inclusive process B --> eta'Xs, where the eta' meson has a momentum in the range 2.0 to 2.7 GeV/c in the upsilon4S center-of-mass frame and Xs represents a system comprising a kaon and zero to four pions.

Search for the rare leptonic decay B+-->mu(+)nu(mu).

We have performed a search for the rare leptonic decay B+-->mu(+)nu(mu) with data collected at the Upsilon(4S) resonance by the BABAR experiment at the PEP-II storage ring. In a sample of 88.4 x 10(6) BB pairs, we find no significant evidence for a signal and set an upper limit on the branching fraction B(B+-->my(+)nu(my))< 6.

Study of B+/ --> J/psi pi+/- and B+/ -->J/psi K+/- decays: measurement of the ratio of branching fractions and search for direct CP violation.

We study B+/ --> J/psi pi(+/-) and B+/ --> J/psi K+/- decays in a sample of about 89 x 10(6) BB pairs collected with the BABAR detector at the PEP-II asymmetric B factory at SLAC. We observe a signal of 244+/-20 B+/ --> J/psi pi(+/-) events and determine the ratio B(B+/ --> J/psi pi(+/-))/B(B+/ --> J/psi K+/-) to be [5.37+/-0.

Measurement of time-dependent CP asymmetries and constraints on sin(2beta+gamma) with partial reconstruction of B0-->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) BBmacr; 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.

Measurement of time-dependent CP asymmetries in B0-->D(*)+/-pi-/+ decays and constraints on sin(2beta+gamma).

We present a measurement of CP-violating asymmetries in fully reconstructed B0-->D(*)+/-pi-/+ decays in approximately 88 x 10(6) upsilon(4S)-->BBmacr; decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. From a time-dependent maximum-likelihood fit we obtain the following for the CP-violating parameters: a=-0.022+/-0.

Limits on the decay-rate difference of neutral B mesons and on CP, T, and CPT violation in B(0-0)B oscillations.

Using events in which one of two neutral B mesons from the decay of an Upsilon(4S) meson is fully reconstructed, we determine parameters governing decay (DeltaGamma(d)/Gamma(d)), CP, and T violation (|q/p|), and CP and CPT violation (Re z,Im z). The results, obtained from an analysis of 88 x 10(6) Upsilon(4S) decays recorded by BABAR, are sgn(Re lambda(CP))DeltaGamma(d)/Gamma(d)=-0.008+/-0.

Measurement of the branching fractions and CP asymmetry of B--->D(0)((CP))K- decays with the BABAR detector.

We present a study of B--->D(0)(CP)K- decays, where D(0)(CP) is reconstructed in CP-even channels, based on a sample of 88.8 x 10(6) Upsilon(4S)-->BB 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--->D(0)(CP)K-)/B(B--->D(0)(CP)pi(-))=[8.

Measurements of branching fractions and CP-violating asymmetries in B meson decays to charmless two-body states containing a K(0).

We present measurements of branching fractions and CP-violating asymmetries in decays of B mesons to two-body final states containing a K0. The results are based on a data sample of approximately 88 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure B(B+-->K(0)pi(+))=(22.

Search for lepton-flavor violation in the decay tau- --> l- l+ l-.

A search for the lepton-flavor-violating decay of the tau into three charged leptons has been performed using 91.5 fb(-1) of data collected at an e(+)e(-)center-of-mass energy around 10.58 GeV with the BABAR detector at the SLAC storage ring PEP-II.

Measurements of the mass and width of the eta(c) meson and of an eta(c)(2S) candidate.

The mass m(eta(c)) and total width Gamma(eta(c))(tot) of the eta(c) meson have been measured in two-photon interactions at the SLAC e(+)e(-) asymmetric B Factory with the BABAR detector. With a sample of approximately 2500 reconstructed eta(c)-->K(0)(S)K+/-pi(-/+) decays in 88 fb(-1) of data, the results are m(eta(c))=2982.5+/-1.

Measurement of the branching fraction and polarization for the decay B--->D*0K*-.

We present a study of the decay B--->D(*0)K(*-) based on a sample of 86 x 10(6) Upsilon(4S)-->BBmacr; decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure the branching fraction B(B--->D(*0)K(*-))=(8.3+/-1.

Search for the radiative decays B-->rhogamma and B0-->omegagamma.

A search of the exclusive radiative decays B-->rho(770)gamma and B0-->omega(782)gamma is performed on a sample of about 84x10(6) BBmacr; 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(B0-->rho(0)gamma)<1.

Measurement of the inclusive charmless semileptonic branching ratio of B mesons and determination of |V ub|.

We report a measurement of the inclusive charmless semileptonic branching fraction of B mesons in a sample of 89 x 10(6) (-)BB events recorded with the BABAR detector at the Upsilon(4S) resonance. Events are selected by fully reconstructing the decay of one B meson and identifying a charged lepton from the decay of the other B meson. The number of signal events is extracted from the mass distribution of the hadronic system accompanying the lepton and is used to determine the ratio of branching fractions B((-)B-->X(u)lnu;)/B((-)B-->Xlnu;)=[2.

Observation of B0-->omega K0, B+-->eta pi+, and B+-->eta K+ and study of related decays.

We present measurements of branching fractions and charge asymmetries for seven B-meson decays with an eta, eta', or omega meson in the final state. The data sample corresponds to 89x10(6) BB pairs produced from e(+)e(-) annihilation at the Upsilon(4S) resonance. We measure the following branching fractions in units of 10(-6): B(B+-->eta pi(+))=5.

Measurements of branching fractions and CP-violating asymmetries in B0-->rho(+/-)h(-/+) decays.

We present measurements of branching fractions and CP-violating asymmetries in B0-->rho(+/-)pi(-/+) and B0-->rho-K+ decays. The results are obtained from a data sample of 88.9 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B Factory.

Evidence for the rare decay B-->K*l+l- and measurement of the B-->Kl+l- branching fraction.

We present evidence for the flavor-changing neutral current decay B-->K*l+l- and a measurement of the branching fraction for the related process B-->K l+l-, where l+l- is either an epsilon+epsilon- or a mu+mu- pair. These decays are highly suppressed in the standard model, and they are sensitive to contributions from new particles in the intermediate state. The data sample comprises 123 x 10(6) Upsilon(4S)-->B(-)B decays collected with the BABAR detector at the SLAC PEP-II epsilon+epsilon- storage ring.

Observation of a significant excess of pi0pi0 events in B meson decays.

We present a study of the decay B0-->pi(0)pi(0) based on a sample of 124 x 10(6) BB pairs recorded by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We observe 46+/-13+/-3 events, where the first error is statistical and the second is systematic, corresponding to a significance of 4.2 standard deviations including systematic uncertainties.

Measurements of CP-violating asymmetries and branching fractions in B meson decays to eta'K.

We present measurements of the branching fractions of the decays B+-->eta'K+ and B0-->eta'K0. For B0-->eta(')K(0)(S) we also measure the time-dependent CP-violation parameters S eta'(K(0)(S)) and C eta'(K(0)(S)), and for B+-->eta'K+ the time-integrated charge asymmetry A(ch). The data sample corresponds to 88.

Rates, polarizations, and asymmetries in charmless vector-vector B meson decays.

With a sample of approximately 89 x 10(6) B(-)B pairs collected with the BABAR detector, we perform a search for B meson decays into pairs of charmless vector mesons (phi, rho, and K*). We measure the branching fractions, determine the degree of longitudinal polarization, and search for CP violation asymmetries in the processes B+-->phiK(*+), B0-->phiK(*0), B+-->rho(0)K(*+), and B+-->rho(0)rho(+). We also set an upper limit on the branching fraction for the decay B0-->rho(0)rho(0).