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1.
Phys Rev Lett ; 103(18): 181801, 2009 Oct 30.
Article in English | MEDLINE | ID: mdl-19905799

ABSTRACT

We search for a light Higgs boson A0 in the radiative decay Upsilon(3S)-->gammaA(0), A(0)-->tau+tau-, tau+-->e+nu(e)nu(tau), or tau+-->mu+nu(mu)nu(tau). The data sample contains 122x10(6) Upsilon(3S) events recorded with the BABAR detector. We find no evidence for a narrow structure in the studied tau+tau- invariant mass region of 4.03gammaA(0))xB(A(0)-->tau+tau-)>(1.5-16)x10(-5) across the m(tau+tau-) range. We also set a 90% C.L. upper limit on the tau+tau- decay of the eta(b) at B(eta(b)-->tau+tau-)<8%.

2.
Phys Rev Lett ; 103(2): 021801, 2009 Jul 10.
Article in English | MEDLINE | ID: mdl-19659196

ABSTRACT

We search for the neutrinoless, lepton-flavor-violating tau decays tau- -->l-}V0, where l is an electron or muon and V0 is a vector meson reconstructed as phi-->K+K-, rho-->pi+pi-, K-->K+pi-, K[over ]-->K-pi+. The analysis has been performed using 451 fb-1 of data collected at an e+e- center-of-mass energy near 10.58 GeV with the BABAR detector at the PEP-II storage rings. The number of events found in the data is compatible with the background expectation, and upper limits on the branching fractions are set in the range (2.6-19)x10-8 at the 90% confidence level.

3.
Phys Rev Lett ; 103(4): 041802, 2009 Jul 24.
Article in English | MEDLINE | ID: mdl-19659341

ABSTRACT

We report an analysis of tau;{-} decaying into omegapi;{-}nu_{tau} with omega --> pi;{+}pi;{-}pi;{0} using a data sample containing nearly 320 x 10;{6}tau pairs collected with the BABAR detector at the PEP-II B-Factory. We find no evidence for second-class currents, and we set an upper limit of 0.69% at 90% confidence level for the fraction of second-class currents in this decay mode.

4.
Phys Rev Lett ; 102(13): 132001, 2009 Apr 03.
Article in English | MEDLINE | ID: mdl-19392347

ABSTRACT

In a search for B-->cc[over ]gammaK decays with the BABAR detector, where cc[over ] includes J/psi and psi(2S), and K includes K(+/-), K(S)(0), and K(*)(892), we find evidence for X(3872)-->J/psigamma and X(3872)-->psi(2S)gamma with 3.6sigma and 3.5sigma significance, respectively. We measure the product of branching fractions B(B(+/-)-->X(3872)K(+/-))xB(X(3872)-->J/psigamma)=[2.8+/-0.8(stat)+/-0.1(syst)]x10(-6) and B(B(+/-)-->X(3872)K(+/-))xB(X(3872)-->psi(2S)gamma)=[9.5+/-2.7(stat)+/-0.6(syst)]x10(-6).

5.
Phys Rev Lett ; 103(21): 211801, 2009 Nov 20.
Article in English | MEDLINE | ID: mdl-20366027

ABSTRACT

We present evidence of D{0}-D[-over ]{0} mixing using a time-dependent amplitude analysis of the decay D{0}-->K+pi{-}pi;{0} in a data sample of 384 fb{-1} collected with the BABAR detector at the PEP-II e+e{-} collider at the Stanford Linear Accelerator Center. Assuming CP conservation, we measure the mixing parameters x{Kpipi{0}}{'}=[2.61{-0.68}{+0.57}(stat)+/-0.39(syst)]%, y{Kpipi;{0}}{'}=[-0.06{-0.64}{+0.55}(stat)+/-0.34(syst)]%. This result is inconsistent with the no-mixing hypothesis with a significance of 3.2 standard deviations. We find no evidence of CP violation in mixing.

6.
Phys Rev Lett ; 101(17): 171804, 2008 Oct 24.
Article in English | MEDLINE | ID: mdl-18999741

ABSTRACT

We perform a measurement of the CP asymmetry in b-->sgamma decays using a sample of 383 x 10(6) B[over] B events collected by the BABAR detector at the SLAC PEP-II asymmetric B factory. We reconstruct 16 flavor-specific B decay modes containing a high-energy photon and a hadronic system X_(s) containing an s quark. We measure the CP asymmetry to be -0.011+/-0.030(stat)+/-0.014(syst) for a hadronic system mass between 0.6 and 2.8 GeV/c(2).

7.
Phys Rev Lett ; 101(9): 091801, 2008 Aug 29.
Article in English | MEDLINE | ID: mdl-18851601

ABSTRACT

Using 383 x 10(6) BBover pairs from the BABAR data sample, we report results for branching fractions of six charged B-meson decay modes, where a charged kaon recoils against a charmless resonance decaying to KKover* or etapipi final states with mass in the range (1.2-1.8) GeV/c2. We observe a significant enhancement at the low KKover* invariant mass which is interpreted as B+-->eta(1475)K+, find evidence for the decay B+-->eta(1295)K+, and place upper limits on the decays B+-->eta(1405)K+, B+-->f1(1285)K+, B+-->f1(1420)K+, and B+-->phi(1680)K+.

8.
Phys Rev Lett ; 101(2): 021801, 2008 Jul 11.
Article in English | MEDLINE | ID: mdl-18764170

ABSTRACT

We present measurements of the branching fraction and time-dependent CP asymmetries in B0-->J/psipi0 decays based on 466 x 10(6) Upsilon(4S)-->BB over events collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. We measure the CP asymmetry parameters S= -1.23+/-0.21(stat)+/-0.04(syst) and C= -0.20+/-0.19(stat)+/-0.03(syst), where the measured value of (S, C) is 4.0 standard deviations from (0, 0) including systematic uncertainties. The branching fraction is determined to be B(B0-->J/psipi0)=[1.69+/-0.14(stat)+/-0.07(syst)]x10(-5).

9.
Phys Rev Lett ; 100(23): 231803, 2008 Jun 13.
Article in English | MEDLINE | ID: mdl-18643485

ABSTRACT

Using 226 x 10(6) BB[overline] events recorded on the Upsilon(4S) resonance with the BABAR detector at the SLAC e(+)e(-) PEP-II storage rings, we reconstruct B(-) ---> D(*0)e(-)nu[overline](e) decays using the decay chain D(*0) --> D(0)pi(0) and D(0)-->K(-)pi(+). From the dependence of their differential rate on w, the dot product of the four velocities of B(-) and D(*0), and using the form factor description by Caprini et al. with the parameters F(1) and rhoA(1)(2), we obtain the results rhoA(1)(2) = 1.16+/-0.06+/-0.08, F(1)|V(cb)|=(35.9+/-0.6+/-1.4) x 10(-3), and B(B(-) --> D(*0)e(-)nu[overline](e))=(5.56+/-0.08+/-0.41)%.

10.
Phys Rev Lett ; 100(2): 021801, 2008 Jan 18.
Article in English | MEDLINE | ID: mdl-18232854

ABSTRACT

We present measurements of the semileptonic decays B--->D0tau-nutau, B--->D*0tau-nutau, B0-->D+tau-nutau, and B0-->D*+tau-nutau, which are potentially sensitive to non-standard model amplitudes. The data sample comprises 232x10(6) Upsilon(4S)-->BB decays collected with the BABAR detector. From a combined fit to B- and B0 channels, we obtain the branching fractions B(B-->Dtau-nutau)=(0.86+/-0.24+/-0.11+/-0.06)% and B(B-->D*tau-nutau)=(1.62+/-0.31+/-0.10+/-0.05)% (normalized for the B0), where the uncertainties are statistical, systematic, and normalization-mode-related.

11.
Phys Rev Lett ; 99(16): 161802, 2007 Oct 19.
Article in English | MEDLINE | ID: mdl-17995239

ABSTRACT

We analyze the decay B0-->K+K-K0 using 383 x 10(6) BB events collected by the BABAR detector at SLAC to extract CP violation parameter values over the Dalitz plot. Combining all K+K-K0 events, we find ACP=-0.015+/-0.077+/-0.053 and beta eff = 0.352+/-0.076+/-0.026 rad, corresponding to a CP violation significance of 4.8 sigma. A second solution near pi/2-beta eff is disfavored with a significance of 4.5 sigma. We also report ACP and beta eff separately for decays to phi(1020)K0, f0(980)K0, and K+K-K0 with mK+K- > 1.1 GeV/c2.

12.
Phys Rev Lett ; 99(6): 062001, 2007 Aug 10.
Article in English | MEDLINE | ID: mdl-17930815

ABSTRACT

We present an analysis of inclusive Omega(c)(0) baryon production and decays in 230.5 fb(-1) of data recorded with the BABAR detector. Omega(c)(0) baryons are reconstructed in four final states (Omega(-)pi(+), Omega(-)pi(+)pi(0), Omega(-)pi(+)pi(+)pi(-), Xi(-)K(-)pi(+)pi(+)) and the corresponding ratios of branching fractions are measured. We also measure the momentum spectrum in the e(+)e(-) center-of-mass frame. From the spectrum, we observe Omega(c)(0) production from B decays and in cc events, and extract the two rates of production.

13.
Phys Rev Lett ; 99(23): 231802, 2007 Dec 07.
Article in English | MEDLINE | ID: mdl-18233357

ABSTRACT

We study the time-dependent Dalitz plot of D-->K_{S};{0}pi;{+}pi;{-} in B;{0}-->D;{(*)}h;{0} decays, where h;{0} is a pi;{0}, eta, eta;{'}, or omega meson and D;{*}-->Dpi;{0}, using a data sample of 383x10;{6} Upsilon(4S)-->BB[over ] decays collected with the BABAR detector. We determine cos2beta=0.42+/-0.49+/-0.09+/-0.13, sin2beta=0.29+/-0.34+/-0.03+/-0.05, and |lambda|=1.01+/-0.08+/-0.02, where the first error is statistical, the second is the experimental systematic uncertainty, and the third, where given, is the Dalitz model uncertainty. Assuming the world average value for sin2beta and |lambda|=1, cos2beta>0 is preferred over cos2beta<0 at 86% confidence level.

14.
Phys Rev Lett ; 99(24): 241803, 2007 Dec 14.
Article in English | MEDLINE | ID: mdl-18233439

ABSTRACT

We present the results of searches for decays of B mesons to final states with a b1 meson and a charged pion or kaon. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 382x10(6) BB[over ] pairs produced in e+e- annihilation. The results for the branching fractions are, in units of 10(-6), B(B+-->b1(0)pi+)=6.7+/-1.7+/-1.0, B(B+-->b1(0)K+)=9.1+/-1.7+/-1.0, B(B0-->b1(-/+)pi(+/-))=10.9+/-1.2+/-0.9, and B(B0-->b1(-)K+)=7.4+/-1.0+/-1.0, with the assumption that B(b1-->omega pi)=1. We also measure charge and flavor asymmetries A(ch)(B+-->b1(0)pi+)=0.05+/-0.16+/-0.02, Ach(B+-->b1(0)K+)=-0.46+/-0.20+/-0.02, A(ch)(B0-->b1(-/+)pi(+/-))=-0.05+/-0.10+/-0.02, C(B0-->b1(-/+)pi(+/-))=-0.22+/-0.23+/-0.05, DeltaC(B0-->b1(-/+)pi(+/-))=-1.04+/-0.23+/-0.08, and A(ch)(B0-->b1(-)K+)=-0.07+/-0.12+/-0.02. The first error quoted is statistical, and the second systematic.

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