-
B. Aubert,
D. Boutigny,
J.-M. Gaillard,
A. Hicheur,
Y. Karyotakis,
J. P. Lees,
P. Robbe,
V. Tisserand,
A. Palano,
A. Pompili, [......],
F. Di Lodovico,
Y. Pan,
R. Prepost,
I. J. Scott,
S. J. Sekula,
J. H. von Wimmersperg-Toeller,
S. L. Wu,
Z. Yu,
T. M. B. Kordich,
H. Neal
[show abstract]
[hide abstract]
ABSTRACT: We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb-1 recorded at the Υ(4S) resonance and 3.9 fb-1 off resonance. One of the neutral B mesons, which are produced in pairs at the Υ(4S), is fully reconstructed in the CP decay modes J/ψKS0, ψ(2S)KS0, χc1KS0, J/ψK*0 (K*0→KS0π0) and J/ψKL0, or in flavor-eigenstate modes involving D(*)π/ρ/a1 and J/ψK*0 (K*0→K+π-). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural network tagging algorithm is used to recover events without a clear lepton or kaon tag. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities, the time-difference resolution function, and the B0-B0 oscillation frequency Δmd are measured with a sample of about 6350 fully-reconstructed B0 decays in hadronic flavor-eigenstate modes. A maximum-likelihood fit to this flavor eigenstate sample finds Δmd=0.516±0.016(stat)±0.010(syst)ps-1. The value of the asymmetry amplitude sin2β is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged B0 decays in the CP-eigenstate modes. We find sin2β=0.59±0.14(stat)±0.05(syst), demonstrating that CP violation exists in the neutral B meson system. We also determine the value of the CP violation parameter |λ|=0.93±0.09(stat)±0.03(syst), which is consistent with the expectation of |λ|=1 for no direct CP violation.
Physical Review D 02/2013; 66(3). · 4.56 Impact Factor
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu,
BaBar Collaboration
[show abstract]
[hide abstract]
ABSTRACT: In a sample of 467×106 BB¯ pairs collected with
the BABAR detector at the PEP-II collider at SLAC we have observed the
decay
B¯0→Λc+p¯π0
and measured the branching fraction to be
(1.94±0.17±0.14±0.50)×10-4, where
the uncertainties are statistical, systematic, and the uncertainty on
the Λc+→pK-π+
branching fraction, respectively. We determine an upper limit of
1.5×10-6 at 90% C.L. for the product branching fraction
B(B¯0→Σc+(2455)p¯)×B(Λc+→pK-π+).
Furthermore, we observe an enhancement at the threshold of the invariant
mass of the baryon-antibaryon pair.
Physical review D: Particles and fields 07/2010; 82(3):31102.
-
B Aubert,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges,
M Martinelli, [......],
G B Mohanty,
E M T Puccio,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: Using 467 fb(-1) of e+e- annihilation data collected with the BABAR detector, we measure (B(τ- → μ- ν(μ) ν(τ)))/(B(τ- → e- ν(e) ν(τ))) =(0.9796±0.0016±0.0036), (B(τ- → π- ν(τ)))/(B(τ- → e- ν(e) ν(τ))) = (0.5945±0.0014±0.0061), and (B(τ- → K- ν(τ)))/(B(τ- → e- ν(e) ν(τ))) = (0.03882±0.00032±0.00057), where the uncertainties are statistical and systematic, respectively. From these precision τ measurements, we test the standard model assumption of μ-e and τ-μ charge current lepton universality and provide determinations of |Vus| experimentally independent of the decay of a kaon.
Physical Review Letters 07/2010; 105(5):051602. · 7.37 Impact Factor
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu,
BaBar Collaboration
[show abstract]
[hide abstract]
ABSTRACT: Using 467fb-1 of e+e- annihilation data
collected with the BABAR detector, we measure
(B(τ-→μ-ν¯μντ))/(B(τ-→e-ν¯eντ))=(0.9796±0.0016±0.0036),
(B(τ-→π-ντ))/(B(τ-→e-ν¯eντ))=(0.5945±0.0014±0.0061),
and
(B(τ-→K-ντ))/(B(τ-→e-ν¯eντ))=(0.03882±0.00032±0.00057),
where the uncertainties are statistical and systematic, respectively.
From these precision τ measurements, we test the standard model
assumption of μ-e and τ-μ charge current lepton universality
and provide determinations of |Vus| experimentally
independent of the decay of a kaon.
Physical Review Letters 06/2010; 105(5):51602. · 7.37 Impact Factor
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
G. B. Mohanty,
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: A search for the Z(3930) resonance in γγ production of the DD̅ system has been performed using a data sample corresponding to an integrated luminosity of 384 fb-1 recorded by the BABAR experiment at the PEP-II asymmetric-energy electron-positron collider. The DD̅ invariant mass distribution shows clear evidence of the Z(3930) state with a significance of 5.8σ. We determine mass and width values of (3926.7±2.7±1.1) MeV/c2 and (21.3±6.8±3.6) MeV, respectively. A decay angular analysis provides evidence that the Z(3930) is a tensor state with positive parity and C parity (JPC=2++); therefore we identify the Z(3930) state as the χc2(2P) meson. The value of the partial width Γγγ×B(Z(3930)→DD̅ ) is found to be (0.24±0.05±0.04) keV.
Phys. Rev. D. 05/2010; 81(9).
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
G. B. Mohanty,
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We report measurements of the branching fractions of neutral and charged B meson decays to final states containing a K1(1270) or K1(1400) meson and a charged pion. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, correspond to 454×106 BB̅ pairs produced in e+e- annihilation. We measure the branching fractions B(B0→K1(1270)+π-+K1(1400)+π-)=3.1-0.7+0.8×10-5 and B(B+→K1(1270)0π++K1(1400)0π+)=2.9-1.7+2.9×10-5 (<8.2×10-5 at 90% confidence level), where the errors are statistical and systematic combined. The B0 decay mode is observed with a significance of 7.5σ, while a significance of 3.2σ is obtained for the B+ decay mode. Based on these results, we estimate the weak phase α=(79±7±11)° from the time-dependent CP asymmetries in B0→a1(1260)±π∓ decays.
Phys. Rev. D. 03/2010; 81(5).
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu,
BaBar Collaboration
[show abstract]
[hide abstract]
ABSTRACT: We present a search for the decay
B+→ℓ+νℓ(ℓ=τ,μ,ore)
in (458.9±5.1)×106 BB¯ pairs recorded with
the BABAR detector at the PEP-II B-factory. We search for these B decays
in a sample of B+B- events where one B-meson is
reconstructed as
B-→D0ℓ-ν¯X. Using the
method of Feldman and Cousins, we obtain
B(B+→τ+ντ)=(1.7±0.8±0.2)×10-4,
which excludes zero at 2.3σ. We interpret the central value in the
context of the standard model and find the B meson decay constant to be
fB2=(62±31)×103MeV2.
We find no evidence for B+→e+νe
and B+→μ+νμ and set upper
limits at the 90% C.L.
B(B+→e+νe)<0.8×10-5
and
B(B+→μ+νμ)<1.1×10-5.
Physical review D: Particles and fields 02/2010; 81(5):51101.
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
G. B. Mohanty,
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We present results for the moments of observed spectra in inclusive semileptonic B-meson decays to charm hadrons B̅ →Xcℓ-ν̅ . Moments of the hadronic-mass and the combined mass-and-energy spectra for different minimum electron or muon momenta between 0.8 and 1.9 GeV/c are obtained from a sample of 232×106 Υ(4S)→BB̅ events, collected with the BABAR detector at the PEP-II asymmetric-energy B-meson factory at SLAC. We also present a reevaluation of the moments of electron-energy spectra and partial decay fractions B(B̅ →Xce-ν̅ ) for minimum electron momenta between 0.6 and 1.5 GeV/c based on a sample of 51×106 Υ(4S)→BB̅ events. The measurements are used for the extraction of the total decay fraction, the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |Vcb|, the quark masses mb and mc, and four heavy-quark QCD parameters in the framework of a Heavy-Quark Expansion (HQE). We find B(B̅ →Xcℓ-ν̅ )=(10.64±0.17±0.06)% and |Vcb|=(42.05±0.45±0.70)×10-3.
Phys. Rev. D. 02/2010; 81(3).
-
B Aubert,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges,
M Martinelli, [......],
G B Mohanty,
E M T Puccio,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V(cb)| and the form-factor slope rho2 in B --> Dl- nu(l) decays based on 460x10(6) BB events recorded at the Upsilon(4S) resonance with the BABAR detector. B --> Dl- nu(l) decays are selected in events in which a hadronic decay of the second B meson is fully reconstructed. We measure B(B- --> D0 l- nu(l))/B(B- --> Xl- nu(l)) = (0.255+/-0.009+/-0.009) and B(B0 --> D+ l- nu(l))/B(B0 --> Xl- nu(l)) = (0.230+/-0.011+/-0.011), along with the differential decay distribution in B --> Dl- nu(l) decays. We then determine G(1)|V(cb)| = (42.3+/-1.9+/-1.4)x10(-3) and rho2 = 1.20+/-0.09+/-0.04, where G(1) is the hadronic form factor at the point of zero recoil.
Physical Review Letters 01/2010; 104(1):011802. · 7.37 Impact Factor
-
B Aubert,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges,
M Martinelli, [......],
G B Mohanty,
E M T Puccio,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: Searches for lepton-flavor-violating decays of a tau lepton to a lighter mass lepton and a photon have been performed with the entire data set of (963+/-7)x10{6} tau decays collected by the BABAR detector near the Upsilon(4S), Upsilon(3S) and Upsilon(2S) resonances. The searches yield no evidence of signals and we set upper limits on the branching fractions of B(tau{+/-}-->e{+/-}gamma)<3.3x10{-8} and B(tau{+/-}-->mu{+/-}gamma)<4.4x10{-8} at 90% confidence level.
Physical Review Letters 01/2010; 104(2):021802. · 7.37 Impact Factor
-
B Aubert,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges,
M Martinelli, [......],
G B Mohanty,
E M T Puccio,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: A precise measurement of the cross section of the process e(+)e(-) --> pi(+)pi(-)(gamma) from threshold to an energy of 3 GeV is obtained with the initial state radiation (ISR) method using 232 fb(-1) of data collected with the BABAR detector at e(+)e(-) center-of-mass energies near 10.6 GeV. The ISR luminosity is determined from a study of the leptonic process e(+)e(-) --> mu(+)mu(-)gamma(gamma). The leading-order hadronic contribution to the muon magnetic anomaly calculated using the pipi cross section measured from threshold to 1.8 GeV is (514.1 +/- 2.2(stat) +/- 3.1(syst)) x 10(-10).
Physical Review Letters 12/2009; 103(23):231801. · 7.37 Impact Factor
-
B Aubert,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges,
M Martinelli, [......],
G B Mohanty,
E M T Puccio,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: We search for invisible decays of the Upsilon(1S) meson using a sample of 91.4 x 10(6) Upsilon(3S) mesons collected at the BABAR/PEP-II B factory. We select events containing the decay Upsilon(3S) --> pi(+)pi(-)Upsilon(1S) and search for evidence of an undetectable Upsilon(1S) decay recoiling against the dipion system. We set an upper limit on the branching fraction B(Upsilon(1S) --> invisible) < 3.0 x 10(-4) at the 90% confidence level.
Physical Review Letters 12/2009; 103(25):251801. · 7.37 Impact Factor
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
G. B. Mohanty,
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We present the result from a precision measurement of the mass of the τ lepton, Mτ, based on 423 fb-1 of data recorded at the Υ(4S) resonance with the BABAR detector. Using a pseudomass endpoint method, we determine the mass to be 1776.68±0.12(stat)±0.41(syst) MeV. We also measure the mass difference between the τ+ and τ-, and obtain (Mτ+-Mτ-)/MAVGτ=(-3.4±1.3(stat)±0.3(syst))×10-4, where MAVGτ is the average value of Mτ+ and Mτ-.
Phys. Rev. D. 11/2009; 80(9).
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
G. B. Mohanty,
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We present measurements of the branching fraction B and longitudinal polarization fraction fL for B0→a1(1260)+a1(1260)- decays, with a1(1260)±→π-π+π±. The data sample, collected with the BABAR detector at the SLAC National Accelerator Laboratory, represents 465×106 produced BB̅ pairs. We measure B(B0→a1(1260)+a1(1260)-)×[B(a1(1260)+→π-π+π+)]2= (11.8±2.6±1.6)×10-6 and fL=0.31±0.22±0.10, where the first uncertainty is statistical and the second systematic. The decay mode is measured with a significance of 5.0 standard deviations including systematic uncertainties.
Phys. Rev. D. 11/2009; 80(9).
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
G. B. Mohanty,
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We observe the decays Ds1*(2710)+→D*K and DsJ*(2860)+→D*K and measure their branching fractions relative to the DK final state. We also observe, in the D*K mass spectrum, a new broad structure at a mass of (3044±8stat(+30/-5)syst) MeV/c2 having a width Γ=(239±35stat(+46/-42)syst) MeV. To obtain this result we use 470 fb-1 of data recorded by the BABAR detector at the PEP-II asymmetric-energy e+e- storage rings at the Stanford Linear Accelerator Center running at center-of-mass energies near 10.6 GeV.
Phys. Rev. D. 11/2009; 80(9).
-
M. N. Achasov,
K. I. Beloborodov,
A. V. Bergyugin,
A. G. Bogdanchikov, A D Bukin,
D. A. Bukin,
T. V. Dimova,
V. P. Druzhinin,
V B Golubev,
I. A. Koop,
A. A. Korol,
S. V. Koshuba,
A. P. Lysenko,
E. V. Pakhtusova,
S I Serednyakov,
Yu. M. Shatunov,
Z. K. Silagadze,
A. N. Skrinsky,
A. V. Vasiljev
[show abstract]
[hide abstract]
ABSTRACT: The search for lepton-flavor-violation process e^+e^-\to e\mu in the energy region \sqrt{s}=984 - 1060 MeV with SND detector at VEPP-2M e^+e^- collider is reported. The model independent 90% CL upper limits on the e^+e^-\to e\mu cross section, \sigma_{e\mu} < 11 pb, as well as on the corresponding \phi\to e\mu branching fraction, B(\phi\to e\mu) < 2 \times 10^{-6}, for the final particles polar angles 55^\circ<\theta<125^\circ, were obtained.
11/2009;
-
B. Aubert,
Y. Karyotakis,
J. P. Lees,
V. Poireau,
E. Prencipe,
X. Prudent,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli, [......],
G. B. Mohanty,
E. M. T. Puccio,
H. R. Band,
X. Chen,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We study the decay B-→DK*- using a sample of 379×106 Υ(4S)→BB̅ events collected with the BABAR detector at the PEP-II B factory. We perform a Gronau-London-Wyler analysis where the D meson decays into either a CP-even (CP+) eigenstate (K+K-, π+π-), CP-odd (CP-) eigenstate (KS0π0, KS0ϕ, KS0ω) or a non-CP state (K-π+). We also analyze D meson decays into K+π- from a Cabibbo-favored D̅ 0 decay or doubly suppressed D0 decay [Atwood-Dunietz-Soni (ADS) analysis]. We measure observables that are sensitive to the Cabibbo-Kobayashi-Maskawa angle γ: the partial-rate charge asymmetries ACP±, the ratios RCP± of the B-decay branching fractions in CP± and non-CP decay, the ratio RADS of the charge-averaged branching fractions, and the charge asymmetry AADS of the ADS decays: ACP+=0.09±0.13±0.06, ACP-=-0.23±0.21±0.07, RCP+=2.17±0.35±0.09, RCP-=1.03±0.27±0.13, RADS=0.066±0.031±0.010, and AADS=-0.34±0.43±0.16, where the first uncertainty is statistical and the second is systematic. Combining all the measurements and using a frequentist approach yields the magnitude of the ratio between the Cabibbo-suppressed and favored amplitudes, rB=0.31 with a one (two) sigma confidence level interval of [0.24, 0.38] ([0.17, 0.43]). The value rB=0 is excluded at the 3.3 sigma level. A similar analysis excludes values of γ in the intervals [0, 7]°, [55, 111]°, and [175, 180]° ([85, 99]°) at the one (two) sigma confidence level.
Phys. Rev. D. 11/2009; 80(9).
-
B Aubert,
M Bona,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges, [......],
G B Mohanty,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
M Pierini,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
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.
Physical Review Letters 11/2009; 103(21):211801. · 7.37 Impact Factor
-
B Aubert,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges,
M Martinelli, [......],
G B Mohanty,
E M T Puccio,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
R Prepost,
C O Vuosalo,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: We present an analysis of the decays B{0}-->K{*0}(892)gamma and B{+}-->K{*+}(892)gamma using a sample of about 383 x 10{6} BB[-over ] events collected with the BABAR detector at the PEP-II asymmetric energy B factory. We measure the branching fractions B(B{0}-->K{*0}gamma)=(4.47+/-0.10+/-0.16) x 10{-5} and B(B{+}-->K{*+}gamma)=(4.22+/-0.14+/-0.16) x 10{-5}. We constrain the direct CP asymmetry to be -0.033<A(B-->K{*}gamma)<0.028 and the isospin asymmetry to be 0.017<Delta{0-} < 0.116, where the limits are determined by the 90% confidence interval and include both the statistical and systematic uncertainties.
Physical Review Letters 11/2009; 103(21):211802. · 7.37 Impact Factor
-
B Aubert,
M Bona,
Y Karyotakis,
J P Lees,
V Poireau,
E Prencipe,
X Prudent,
V Tisserand,
J Garra Tico,
E Grauges, [......],
G B Mohanty,
E M T Puccio,
H R Band,
X Chen,
S Dasu,
K T Flood,
Y Pan,
R Prepost,
C O Vuosalo,
S L Wu
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ABSTRACT: We have performed a search for the eta_{b}(1S) meson in the radiative decay of the Upsilon(2S) resonance using a sample of 91.6x10(6) Upsilon(2S) events recorded with the BABAR detector at the PEP-II B factory at the SLAC National Accelerator Laboratory. We observe a peak in the photon energy spectrum at Egamma=609.3(-4.5)(+4.6)(stat)+/-1.9(syst) MeV, corresponding to an eta(b)(1S) mass of 9394.2(-4.9)(+4.8)(stat)+/-2.0(syst) MeV/c2. The branching fraction for the decay Upsilon(2S)-->gamma(eta)b(1S) is determined to be [3.9+/-1.1(stat)-0.9+1.1(syst)]x10(-4). We find the ratio of branching fractions B[Upsilon(2S)-->gamma(eta)b(1S)]/B[Upsilon(3S)-->gamma(eta)b(1S)]=0.82+/-0.24(stat)(-0.19)(+0.20)(syst).
Physical Review Letters 10/2009; 103(16):161801. · 7.37 Impact Factor
