-
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
-
The Babar Collaboration,
J. P. Lees,
V. Poireau,
V. Tisserand,
E. Grauges,
A. Palano,
G. Eigen,
B. Stugu,
D. N. Brown,
L. T. Kerth, [......],
R. J. Sobie,
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We study the decay
$\bar{B}^{0}\rightarrow\Lambda_{c}^{+}\bar{p}\pi^{+}\pi^{-}$, reconstructing
the \Lambda_{c}^{+} baryon in the $p K^{-}\pi^{+}$ mode, using a data sample of
$467\times 10^{6}$ $B\bar{B}$ pairs collected with the BaBar detector at the
PEP-2 storage rings at SLAC. We measure branching fractions for decays with
intermediate $\Sigma_{c}$ baryons to be ${\cal
B}[\bar{B}^{0}\rightarrow\Sigma_{c}(2455)^{++}\bar{p}\pi^{-}]=(21.3 \pm 1.0 \pm
1.0 \pm 5.5) \times 10^{-5}$, ${\cal
B}[\bar{B}^{0}\rightarrow\Sigma_{c}(2520)^{++}\bar{p}\pi^{-}]=(11.5\pm 1.0 \pm
0.5 \pm 3.0)\times 10^{-5}$, ${\cal
B}[\bar{B}^{0}\rightarrow\Sigma_{c}(2455)^{0}\bar{p}\pi^{+}]=(9.1 \pm 0.7 \pm
0.4 \pm 2.4)\times10^{-5}$, and ${\cal
B}[\bar{B}^{0}\rightarrow\Sigma_{c}(2520)^{0}\bar{p}\pi^{+}]= (2.2 \pm 0.7 \pm
0.1\pm 0.6) \times 10^{-5}$, where the uncertainties are statistical,
systematic, and due to the uncertainty on the
$\Lambda_{c}^{+}\rightarrow\proton\Km\pi^{+}$ branching fraction, respectively.
For decays without $\Sigma_{c}(2455)$ or $\Sigma_{c}(2520)$ resonances, we
measure ${\cal
B}[\bar{B}^{0}\rightarrow\Lambda_{c}^{+}\bar{p}\pi^{+}\pi^{-}]_{\mathrm{non-\Sigma_{c}}}=(79
\pm 4 \pm 4 \pm 20)\times10^{-5}$. The total branching fraction is determined
to be ${\cal
B}[\bar{B}^{0}\rightarrow\Lambda_{c}^{+}\bar{p}\pi^{+}\pi^{-}]_{\mathrm{total}}=(123
\pm 5 \pm 7 \pm 32)\times10^{-5}$. We examine multibody mass combinations in
the resonant three-particle $\Sigma_{c}\bar{p}\pi$ final states and in the
four-particle $\Lambda_{c}^{+}\bar{p}\pi^{+}\pi^{-}$ final state, and observe
different characteristics for the $\bar{p}\pi$ combination in neutral versus
doubly-charged $\Sigma_{c}$ decays.
02/2013;
-
BaBar Collaboration,
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
A. Palano,
G. Eigen,
B. Stugu,
D. N. Brown, [......],
R. J. Sobie,
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We report on a search for direct CP asymmetry in the singly
Cabibbo-suppressed decay D+- --> K+ K- pi+- using a data sample of 476 fb-1
accumulated with the BaBar detector running at and just below the Y(4S)
resonance. The CP-violating decay rate asymmetry A_CP is determined to be (0.35
+- 0.30 +- 0.15)%. Model-dependent and model-independent Dalitz plot analysis
techniques are used to search for CP-violating asymmetries in the various
intermediate states.
12/2012;
-
J P Lees,
V Poireau,
V Tisserand,
J Garra Tico,
E Grauges,
A Palano,
G Eigen,
B Stugu,
D N Brown,
L T Kerth, [......],
R J Sobie,
N Tasneem,
T J Gershon,
P F Harrison,
T E Latham,
H R Band,
S Dasu,
Y Pan,
R Prepost,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time-reversal violation. The decays of entangled neutral B mesons into definite flavor states (B^{0} or B[over ¯]^{0}), and J/ψK_{L}^{0} or cc[over ¯]K_{S}^{0} final states (referred to as B_{+} or B_{-}), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, B[over ¯]^{0}→B_{-} and B_{-}→B[over ¯]^{0}, as a function of the time difference between the two B decays. Using 468×10^{6} BB[over ¯] pairs produced in Υ(4S) decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding ΔS_{T}^{+}=-1.37±0.14(stat)±0.06(syst) and ΔS_{T}^{-}=1.17±0.18(stat)±0.11(syst). These nonzero results represent the first direct observation of T violation through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.
Physical Review Letters 11/2012; 109(21):211801. · 7.37 Impact Factor
-
J P Lees,
V Poireau,
V Tisserand,
J Garra Tico,
E Grauges,
A Palano,
G Eigen,
B Stugu,
D N Brown,
L T Kerth, [......],
N Tasneem,
T J Gershon,
P F Harrison,
T E Latham,
E M T Puccio,
H R Band,
S Dasu,
Y Pan,
R Prepost,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: The photon spectrum in the inclusive electromagnetic radiative decays of the B meson, B→X_{s}γ plus B→X_{d}γ, is studied using a data sample of (382.8±4.2)×10^{6}Υ(4S)→BB[over ¯] decays collected by the BABAR experiment at SLAC. The spectrum is used to extract the branching fraction B(B→X_{s}γ)=(3.21±0.33)×10^{-4} for E_{γ}>1.8 GeV and the direct CP asymmetry A_{CP}(B→X_{s+d}γ)=0.057±0.063. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the B meson rest frame.
Physical Review Letters 11/2012; 109(19):191801. · 7.37 Impact Factor
-
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
A. Palano,
G. Eigen,
B. Stugu,
D. N. Brown,
L. T. Kerth, [......],
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We use 429 fb-1 of e+e- collision data collected at the Υ(4S) resonance with the BABAR detector to measure the radiative transition rate of b→sγ with a sum of 38 exclusive final states. The inclusive branching fraction with a minimum photon energy of 1.9 GeV is found to be B(B̅ →Xsγ)=(3.29±0.19±0.48)×10-4 where the first uncertainty is statistical and the second is systematic. We also measure the first and second moments of the photon energy spectrum and extract the best-fit values for the heavy-quark parameters, mb and μπ2, in the kinetic and shape function models.
Phys. Rev. D. 09/2012; 86(5).
-
J P Lees,
V Poireau,
V Tisserand,
J Garra Tico,
E Grauges,
A Palano,
G Eigen,
B Stugu,
D N Brown,
L T Kerth, [......],
R J Sobie,
N Tasneem,
T J Gershon,
P F Harrison,
T E Latham,
H R Band,
S Dasu,
Y Pan,
R Prepost,
S L Wu
[show abstract]
[hide abstract]
ABSTRACT: Based on the full BABAR data sample, we report improved measurements of the ratios R(D^{(*)})=B(B[over ¯]→D^{(*)}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{(*)}ℓ_{ℓ}^{-}ν[over ¯]_{ℓ}), where ℓ is either e or μ. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D)=0.440±0.058±0.042 and R(D^{*})=0.332±0.024±0.018, which exceed the standard model expectations by 2.0σ and 2.7σ, respectively. Taken together, our results disagree with these expectations at the 3.4σ level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.
Physical Review Letters 09/2012; 109(10):101802. · 7.37 Impact Factor
-
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
A. Palano,
G. Eigen,
B. Stugu,
D. N. Brown,
L. T. Kerth, [......],
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: A precise measurement of the cross section of the process e+e-→π+π-(γ) 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-→μ+μ-(γ)γISR, which is found to agree with the next-to-leading-order QED prediction to within 1.1%. The cross section for the process e+e-→π+π-(γ) is obtained with a systematic uncertainty of 0.5% in the dominant ρ resonance region. The leading-order hadronic contribution to the muon magnetic anomaly calculated using the measured ππ cross section from threshold to 1.8 GeV is (514.1±2.2(stat)±3.1(syst))×10-10.
Phys. Rev. D. 08/2012; 86(3).
-
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
A. Palano,
G. Eigen,
B. Stugu,
D. N. Brown,
L. T. Kerth, [......],
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: In a sample of 471×106 BB̅ events collected with the BABAR detector at the PEP-II e+e- collider we study the rare decays B→K(*)ℓ+ℓ-, where ℓ+ℓ- is either e+e- or μ+μ-. We report results on partial branching fractions and isospin asymmetries in seven bins of dilepton mass-squared. We further present CP and lepton-flavor asymmetries for dilepton masses below and above the J/ψ resonance. We find no evidence for CP or lepton-flavor violation. The partial branching fractions and isospin asymmetries are consistent with the Standard Model predictions and with results from other experiments.
Phys. Rev. D. 08/2012; 86(3).
-
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli,
D. A. Milanes,
A. Palano,
M. Pappagallo,
G. Eigen, [......],
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We report measurements of partial branching fractions for inclusive charmless semileptonic B decays B̅ →Xuℓν̅ and the determination of the Cabibbo–Kobayashi–Maskawa (CKM) matrix element |Vub|. The analysis is based on a sample of 467×106 Υ(4S)→BB̅ decays recorded with the BABAR detector at the PEP-II e+e- storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions ΔB in several restricted regions of phase space and determine the CKM element |Vub| based on different QCD predictions. For decays with a charged lepton momentum pℓ*>1.0 GeV in the B meson rest frame, we obtain ΔB=(1.80±0.13stat±0.15sys±0.02theo)×10-3 from a fit to the two-dimensional MX-q2 distribution. Here, MX refers to the invariant mass of the final state hadron X and q2 is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract |Vub|=(4.33±0.24exp±0.15theo)×10-3 as the arithmetic average of four results obtained from four different QCD predictions of the partial rate. We separately determine partial branching fractions for B̅ 0 and B- decays and derive a limit on the isospin breaking in B̅ →Xuℓν̅ decays.
Phys. Rev. D. 08/2012; 86(3).
-
BABAR Collaboration,
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
A. Palano,
G. Eigen,
B. Stugu,
D. N. Brown, [......],
R. J. Sobie,
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We report the results of a study of the exclusive charmless semileptonic
decays, B^0 --> pi^- l^+ nu, B^+ --> pi^0 l^+ nu, B^+ --> omega l^+ nu, B^+ -->
eta l^+ nu and B^+ --> eta^' l^+ nu, (l = e or mu) undertaken with
approximately 462x10^6 B\bar{B} pairs collected at the Upsilon(4S) resonance
with the BABAR detector. The analysis uses events in which the signal B decays
are reconstructed with a loose neutrino reconstruction technique. We obtain
partial branching fractions in several bins of q^2, the square of the momentum
transferred to the lepton-neutrino pair, for B^0 --> pi^- l^+ nu, B^+ --> pi^0
l^+ nu, B^+ --> omega l^+ nu and B^+ --> eta l^+ nu. From these distributions,
we extract the form-factor shapes f_+(q^2) and the total branching fractions
BF(B^0 --> pi^- l^+ nu) = (1.45 +/- 0.04_{stat} +/- 0.06_{syst})x10^-4
(combined pi^- and pi^0 decay channels assuming isospin symmetry), BF(B^+ -->
omega l^+ nu) = (1.19 +/- 0.16_{stat} +/- 0.09_{syst})x10^-4 and BF(B^+ --> eta
l^+ nu) = (0.38 +/- 0.05_{stat} +/- 0.05_{syst})x10^-4. We also measure BF(B^+
--> eta^' l^+ nu) = (0.24 +/- 0.08_{stat} +/- 0.03_{syst})x10^-4. We obtain
values for the magnitude of the CKM matrix element V_{ub} by direct comparison
with three different QCD calculations in restricted q^2 ranges of B --> pi l^+
nu decays. From a simultaneous fit to the experimental data over the full q^2
range and the FNAL/MILC lattice QCD predictions, we obtain |V_{ub}| = (3.25 +/-
0.31)x10^-3, where the error is the combined experimental and theoretical
uncertainty.
08/2012;
-
J. P. Lees,
V. Poireau,
E. Prencipe,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli,
D. A. Milanes,
A. Palano,
M. Pappagallo, [......],
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We study the processes e+e-→K+K-π+π-γ, K+K-π0π0γ, and K+K-K+K-γ, where the photon is radiated from the initial state. About 84 000, 8000, and 4200 fully reconstructed events, respectively, are selected from 454 fb-1 of BABAR data. The invariant mass of the hadronic final state defines the e+e- center-of-mass energy, so that the K+K-π+π-γ data can be compared with direct measurements of the e+e-→K+K-π+π- reaction. No direct measurements exist for the e+e-→K+K-π0π0 or e+e-→K+K-K+K- reactions, and we present an update of our previous result based on a data sample that is twice as large. Studying the structure of these events, we find contributions from a number of intermediate states and extract their cross sections. In particular, we perform a more detailed study of the e+e-→ϕ(1020)ππγ reaction and confirm the presence of the Y(2175) resonance in the ϕ(1020)f0(980) and K+K-f0(980) modes. In the charmonium region, we observe the J/ψ in all three final states and in several intermediate states, as well as the ψ(2S) in some modes, and measure the corresponding products of branching fraction and electron width.
Phys. Rev. D. 07/2012; 86(1).
-
The BABAR Collaboration,
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
A. Palanoab,
G. Eigen,
B. Stugu,
D. N. Brown, [......],
R. J. Sobie,
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: Although CP violation in the B meson system has been well established by the
B factories, there has been no direct observation of time reversal violation.
The decays of entangled neutral B mesons into definite flavor states ($B^0$ or
$\bar{B}^0$), and $J/\psi K_S^0$ or $c\bar{c} K_S^0$ final states (referred to
as $B_+$ or $B_-$), allow comparisons between the probabilities of four pairs
of T-conjugated transitions, for example, $\bar{B}^0 \rightarrow B_-$ and $B_-
\rightarrow \bar{B}^0$, as a function of the time difference between the two B
decays. Using 468 million $B\bar{B}$ pairs produced in $\Upsilon(4S)$ decays
collected by the BABAR detector at SLAC, we measure T-violating parameters in
the time evolution of neutral B mesons, yielding $\Delta S_T^+ = -1.37 \pm 0.14
(stat.) \pm 0.06 (syst.)$ and $\Delta S_T^- = 1.17 \pm 0.18 (stat.) \pm 0.11
(syst.)$. These nonzero results represent the first direct observation of T
violation through the exchange of initial and final states in transitions that
can only be connected by a T-symmetry transformation.
07/2012;
-
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
D. A. Milanes,
A. Palano,
M. Pappagallo,
G. Eigen,
B. Stugu, [......],
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We present a search for the lepton flavor violating decay modes B±→h±τℓ (h=K, π; ℓ=e, μ) using the BABAR data sample, which corresponds to 472×106 BB̅ pairs. The search uses events where one B meson is fully reconstructed in one of several hadronic final states. Using the momenta of the reconstructed B, h, and ℓ candidates, we are able to fully determine the τ four-momentum. The resulting τ candidate mass is our main discriminant against combinatorial background. We see no evidence for B±→h±τℓ decays and set a 90% confidence level upper limit on each branching fraction at the level of a few times 10-5.
Phys. Rev. D. 07/2012; 86(1).
-
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
D. A. Milanes,
A. Palano,
M. Pappagallo,
G. Eigen,
B. Stugu, [......],
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We perform amplitude analyses of the decays B0→K+K-KS0, B+→K+K-K+, and B+→KS0KS0K+, and measure CP-violating parameters and partial branching fractions. The results are based on a data sample of approximately 470×106 BB̅ decays, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory. For B+→K+K-K+, we find a direct CP asymmetry in B+→ϕ(1020)K+ of ACP=(12.8±4.4±1.3)%, which differs from zero by 2.8σ. For B0→K+K-KS0, we measure the CP-violating phase βeff(ϕ(1020)KS0)=(21±6±2)°. For B+→KS0KS0K+, we measure an overall direct CP asymmetry of ACP=(4-5+4±2)%. We also perform an angular-moment analysis of the three channels and determine that the fX(1500) state can be described well by the sum of the resonances f0(1500), f2′(1525), and f0(1710).
Phys. Rev. D. 06/2012; 85(11).
-
P. del Amo Sanchez,
J. P. Lees,
V. Poireau,
E. Prencipe,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli,
A. Palano,
M. Pappagallo, [......],
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
K. T. Flood,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We present results for B-meson decay modes involving a charm meson, protons, and pions using 455×106 BB̅ pairs recorded by the BaBar detector at the SLAC PEP-II asymmetric-energy e+e- collider. The branching fractions are measured for the following ten decays: B̅ 0→D0pp̅ , B̅ 0→D*0pp̅ , B̅ 0→D+pp̅ π-, B̅ 0→D*+pp̅ π-, B-→D0pp̅ π-, B-→D*0pp̅ π-, B̅ 0→D0pp̅ π-π+, B̅ 0→D*0pp̅ π-π+, B-→D+pp̅ π-π-, and B-→D*+pp̅ π-π-. The four B- and the two five-body B̅ 0 modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(pp̅ ) and M(D(*)0p) invariant-mass distributions show enhancements near threshold values. In the four-body mode B̅ 0→D+pp̅ π-, the M(pπ-) distribution shows a narrow structure of unknown origin near 1.5 GeV/c2. The distributions for the five-body modes, in contrast to the others, are similar to the expectations from uniform phase-space predictions.
Phys. Rev. D. 05/2012; 85(9).
-
J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli,
D. A. Milanes,
A. Palano,
M. Pappagallo,
G. Eigen, [......],
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
C. O. Vuosalo,
S. L. Wu
[show abstract]
[hide abstract]
ABSTRACT: We present branching fraction measurements for the decays B0→ρ0K*0, B0→f0K*0, and B0→ρ-K*+, where K* is an S-wave (Kπ)0* or a K*(892) meson; we also measure B0→f0K2*(1430)0. For the K*(892) channels, we report measurements of longitudinal polarization fractions (for ρ final states) and direct CP violation asymmetries. These results are obtained from a sample of (471.0±2.8)×106 BB̅ pairs collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. We observe ρ0K*(892)0, ρ0(Kπ)0*0, f0K*(892)0, and ρ-K*(892)+ with greater than 5σ significance, including systematics. We report first evidence for f0(Kπ)0*0 and f0K2*(1430)0, and place an upper limit on ρ-(Kπ)0*+. Our results in the K*(892) channels are consistent with no direct CP violation.
Phys. Rev. D. 04/2012; 85(7).
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J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli,
D. A. Milanes,
A. Palano,
M. Pappagallo,
G. Eigen, [......],
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
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ABSTRACT: We present the first results on the Dalitz-plot structure and improved measurements of the time-dependent CP-violation parameters of the process B0→KS0KS0KS0 obtained using 468×106 BB̅ decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The Dalitz-plot structure is probed by a time-integrated amplitude analysis that does not distinguish between B0and B̅ 0 decays. We measure the total inclusive branching fraction B(B0→KS0KS0KS0)=(6.19±0.48±0.15±0.12)×10-6, where the first uncertainty is statistical, the second is systematic, and the third represents the Dalitz-plot signal model dependence. We also observe evidence for the intermediate resonant states f0(980), f0(1710), and f2(2010). Their respective product branching fractions are measured to be (2.70-1.19+1.25±0.36±1.17)×10-6, (0.50-0.24+0.46±0.04±0.10)×10-6, and (0.54-0.20+0.21±0.03±0.52)×10-6. Additionally, we determine the mixing-induced CP-violation parameters to be S=-0.94-0.21+0.24±0.06 and C=-0.17±0.18±0.04, where the first uncertainty is statistical and the second is systematic. These values are in agreement with the standard model expectation. For the first time, we report evidence of CP violation in B0→KS0KS0KS0 decays; CP conservation is excluded at 3.8 standard deviations including systematic uncertainties.
Phys. Rev. D. 03/2012; 85(5).
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J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli,
D. A. Milanes,
A. Palano,
M. Pappagallo,
G. Eigen, [......],
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
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ABSTRACT: We search for the Z1(4050)+ and Z2(4250)+ states, reported by the Belle Collaboration, decaying to χc1π+ in the decays B̅ 0→χc1K-π+ and B+→χc1KS0π+ where χc1→J/ψγ. The data were collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e+e- collider operating at center-of-mass energy 10.58 GeV, and correspond to an integrated luminosity of 429 fb-1. In this analysis, we model the background-subtracted, efficiency-corrected χc1π+ mass distribution using the Kπ mass distribution and the corresponding normalized Kπ Legendre-polynomial moments, and then test the need for the inclusion of resonant structures in the description of the χc1π+ mass distribution. No evidence is found for the Z1(4050)+ and Z2(4250)+ resonances, and 90% confidence level upper limits on the branching fractions are reported for the corresponding B-meson decay modes.
Phys. Rev. D. 03/2012; 85(5).
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J. P. Lees,
V. Poireau,
V. Tisserand,
J. Garra Tico,
E. Grauges,
M. Martinelli,
D. A. Milanes,
A. Palano,
M. Pappagallo,
G. Eigen, [......],
N. Tasneem,
T. J. Gershon,
P. F. Harrison,
T. E. Latham,
E. M. T. Puccio,
H. R. Band,
S. Dasu,
Y. Pan,
R. Prepost,
S. L. Wu
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ABSTRACT: We study the process e+e- -> pi+pi-pi+pi-gamma, with a photon emitted from
the initial-state electron or positron, using 454.3 fb^-1 of data collected
with the BABAR detector at SLAC, corresponding to approximately 260,000 signal
events. We use these data to extract the non-radiative sigma(e+e-
->pi+pi-pi+pi-) cross section in the energy range from 0.6 to 4.5 Gev. The
total uncertainty of the cross section measurement in the peak region is less
than 3%, higher in precision than the corresponding results obtained from
energy scan data.
01/2012;
