0000000000083082
AUTHOR
Patricia R. Burchat
Precise branching ratio measurements of the decaysD0→π−π+π0andD0→K−K+π0relative to theD0→K−π+π0decay
Using 232 fb-1 of e+e- collision data recorded by the BaBar experiment, we measure the ratios of three-body Cabibbo-suppressed decay rates of the D^0 meson relative to that of the Cabibbo-favored decay: B(D0 --> pi- pi+ pi0)/ B(D0 --> K- pi+ pi0) = (10.59 +/- 0.06 +/- 0.13).10^{-2} and B(D0 --> K- K+ pi0)/ B(D0 --> K- pi+ pi0) = (2.37 +/- 0.03 +/- 0.04). 10^{-2}, where the errors are statistical and systematic respectively. The precisions of these measurements are significantly better than those of the current world average values.We note that the second result differs significantly from the current world average value. Using the PDG-2006 value for D0 --> K- pi+ pi0 branching fraction, we o…
Observation of an Excited Charm BaryonΩc*Decaying toΩc0γ
We report the first observation of an excited singly-charm baryon OmegaC* (css) in the radiative decay OmegaC0 Gamma, where the OmegaC0 baryon is reconstructed in the decays to the final states Omega-pi+, Omega-pi+pi0, Omega-pi+pi-pi+, and Cascade-K-pi+pi+. This analysis is performed using a dataset of 230.7 fb$-1} collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The mass difference between the OmegaC* and the OmegaC0 baryons is measured to be 70.8 +/- 1.0 (stat) +/- 1.1 (syst) MeV/c2. We also measure the ratio of inclusive production cross sections of OmegaC* and OmegaC0 in e+e- annihilation.
Measurement of branching fractions in radiativeBdecays toηKγand search forBdecays toη′Kγ
We present measurements of the B ->eta K gamma branching fractions and upper limits for the B ->eta K-'gamma branching fractions. For B+->eta K+gamma we also measure the time-integrated charge asymmetry. The data sample, collected with the BABAR detector at the Stanford Linear Accelerator Center, represents 232x10(6) produced B (B) over bar pairs. The results for branching fractions and upper limits at 90% confidence level in units of 10(-6) are: B(B-0 ->eta K-0 gamma)=11.3(-2.6)(+2.8)+/- 0.6, B(B+->eta K+gamma)=10.0 +/- 1.3 +/- 0.5, B(B-0 ->eta K-'(0)gamma) eta K-'(+)gamma) eta K+gamma is A(ch)=-0.09 +/- 0.12 +/- 0.01. The first errors are statistical and the second systematic.
Evidence forB+→K¯0K+andB0→K0K¯0, and Measurement of the Branching Fraction and Search for DirectCPViolation inB+→K0π+
The authors present evidence for the b {yields} d penguin-dominated decays B{sup +} {yields} {bar K}{sup 0}K{sup +} and B{sup 0} {yields} K{sup 0}{bar K}{sup 0} with significances of 3.5 and 4.5 standard deviations, respectively. The results are based on a sample of 227 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. We measure the branching fractions {Beta}(B{sup +} {yields} {bar K}{sup 0}K{sup +}) = (1.5 {+-} 0.5 {+-} 0.1) x 10{sup -6} (< 2.4 x 10{sup -6}) and {Beta}(B{sup 0} {yields} K{sup 0}{bar K}{sup 0}) = (1.19{sub -0.35}{sup +0.40} {+-} 0.13) x 10{sup -6}, where the uncertainties are …
Measurements of the decaysB0→D¯0pp¯,B0→D¯*0pp¯,B0→D−pp¯π+, andB0→D*−pp¯π+
We present measurements of branching fractions of $B^0$ decays to multi-body final states containing protons, based on 232 million $\Upsilon(4S)\to B\bar{B}$ decays collected with the BaBar detector at the SLAC PEP-II asymmetric-energy $B$ factory. We measure the branching fractions ${\cal B}(B^0 \to \bar{D}^0\proton\antiproton)=(1.13\pm0.06\pm0.08)\times 10^{-4}$, ${\cal B}(B^0 \to \bar{D}^{*0}\proton\antiproton)=(1.01\pm0.10\pm0.09)\times 10^{-4}$, ${\cal B}(B^0 \to D^{-}\proton\antiproton\pi^+)=(3.38\pm0.14\pm0.29)\times 10^{-4}$, and ${\cal B}(B^0 \to D^{*-}\proton\antiproton\pi^+)=(4.81\pm0.22\pm0.44)\times 10^{-4}$ where the first error is statistical and the second systematic. We pre…
Branching fraction limits forB0decays toη′η,η′π0andηπ0
We describe searches for decays to two-body charmless final states eta(')eta, eta(')pi(0) and eta pi(0) of B-0 mesons produced in e(+)e(-) annihilation. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 232x10(6) produced B (B) over bar pairs. The results for branching fractions are, in units of 10(-6) (upper limits at 90% C.L.): B(B-0->eta(')eta)=0.2(-0.5)(+0.7)+/- 0.4( eta pi(0))=0.6(-0.4)(+0.5)+/- 0.1( eta(')pi(0))=0.8(-0.6)(+0.8)+/- 0.1(< 2.1). The first error quoted is statistical and the second systematic.
Limit on theB0→ρ0ρ0Branching Fraction and Implications for the Cabibbo-Kobayashi-Maskawa Angleα
The authors search for the decay B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} in a data sample of about 227 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. They find no significant signal and set an upper limit of 1.1 x 10{sup -6} at 90% CL on the branching fraction. As a result, the uncertainty due to penguin contributions on the CKM unitarity angle {alpha} measured in B {yields} {rho}{rho} decays is 11{sup o} at 68% CL.
Measurement of the spin of the Xi(1530) resonance
The properties of the Xi(1530) resonance are investigated in the Lambdac+ --> Xi- pi+ K+ decay process. The data sample was collected with the BaBar detector at the SLAC PEP-II asymmetric-energy e+ e- collider operating at center of mass energies 10.58 and 10.54 GeV. The corresponding integrated luminosity is approximately 230 inverse fb. The spin of the Xi(1530) is established to be 3/2. The existence of an S-wave amplitude in the Xi- pi+ system is inferred, and its interference with the Xi(1530)0 amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected for the Xi(1530). The P_1(cos[theta(Xi-)]) Legendre polynomial moment indicates the presence of a sig…
Study of the reactione+e−→J/ψπ+π−via initial-state radiation atBABAR
We study the process e +e -→J/ψπ +π - with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BABAR detector at center-of-mass energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454fb -1. We investigate the J/ψπ +π - mass distribution in the region from 3.5 to 5.5GeV/c2. Below 3.7GeV/c2 the ψ(2S) signal dominates, and above 4GeV/c2 there is a significant peak due to the Y(4260). A fit to the data in the range 3.74-5.50GeV/c2 yields a mass value 4245±5(stat)±4(syst)MeV/c2 and a width value 114-15+16(stat) ±7(syst)MeV for this state. We do not confirm the report from the Belle Collaboration of a broad stru…
Time-dependent and time-integrated angular analysis ofB→φKS0π0andφK±π∓
We perform a time-dependent and time-integrated angular analysis of the B{sup 0} {yields} {psi}K*(892){sup 0}, {psi}K*{sub 2}(1430{sup 0}), and {psi}(K{pi}){sub S-wave}{sup 0} decays with the final sample of about 465 million B{bar B} pairs recorded with the BABAR detector. Overall, twelve parameters are measured for the vector-vector decay, nine parameters for the vector-tensor decay, and three parameters for the vector-scalar decay, including the branching fractions, CP-violation parameters, and parameters sensitive to final state interaction. We use the dependence on the K{pi} invariant mass of the interference between the scalar and vector or tensor components to resolve discrete ambigu…
Measurement of branching fractions andCP-violating charge asymmetries forB-meson decays toD(*)D¯(*), and implications for the Cabibbo-Kobayashi-Maskawa angleγ
We present measurements of the branching fractions and charge asymmetries of B decays to all D^(*)D^(*) modes. Using 232×10^6 BB pairs recorded on the Υ(4S) resonance by the BABAR detector at the e^+e^- asymmetric B factory PEP-II at the Stanford Linear Accelerator Center, we measure the branching fractions B(B^0→D^(*+)D^(*-))=(8.1±0.6±1.0)×10^(-4), B(B^0→D^(*±)D^∓)=(5.7±0.7±0.7)×10^(-4), B(B^0→D^+D^-)=(2.8±0.4±0.5)×10^(-4), B(B^+→D^(*+)D^(*0))=(8.1±1.2±1.2)×10^(-4), B(B^+→D^*+D^0)=(3.6±0.5±0.4)×10^(-4), B(B^+→D^+D^(*0))=(6.3±1.4±1.0)×10^(-4), and B(B^+→D^+D^(0))=(3.8±0.6±0.5)×10^(-4), where in each case the first uncertainty is statistical and the second systematic. We also determine the l…
Review of Particle Properties
This biennial Review summarizes much of Particle Physics. Using data from previous editions, plus 2205 new measurements from 667 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. This edition features expanded coverage of CP violation in B mesons and of neutrino oscillations. For the fir…
Observation ofe+e−→ρ+ρ−nears=10.58 GeV
We report the first observation of e^+e^- → ρ^+ρ^-, in a data sample of 379 fb^(-1) collected with the BABAR detector at the PEP-II e+e- storage ring at center-of-mass energies near √s = 10:58 GeV. We measure a cross section of σ(e^+e^- → ρ^+ρ^-)= 8:3 ± 0:7(stat)± 0:8(syst) fb within the range of │cosθ^*│ < 0:8 and │ cosθ_±│ < 0:85, where θ^* is the center-of-mass polar angle of the ρ^± meson and θ_± are the angles in the ρ^± rest frame between the direction of the boost from the laboratory frame and the direction of the π^±. Assuming production through single-photon annihilation, there are three independent helicity amplitudes. We measure the ratios of their squared moduli to be │F_(00)│^2…
Search for flavor-changing neutral current and lepton-flavor violating decays of D-0 -> l(+)l(-)
We report on a search for the flavor-changing neutral current decays $\Dz\to e^+e^-$ and $\Dz\to\mu^+\mu^-$, and the lepton-flavor violating decay $\Dz\to e^\pm\mu^\mp$. The measurement is based on $122 {fb}^{-1}$ of data collected by the \babar detector at the PEP-II asymmetric $e^+e^-$ collider. No evidence is found for any of the decays. The upper limits on the branching fractions, at the 90 % confidence level, are $1.2\times 10^{-6}$ for $\Dz\to e^+e^-$, $1.3\times 10^{-6}$ for $\Dz\to\mu^+\mu^-$, and $8.1\times 10^{-7}$ for $\Dz\to e^\pm\mu^\mp$.
Measurement of the Spin of the Ω− Hyperon
A measurement of the spin of the Omega(-) hyperon produced through the exclusive process Xi(c)(0)--Omega(-)K(+) is presented using a total integrated luminosity of 116 fb(-1) recorded with the BABAR detector at the e(+)e(-) asymmetric-energy B factory at SLAC. Under the assumption that the Xi(c)(0) has spin 1/2, the angular distribution of the Lambda from Omega(-)--LambdaK(-) decay is inconsistent with all half-integer Omega(-) spin values other than 3/2. Lower statistics data for the process Omega(c)(0)--Omega(-)pi(+) from a 230 fb(-1) sample are also found to be consistent with Omega(-) spin 3/2. If the Xi(c)(0) spin were 3/2, an Omega(-) spin of 5/2 could not be excluded.
Search forBmeson decays toη′η′K
We describe searches for decays of B mesons to the charmless final states eta' eta' K. The data consist of 228 million B Bbar pairs produced in e+ e- annihilation, collected with the BaBar detector at the Stanford Linear Accelerator Center. The 90% confidence level upper limits for the branching fractions are Br(B0->eta' eta' K0) eta' eta' K+)<25 10^{-6}.
Search for the Radiative DecaysB→ργandB0→ωγ
A search for the exclusive radiative decays B {yields} {rho}(770){gamma} and B{sup 0} {yields} {omega}(782){gamma} is performed on a sample of about 84 million B{bar B} events collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring. No significant signal is seen in any of the channels. We set upper limits on the branching fractions {Beta} of {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) < 1.2 x 10{sup -6}, {Beta}(B{sup +} {yields} {rho}{sup +}{gamma}) < 2.1 x 10{sup -6}, and {Beta}(B{sup 0} {yields} {omega}{gamma}) < 1.0 x 10{sup -6} at 90% confidence level (C.L.). Using the assumption that {Lambda}(B {yields} {rho}{gamma}) = {Lambda}(B{sup +} {yields} …
Evidence of a Broad Structure at an Invariant Mass of4.32 GeV/c2in the Reactione+e−→π+π−ψ(2S)Measured atBABAR
The authors measure the cross section for the process e{sup +}e{sup -} {yields} {pi}{sup +}{pi}{sup -}{psi}(2S) from threshold up to 8 GeV center-of-mass energy using events containing initial-state radiation, produced at the PEP-II e{sup +}e{sup -} storage rings. The study is based on 298 fb{sup -1} of data recorded with the BABAR detector. A structure is observed in the cross-section not far above threshold, near 4.32 GeV. This structure is not compatible with the Y(4260) previously reported by this experiment. A single resonance is adequate to describe the cross-section in the low-energy region (< 5.7 GeV).
Measurement of theB0→D*−Ds*+andDs+→ϕπ+branching fractions
The authors present measurements of the branching fractions {Beta}(B{sup 0} {yields} D*{sup -}D*{sub s}{sup +}) and {Beta}(D{sub s}{sup +} {yields} {phi}{pi}{sup +}), based on 123 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} B factory. A partial reconstruction technique is used to measure {Beta}(B{sup 0} {yields} D*{sup -}D*{sub s}{sup +}) and the decay chain is fully reconstructed to measure the branching fraction product {Beta}(B{sup 0} {yields} D*{sup -} D*{sub s}{sup +}) x {Beta}(D{sub s}{sup +} {yields} {phi}{pi}{sup +}). Comparing these two measurements provides a model-independent determination of …
Study of the decayB¯0→D*+ωπ−
We report on a study of the decay B0bar -> D*+ omega pi- with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232 million BBbar decays, we measure the branching fraction BF(B0bar -> D*+ omega pi-) = (2.88 +/- 0.21(stat.) +/- 0.31(syst.)) \times 10^{-3}. We study the invariant mass spectrum of the omega pi- system in this decay. This spectrum is in good agreement with expectations based on factorization and the measured spectrum in tau- -> omega pi- nu_tau. We also measure the polarization of the D*+ as a function of the omega pi- mass. In the mass region 1.1 to 1.9 GeV we measure the fraction of longitudinal polarization of the D*+ …
Measurement of Branching Fractions and Charge Asymmetries inB±→ρ±π0andB±→ρ0π±Decays, and Search forB0→ρ0π0
We present measurements of branching fractions and charge asymmetries in $B$-meson decays to ${\ensuremath{\rho}}^{+}{\ensuremath{\pi}}^{0}$, ${\ensuremath{\rho}}^{0}{\ensuremath{\pi}}^{+}$, and ${\ensuremath{\rho}}^{0}{\ensuremath{\pi}}^{0}$. The data sample comprises $89\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}B\overline{B}$ decays collected with the BABAR detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. We find the charge-averaged branching fractions $\mathcal{B}({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\rho}}^{+}{\ensuremath{\pi}}^{0})=[10.9\ifmmode\pm\else\textpm\fi{}1.9\mathrm{(}\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{…
Study ofB±→J/ψπ±andB±→J/ψK±Decays: Measurement of the Ratio of Branching Fractions and Search for DirectCPViolation
Decays that measure the ratio of branching fractions and searches for direct CP violations were analyzed. The decays were collected with the BABAR detector at the PEP-II asymmetric B factory at SLAC. The fitted asymmetries for the small observed differences in the tracking efficiency were corrected between positively and negatively charged track. It was found that the uncertainty in the fixed parameters of the PDFs, determined by fits to stimulated or nonsignal data sets, contributed 0.001 to the systematic errors.
Measurements of neutralBdecay branching fractions toKS0π+π−final states and the charge asymmetry ofB0→K*+π−
Branching fraction measurements using B-meson decays to Kspi+pi- are presented. These measurements were obtained by analyzing a data sample of 88.9 million Y(4S) --> BB decays collected with the BaBar detector at the SLAC PEP-II asymmetric-energy B factory. Using a maximum likelihood fit, the following branching fraction results were obtained: Br(B0 -> K0pi+pi- = (43.7 +/- 3.8 +/- 3.4) * 10^-6, Br(B0 --> K{*+}pi-) = (12.9 +/- 2.4 +/- 1.4) * 10$^-6} and Br(B0 --> D-(--> Kspi-)pi+ = (42.7 +/- 2.1 +/- 2.2) * 10^{-6}. The CP violating char ge asymmetry A(K*pi} for the decay B0 --> $K{*+}pi-$ was measured to be A(K*pi} = 0.23 +/- $0.18^{+0.09}_{-0.06}$. For all these measurements the first error…
Branching fraction measurements of chargedBdecays toK*+K+K−,K*+π+K−,K*+K+π−andK*+π+π−final states
Branching fraction and asymmetry measurements of charmless B+-> K(*+)h(1)(+)h(2)(-) (where h(1,2)=K, pi) decays are presented, using a data sample of 232x10(6) Upsilon(4S)-> B (B) over bar decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. Using a maximum likelihood fit, the following branching fraction results were obtained: B(B+-> K*+K+K-)=(36.2 +/- 3.3 +/- 3.6)x10(-6) and B(B+-> K*+pi(+)pi(-))=(75.3 +/- 6.0 +/- 8.1)x10(-6). Upper limits were set for B(B+-> K*+pi K-+(-)) K*+K+pi(-)) K*+K+K- and B+-> K*+pi(+)pi(-) were measured to be A(K)(*)KK=0.11 +/- 0.08 +/- 0.03 and A(K)(*)pi pi=0.07 +/- 0.07 +/- 0.04, respectively. The first error quoted on branch…
Measurement of Branching Fractions and Charge Asymmetries inBDecays to anηMeson and aK*Meson
We present measurements of branching fractions and charge asymmetries for the decays B-->etaK*, where K* indicates a spin 0, 1, or 2 Kpi system. The data sample corresponds to 344x10(6) BB pairs collected with the BABAR detector at the PEP-II asymmetric-energy e+ e- collider at SLAC. We measure the branching fractions (in units of 10(-6): B(B0-->etaK*0(892))=16.5+/-1.1+/-0.8, B(B+-->etaK*+(892))=18.9+/-1.8+/-1.3, B(B0-->eta(Kpi)0*0)=11.0+/-1.6+/-1.5, B(B+-->eta(Kpi)0*+)=18.2+/-2.6+/-2.6, B(B0-->etaK2*0(1430))=9.6+/-1.8+/-1.1, and B(B+-->etaK2*+(1430))=9.1+/-2.7+/-1.4. We also determine the charge asymmetries for all decay modes.
Evidence for theB0→pp¯K*0andB+→ηcK*+decays and study of the decay dynamics ofBmeson decays intopp¯hfinal states
With a sample of 232x10^6 Upsilon(4S)->BBbar events collected with the BaBar detector, we study the decays of B mesons to ppbarh final states, where h=pi+,Ks,K*0 or K*+. We report evidence for the B->ppbarK*0 decay, with a branching fraction (1.5+/-0.5(stat)+/-0.4(syst))x10^-6, and for the B+->eta_cK*+ decay, with the branching fraction of Br(B+->eta_cK*+)xBr(eta_c->ppbar)=(1.57^{+0.56}_{-0.45}(stat)^{+0.46}_{-0.36}(syst))x10^-6, and provide improved measurements of the branching fractions of the other modes of this type. We also report the measurements of the charge asymmetry consistent with zero in the B+->ppbarpi+, B0->ppbarK*0 and B+->ppbarK*+ modes. No evidence is found for the pentaqu…
Observation ofe+e−Annihilation into theC=+1Hadronic Final Statesρ0ρ0andϕρ0
The authors report the first observation of e{sup +}e{sup -} annihilations into states of positive C-parity, namely {rho}{sup 0}{rho}{sup 0} and {phi}{rho}{sup 0}. The two states are observed in the {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} and K{sup +}K{sup -} {pi}{sup +}{pi}{sup -} final states, respectively, in a data sample of 225 fb{sup -1} collected by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage rings at energies near {radical}s = 10.58 GeV. The distributions of cos {theta}*, where {theta}* is the center-of-mass polar angle of the {phi} meson or the forward {rho}{sup 0} meson, suggest production by two-virtual-photon annihilation. They measure cross sections within …
Measurement of branching fractions and charge asymmetries for exclusive B decays to charmonium
We report measurements of branching fractions and charge asymmetries of exclusive decays of neutral and charged B mesons into two-body final states containing a charmonium state and a light strange meson. The charmonium mesons considered are J/Psi, Psi(2S) and Chi_c1, and the light meson is either K or K*. We use a sample of about 124 million BBbar events collected with the BABAR detector at the PEP-II storage ring at the Stanford Linear Accelerator Center.
Precision measurement of the Λ+c baryon mass
The $\Lambda_c^+$ baryon mass is measured using $\Lambda_c^+\to\Lambda K^0_S K^+$ and $\Lambda_c^+\to\Sigma^0 K^0_S K^+$ decays reconstructed in 232 fb$^{-1}$ of data collected with the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ storage ring. The $\Lambda_c^+$ mass is measured to be $2286.46\pm0.14\mathrm{MeV}/c^2$. The dominant systematic uncertainties arise from the amount of material in the tracking volume and from the magnetic field strength.
Measurements of the Absolute Branching Fractions of B±→K±Xcc̅
We study the two-body decays of ${B}^{\ifmmode\pm\else\textpm\fi{}}$ mesons to ${K}^{\ifmmode\pm\else\textpm\fi{}}$ and a charmonium state ${X}_{c\overline{c}}$ in a sample of $210.5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data from the BABAR experiment. We perform measurements of absolute branching fractions $\mathcal{B}({B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{K}^{\ifmmode\pm\else\textpm\fi{}}{X}_{c\overline{c}})$ using a missing mass technique, and report several new or improved results. In particular, the upper limit $\mathcal{B}\mathbf{(}{B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{K}^{\ifmmode\pm\else\textpm\fi{}}X(3872)\mathbf{)}l3.2\ifmmode…
Search for a light Higgs boson decaying to two gluons orss¯in the radiative decays ofΥ(1S)
We search for the decay Υ(1S)→γA^0, A^0→gg or ss , where A^0 is the pseudoscalar light Higgs boson predicted by the next-to-minimal supersymmetric Standard Model. We use a sample of (17.6±0.3)×10^6 Υ(1S) mesons produced in the BABAR experiment via e^+e^-→Υ(2S)→π^+π^-Υ(1S). We see no significant signal and set 90%-confidence-level upper limits on the product branching fraction B(Υ(1S)→γA^0)·B(A^0→gg or ss) ranging from 10^(-6) to 10^(-2) for A^0 masses in the range 0.5–9.0 GeV/c^2.
Measurement of theD+→π+π0andD+→K+π0branching fractions
We present measurements of the branching fractions for the Cabbibo suppressed decays D+->pi(+)pi(0) and D+-> K+pi(0) based on a data sample corresponding to an integrated luminosity of 124.3 fb(-1). The data were taken with the BABAR detector at the PEP-II B Factory operating on and near the Upsilon(4S) resonance. We find B(D+->pi(+)pi(0))=(1.25 +/- 0.10 +/- 0.09 +/- 0.04)x10(-3) and B(D+-> K+pi(0))=(2.52 +/- 0.47 +/- 0.25 +/- 0.08)x10(-4), where the first uncertainty is statistical, the second systematic and the last error is due to the uncertainties in the absolute branching fraction scale for D+ mesons. This represents the first observation of the doubly Cabibbo-suppressed D+-> K+pi(0) d…
Search for the decayB0→J/ψγ
We present the results of a search for the radiative decay B0 --> J/psi gamma in a data set containing 123 million Y(4S)--> B B-bar decays, collected by the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring at SLAC. We find no evidence for a signal and place an upper limit of B(B0 --> J/psi gamma) < 1.6 x 10^-6 at 90% confidence level.
Measurement ofCPobservables for the decaysB±→DCP0K*±
We present a study of the decay B^- → D^0_(CP)K^± and its charge conjugate, where D^0_CP) is reconstructed in CP-even, CP-odd, and non-CP flavor eigenstates, based on a sample of 232 x 10^6 Y(4S) → BB decays collected with the BABAR detector at the PEP-II e^+e^- storage ring. We measure the partial-rate charge asymmetries A_(CP±) and the ratios R_(CP±) of the B → D^0K decay branching fractions as measured in CP^± and non-CP D^0 decays: A_(CP±) 0:35 ± 0.13(stat) ± 0.04(syst), A_(CP-)= -0.06 ± 0.13(stat) ± 0.04(syst), R_(CP+) = 0.90 ± 0.12(stat) ± 0.049syst), and R_(CP-) = 0:86 ± 0.10(stat) ± 0.05(syst).
Measurement of branching fractions andCPand isospin asymmetries forB→K*γ
We present a preliminary analysis of the decays B{sup 0} {yields} K*{sup 0}{gamma} and B{sup +} {yields} K*{sup +}{gamma} using a sample of 383 million B{bar B} events collected with the BABAR detector at the PEP-II asymmetric energy B factory. We measure the branching fractions {Beta}(B{sup 0} {yields} K*{sup 0}{gamma}) = (4.58 {+-} 0.10 {+-} 0.16) x 10{sup -5} and {Beta}(B{sup +} {yields} K*{sup +}{gamma}) = (4.73 {+-} 0.15 {+-} 0.17) x 10{sup -5}. We measure the direct CP asymmetry to be -0.043 < {Alpha}(B {yields} K*{gamma}) < 0.025 and the isospin asymmetry to be -0.021 < {Delta}{sub 0-} < 0.079, where the limits are determined at the 90% confidence interval and include both the statis…
Study of thee+e−→π+π−π0process using initial state radiation withBABAR
The process e+e- --> pi+ pi- pi0 gamma has been studied at a center-of-mass energy near the Y(4S) resonance using a 89.3 fb-1 data sample collected with the BaBar detector at the PEP-II collider. From the measured 3pi mass spectrum we have obtained the products of branching fractions for the omega and phi mesons, B(omega --> e+e-)B(omega --> 3pi)=(6.70 +/- 0.06 +/- 0.27)10-5 and B(phi --> e+e-)B(phi --> 3pi)=(4.30 +/- 0.08 +/- 0.21)10-5, and evaluated the e+e- --> pi+ pi- pi0 cross section for the e+e- center-of-mass energy range 1.05 to 3.00 GeV. About 900 e+e- --> J/psi gamma --> pi+ pi- pi0 gamma events have been selected and the branching fraction B(J/psi --> pi+ pi- pi0)=(2.18 +/- 0.19…
Determinations of|Vub|from Inclusive SemileptonicBDecays with Reduced Model Dependence
We report two novel determinations of |V{sub ub}| with reduced model dependence, based on measurements of the mass distribution of the hadronic system in semileptonic B decays. 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 from {Upsilon}(4S) {yields} (B{bar B}) events. In one approach, we combine the inclusive {bar B} {yields} X{sub u}{ell}{bar {nu}} rate with a measurement of the inclusive B {yields} X{sub s}{gamma} photon energy spectrum. We obtain |V{sub ub}| = (4.43 {+-} 0.38{sub stat} {+-} 0.25{sub syst} {+-} 0.29{sub theo}) x 10{sup -3}. In another approach we measure the total {bar B} {yields}…
Evidence for the decayB±→K*±π0
We have measured the process B±→ (K*±→K±π0)π0 with 232×106 Υ(4S) →BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. From a signal yield of 89±26 events we obtain the branching fraction B(B±→K*±π0)=[6. 9±2.0(stat)±1.3(syst)]×10-6 with a statistical significance of 3.6 standard deviations including systematic uncertainties, and a charge asymmetry of 0.04±0.29(stat)±0.05(syst). © 2005 The American Physical Society.
Time-dependent Dalitz plot analysis ofB0→D∓K0π±decays
We present for the first time a measurement of the weak phase 2 beta+gamma obtained from a time-dependent Dalitz plot analysis of B-0 ->(DK0)-K--/+pi(+/-) decays. Using a sample of approximately 347x10(6) B (B) over bar pairs collected by the BABAR detector at the PEP-II asymmetric-energy storage rings and assuming the ratio r of the b -> u and b -> c decay amplitudes to be 0.3, we obtain 2 beta+gamma=(83 +/- 53 +/- 20)degrees and the equivalent solution at +180 degrees. The magnitudes and phases for the resonances associated with the b -> c transitions are also extracted from the fit.
Study of High Momentumη′Production inB→η′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. We find B(B --> eta'Xs) = [3.9 +/- 0.8(stat) +/- 0.5(syst) +/- 0.8(model)] x 10(-4). We also obtain the Xs mass spectrum and find that it fits models predicting high masses.
Measurement of Branching Fractions and Resonance Contributions forB0→D¯0K+π−and Search forB0→D0K+π−Decays
Using 226×10^6 Υ(4S)→BB events collected with the BABAR detector at the PEP-II e^+e^- storage ring at the Stanford Linear Accelerator Center, we measure the branching fraction for B^0→D^0K^+π^-, excluding B^0→D^(*-)K^+, to be B(B^0→D^0K^+π^-)=(88±15±9)×10^(-6). We observe B^0→D^0K^*(892)^0 and B^0→D_2^*(2460)^-K^+ contributions. The ratio of branching fractions B(B^0→D^(*-)K^+)/B(B^0→D^(*-)π^+)=(7.76±0.34±0.29)% is measured separately. The branching fraction for the suppressed mode B^0→D^0K^+π^- is B(B^0→D^0K^+π^-)<19×10^(-6) at the 90% confidence level.
Search for the Rare Leptonic Decay B+→μ+νμ
A search for the rare leptonic decay with data collected at the resonance by the BABAR experiment was carried out. The decay rate was sensitive to the product of the Cabibbo Kobayashi Maskawa matrix element (Vub and the B decay constant fb, which was propotional to the wave function for zero separation between the quarks. The data used in the analysis was collectd with BABAR detector at the PEP-II storage ring and the sample consisted of an integrity luminosity of 81.4 fb-1. The systematic uncertainty in the signal efficiency was evaluated which included the muon candidate selection and the reconstruction efficiency of the companion B.
Measurements of theB→D*form factors using the decayB¯0→D*+e−ν¯e
We measure the dependence of (B) over bar (0)-> D(*+)e(-)(B) over bar (e) on the decay angles and momentum transfer. The data sample consists of similar to 86x10(6) B (B) over bar -pairs accumulated on the Upsilon(4S) resonance by the BABAR detector at the asymmetric e(+)e(-) collider PEP-II. We specify the three form factors by two ratios R-1 and R-2, and by a single parameter rho(2) characterizing the polynomial representing h(A1), the function which describes the momentum-transfer dependence of the form factor A(1). We determine R-1, R-2, and rho(2) using an unbinned maximum likelihood fit to the full decay distribution. The results are R-1=1.396 +/- 0.060 +/- 0.035 +/- 0.027, R-2=0.885 …
Measurements of branching fractions, rate asymmetries, and angular distributions in the rare decays B→K + - and B→K* + -
We present measurements of the flavor-changing neutral current decays B -> K center dot(+)center dot(-) and B -> K-*center dot(+)center dot(-), where center dot(+)center dot(-) is either an e(+)e(-) or mu(+)mu(-) pair. The data sample comprises 229x10(6) Upsilon(4S)-> B (B) over bar decays collected with the BABAR detector at the PEP-II e(+)e(-) storage ring. Flavor-changing neutral current decays are highly suppressed in the standard model and their predicted properties could be significantly modified by new physics at the electroweak scale. We measure the branching fractions B(B -> K center dot(+)center dot(-))=(0.34 +/- 0.07 +/- 0.02)x10(-6), B(B -> K-*center dot(+)center dot(-))=(0.78(-…
Measurements of the Branching Fraction andCP-Violation Asymmetries inB0→f0(980)KS0
The authors present measurements of the branching fraction and CP-violating asymmetries in the decay B{sup 0} {yields} f{sub 0}(980)K{sub S}{sup 0}. The results are obtained from a data sample of 123 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays. From a time-dependent maximum likelihood fit they measure the branching fraction {Beta}(B{sup 0} {yields} f{sub 0}(980)({yields}{Pi}{sup +}{pi}{sup 0})K{sup 0}) = (6.0 {+-} 0.9 {+-} 0.6 {+-} 1.2) x 10{sup -6}, the mixing-induced CP violation parameter S = 1.62{sub -0.51}{sup +0.56} {+-} 0.09 {+-} 0.04 and the direct CP violation parameter C = 0.27 {+-} 0.36 {+-} 0.10 {+-} 0.07, where the first errors are statistical, the second systematic and …
Search for the decayB+→τ+ντ
We search for the rare leptonic decay B^+ → τ^+ν_τ in a sample of 232 × 10^6 BB pairs collected with the BABAR detector at the SLAC PEP-II B-Factory. Signal events are selected by examining the properties of the B meson recoiling against the semileptonic decay B^- → D^9*0)l^-ν_ l. We find no evidence for a signal and set an upper limit on the branching fraction of B(B^+ → τ^+ν_τ)<2.8 × 10^9-4) at the 90% confidence level. We combine this result with a previous, statistically independent BABAR search for B+→τ+ντ to give an upper limit of B(B^+ → τ^+ν_τ)<2.6 × 10^(-4) at the 90% confidence level.
Study ofX(3915)→J/ψωin two-photon collisions
We study the process $\gamma \gamma \to J/\psi \omega$ using a data sample of 519.2 $fb^{-1}$ recorded by the BaBar detector at SLAC at the PEP-II asymmetric-energy $e^+ e^-$ collider at center-of-mass energies near the $\Upsilon(nS)$ ($n = 2,3,4$) resonances. We confirm the existence of the charmonium-like resonance X(3915) decaying to $J/\psi \omega$ with a significance of 7.6 standard deviations, including systematic uncertainties, and measure its mass $(3919.4 \pm 2.2 \pm 1.6) MeV/c^2$ and width $(13 \pm 6 \pm 3) MeV$, where the first uncertainty is statistical and the second systematic. A spin-parity analysis supports the assignment $J^P=0^+$ and therefore the ident ification of the si…
Study of theX(3872)andY(4260)inB0→J/ψπ+π−K0andB−→J/ψπ+π−K−decays
We present results of a search for the X(3872) in B{sup 0}{yields}X(3872)K{sub S}{sup 0},X(3872){yields}J/{psi}{pi}{sup +}{pi}{sup -}, improved measurements of B{sup -}{yields}X(3872)K{sup -}, and a study of the J/{psi}{pi}{sup +}{pi}{sup -} mass region above the X(3872). We use 232x10{sup 6} BB pairs collected at the {upsilon}(4S) resonance with the BABAR detector at the PEP-II e{sup +}e{sup -} asymmetric-energy storage rings. The results include the 90% confidence interval 1.34x10{sup -6}<B(B{sup 0}{yields}X(3872)K{sup 0},X{yields}J/{psi}{pi}{sup +}{pi}{sup -})<10.3x10{sup -6} and the branching fraction B(B{sup -}{yields}X(3872)K{sup -},X{yields}J/{psi}{pi}{sup +}{pi}{sup -})=(10.1{+-}2.5…
Study ofB→DsJ(*)+D¯(*)Decays
We report a study of D-sJ(*)(2317)(+) and D-sJ(2460)(+) meson production in B decays. We observe the decays B+--> D-sJ((*)+)(D) over bar ((*)0) and B-0 --> DsJ(*)+D(*)- with the subsequent decays D-sJ(*)(2317)(+)-->D(s)(+)pi(0), D-sJ(2460)(+)-->D(s)(+)gamma, and D-sJ(2460)(+)-->D(s)(*+)pi(0). Based on a data sample of 122.1x10(6) B(B) over bar pairs collected with the BABAR detector at the PEP-II B factory, we obtain branching fractions for these modes, including the previously unseen decays B-->(DsJ(*)+D*). In addition, we perform an angular analysis of D-sJ(2460)(+)-->D(s)(+)gamma decays to test the different D-sJ(2460)(+) spin hypotheses.
InclusiveΛc+production ine+e−annihilations ats=10.54 GeVand inΥ(4S)decays
We present measurements of the total production rates and momentum distributions of the charmed baryon Lambda(+)(c) in e(+)e(-)-> hadrons at a center-of-mass energy of 10.54 GeV and in Upsilon(4S) decays. In hadronic events at 10.54 GeV, charmed hadrons are almost exclusively leading particles in e(+)e(-)-> cc events, allowing direct studies of c-quark fragmentation. We measure a momentum distribution for Lambda(+)(c) baryons that differs significantly from those measured previously for charmed mesons. Comparing with a number of models, we find none that can describe the distribution completely. We measure an average scaled momentum of =0.574 +/- 0.009 and a total rate of N-Lambda c(qq)=0.0…
Branching Fraction Measurements ofB+→ρ+γ,B0→ρ0γ, andB0→ωγ
The authors present a study of the decays B{sup +} {yields} {rho}{sup +}{gamma}, B{sup 0} {yields} {rho}{sup 0}{gamma}, and B{sup 0} {yields} {omega}{gamma}. The analysis is based on data containing 347 million B{bar B} events recorded with the BABAR detector at the PEP-II asymmetric B factory. They measure the branching fractions {Beta}(B{sup +} {yields} {rho}{sup +}{gamma}) = (1.10{sub -0.33}{sup +0.37} {+-} 0.09) x 10{sup -6} and {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) = (0.79{sub -0.20}{sup +0.22} {+-} 0.06) x 10{sup -6}, and set a 90% C.L. upper limit {Beta}(B{sup 0} {yields} {omega}{gamma}) < 0.78 x 10{sup -6}. They also measure the isospin-averaged branching fraction {Beta}[B {…
Measurement of Time-DependentCPAsymmetries inB0→D(*)±D∓Decays
We present updated results on time-dependent CP asymmetries in fully reconstructed B-0 -> D-(*)+/-pi(-/+) and B-0 -> D-+/-rho(-/+) decays in approximately 232x10(6) Upsilon(4S)-> B (B) over bar events collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. From a time-dependent maximum-likelihood fit we obtain for the parameters related to the CP violation angle 2 beta+gamma: a(D pi)=-0.010 +/- 0.023 +/- 0.007, c(lep)(D pi)=-0.033 +/- 0.042 +/- 0.012, a(D*)pi=-0.040 +/- 0.023 +/- 0.010, c(lep)(D*)pi=0.049 +/- 0.042 +/- 0.015,a(D rho)=-0.024 +/- 0.031 +/- 0.009, c(lep)(D rho)=-0.098 +/- 0.055 +/- 0.018, where the first error is statistical and the second is syste…
Observation ofB0Meson Decay toa1±(1260)π∓
We present a measurement of the branching fraction of the decay B-0 -> a(1)(+/-)(1260)pi(-/+) with a(1)(+/-)(1260)->pi(-/+)pi(+/-)pi(+/-). The data sample corresponds to 218x10(6) B (B) over bar pairs produced in e(+)e(-) annihilation through the Upsilon(4S) resonance. We measure the branching fraction B(B-0 -> a(1)(+/-)(1260)pi(-/+))B(a(1)(+/-)(1260)->pi(-/+)pi(+/-)pi(+/-))=(16.6 +/- 1.9 +/- 1.5)x10(-6), where the first error quoted is statistical and the second is systematic.