We present the first observation of the bottomonium ground state eta_b(1S) in the photon energy spectrum using a sample of 109+/-1 million of Upsilon(3S) events recorded at the Upsilon(3S) energy with the BaBar detector at the PEP-II B factory at SLAC. A peak at E_gamma = 921.2 {+2.1}{-2.8}(stat) +/- 2.4(syst) MeV observed with a significance of 10 standard deviations in the photon energy spectrum is interpretated as being due to the radiative transition Upsilon(3S) -> gamma eta_b(1S). This photon energy corresponds to an eta_b(1S) mass of 9388.9 {+3.1}{-2.3}(stat) +/- 2.7(syst) MeV/c2. The hyperfine Upsilon(1S)-eta_b(1S) mass splitting is 71.4 {+2.3}{-3.1}(stat) +/- 2.7(syst) MeV/c2. The branching fraction for this radiative Υ(3S) decay is obtained as (4.8 +/- 0.5(stat) +/- 1.2 (syst)) x 10^(-4).
We present studies in bottomonium spectroscopy carried out with samples of $(98\pm1)$ million $Υ(2S)$ and $(121\pm1)$ million $Υ(3S)$ events recorded with the BaBar detector at the PEP-II asymmetric-energy $e^+ e^-$ collider at SLAC. Precise measurements of the branching fractions for $χ_{b1,2}(1P, 2P)\rightarrow γΥ(1S)$ and $χ_{b1,2}(2P)\rightarrow γΥ(2S)$ transitions, and searches for radiative decay to the $η_b(1S)$ and $η_b(2S)$ states are performed using photons that have converted into an $e^+ e^-$ pair. In addition, we summarize the results of a search for the spin-singlet partner of th…
Originally designed for CP violation studies in the B meson system, the B-Factories recently showed an exciting capability for improving our experimental knowledge in the field of hadron spectroscopy. Here I will present some of the most recent BABAR results concerning bottomonium spectroscopy. In particular, I will report the first observation of the ground state eta_b in Y(nS) gamma eta_b and the results of an energy scan in the range of 10.54 to 11.20 GeV, that produced a new measurement of the e+e- -> bb cross section in the region of the Y(4S) and candidate Y(5S) and Y(6S) resonances, wit…
Spectroscopy results for Belle and BaBar are reported. A particular focus is put on new results of the X(3872) state with its radiative decays to $J$/$ψ$$γ$ and $ψ'$$γ$, its decay into $J$/$ψ$3$π$ and the search for production in radiative Upsilon decays. Another focus is $L$=2 mesons, in particlar a possible $D$-wave assignment to the X(3872) and the confirmation of an Upsilon $D$-wave state.
After nine years of operation the BABAR experiment at the B factory PEPII (Standford Linear Accelerator Center) stopped data taking in April 2008. The last three month of data taking were devoted to e+e- collisions at center of mass energies of the Upsilon(2S), Upsilon(3S) and to an energy scan above the Upsilon(4S). Besides the observation of the bottomonium ground state eta_b, the center of mass energy dependent e+e- -> b bbar cross section was measured in the energy range from 10.54 to 11.20 GeV. BELLE observed an enhancement in the production cross section for e+e- -> Upsilon(nS) pi+ pi- -…
We use $(121\pm1)$ million $Υ(3S)$ and $(98\pm1)$ million $Υ(2S)$ mesons recorded by the BABAR detector at the PEP-II $e^+e^-$ collider at SLAC to perform a study of radiative transitions involving the $χ_{b\mathrm{J}}(1P,2P)$ states in exclusive decays with $μ^+μ^-γγ$ final states. We reconstruct twelve channels in four cascades using two complementary methods. In the first we identify both signal photon candidates in the Electromagnetic Calorimeter (EMC), employ a calorimeter timing-based technique to reduce backgrounds, and determine branching-ratio products and fine mass splittings. These …
Results of the latest CLEO contribution to bottomonium spectroscopy is presented, the confirmation of the eta_b(1S0) ground state of bottomonium in the radiative decay Upsilon(3S) -> gamma eta_b. The bottomonium hyperfine splitting is determined to be Delta M_hf(1S) = 68.5+-6.6+-2.0 MeV and the branching fraction B(Upsilon(3S) -> gamma eta_b=(7.1+-1.8+-1.1)x10^-4. These results are in good agreement with those reported by BaBar.
We report the results of a search for the bottomonium ground state eta_b(1S) in the photon energy spectrum with a sample of (109 +/- 1) million of Upsilon(3S) recorded at the Upsilon(3S) energy with the BABAR detector at the PEP-II B factory at SLAC. We observe a peak in the photon energy spectrum at E_gamma = 921.2 {+2.1} {-2.8} (stat) +/- 2.4(syst) MeV with a significance of 10 standard deviations. We interpret the observed peak as being due to monochromatic photons from the radiative transition Upsilon(3S) -> gamma eta_b(1S). This photon energy corresponds to an eta_b(1S) mass of $9388.9 {+…
We review recent charmonium and bottomonium spectroscopy results from the B-factories Belle and \babar. A particular focus is given to the new $η_{c}(1S)$ and $η_{c}(2S)$ measurement and to the radiative transitions from $Υ(2S)$ and $Υ(3S)$ with converted photons.
We report on analyses of tau lepton decays $τ^- \to ηK^- ν_τ$ and $τ^- \to ηπ^- ν_τ$, with $η\to π^+ π^- π^0$, using 470 fb$^{-1}$ of data from the Babar experiment at PEP-II, collected at center-of-mass energies at and near the $Υ(4S)$ resonance. We measure the branching fraction for the $τ^- \to ηK^- ν_τ$ decay mode, $\Br(τ^- \to ηK^- ν_τ) = (1.42\pm0.11\text{(stat)}\pm0.07\text{(syst)})\times10^{-4}$, and report a 95% confidence level upper limit for the second-class current process $τ^- \to ηπ^- ν_τ$, $\Br(τ^- \to ηπ^- ν_τ) < 9.9\times10^{-5}$.
Recent BABAR results on two-photon processes are presented. A high statistics study of the two-photon production of the charmonium states eta_c and eta_c(2S) is performed. The mass and width of eta_c and eta_c(2S) are measured; the ratio of the decay probabilities to KS K+pi- and K+K-pi+pi-pi0 are determined. The latter mode is studied for the first time. The reactions e+e- --> e+e- gamma* gamma* --> e+e- + pseudoscalar meson are studied in the single-tag mode for pi0, eta, eta', and eta_c. From the measured differential cross sections the Q^2 dependencies of the photon-meson transition form f…
We review recent experimental results on Bd and Bs mesons decays by the BaBar and Belle experiments. These include measurements of the color-suppressed decays B0bar to D(*)0h0, h0=pi0, eta, etaprime, omega, observation of the baryonic decay B0bar to Lambdac+ Lambdabar K-, measurements of the charmless decays B to eta h, h=K, pi, B to Kpi and observation of CP eigenstates in the Bs decays: B0s to J/psi f0(980), B0s to J/psi f0(1370) and B0s to J/psi eta. The theoretical implications of these results will be considered.
We present measurements of branching fraction, polarization and charge asymmetry in charmless hadronic B decays with eta, eta', omega, and b_1 in the final state. All the results use the final BABAR dataset.
We report results from five analyses based on data taken with the BABAR detector at the PEP-II asymmetric e+e- collider. Included are branching fraction measurements for many B-meson decays involving eta, eta', omega, phi or a0 mesons and the final state Kspi+pi-, and a full angular analysis of the decay B->phiK*0.
A brief review of experimental results on charmonium and charmonium-like hadron spectroscopy at B-factories is presented. A special focus is put on recent results of eta_c and eta_c(2S) study, X(3872) radiative decays, omega J/psi final state study and search for charmonium production in radiative Upsilon decays.
We present measurements of the gamma gamma* --> pi0 transition form factor for the momentum transfer range Q^2=4-40 GeV^2 and the gamma gamma* --> eta_c transition form factor for the range Q^2=2-50 GeV^2. The results of the measurement of the eta_c mass, total and two-photon widths are also presented.
We present a measurement of the total width, Gamma_tot, and mass, M, of the eta_c meson with the BABAR detector at the PEP-II B-factory at SLAC. The results based on a data sample of 88 fb^-1 are Gamma_tot = (33.3 +- 2.5(stat.) +- 0.8(sys.))MeV and M = (2983.3 +- 1.2 +- 1.8) MeV. An enhancement observed around 3.63 GeV can be interpreted as an evidence for the eta_c(2S) state. In addition a preliminary measurement of the tau lepton lifetime using 30.2 fb^-1 is described. The measured tau lifetime is: (290.8 +- 1.5(stat.) +- 1.6(syst.))fs.
The Born cross section and dressed cross section of $e^+e^-$ to $b\bar{b}$ and the total hadronic cross section in $e^+e^-$ annihilation in the bottomonium energy region are calculated based on the Rb values measured by the BaBar and Belle experiments. The data are used to calculate the vacuum polarization factors in the bottomonium energy region, and to determine the resonant parameters of the vector bottomonium(-like) states, the Y(10750), Upsilon(5S), and Upsilon(6S).
We study inclusive di-pion decays using a sample of 108 x 10^6 Upsilon(3S) events recorded with the BABAR detector. We search for the decay mode Upsilon(3S) --> pi+ pi- h_b(1P) and find no evidence for the bottomonium spin-singlet state h_b(1P) in the invariant mass distribution recoiling against the pi+ pi- system. Assuming the h_b(1P) mass to be 9.900 GeV/c^2, we measure the upper limit on the branching fraction B[Upsilon(3S) --> pi+ pi- h_b(1P)] < 1.2 x 10^{-4}, at 90% confidence level. We also investigate the chi_{bJ}(2P) --> pi+ pi- chi_{bJ}(1P), Upsilon(3S) --> pi+ pi- Upsilon(2S), and U…
Recent experimental results on charmonium $h_c(^1P_1)$, $η_c(1S)$ and $η_c(2S)$ from Belle, BaBar, CLEO and BESIII are reviewed. $h_c$ production and properties, the $η_c(1S)$ lineshape and the observation of $η_c(2S)$ in $ψ'$ decays are discussed.
We have searched for the bottomonium eta_b(1S) via the hindered magnetic dipole (M1) photon transition Upsilon(3S) -> gamma eta_b(1S). No evidence for such a transition is found in the data sample of 4.7 x 10^6 Upsilon(3S)'s collected with the CLEO-III detector. We set upper limits on the branching ratio from 9.30 to 9.43 GeV/c^2 of eta_b(1S) masses. These upper limits rule out many previously published phenomenological estimates of the rate for this transition.
Using CLEO data, we report on the confirmation of the eta_b(1S0) ground state of bottomonium in the radiative decay Upsilon(3S) -> gamma eta_b. We determine its mass to be M(eta_b) = 9391.8 +- 6.6 +- 2.1 MeV, which corresponds to the hyperfine splitting Delta M_hf(1S) = 68.5 +- 6.6 +- 2.0 MeV, and the branching fraction B(Upsilon(3S) -> gamma eta_b) = (7.1 +- 1.8 +- 1.1) x 10^-4. These results agree with those previously reported by BaBar.
We present preliminary results of several searches for rare charmless hadronic decays of the B meson using data collected by the BABAR detector at the Stanford Linear Accelerator Center's PEP-II storage ring. We search for the decays h^+h^-, h^+h^-h^+, h^+h^-pi^0, X^0h^+, and X^0 K_S^0, where h = pi or K, and X^0 = eta^prime or omega. In a sample of 8.8 million B-anti-B decays we measure the branching fractions: BF(B^0 --> pi^+pi^-) = (9.3^{+2.6}_{-2.3}^{+1.2}_{-1.4}) x 10^{-6}, BF(B^0 --> K^+pi^-) = (12.5^{+3.0}_{-2.6}^{+1.3}_{-1.7}) x 10^{-6}, BF(B^0 --> rho^-pi^+) = (49 +/- 13^{+6}_{-5}) x …
Based on $122\times 10^6$ \ThreeS events collected with the \babar\ detector, we have observed the \OneDJ bottomonium state through the $\ThreeS\to\g\g\OneDJ\to\g\g\pip\pim\OneS$ decay chain.The significance for the $J=2$ member of the \OneDJ triplet is 5.8 standard deviations including systematic uncertainties.The mass of the $J=2$ state is determined to be $10164.5\pm0.8\,\rm{(stat.)}\pm0.5\,\rm{(syst.)}$~\mevcc.We use the $\pip\pim$ invariant mass distribution to confirm the consistency of the observed state with the orbital angular momentum assignment of the \OneDJ.
We report the updated results of direct CP violation measurements from Belle and BaBar for the following modes: B -> h+h-/h+-pi^0, B -> eta(') h+- and B -> K+-pi+-pi-+, where h stands for a charged kaon or pion. The data used in these studies are up to 386 million BBbar pairs for Belle and 232 million BBbar pairs for BaBar. The current significant measurements include: Acp(B -> K+ pi-)=-0.108+/-0.016, Acp(B -> rho0(770) K+)=0.31+0.11-0.10, and Acp(B -> eta K+)=-0.33+/-0.12.
Using 383 million BBbar 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 KKbar* or etapipi final states with mass in the range (1.2-1.8)gev/c^2. We observe a significant enhancement at the low KK*bar 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+ --> f_1(1285)K+, B+ --> f_1(1420)K+, and B+ --> phi(1680)K+.
We present preliminary measurements of the B meson decays B+->etapi+, B+->etaK+, and B0->etaK0. The data were recorded with the BABAR detector at PEP II and correspond to 88.9 million BBbar pairs produced in e+e- annihilation through the Upsilon(4S) resonance. We find the branching fractions B(B+->etapi+) = (4.2 +1.0-0.9 +/- 0.3)x 10^-6 and B(B+->etaK+) = (2.8 +0.8-0.7 +/-0.2)x10^-6. We set a 90% CL upper limit of B(B0->etaK0) < 4.6x10^-6. The time-integrated charge asymmetries are Ach(B+->etapi+) = -0.51 +0.20-0.18 +/-0.01 and Ach(B+->etaK+) = -0.32 +0.22-0.18 +/-0.01.
We present measurements of branching fractions for five B-meson decays to two-body charmless final states. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 459 million BBbar pairs. The results for branching fractions are, in units of 10^{-6} (upper limits at 90% C.L.): BR(B+ -> etarho+) = 9.9 +/- 1.2 +/- 0.8, BR(B0 -> eta'eta) = 0.5 +/- 0.4 +/- 0.1 (<1.2), BR(B0 -> etapi0) = 0.9 +/- 0.4 +/- 0.1 (<1.5), BR(B0 -> eta'pi0) = 0.9 +/- 0.4 +/- 0.1 (<1.5), and BR(B0 -> omegapi0) = 0.07 +/- 0.26 +/- 0.02 (<0.5). The first error quoted is statistical and …
We present measurements from Belle and BABAR of the time-dependent CP-violation parameters S and C in B->eta'K0 decays. Both experiments observe mixing-induced CP violation with a significance of more than 5 standard deviations in this b-> s penguin dominated mode. We also compare with theoretical expectations and discuss the latest results for SU(3)-related decays which are useful for obtaining bounds on the expected values of S and C.
The $η$ production in the $(n,n')$ bottomonium transitions $Υ(n) \to Υ(n') η, $ is studied in the method used before for dipion heavy quarkonia transitions. The widths $Γ_η(n,n')$ are calculated without fitting parameters for $n=2,3,4,5, n'=1$.Resulting $Γ_η(4,1)$ is found to be large in agreement with recent data.
We study the reaction e+e- --> e+e- eta_c, eta_c --> K_S K+- pi-+ and obtain eta_c mass and width values 2982.2+-0.4+-1.6 MeV/c^2 and 31.7+-1.2+-0.8 MeV, respectively. We find Gamma(eta_c --> gamma gamma)B(eta_c --> K anti-K pi)=0.374+-0.009+-0.031 keV, and measure the gamma gamma* --> eta_c transition form factor in the momentum transfer range from 2 to 50 GeV^2. The analysis is based on 469 fb-1 of integrated luminosity collected at PEP-II with the BABAR detector at e+e- center-of-mass energies near 10.6 GeV.
We present a preliminary measurement of CP-violating parameters S and C from fits of the time-dependence of B0 meson decays to eta' K0. The data were recorded with the BaBar detector at PEP-II and correspond to 227 * 10^6 B-Bbar pairs produced in e+e- annihilation through the Upsilon(4S) resonance. From a maximum likelihood fit we measure the CP-violation parameters S = 0.27 +/- 0.14 (stat) +/- 0.03 (syst) and C = -0.21 +/- 0.10 (stat) +/- 0.03 (syst).
We present a study of the charmless semileptonic B-meson decays B+ -> omega l+ nu and B+ -> eta l+ nu. The analysis is based on 383 million BBbar pairs recorded at the Upsilon(4S) resonance with the BABAR detector. The omega mesons are reconstructed in the channel omega -> pi+ pi- pi0 and the eta mesons in the channels eta -> pi+ pi- pi0 and eta -> gamma gamma. We measure the branching fractions B(B+ -> omega l+ nu) = (1.14 +- 0.16 (stat) +- 0.08 (syst)) x 10^-4 and B(B+ -> eta l+ nu) = (0.31 +- 0.06 (stat) +- 0.08 (syst)) x 10^-4.
We report a study of the processes e+e- -> eta gamma and e+e- -> etaprime gamma at a center-of-mass energy of 10.58 GeV, using a 232 fb^-1 data sample collected with the BABAR detector at the PEP-II collider at SLAC. We observe 20+6-5 eta gamma and 50+8-7 etaprime gamma events over small backgrounds, and measure the cross sections sigma(e+e- -> eta gamma) =4.5+1.2-1.1(stat)+-0.3(sys) fb and sigma(e+e- -> etaprime gamma)=5.4+-0.8(stat)+-0.3(sys) fb. The corresponding transition form factors at q^2 = 112 GeV^2 are q^2|F_eta(q^2)|=0.229+-0.030+-0.008 GeV, and q^2|F_etaprime(q^2)|=0.251+-0.019+-0.…
The mass and total width of the eta_c meson have been measured in two-photon interactions at the SLAC asymmetric B-Factory with the BABAR detector. With a sample of approximately 2500 reconstructed eta_c -> Ks K pi decays in 88 fb-1 of data, the measured eta_c mass and width are respectively 2982.5 +- 1.1 (stat) +- 0.9 (syst) MeV/c2 and 34.3 +- 2.3 (stat) +- 0.9 (syst) MeV/c2. Using the same decay mode, a second resonance with 112 +- 24 events is observed with a mass of 3630.8 +- 3.4 (stat) +- 1.0 (syst) MeV/c2 and width of 17.0 +- 8.3 (stat) +- 2.5 (syst) MeV/c2. This observation is consisten…
We search for evidence of a light Higgs boson (A0) in the radiative decays of the narrow Upsilon(3S) resonance: Upsilon(3S) -> gamma A0, where A0 -> invisible or A0 -> mu+mu-. Such an object appears in extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence for such processes in a sample of 122 million Upsilon(3S) decays collected by the BaBar collaboration at the PEP II B-factory, and set 90% C.L. upper limits on the product of the corresponding branching fractions. We also set a limit on the di-muon branching fraction of …
We report evidence for the $B$ meson decays, $B^\pm\to J/ψηK^\pm$ and $B^0\to J/ψηK^0_S$, using {90} million $B\bar B$ events collected at the $\ensuremath{Υ{(4S)}}$ resonance with the \babar detector at the PEP-II $e^+ e^-$ asymmetric-energy storage ring. We obtain preliminary branching fractions in the charged and neutral channels of $(10.8\pm 2.3(stat.)\pm 2.4(syst.))\times 10^{-5}$ and $(8.4\pm 2.6(stat.)\pm 2.7(syst.))\times 10^{-5}$, respectively.
We report preliminary measurements of the exclusive charmless semileptonic branching fractions of the B+ --> eta l+ nu and B+ --> eta' l+ nu decays. These measurements are based on 316 fb-1 of data collected at the Y(4S) resonance by the BABAR detector. In events in which the decay of one B meson to a hadronic final state is fully reconstructed, the semileptonic decay of the recoiling B meson is identified by the detection of a charged lepton and an eta or eta'. We measure the branching fraction BR(B+ --> eta l+ nu) = (0.84 +/- 0.27 +/- 0.21) x 10-4, where the first error is statistical and th…
A universal description of the hyperfine splittings (HFS) in bottomonium and the $B_q (q=n,s,c)$ mesons is obtained with a universal strong coupling constant $α_s(μ)=0.305(2)$ in a spin-spin potential. Other characteristics are calculated within the Field Correlator Method, taking the freezing value of the strong coupling independent of $n_f$. The HFS $M(B^*)- M(B)=45.3(3)$ MeV, $M(B_s^*) - M(B_s)=46.5(3)$ MeV are obtained in full agreement with experiment both for $n_f=3$ and $n_f=4$. In bottomonium, $M(Υ(9460))- M(η_b)=70.0(4)$ MeV for $n_f=5$ agrees with the BaBar data, while a smaller HFS,…
We report on recent measurements, from the BaBar and Belle experiments, of B-meson decays to purely hadronic final states that do not contain charm. The studies are based on large samples of BBbar pairs collected at the Upsilon(4S) or B_s(*)B_s(*) pairs collected at the Upsilon(5S) by the BaBar and Belle detectors at the asymmetric energy e+e- colliders at SLAC and KEK-B, respectively. This paper includes the following results: measurements of branching fractions and charge asymmetries of B meson decays to eta' rho, eta' f0, and eta' K*, where the K* stands for a vector, tensor, or scalar stra…
We have performed a search for the eta_b(1S) meson in the radiative decay of the Upsilon(2S) resonance using a sample of 91.6 million 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 E_gamma = 609.3 {+4.6} {-4.5} (stat) +/- 1.9 (syst) MeV, corresponding to an eta_b(1S) mass of 9394.2 {+4.8} {-4.9} (stat) +/- 2.0 (syst) MeV/c^2. The branching fraction for the decay Upsilon(2S) --> gamma eta_b(1S) is determined to be [3.9 +/-1.1 (stat) {+1.1} {-0.9} (syst)] x 10^(-4). We fin…
We report measurements of the decays B+ -> Phi Phi K+ and B0 -> hi Phi K0 using a sample of 231 million BBbar pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The branching fractions are measured to be Br(B+ -> Phi Phi K+) = (7.5 +/- 1.0 stat. +/- 0.7 syst.) * 10^-6 and Br(B0 -> Phi Phi K0) = (4.1 +1.7/-1.4 stat. +/- 0.4 syst.) * 10^-6 for a Phi Phi invariant mass below 2.85 GeV/c2.
We review selected recent Belle results in quarkonium physics, that include precision measurement of the eta_b(1S) parameters, evidence for the eta_b(2S); evidence for the psi_2(1D); observation of the psi(4040) and psi(4160) transitions to J/psi eta with anomalously high rates; observation of the Upsilon(5S) transitions to Upsilon(1D)pi+pi- and Upsilon(1S,2S)eta. The low excitations of charmonium and bottomonium are in agreement with the Lattice QCD and effective theories calculations, while high excitations show unexpected properties.
We report preliminary results of an experimental investigation of the color-suppressed decays bar{B^0} --> D^0 pi^0, D^0 eta, and D^0 omega. We measure the branching fractions B (bar{B^0} --> D^0 pi^0) = (2.89 +/- 0.29 (stat.) +/- 0.38 (syst.)) times 10^{-4}, B (\bar{B^0} \to D^0 η) = (2.41 \pm 0.39 (stat.) +/- 0.32 (syst.)) times 10^{-4}, and B (bar{B^0} --> D^0 omega) = (2.48 +/- 0.40 (stat.) +/- 0.32 (syst.)) times 10^{-4}. The results are based on (48.8 +/- 0.5) times 10^6 B B-bar pairs collected with the BaBar detector. The branching fractions of these color-suppressed decays are signific…
We report measurements of branching fractions for the decays B --> P l nu, where P are the pseudoscalar charmless mesons pi-, pi0, eta and eta', based on 348 fb-1 of data collected with the BABAR detector, using B0 and B+ mesons found in the recoil of a second B meson decaying as B --> D(*) l nu. Assuming isospin symmetry, we combine pionic branching fractions to obtain B(B0 --> pi- l+ nu) = (1.54 +/- 0.17(stat) +/- 0.09(syst)) x 10-4; we find 3.2 sigma evidence of the decay B+ --> eta l+ nu and measure its branching fraction to be (0.64 +/- 0.20 (stat) +/- 0.03 (syst)) x 10-4, and determine B…
The status of analysis of processes with hard photon emitted from the initial state (ISR) at BABAR is presented. We tag events by the presence of a hard photon in the detector, then reconstruct mu+mu- and several exclusive hadronic final states. The invariant mass of the final state determines an effective collision center of mass energy at which these measurements can be compared with results from direct e+e- annihilation process. The first results on e+e- --> 2h+2h-, where h=pi,K and on e+e- --> J/psi, obtained with a sample of 89.3/fb, are presented. Measurements of inclusive eta, pi+, K+ a…
The $η$ production in the $(n,n')$ bottomonium transitions $Υ(n) \to Υ(n') η, $ is studied in the method used before for dipion heavy quarkonia transitions. The widths $Γ_η(n,n')$ are calculated without fitting parameters for $n=2,3,4,5, n'=1$. Resulting $Γ_η(4,1)$ is found to be large in agreement with recent data. Multipole expansion method is shown to be inadequate for large size systems considered.
We study two-body $B$-meson decays to a charmonium state ($η_c$, $η_c(2S)$ or $h_c$) and a $K^+$ or $K^{*0}(892)$ meson using a sample of $349 fb^{-1}$ of data collected with the BABAR detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. We measure $BR(B^0\toη_c K^{*0})=(5.7\pm0.6 (stat)\pm0.9 (syst))\times 10^{-4}$, $BR(B^0\toη_c(2S) K^{*0})<3.9\times 10^{-4}$, $BR(B^+\to h_c K^+)\times BR(h_c\toη_cγ)<4.8\times 10^{-5}$ and $BR(B^0\to h_c K^{*0})\times BR(h_c\toη_cγ)<2.2\times 10^{-4}$ at the 90% C.L., and $BR(η_c(2S)\to K \bar{K} π)=(1.9\pm0.4 (stat) \pm1.1 (syst))%$. We also measur…
We study the Upsilon(3S,2S)->eta Upsilon(1S) and Upsilon(3S,2S)->pi+pi- Upsilon(1S) transitions with 122 million Upsilon(3S) and 100 million Upsilon(2S) mesons collected by the BaBar detector at the PEP-II asymmetric energy e+e- collider. We measure B[Upsilon(2S)->eta Upsilon(1S)]=(2.39+/-0.31(stat.)+/-0.14(syst.))10^-4 and Gamma[Upsilon(2S)->eta Upsilon(1S)]/Gamma[Upsilon(2S)-> pi+pi- Upsilon(1S)]=(1.35+/-0.17(stat.)+/-0.08(syst.))10^-3. We find no evidence for Upsilon(3S)->eta Upsilon(1S) and obtain B[Upsilon(3S)->eta Upsilon(1S)]<1.0 10^-4 and Gamma[Upsilon(3S)->eta Upsilon(1S)]/Gamma[Upsil…
We report the observation of the $B$ meson decay $B^\pm\to J/ψηK^\pm$ and evidence for the decay $B^0\to J/ψηK^0_S$, using {90} million $BBbar$ events collected at the $\ensuremath{Υ{(4S)}}\xspace$ resonance with the $BaBar$ detector at the PEP-II $e^+ e^-$ asymmetric-energy storage ring. We obtain branching fractions of $\cal{B}$$(B^\pm\to J/ψηK^{\pm}$)=$(10.8\pm 2.3(\rm{stat.})\pm 2.4(\rm{syst.}))\times 10^{-5}$ and $\cal{B}$$(B^0\to J/ψηK_{\rm{S}}^{0}$)=$(8.4\pm 2.6(\rm{stat.})\pm 2.7(\rm{syst.}))\times 10^{-5}$. We search for the new narrow mass state, the X(3872), recently reported by the…
We study the processes gamma gamma -> K^0_S K pi and gamma gamma -> K+ K- pi+ pi- pi0 using a data sample of 519.2 fb-1 recorded by the BaBar detector at the PEP-II asymmetric-energy e+e- collider at center-of-mass energies near the Upsilon(nS) (n = 2,3,4) resonances. We observe the eta_c(1S), chi_c0(1P) and eta_c(2S) resonances produced in two-photon interactions and decaying to K+K-pi+pi-pi0, with significances of 18.1, 5.4 and 5.3 standard deviations (including systematic errors), respectively, and report 4.0sigma evidence of the chi_c2(1P) decay to this final state. We measure the eta_c(2S…
We report a study of the process gamma gamma -> X -> eta_c pi+ pi-, where X stands for one of the resonances chi_{c2}(1P), eta_c(2S), X(3872), X(3915), or chi_{c2}(2P). The analysis is performed with a data sample of 473.9 fb^{-1} collected with the BaBar detector at the PEP-II asymmetric-energy electron-positron collider. We do not observe a significant signal for any channel, and calculate 90% confidence-level upper limits on the products of branching fractions and two-photon widths Gamma(X -> gamma gamma)BR(X -> eta_c pi+ pi-): 15.7 eV for chi_{c2}(1P), 133 eV for eta_c(2S), 11.1 eV for X(3…
Using a sample of 88.8 10**6 BBbar events collected with the BaBar detector at the PEP-II storage rings at the Stanford Linear Accelerator Center, we measure the branching fractions of seven color-suppressed B-meson decays: BF(B0bar to D0 pi0)=(2.9 +/- 0.2(stat.)+/- 0.3(syst.))*10**-4, BF(B0bar to D*0 pi0)=(2.9 +/- 0.4(stat.)+/- 0.5(syst.))*10**-4, BF(B0bar to D0 eta)=(2.5 +/- 0.2(stat.)+/- 0.3(syst.))*10**-4, BF(B0bar to D*0 eta)=(2.6 +/- 0.4(stat.)+/- 0.4(syst.))*10**-4, BF(B0bar to D0 omega)=(3.0 +/- 0.3(stat.)+/- 0.4(syst.))*10**-4, BF(B0bar to D*0 omega)=(4.2 +/- 0.7(stat.)+/- 0.9(syst.))…
We present a study of hadronic transitions between Y(mS) (m=4,3,2) and Y(nS) (n=2,1) resonances based on 347.5\invfb of data taken with the BABAR detector at the PEP-II storage rings. We report the first observation of Y(4S)-> eta Y(1S) decay with a branching fraction BR((Y(4S)->eta Y(1S))=(1.96+-0.06_{stat} +-0.09_{syst}) x 10^{-4} and measure the ratio of partial widths Gamma(Y(4S)->etaY(1S))/Gamma(Y(4S)->pi+pi-Y(1S))=2.41+- 0.40_{stat}+- 0.12_{syst}. We set 90% CL upper limits on the ratios Gamma(Y(2S)->etaY(1S))/Gamma(Y(2S)->pi+pi-Y(1S))<5.2 x10^{-3}$ and Gamma(Y(3S)->etaY(1S))/Gamma(Y(3S)…
We present an observation of $B\toη^\prime K^*$. The data sample corresponds to 232 million $B\bar{B}$ pairs collected with the BABAR detector at the PEP-II asymmetric-energy $B$ Factory at SLAC. We measure the branching fractions (in units of $10^{-6}$) $\mathcal{B}(B^0\toη^\prime K^{*0}) = 3.8\pm1.1\pm0.5$ and $\mathcal{B}(B^+\toη^\prime K^{*+}) = 4.9^{+1.9}_{-1.7}\pm0.8$, where the first error is statistical and the second systematic. A simultaneous fit results in the observation of $B\toη^\prime K^*$ with $\mathcal{B}(B\toη^\prime K^*) = 4.1_{-0.9}^{+1.0} \pm 0.5$. We also search for $B\to…
We report a study of the B meson decays, B+ -> J/psi phi K+, B0 -> J/psi phi K0S, B0 -> J/psi phi, B0 -> J/psi eta and B0 -> J/psi eta' using 56 million BBbar events collected at the Y(4S) resonance with the BABAR detector at the PEP-II e+ e- asymmetric-energy storage ring. We measure the branching fractions B(B+ -> J/psi phi K+) = (4.4 +- 1.4(stat) +- 0.5(syst)) * 10-5 and B(B0 -> J/psi phi K0S) = (5.1 +- 1.9(stat) +- 0.5(syst)) * 10^-5, and set upper limits at 90% confidence level for the branching fractions B(B0 -> J/psi phi) < 9.2 * 10^-6, B(B0 -> J/psi eta)< 2.7 * 10^-5, and B(B0 -> J/psi…
We present several recent results from the BaBar collaboration in the areas of initial state radiation physics and transition form factors. An updated study of the processes e+e- -> K+K-pi+pi- and e+e- -> K+K-pi0pi0 provides an improved understanding of the Y(2175) meson. A very precise study of the process e+e- -> pi+pi- improves the precision on the calculated anomalous magnetic moment of the muon and provides by far the best information on excited rho states. Our previous measurements of the timelike transition form factors (TFF) of the eta and eta' mesons at Q^2=112 GeV^2, combined with ne…
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 …
We report the observation of $\e^+e^-\to ϕη$ near $\sqrt{s}$ = 10.58 GeV with 6.5 $σ$ significance in the $K^+K^-γγ$ final state in a data sample of 224 $fb^{-1}$ collected by the BaBar experiment at the PEP-II $e^+e^-$ storage rings. We measure the restricted radiation-corrected cross section to be $σ(\e^+e^- \to ϕη) =$$2.1\pm 0.4 (\mathrm{stat})\pm 0.1(\mathrm{syst}) \mathrm{fb}$ within the range $|\cosθ^*| < 0.8$, where $θ^*$ is the center-of-mass polar angle of the $ϕ$ meson. The $ϕ$ meson is required to be in the invariant mass range of 1.008 $< m_ϕ <$ 1.035 \gevcc. The radiation-correcte…
We search for bottomonium states in Upsilon(2S)-> (bb-bar) gamma decays with an integrated luminosity of 24.7fb^-1 recorded at the Upsilon(2S) resonance with the Belle detector at KEK, containing (157.8+-3.6) X 10^6 Upsilon(2S) events. The (bb-bar) system is reconstructed in 26 exclusive hadronic final states composed of charged pions, kaons, protons, and K^0_S mesons. We find no evidence for the state recently observed around 9975 MeV (X_(bb-bar)) in an analysis based on a data sample of 9.3 X 10^6 Upsilon(2S) events collected with the CLEO III detector. We set a 90 % confidence-level upper l…
We report evidence for the ground state of bottomonium, eta_b(1S), in the radiative decay Upsilon(3S) --> gamma eta_b in e^+e^- annihilation data taken with the CLEO III detector. Using 6 million Upsilon(3S) decays, and assuming Gamma(eta_b) = 10 MeV/c^2, we obtain B(Upsilon(3S) --> gamma eta_b) = (7.1 +- 1.8 +- 1.1) X 10^{-4}, where the first error is statistical and the second is systematic. The statistical significance is about 4 sigma. The mass is determined to be M(eta_b) = 9391.8 +- 6.6 +- 2.0 MeV/c^2, which corresponds to the hyperfine splitting Delta M_{hf}(1S)_b = 68.5 +- 6.6 +- 2.0 M…
