80 research outputs found

    Power corrections in e+ e- --> pi+ pi-, K+ K- and B --> K pi, pi pi

    Get PDF
    CLEO-c measurements of the timelike form factors F_pi, F_K at \sqrt{s}=3.671 GeV provide a direct probe of power corrections (PC's) at energies near m_B. PC's in F_pi, F_K and B \to K pi, pi pi are separated into perturbative and soft parts. In F_pi, F_K the latter are \ge O(10) larger. A PC fit to the B \to K pi, pi pi data also yields a \ge O(10) soft-to-perturbative hierarchy for the QCD penguin PC's. Hence, both can be attributed to dominance of the soft-ovelap between energetic (approximately) back-to-back collinear partons, and consistency of the B\to K pi, pi pi fit with the Standard Model appears to be naturally realized. The CP asymmetries S_{K_s pi^0}, C_{K_s pi^0} are well determined, providing a clean test for new physics.Comment: 4 pages, 4 figures, version published in Eur. Phys. J. C; elaborated on the connection between power corrections in e+e- ->M1 M2 and the B-> M1 M2 QCD penguin amplitudes; removed speculation that soft-overlaps are much larger for PP than for VP and VV final states, this is not supported by a new analysis in preparatio

    New determination of the D0→K−π+π0 and D0→K−π+π+π− coherence factors and average strong-phase differences

    Get PDF
    AbstractMeasurements of the coherence factors (RKππ0 and RK3π) and the average strong-phase differences (δDKππ0 and δDK3π) for the decays D0→K−π+π0 and D0→K−π+π+π− are presented. These parameters are important inputs to the determination of the unitarity triangle angle γ in B∓→DK∓ decays, where D designates a D0 or D¯0 meson decaying to a common final state. The measurements are made using quantum correlated DD¯ decays collected by the CLEO-c experiment at the ψ(3770) resonance, and augment a previously published analysis by the inclusion of new events in which the signal decay is tagged by the mode D→KS0π+π−. The measurements also benefit from improved knowledge of external inputs, namely the D0D¯0 mixing parameters, rDKπ and several D-meson branching fractions. The measured values are RKππ0=0.82±0.07, δDKππ0=(164−14+20)°, RK3π=0.32−0.28+0.20 and δDK3π=(225−78+21)°. Consideration is given to how these measurements can be improved further by using the larger quantum-correlated data set collected by BESIII

    Final state interactions in the decay B0→ηcK∗B^0 \to \eta_c K^*

    Full text link
    In this article, we study the final-state rescattering effects in the decay B0→ηcK∗B^0 \to \eta_cK^*, the numerical results indicate the corrections are comparable with the contribution from the naive factorizable amplitude, and the total amplitudes can accommodate the experimental data.Comment: 11 pages, 1 figure, revised version, to appear in EPJ

    Search for Exotic Mesons in pi- P Interactions at 18 GeV/c

    Full text link
    The recent search for non qqˉq \bar{q} mesons in π−p\pi^{-}p interactions at Brookhaven National Laboratory is summarized. Many final states such as ηπ\eta \pi, η′π−\eta' \pi^{-}, a0πa_{0} \pi, f1πf_{1} \pi, a2πa_{2} \pi, b1πb_{1} \pi, which are favored decay modes of exotics, are under investigation.Comment: 9 pages, PostScript, Presented at the International School of Nuclear Physics, Erice, Sicily, Italy, September 199

    Confirmation of a pi_1^0 Exotic Meson in the \eta \pi^0 System

    Full text link
    The exclusive reaction π−p→ηπ0n\pi^- p \to \eta \pi^0 n, η→π+π−π0\eta \to \pi^+ \pi^- \pi^0 at 18 GeV/c/c has been studied with a partial wave analysis on a sample of 23~492 ηπ0n\eta \pi^0 n events from BNL experiment E852. A mass-dependent fit is consistent with a resonant hypothesis for the P+P_+ wave, thus providing evidence for a neutral exotic meson with JPC=1−+J^{PC} = 1^{-+}, a mass of 1257±20±251257 \pm 20 \pm 25 MeV/c2/c^2, and a width of 354±64±60354 \pm 64 \pm 60 MeV/c2/c^2. New interpretations of the meson exotics in neutral ηπ0\eta \pi^0 system observed in E852 and Crystal Barrel experiments are discussed.Comment: p3, rewording the paragraph (at the bottom) about the phase variations. p4, rewording paragrath "The second method ..." . p4, at the bottom of paragrath "The third method ..." added consistent with the results of methods 1 and 2

    Heavy quarkonium 2S states in light-front quark model

    Full text link
    We study the charmonium 2S states ψ′\psi' and ηc′\eta_c', and the bottomonium 2S states Υ′\Upsilon' and ηb′\eta_b', using the light-front quark model and the 2S state wave function of harmonic oscillator as the approximation of the 2S quarkonium wave function. The decay constants, transition form factors and masses of these mesons are calculated and compared with experimental data. Predictions of quantities such as Br(ψ′→γηc′)(\psi' \to \gamma \eta_c') are made. The 2S wave function may help us learn more about the structure of these heavy quarkonia.Comment: 5 latex pages, final version for journal publicatio

    Exotic Meson Production in the f1(1285)π−f_{1}(1285)\pi^{-} System observed in the Reaction π−p→ηπ+π−π−p\pi^{-} p \to \eta\pi^{+}\pi^{-}\pi^{-} p at 18 GeV/c

    Get PDF
    This letter reports results from the partial wave analysis of the π−π−π+η\pi^{-}\pi^{-}\pi^{+}\eta final state in π−p\pi^{-}p collisions at 18GeV/c. Strong evidence is observed for production of two mesons with exotic quantum numbers of spin, parity and charge conjugation, JPC=1−+J^{PC} = 1^{-+} in the decay channel f1(1285)π−f_{1}(1285)\pi^{-}. The mass M=1709±24±41M = 1709 \pm 24 \pm 41 MeV/c^2 and width Γ=403±80±115\Gamma = 403 \pm 80 \pm 115 MeV/c^2 of the first state are consistent with the parameters of the previously observed π1(1600)\pi_{1}(1600). The second resonance with mass M=2001±30±92M = 2001 \pm 30 \pm 92 MeV/c^2 and width Γ=333±52±49\Gamma = 333 \pm 52 \pm 49 MeV/c^2 agrees very well with predictions from theoretical models. In addition, the presence of π2(1900)\pi_{2}(1900) is confirmed with mass M=2003±88±148M = 2003 \pm 88 \pm 148 MeV/c^2 and width Γ=306±132±121\Gamma = 306 \pm 132 \pm 121 MeV/c^2 and a new state, a1(2096)a_{1}(2096), is observed with mass M=2096±17±121M = 2096 \pm 17 \pm 121 MeV/c^2 and width Γ=451±41±81\Gamma = 451 \pm 41 \pm 81 MeV/c^2. The decay properties of these last two states are consistent with flux tube model predictions for hybrid mesons with non-exotic quantum numbers

    Observation of a New J(PC)=1(+-) Isoscalar State in the Reaction Pi- Proton -> Omega Eta Neutron at 18 GeV/c

    Full text link
    Results are presented on a partial wave analysis of the Omega Eta final state produced in Pi- Proton interactions at 18 GeVc where Omega -> Pi+ Pi- Pi0, Pi0 -> 2 Gammas, and Eta -> 2 Gammas. We observe the previously unreported decay mode Omega(1650) -> Omega Eta and a new 1(+-) meson state h1(1595) with a mass M=1594(15)(+10)(-60) MeV/c^2 and a width Gamma=384(60)(+70)(-100) MeV/c^2. The h1(1595) state exhibits resonant-like phase motion relative to the Omega(1650).Comment: Submitted to Physics Letters B Eight total pages including 11 figures and 1 tabl

    Observation of Pseudoscalar and Axial Vector Resonances in pi- p -> K+ K- pi0 n at 18 GeV

    Get PDF
    A new measurement of the reaction pi- p -> K+ K- pi0 n has been made at a beam energy of 18 GeV. A partial wave analysis of the K+ K- pi0 system shows evidence for three pseudoscalar resonances, eta(1295), eta(1416), and eta(1485), as well as two axial vectors, f1(1285), and f1(1420). Their observed masses, widths and decay properties are reported. No signal was observed for C(1480), an IG J{PC} = 1+ 1{--} state previously reported in phi pi0 decay.Comment: 7 pages, 6 figs, to be submitted to Phys. Let

    Observation of a Narrow Resonance of Mass 2.46 GeV/c^2 Decaying to D_s^*+ pi^0 and Confirmation of the D_sJ^* (2317) State

    Full text link
    Using 13.5 inverse fb of e+e- annihilation data collected with the CLEO II detector we have observed a narrow resonance in the Ds*+pi0 final state, with a mass near 2.46 GeV. The search for such a state was motivated by the recent discovery by the BaBar Collaboration of a narrow state at 2.32 GeV, the DsJ*(2317)+ that decays to Ds+pi0. Reconstructing the Ds+pi0 and Ds*+pi0 final states in CLEO data, we observe peaks in both of the corresponding reconstructed mass difference distributions, dM(Dspi0)=M(Dspi0)-M(Ds) and dM(Ds*pi0)=M(Ds*pi0)-M(Ds*), both of them at values near 350 MeV. We interpret these peaks as signatures of two distinct states, the DsJ*(2317)+ plus a new state, designated as the DsJ(2463)+. Because of the similar dM values, each of these states represents a source of background for the other if photons are lost, ignored or added. A quantitative accounting of these reflections confirms that both states exist. We have measured the mean mass differences = 350.0 +/- 1.2 [stat] +/- 1.0 [syst] MeV for the DsJ*(2317) state, and = 351.2 +/- 1.7 [stat] +/- 1.0 [syst] MeV for the new DsJ(2463)+ state. We have also searched, but find no evidence, for decays of the two states via the channels Ds*+gamma, Ds+gamma, and Ds+pi+pi-. The observations of the two states at 2.32 and 2.46 GeV, in the Ds+pi0 and Ds*+pi0 decay channels respectively, are consistent with their interpretations as (c anti-strange) mesons with orbital angular momentum L=1, and spin-parities of 0+ and 1+.Comment: 16 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, version to be published in Physical Review D; minor modifications and fixes to typographical errors, plus an added section on production properties. The main results are unchanged; they supersede those reported in hep-ex/030501
    • …
    corecore