339 research outputs found

    Constructing Elliptic Curves over Q(T)\mathbb{Q}(T) with Moderate Rank

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    We give several new constructions for moderate rank elliptic curves over Q(T)\mathbb{Q}(T). In particular we construct infinitely many rational elliptic surfaces (not in Weierstrass form) of rank 6 over Q\mathbb{Q} using polynomials of degree two in TT. While our method generates linearly independent points, we are able to show the rank is exactly 6 \emph{without} having to verify the points are independent. The method generalizes; however, the higher rank surfaces are not rational, and we need to check that the constructed points are linearly independent.Comment: 11 page

    Update of the measurement of the cross section for e^+e^- -> psi(3770) -> hadrons

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    We have updated our measurement of the cross section for e^+e^- -> psi(3770) -> hadrons, our publication "Measurement of sigma(e^+e^- -> psi(3770) -> hadrons) at E_{c.m.} = 3773 MeV", arXiv:hep-ex/0512038, Phys.Rev.Lett.96, 092002 (2006). Simultaneous with this arXiv update, we have published an erratum in Phys.Rev.Lett.104, 159901 (2010). There, and in this update, we have corrected a mistake in the computation of the error on the difference of the cross sections for e^+e^- -> psi(3770) -> hadrons and e^+e^- -> psi(3770) -> DDbar. We have also used a more recent CLEO measurement of cross section for e^+e^- -> psi(3770) -> DDbar. From this, we obtain an upper limit on the branching fraction for psi(3770) -> non-DDbar of 9% at 90% confidence level.Comment: 3 pages, 0 figures. This is an erratum to Phys.Rev.Lett.96:092002,2006. Added a reference

    Di-electron Widths of the Upsilon(1S,2S,3S) Resonances

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    We determine the di-electron widths of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) resonances with better than 2% precision by integrating the cross-section of e+e- -> Upsilon over the e+e- center-of-mass energy. Using e+e- energy scans of the Upsilon resonances at the Cornell Electron Storage Ring and measuring Upsilon production with the CLEO detector, we find di-electron widths of 1.354 +- 0.004 (stat) +- 0.020 (syst) keV, 0.619 +- 0.004 +- 0.010 keV, and 0.446 +- 0.004 +- 0.007 keV for the Upsilon(1S), Upsilon(2S), and Upsilon(3S), respectively.Comment: 9 pages, 4 figures, also available through http://www.lns.cornell.edu/public/CLNS/2005/, published in PRL; corrected numerical values in abstrac

    Evidence for B^(*)_s bar{B}^(*)_s Production at the Upsilon(5S)

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    Using data collected by the CLEO III detector at CESR, we started a series of investigations on the Upsilon(5S) resonance decay properties. The data sample used for this analysis consists of 0.42 fb-1 of data taken on the Upsilon(5S) resonance, 6.34 fb-1 of data collected on the Upsilon(4S) and 2.32 fb-1 of data taken in the continuum below the Upsilon(4S). B_s mesons are expected to decay predominantly into D_s meson, while the lighter B mesons decay into D_s only about 10% of the time. We exploit this difference to make a preliminary model dependent estimate of the ratio of B_s(*) anti-B_s(*) to the total b anti-b quark pair production at the Upsilon(5S) energy to be (21 +- 3 +- 9)%.Comment: 17 pages postscript,also available through http://www.lns.cornell.edu/public/CONF/2004/, Presented at ICHEP Aug 16-22,2004, Beijing, Chin

    Observation of the Hadronic Transitions Chi_{b 1,2}(2P) -> omega Upsilon(1S)

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    The CLEO Collaboration has observed the first hadronic transition among bottomonium (b bbar) states other than the dipion transitions among vector states, Upsilon(nS) -> pi pi Upsilon(mS). In our study of Upsilon(3S) decays, we find a significant signal for Upsilon(3S) -> gamma omega Upsilon(1S) that is consistent with radiative decays Upsilon(3S) -> gamma chi_{b 1,2}(2P), followed by chi_{b 1,2} -> omega Upsilon(1S). The branching ratios we obtain are Br(chi_{b1} -> omega Upsilon(1S) = 1.63 (+0.35 -0.31) (+0.16 -0.15) % and Br(chi_{b2} -> omega Upsilon(1S) = 1.10 (+0.32 -0.28) (+0.11 - 0.10)%, in which the first error is statistical and the second is systematic.Comment: submitted to XXI Intern'l Symp on Lepton and Photon Interact'ns at High Energies, August 2003, Fermila

    New Measurements of Upsilon(1S) Decays to Charmonium Final States

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    Using substantially larger data samples collected by the CLEO III detector, we report on new measurements of the decays of Upsilon(1S) to charmonium final states, including J/Psi, psi(2S), and chi_cJ. The latter two are first observations of these decays. We measure the branching fractions as follows: B(Y(1S)--> J/Psi+X)=(6.4+-0.4+-0.6)x10^-4, B(Y(1S)--> psi(2S)+X)/B(Y(1S)--> J/Psi+X)=0.41+-0.11+-0.08, B(Y(1S)--> chi_c1+X)/B(Y(1S)--> J/Psi+X)=0.35+-0.08+-0.06, B(Y(1S)--> chi_c2+X)/B(Y(1S)--> J/Psi+X)=0.52+-0.12+-0.09, and B(Y(1S)--> chi_c0+X)/B(Y(1S)--> J/Psi+X)<7.4% at 90% confidence level. We also report on the momentum and angular spectra of J/Psi's in Upsilon(1S) decay. The results are compared to predictions of the color octet and color singlet models.Comment: 27 pages postscript,also available through http://w4.lns.cornell.edu/public/CLNS/, submitted to PR

    The Search for eta(1440) --> K^0_S K^pm \pi^mp in Two-Photon Fusion at CLEO

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    We analyze 13.8 \rm fb^{-1} of the integrated e^+e^- luminosity collected at 10.6 GeV center-of-mass energy with the CLEO II and CLEO II.V detectors to study exclusive two-photon production of hadrons with masses below 1.7{\rm \ GeV/c^2} decaying into the K^0_S K^\pm \pi^\mp final state. We observe two statistically significant enhancements in the \eta(1440) mass region. These enhancements have large transverse momentum which rules them out as being due to pseudoscalar resonances but is consistent with the production of axial-vector mesons. We use tagged two-photon events to study the properties of the observed enhancements and associate them with the production of f_1(1285) and f_1(1420). Our non-observation of \eta(1440) is inconsistent by more than two standard deviations with the first observation of this resonance in two-photon collisions by the L3 experiment. We present our estimates for 90% confidence level upper limits on the products of two-photon partial widths of pseudoscalar hadrons and their branching fractions into K^0_S(\pi^+\pi^-)K^\pm\pi^\mp.Comment: 24 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2004/, submitted to PR

    Radiative Decays of the Upsilon(1S) to a Pair of Charged Hadrons

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    Using data obtained with the CLEO~III detector, running at the Cornell Electron Storage Ring (CESR), we report on a new study of exclusive radiative Upsilon(1S) decays into the final states gamma pi^+ pi^-, gamma K^+ K^-, and gamma p pbar.. We present branching ratio measurements for the decay modes Upsilon(1S) to gamma f_2(1270), Upsilon(1S) to gamma f_2'(1525), and Upsilon(1S) to gamma K^+K^-; helicity production ratios for f_2(1270) and f_2'(1525); upper limits for the decay Upsilon(1S) to gamma f_J(2200), with f_J(2220) to pi^+ pi^-, K^+ K^-, p pbar; and an upper limit for the decay Upsilon(1S) to gamma X(1860), with X(1860) to gamma p pbar.Comment: 17 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2005/, Submitted to PR

    Study of tau Decays to Four-Hadron Final States with Kaons

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    The tau decays to four hadrons have been studied with the CLEO III detector at the Cornell Electron Storage Ring (CESR) using (7.56 +- 0.15) fb^{-1} of data collected near the Y(4S) resonance. We present the first statistically significant measurements of B(tau- -> K- pi+pi- pi0 nu, excluding K^0) = (7.4 +- 0.8 +- 1.1) x 10^{-4} and B(tau--> K- K+ pi- pi0 nu) = (5.5 +- 1.4 +- 1.2) x 10^{-5}, including the first observation of the decay, tau- -> K- omega nu, with branching fraction (4.1 +- 0.6 +- 0.7) x 10^{-4}. We also publish the first upper limit for B(tau- -> K- K+ K- pi0 nu) < 4.8 (6.1) x 10^{-6} at 90% (95%) confidence level (C.L.).Comment: 9 pages postscript, also available from http://www.lns.cornell.edu/public/CLNS/2004/, submitted to PR

    Photon transitions in Upsilon(2S) and Upsilon(3S)

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    We have studied the inclusive photon spectra in Upsilon(2S) and \Upsilon(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates and photon energies for Upsilon(2S)->gamma chi_bJ(1P) and Upsilon(3S)->gamma chi_bJ(2P) J=0,1,2. We measure the rate for a rare E1 transition Upsilon(3S)->gamma chi_b0(1P) for the first time. We also set upper limits on the rates for the hindered magnetic dipole (M1) transitions to the eta_b(1S) and eta_b(2S) states.Comment: 10 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2004/, submitted to PR
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