M. Goldberg

Limits on rare exclusive decays of B mesons

Abstract We have set upper limits for rare exclusive decays of B mesons arising from higher order processes in the standard model of electroweak interactions. Such decays may occur via “penguin diagrams” in B decay. We also set an upper limit on a lepton-number-violating decay mode of the neutral B meson.

Production of π0 at large transverse momentum in αα and αp collisions at the CERN intersecting storage rings

Abstract Inclusive π0 production has been measured at the CERN Intersecting Storage Rings in αα and αp collisions near 90°, for pT between 2 and 5 GeV/c. The differential cross sections show a slower exponential fall-off with pT than has been observed in pp collisions at the corresponding nucleon-nucleon centre-of-mass energies at large pT. The ratio of the π0 production cross sections for αα collisions to those for pp collisions is observed to be larger than 16.

Measurement of the isospin mass splitting Ξ+cΞ0c

Abstract Using the CLEO detector, we present a measurement of the mass of the charged charmed strange baryon Ξ + c and its neutral counterpart the Ξ 0 c . The Ξ + c is observed through its decay to Ξ - π + π + , and its mass is measured to be (2467±3±4) MeV. The isospin mass splitting of the Ξ c system is found to be M ( Ξ + c )- M ( Ξ 0 c )=(−5±4±1)MeV.

A measurement of the tau lifetime

The tau lepton lifetime is measured using four different methods with the DELPHI detector. Three measurements using one prong decays are combined, accounting for correlations, resulting in ττ=298 ±7 (stat.)±4 (syst.) fs while the decay length distribution of three prong decays gives ππ=298±13 (stat)±(syst.) fs. The combined result is ττ=298±7 fs. The ratio of the Fermi coupling constant from tau decay relative to that from muon decay is found to be 0.985±0.013, compatible with lepton universality.

Determination of B(Ds+) via observation of Ds+l+1/2

Using the CLEO detector at the Cornell Electron Storage Ring (CESR), we have determined the ratio {Gamma}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{ital l}{sup +}{nu})/{Gamma}({ital D}{sub {ital s}}{sup +} {r arrow}{phi}{pi}{sup +})=0.49{plus minus}0.10{sub {minus}0.14}{sup +0.10}. We use this measurement to derive {ital B}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{pi}{sup +}).

Measurement of γγ widths of charmonium states

Abstract Using the CLEO detector at the Cornell Electron Storage Ring, we have searched for two-photon production of charmonium in four-track final states. We have measured Γ γγ ( η c )=5.9 +2.1 −1.8 ±1.9 keV, and we have obtained 95% CL upper limits of Γ γγ ( X c 0 ) Γ γγ ( X c 2 )

Investigation of Semileptonic {ital B} Meson Decays to {ital p} -Wave Charm Mesons

We have studied semileptonic B meson decays with a P-wave charm meson in the final state using 3.29 × 10 BB̄ events collected by the CLEO II detector at the Cornell Electron-positron Storage Ring. We find a value for the exclusive semileptonic product branching fraction: B(B− → D 1`ν̄`)B(D 1 → Dπ) = (0.373 ± 0.085 ± 0.052 ± 0.024)% and an upper limit for B(B− → D 2 `ν̄`)B(D 2 → Dπ) < 0.16% (90% C.L.). These results indicate that at least 20% of the total B− semileptonic rate is unaccounted for by the observed exclusive decays, B− → D`ν̄, B− → D`ν̄, B− → D 1`−ν̄, and B− → D 2 `−ν̄. (Submitted to Physical Review Letters) SLAC-PUB-9836 hep-ex/9708035 Work supported in part by Department of Energy Contract DE-AC03-76SF00515 Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94309, USA A. Anastassov, J. E. Duboscq, D. Fujino, K. K. Gan, T. Hart, K. Honscheid, H. Kagan, R. Kass, J. Lee, M. B. Spencer, M. Sung, A. Undrus, R. Wanke, A. Wolf, M. M. Zoeller, B. Nemati, S. J. Richichi, W. R. Ross, P. Skubic, M. Bishai, J. Fast, J. W. Hinson, N. Menon, D. H. Miller, E. I. Shibata, I. P. J. Shipsey, M. Yurko, S. Glenn, S. D. Johnson, Y. Kwon, S. Roberts, E. H. Thorndike, C. P. Jessop, K. Lingel, H. Marsiske, M. L. Perl, V. Savinov, D. Ugolini, R. Wang, X. Zhou, T. E. Coan, V. Fadeyev, I. Korolkov, Y. Maravin, I. Narsky, V. Shelkov, J. Staeck, R. Stroynowski, I. Volobouev, J. Ye, M. Artuso, A. Efimov, M. Goldberg, D. He, S. Kopp, G. C. Moneti, R. Mountain, S. Schuh, T. Skwarnicki, S. Stone, G. Viehhauser, X. Xing, J. Bartelt, S. E. Csorna, V. Jain, K. W. McLean, S. Marka, R. Godang, K. Kinoshita, I. C. Lai, P. Pomianowski, S. Schrenk, G. Bonvicini, D. Cinabro, R. Greene, L. P. Perera, G. J. Zhou, B. Barish, M. Chadha, S. Chan, G. Eigen, J. S. Miller, C. O’Grady, M. Schmidtler, J. Urheim, A. J. Weinstein, F. Würthwein, D. W. Bliss, G. Masek, H. P. Paar, S. Prell, V. Sharma, D. M. Asner, J. Gronberg, T. S. Hill, D. J. Lange, S. Menary, R. J. Morrison, H. N. Nelson, T. K. Nelson, C. Qiao, J. D. Richman, D. Roberts, A. Ryd, M. S. Witherell, R. Balest, B. H. Behrens, W. T. Ford, H. Park, J. Roy, J. G. Smith, J. P. Alexander, C. Bebek, B. E. Berger, K. Berkelman, K. Bloom, D. G. Cassel, H. A. Cho, D. S. Crowcroft, M. Dickson, P. S. Drell, K. M. Ecklund, R. Ehrlich, A. D. Foland, P. Gaidarev, L. Gibbons, B. Gittelman, S. W. Gray, D. L. Hartill, B. K. Heltsley, P. I. Hopman, S. L. Jones, J. Kandaswamy, P. C. Kim, D. L. Kreinick, T. Lee, Y. Liu, N. B. Mistry, C. R. Ng, E. Nordberg, M. Ogg, J. R. Patterson, D. Peterson, D. Riley, A. Soffer, B. Valant-Spaight, C. Ward, M. Athanas, P. Avery, C. D. Jones, M. Lohner, C. Prescott, J. Yelton, J. Zheng, G. Brandenburg, R. A. Briere, A. Ershov, Y. S. Gao, D. Y.-J. Kim, R. Wilson, H. Yamamoto, aPermanent address: Lawrence Livermore National Laboratory, Livermore, CA 94551. bPermanent address: BINP, RU-630090 Novosibirsk, Russia. cPermanent address: Yonsei University, Seoul 120-749, Korea. dPermanent address: Brookhaven National Laboratory, Upton, NY 11973. ePermanent address: University of Texas, Austin TX 78712

Measurement of the Decay Amplitudes and Branching Fractions of {ital B} {r_arrow} {ital J/}{psi}{ital K*} and {ital B} {r_arrow} {ital J/}{psi}{ital K} Decays

Using data taken with the CLEO II detector, we present the first full angular analysis in the color-suppressed modes B{sup 0} {yields} J/{psi} K*{sup 0} and B{sup +} {yields} J/{psi} K*{sup +}. This leads to a complete determination of the decay amplitudes of these modes. In addition, we update the branching fractions for B {yields} J/{psi} K and B {yields} J/{psi} K*.

First observation of inclusive ψ production in ψ decays

The branching ratio for inclusive ψ production in ψ(1S) decays is measured to be (0.11 ± 0.04 ± 0.02)%.

Measurement of Ds decay modes

Abstract Using the CLEO detector, we have measured the branching ratios for the exclusive decays of the D s + meson into K ∗0 K + , K 0 K + , and K ∗+ K 0 relative to the decay D s + →φπ + to be close to unity. We have also measured the mass diference between the D s + and D + meson to be 98.5±1.5 MeV/ c 2 .