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6 results on '"R. van Tyen"'

1. Measurement of the total hadronic cross section in taggedγγreactions

Author

N. A. Nicol, Orin I. Dahl, F. R. Rouse, J. G. Layter, J. J. Eastman, R. Belcinski, S. Toutounchi, G. Masek, Robert W. Kenney, D. H. Stork, C. Ho, M. K. Sullivan, L. G. Mathis, C. Zeitlin, H. Aihara, Philippe Eberhard, A. R. Clark, S. J. Maxfield, R. E. Avery, M. G. Strauss, S. K. Park, T. Kamae, E. M. Wang, T. K. Edberg, S. C. Loken, William A. Wenzel, Z. R. Wolf, W. Vernon, M. Pripstein, Willem G. J. Langeveld, J. S. Steinman, K. A. Derby, M. T. Ronan, M. L. Stevenson, Werner Hofmann, P. J. Oddone, W. T. Lin, W. Wagner, D. A. Bauer, R. R. McNeil, George P Yost, Y. T. Oyang, D. E. Pellett, Tadayuki Takahashi, G. Godfrey, J. Lys, A. Fridman, M. Daoudi, R. R. Kofler, H. Yamamoto, B. D. Magnuson, H. Oh, D. R. Nygren, J. C. Sens, H. H. Bingham, Gilbert Shapiro, D. O. Caldwell, S. Khacheryan, S. J. Yellin, J. R. Smith, S. B. Chun, R. W. Stephens, G. Lynch, F. C. Erné, A. M. Eisner, Ronald R. Ross, K. H. Fairfield, H. P. Paar, G. J. VanDalen, J. M. Hauptman, C. D. Buchanan, K. A. Schwitkis, H. Marsiske, A. P.T. Palounek, G. D. Cowan, A. Bay, D. J. Lambert, G. Zapalac, Margaret Alston-Garnjost, R. van Tyen, A. R. Barker, H. Y. Chao, D. A. Crane, F.L. Linde, R. J. Madaras, B. C. Shen, A. Lu, Elliott D. Bloom, Y. X. Wang, and E. S. Miller

Subjects
Physics, Quantum chromodynamics, Nuclear physics, Particle physics, Photon, Scattering, Hadron, Elementary particle, Parton, Fermion, Energy (signal processing)
Abstract

We present a measurement of the total cross section for {gamma}{gamma}{r arrow}hadrons, with one photon quasireal and the other a spacelike photon of mass squared {minus}{ital Q}{sup 2}. Results are presented as a function of {ital Q}{sup 2} and the {gamma}{gamma} center-of-mass energy {ital W}, with the {ital Q}{sup 2} range extending from 0.2 to 60 GeV{sup 2}, and {ital W} in the range from 2 to 10 GeV. The data were taken with the TPC/Two-Gamma facility at the SLAC {ital e}{sup +}{ital e}{sup {minus}} storage ring PEP, which was operated at a beam energy of 14.5 GeV. The cross section exhibits a gentle falloff with increasing {ital W}. Its {ital Q}{sup 2} dependence is shown to be well described by an incoherent sum of vector-meson and pointlike scattering over most of the observed {ital W} range. Agreement at high {ital Q}{sup 2} is improved if a minimum-{ital p}{sub {ital T}} cutoff (motivated by QCD) is imposed on the pointlike contribution.

Published
1990
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2. Study ofη’formation in photon-photon collisions

Author

H. Aihara, M. Alston-Garnjost, R. E. Avery, A. Barbaro-Galtieri, A. R. Barker, A. V. Barnes, B. A. Barnett, D. A. Bauer, H. -U. Bengtsson, D. L. Bintinger, G. J. Bobbink, T. S. Bolognese, A. D. Bross, C. D. Buchanan, A. Buijs, D. O. Caldwell, A. R. Clark, G. D. Cowan, D. A. Crane, O. I. Dahl, K. A. Derby, J. J. Eastman, P. H. Eberhard, T. K. Edberg, A. M. Eisner, R. Enomoto, F. C. Erné, T. Fujii, J. W. Gary, W. Gorn, J. M. Hauptman, W. Hofmann, J. E. Huth, J. Hylen, T. Kamae, H. S. Kaye, K. H. Kees, R. W. Kenney, L. T. Kerth, Winston Ko, R. I. Koda, R. R. Kofler, K. K. Kwong, R. L. Lander, W. G. J. Langeveld, J. G. Layter, F. L. Linde, C. S. Lindsey, S. C. Loken, A. Lu, X-Q. Lu, G. R. Lynch, R. J. Madaras, K. Maeshima, B. D. Magnuson, J. N. Marx, G. E. Masek, L. G. Mathis, J. A. J. Matthews, S. J. Maxfield, S. O. Melnikoff, E. S. Miller, W. Moses, R. R. McNeil, P. Nemethy, D. R. Nygren, P. J. Oddone, H. P. Paar, D. A. Park, S. K. Park, D. E. Pellett, M. Pripstein, M. T. Ronan, R. R. Ross, F. R. Rouse, K. A. Schwitkis, J. C. Sens, G. Shapiro, M. D. Shapiro, B. C. Shen, W. E. Slater, J. R. Smith, J. S. Steinman, M. L. Stevenson, D. H. Stork, M. G. Strauss, M. K. Sullivan, T. Takahashi, J. R. Thompson, N. Toge, S. Toutounchi, R. van Tyen, B. van Uitert, G. J. VanDalen, R. F. van Daalen Wetters, W. Vernon, W. Wagner, E. M. Wang, Y. X. Wang, M. R. Wayne, W. A. Wenzel, J. T. White, M. C. S. Williams, Z. R. Wolf, H. Yamamoto, S. J. Yellin, C. Zeitlin, and W-M. Zhang

Subjects
Physics, Nuclear physics, Particle physics, Photon, Prime (order theory)
Published
1987
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3. Study of Bose-Einstein correlations ine+e−annihilation at 29 GeV

Author

H. K. Ticho, L. T. Kerth, Em Wang, D. R. Nygren, G. R. Lynch, W. A. Wenzel, W. E. Slater, A. R. Clark, X. Q. Lu, M. Yamauchi, F. R. Rouse, L. Madansky, M. L. Stevenson, N. Toge, A. D. Bross, R. W. Kenney, J. Hylen, W. M. Zhang, D. L. Fancher, J. M. Hauptman, C. Y. Chien, R. I. Koda, M. Pripstein, S. C. Loken, K. Maruyama, R. R. Kofler, A. Cordier, M. Alston-Garnjost, C. S. Lindsey, M. D. Shapiro, R. F. van Daalen Wetters, Hirotsugu Fujii, O. Chamberlain, K. A. Derby, H. Yamamoto, M. R. Wayne, A. V. Barnes, R. R. Sauerwein, M. T. Ronan, R. van Tyen, A. Pevsner, B. A. Barnett, G. J. Vandalen, W. Gorn, S. O. Melnikoff, A. Barbaro-Galtieri, R. J. Madaras, J. N. Marx, K. K. Kwong, T. Fujii, B. J. Blumenfeld, J. G. Layter, W. Moses, H. S. Kaye, O. I. Dahl, Tuneyoshi Kamae, H. U. Bengtsson, Hiroaki Aihara, C. D. Buchanan, C. T. Day, J. E. Huth, W. Hofmann, R. R. Ross, P. J. Oddone, D. H. Stork, B. Gabioud, D. A. Park, G. Shapiro, J. A. Bakken, P. H. Eberhard, J. W. Gary, B. C. Shen, P. R. Robrish, N. J. Hadley, Peter Nemethy, and J. A J Matthews

Subjects
Physics, Particle physics, Time projection chamber, Annihilation, Meson, Hadron, Bose–Einstein correlations, Nuclear physics, symbols.namesake, Pion, Pair production, Bose–Einstein statistics, symbols, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Bose-Einstein correlations between like-sign pions have been investigated in e/sup +/e/sup -/ annihilation at ..sqrt..s = 29 GeV using the Time Projection Chamber detector at the SLAC e/sup +/e/sup -/ storage ring PEP. The production rate of like-sign pion pairs with small relative momentum is found to be increased by more than 50% over the rate expected for uncorrelated production of pions. From the correlation length, a typical source radius of 0.65 fm is derived. Data are consistent with a spherical shape of the pion source. No dependence of radius or correlation strength on the event multiplicity is observed.

Published
1985
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4. Prompt muon production ine+e−annihilations at 29 GeV

Author

R. I. Koda, C. T. Day, J. E. Huth, D. R. Nygren, P. J. Oddone, M. Pripstein, H. U. Bengtsson, A. Cordier, D. H. Stork, B. Gabioud, J. A. Bakken, Hiroaki Aihara, A. Pevsner, G. R. Lynch, C. S. Lindsey, K. A. Derby, H. Yamamoto, B. A. Barnett, D. A. Park, L. T. Kerth, R. R. Sauerwein, R. R. Ross, Tuneyoshi Kamae, J. W. Gary, M. Yamauchi, P. R. Robrish, W. E. Slater, D. H. Badtke, O. Chamberlain, R. J. Madaras, J. N. Marx, Em Wang, B. C. Shen, A. Barbaro-Galtieri, W. Moses, F. R. Rouse, W. M. Zhang, Peter Nemethy, O. I. Dahl, L. Madansky, R. F. van Daalen Wetters, M. Alston-Garnjost, J. Hylen, R. W. Kenney, H. K. Ticho, A. R. Clark, X. Q. Lu, W. A. Wenzel, Hirotsugu Fujii, A. V. Barnes, N. Toge, A. D. Bross, M. T. Ronan, J. G. Layter, M. R. Wayne, G. J. Vandalen, W. Gorn, W. Hofmann, S. O. Melnikoff, C. Y. Chien, M. D. Shapiro, G. Shapiro, P. H. Eberhard, J. M. Hauptman, D. L. Fancher, N. J. Hadley, K. K. Kwong, T. Fujii, J. A J Matthews, B. J. Blumenfeld, S. C. Loken, K. Maruyama, R. R. Kofler, R. van Tyen, M. L. Stevenson, H. S. Kaye, and C. D. Buchanan

Subjects
Nuclear physics, Quark, Physics, Particle physics, Muon, Annihilation, Hadron, Bottom quark, Charm quark
Abstract

We have studied the production of prompt muons in hadronic events from ${e}^{+}$${e}^{\mathrm{\ensuremath{-}}}$ annihilation at a center-of-mass energy of 29 GeV with the PEP4-TPC (Time Projection Chamber) detector. The muon p and ${p}_{t}$ distributions are well described by a combination of bottom- and charm-quark decays, with fitted semimuonic branching fractions of (15.2\ifmmode\pm\else\textpm\fi{}1.9\ifmmode\pm\else\textpm\fi{}1.2)% and (6.9\ifmmode\pm\else\textpm\fi{}1.1\ifmmode\pm\else\textpm\fi{}1.1)%, respectively. The muon spectra imply hard fragmentation functions for both b and c quarks, with 〈z(b quark)〉=0.80\ifmmode\pm\else\textpm\fi{}0.05\ifmmode\pm\else\textpm\fi{}0.05 and 〈z(c quark)〉=0.60\ifmmode\pm\else\textpm\fi{}0.06\ifmmode\pm\else\textpm\fi{}0.04. We derive neutral-current axial-vector couplings of a(b quark)=-0.9\ifmmode\pm\else\textpm\fi{}1.1\ifmmode\pm\else\textpm\fi{}0.3 and a(c quark)=1.5\ifmmode\pm\else\textpm\fi{}1.5\ifmmode\pm\else\textpm\fi{}0.5 from the forward-backward asymmetries.

Published
1985
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5. Exclusive production ofpp¯π+π−in photon-photon collisions

Author

T. K. Edberg, H. Y. Chao, K. A. Derby, W. T. Lin, M. K. Sullivan, S. K. Park, T. Kamae, E. S. Miller, J. J. Eastman, S. Toutounchi, S. Khacheryan, H. S. Kaye, J. A. J. Matthews, Robert W. Kenney, J. C. Sens, F.L. Linde, D. O. Caldwell, A. Bay, J. G. Layter, G. D. Cowan, C. D. Buchanan, M. G. Strauss, D. A. Crane, C. Zeitlin, H. P. Paar, K. A. Schwitkis, D. E. Pellett, W. Moses, Y. X. Wang, J. M. Hauptman, M. Pripstein, Angela Barbaro-Galtieri, F. C. Erné, Margaret Alston-Garnjost, R. van Tyen, A. M. Eisner, M. Daoudi, R. E. Avery, Ronald R. Ross, Orin I. Dahl, Tadayuki Takahashi, B. C. Shen, Z. R. Wolf, E. M. Wang, Willem G. J. Langeveld, J. Hylen, G. Masek, F. R. Rouse, H. Yamamoto, J. R. Smith, S. J. Yellin, A. R. Barker, R. W. Stephens, S. C. Loken, R. J. Madaras, D. H. Stork, A. R. Clark, M. L. Stevenson, Gilbert Shapiro, D. A. Bauer, W. Wagner, G. J. Bobbink, J. S. Steinman, Werner Hofmann, William A. Wenzel, L. G. Mathis, K. H. Fairfield, H. Aihara, P. J. Oddone, B. A. Barnett, R. R. Kofler, S. B. Chun, G. Lynch, B. D. Magnuson, D. R. Nygren, Philippe Eberhard, S. J. Maxfield, A. Buijs, W. Vernon, and M. T. Ronan

Subjects
Physics, Particle physics, Crystallography, Antiparticle, Meson, Hadron, Production (computer science), Elementary particle, Lambda baryon, Energy (signal processing), Bar (unit)
Abstract

We report a measurement of the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}p\overline{p}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ process with the TPC/Two-Gamma facility at the PEP ${e}^{+}{e}^{\ensuremath{-}}$ storage ring at SLAC. Forty-five $p\overline{p}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ events were identified in data corresponding to an integrated ${e}^{+}{e}^{\ensuremath{-}}$ luminosity of 142 ${\mathrm{pb}}^{\ensuremath{-}1}$. The cross section for $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}p\overline{p}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ is given both as a function of the $\ensuremath{\gamma}\ensuremath{\gamma}$ center-of-mass energy ${W}_{\ensuremath{\gamma}\ensuremath{\gamma}}$, with ${W}_{\ensuremath{\gamma}\ensuremath{\gamma}}$ between 2.5 and 5.5 GeV, and as a function of the in variant mass squared ${q}^{2}$ of one of the photons, with $\ensuremath{-}{q}^{2}l7$ Ge${\mathrm{V}}^{2}$. This cross section falls much less rapidly with ${W}_{\ensuremath{\gamma}\ensuremath{\gamma}}$ than does the cross section for a similar process, $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}p\overline{p}$. No ${\ensuremath{\Delta}}^{0}{\overline{\ensuremath{\Delta}}}^{0}$ production is observed, and only a small fraction of the events at low ${W}_{\ensuremath{\gamma}\ensuremath{\gamma}}$ is consistent with $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}{\ensuremath{\Delta}}^{++}{\overline{\ensuremath{\Delta}}}^{\ensuremath{-}\ensuremath{-}}$, ${\ensuremath{\Delta}}^{++}\overline{p}{\ensuremath{\pi}}^{\ensuremath{-}}$, or ${\overline{\ensuremath{\Delta}}}^{\ensuremath{-}\ensuremath{-}}p{\ensuremath{\pi}}^{+}$. In an expanded search through the same data, four events compatible with either $\ensuremath{\Lambda}\overline{\ensuremath{\Lambda}}(\ensuremath{\Lambda}\ensuremath{\rightarrow}p{\ensuremath{\pi}}^{\ensuremath{-}})$ or ${\ensuremath{\Sigma}}^{0}\overline{\ensuremath{\Lambda}}({\ensuremath{\Sigma}}^{0}\ensuremath{\rightarrow}\ensuremath{\Lambda}\ensuremath{\gamma})$ production were found.

Published
1989
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6. Measurement ofτbranching ratios

Author

H. Aihara, M. Alston-Garnjost, R. E. Avery, J. A. Bakken, A. Barbaro-Galtieri, A. R. Barker, A. V. Barnes, B. A. Barnett, D. A. Bauer, H.-U. Bengtsson, D. L. Bintinger, G. J. Bobbink, T. S. Bolognese, A. D. Bross, C. D. Buchanan, A. Buijs, D. O. Caldwell, C-Y. Chien, A. R. Clark, G. D. Cowan, D. A. Crane, O. I. Dahl, K. A. Derby, J. J. Eastman, T. K. Edberg, P. H. Eberhard, A. M. Eisner, R. Enomoto, F. C. Erné, T. Fujii, J. W. Gary, W. Gorn, J. M. Hauptman, W. Hofmann, J. E. Huth, J. Hylen, T. Kamae, H. S. Kaye, K. H. Kees, R. W. Kenney, L. T. Kerth, Winston Ko, R. I. Koda, R. R. Kofler, K. K. Kwong, R. L. Lander, W. G. J. Langeveld, J. G. Layter, F. L. Linde, C. S. Lindsey, S. C. Loken, A. Lu, X-Q. Lu, G. R. Lynch, L. Madansky, R. J. Madaras, K. Maeshima, B. D. Magnuson, J. N. Marx, G. E. Masek, L. G. Mathis, J. A. J. Matthews, S. J. Maxfield, S. O. Melnikoff, E. S. Miller, W. Moses, R. R. McNeil, P. Nemethy, D. R. Nygren, P. J. Oddone, H. P. Paar, D. A. Park, S. K. Park, D. E. Pellett, A. Pevsner, M. Pripstein, M. T. Ronan, R. R. Ross, F. R. Rouse, K. A. Schwitkis, J. C. Sens, G. Shapiro, M. D. Shapiro, B. C. Shen, W. E. Slater, J. R. Smith, J. S. Steinman, M. L. Stevenson, D. H. Stork, M. G. Strauss, M. K. Sullivan, T. Takahashi, J. R. Thompson, N. Toge, S. Toutounchi, R. van Tyen, B. van Uitert, G. J. VanDalen, R. F. van Daalen Wetters, W. Vernon, W. Wagner, E. M. Wang, Y. X. Wang, M. R. Wayne, W. A. Wenzel, J. T. White, M. C. S. Williams, Z. R. Wolf, H. Yamamoto, S. J. Yellin, C. Zeitlin, and W-M. Zhang

Subjects
Nuclear physics, Physics, Semileptonic decay, Particle decay, Particle physics, Muon, Pion, Meson, Branching fraction, Hadron, Lepton
Abstract

Using the data accumulated at LEP in 1989 and 1990 with the ALEPH detector, the inclusive and exclusive branching ratios of the τ lepton have been measured assuming lepton universality inZ0 decays. The inclusive branching fractions for the τ decay into one, three, and five charged particles have been determined to be (85.45±0.97)%, (14.35±0.48)%, and (0.10±0.05)%, respectively, in agreement with the world averages. New undetected decay modes are determined to have a branching fraction of less than 2.1% at 95% CL. The measured branching ratios for quasi-exclusive channels are slightly larger than, but consistent with the world averages, except for the modes τ→3 hadrons+v τ andτ→hadron+2π0v τ , which are significantly larger. These latter branching ratios have been found to be (9.5±0.7)% and (10.2±1.1)%, respectively. The sum of all the measured quasi-exclusive branching ratios is (100.4±1.8)%. A fully exclusive analysis of modes with neutral pions shows no evidence for new photonic decay modes with a branching fraction limit of 3.4% at 95% CL.

Published
1987
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