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11 results on '"I. F. Albuquerque"'

1. ptandxFdependence of the polarization ofΣ+hyperons produced by 800 GeV/cprotons

Author

A. Morelos, I. F. Albuquerque, N. F. Bondar, R. Carrigan, D. Chen, P. S. Cooper, Dai Lisheng, A. S. Denisov, A. V. Dobrovolsky, T. Dubbs, A. M. F. Endler, C. O. Escobar, M. Foucher, V. L. Golovtsov, H. Gottschalk, P. Gouffon, V. T. Grachev, A. V. Khanzadeev, M. A. Kubantsev, N. P. Kuropatkin, J. Lach, null Lang Pengfei, V. N. Lebedenko, null Li Chengze, null Li Yunshan, M. Luksys, J. R. P. Mahon, E. McCliment, C. Newsom, M. C. Pommot Maia, V. M. Samsonov, V. A. Schegelsky, null Shi Huanzhang, V. J. Smith, Tang Fukun, N. K. Terentyev, S. Timm, I. I. Tkatch, L. N. Uvarov, A. A. Vorobyov, null Yan Jie, Zhao Wenheng, null Zheng Shuchen, and null Zhong Yuanyuan

Subjects
Physics, Nuclear physics, Hyperon, Sigma, Nuclear Experiment, Polarization (waves), Lambda
Abstract

We utilize the angle and momentum resolution of our apparatus to study the polarization of 375 GeV/c Sigma(+) hyperons produced by 800 GeV/c protons incident on a Cu target. By examining in detail two of our high statistics data samples, we find evidence for structure in the p(t) dependence of Sigma(+) polarization and are able to extract the x(F) dependence of the Sigma(+) polarization and compare it with x(F) behavior in the Lambda(0) and Xi(-) systems.

Published
1995

2. Measurement of the branching ratio and asymmetry parameter for theΣ+→pγ radiative decay

Author

Lang Pengfei, N. P. Kuropatkin, V. T. Grachev, Vincent J Smith, Shi Huanzhang, M. C. Pommot Maia, I. I. Tkatch, N. F. Bondar, A. Morelos, A. V. Dobrovolsky, M. A. Kubantsev, M. Luksys, Yan Jie, V.A. Schegelsky, T. Dubbs, V. L. Golovtsov, Zhao Wenheng, Zheng Shuchen, Alexei Khanzadeev, I. F. Albuquerque, Li Chengze, An.A. Vorobyov, A. S. Denisov, P. Gouffon, Carlos Escobar, E. McCliment, J. R. P. Mahon, M. Foucher, L. N. Uvarov, Dai Lisheng, R.A. Carrigan, P. S. Cooper, Tang Fukun, A. M. F. Endler, C. R. Newsom, H. Gottschalk, Li Yunshan, D Chen, N. K. Terentyev, S. Timm, J. Lach, Zhong Yuanyuan, V. M. Samsonov, and J. Langland

Subjects
Nuclear physics, Physics, Particle physics, Branching fraction, media_common.quotation_subject, Hyperon, Radiative decay, Sigma, High Energy Physics::Experiment, Asymmetry, media_common
Abstract

We have measured the branching ratio for the hyperon radiative decay ${\mathrm{\ensuremath{\Sigma}}}^{+}$\ensuremath{\rightarrow}p\ensuremath{\gamma} using the Fermilab polarized charged hyperon beam. This measurement and our previously published result on the asymmetry parameter in the same decay are part of Fermilab experiment E761. We find B(${\mathrm{\ensuremath{\Sigma}}}^{+}$\ensuremath{\rightarrow}p\ensuremath{\gamma})/B(${\mathrm{\ensuremath{\Sigma}}}^{+}$\ensuremath{\rightarrow}p${\mathrm{\ensuremath{\pi}}}^{0}$) to be [2.32\ifmmode\pm\else\textpm\fi{}0.11(stat)\ifmmode\pm\else\textpm\fi{}0.10(syst)]\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}3}$ with a sample of 31 901 events. The higher statistics and careful attention to systematic uncertainties make these significant improvements over previous measurements. We describe how our measurements were performed and briefly review the theoretical implications of these results.

Published
1995

3. Measurement of the branching ratio for theΞ−→Σ−γ radiative decay

Author

Yan Jie, Dai Lisheng, Shi Huanzhang, Lang Pengfei, D. Chen, M. C. Pommot Maia, A. V. Dobrovolsky, M. Luksys, J. R. P. Mahon, N. K. Terentyev, E. McCliment, Tang Fukun, A. M. F. Endler, H. Gottschalk, A. V. Khanzadeev, N. F. Bondar, V.A. Schegelsky, A. A. Vorobyov, Zhong Yuanyuan, P. S. Cooper, M. A. Kubantsev, M. Foucher, A. Morelos, J. Lach, P. Gouffon, A. S. Denisov, C. R. Newsom, I. F. Albuquerque, S. Timm, L. N. Uvarov, Zhao Wenheng, Li Yunshan, Zheng Shuchen, N. P. Kuropatkin, V. T. Grachev, Li Chengze, I. I. Tkatch, T. Dubbs, Carlos Escobar, R. Carrigan, Vincent J Smith, V. L. Golovtsov, and V. M. Samsonov

Subjects
Physics, Baryon, Particle physics, Particle decay, Branching fraction, Hadron, Hyperon, General Physics and Astronomy, Lambda, Xi baryon, Sigma baryon
Abstract

We have measured the branching ratio for the hyperon radiative decay [Xi][sup [minus]][r arrow][Sigma][sup [minus]][gamma] from a sample of 211[plus minus]33 events obtained in the polarized 375 GeV/[ital c] charged hyperon beam at Fermilab. We find [ital B]([Xi][sup [minus]][r arrow][Sigma][sup [minus]][gamma]/[Xi][sup [minus]][r arrow][Lambda][sup 0][pi][sup [minus]])=(1.22[plus minus]0.23[plus minus]0.06)[times]10[sup [minus]4] where the quoted errors are statistical and systematic, respectively. We have also obtained an indication that the sign of the asymmetry parameter of this decay is positive.

Published
1994

4. Measurement of the magnetic moments of theΣ+and Σ¯−hyperons

Author

N. P. Kuropatkin, V. T. Grachev, P. Gouffon, I. F. Albuquerque, M. Foucher, Lang Pengfei, Carlos Escobar, Tkatch, V. M. Samsonov, L. N. Uvarov, A. V. Dobrovolsky, Dai Lisheng, Li Chengze, Li Yunshan, E. McCliment, A. S. Denisov, M. Luksys, V.A. Schegelsky, N. K. Terentyev, P. S. Cooper, R.A. Carrigan, C. R. Newsom, S. Timm, A. Morelos, Zhong Yuanyuan, M. A. Kubantsev, N. F. Bondar, Shi Huanzhang, An.A. Vorobyov, T. Dubbs, J. Lach, Pommot Maia Mc, Tang Fukun, A. M. F. Endler, H. Gottschalk, Alexei Khanzadeev, D Chen, Zhao Wenheng, Zheng Shuchen, V. L. Golovtsov, Vincent J Smith, Yan Jie, and Mahon

Subjects
Baryon, Physics, Antiparticle, Proton, Magnetic moment, CPT symmetry, General Physics and Astronomy, Sigma, High Energy Physics::Experiment, Fermion, Statistical physics, Atomic physics, Sigma baryon
Abstract

We have measured the magnetic moments of the SIGMA+ and SIGMABAR- hyperons produced by 800-GeV protons incident on a Cu target. We determine the SIGMA+ magnetic moment to be (2.4613 +/- 0.0034 +/- 0.0040)mu(N) where the uncertainties are statistical and systematic, respectively. In this first measurement we determine the magnetic moment of the SIGMABAR- to be -(2.428 +/- 0.036 +/- 0.007)mu(N). The magnetic moments of the SIGMA+ and SIGMABAR- are consistent with each other in magnitude but opposite in sign as required by CPT invariance.

Published
1993

5. Polarization ofΣ+and Σ¯−hyperons produced by 800-GeV/cprotons

Author

P. Gouffon, M. Foucher, M. Luksys, V.A. Schegelsky, A. V. Dobrovolsky, Li Yunshan, Zhao Wenheng, Zheng Shuchen, I. I. Tkatch, Lang Pengfei, Yan Jie, Vincent J Smith, J. Lach, N. P. Kuropatkin, V. T. Grachev, J. R. P. Mahon, Tang Fukun, A. M. F. Endler, Dai Lisheng, H. Gottschalk, Shi Huanzhang, A. A. Vorobyov, N. K. Terentyev, A. V. Khanzadeev, M. A. Kubantsev, A. S. Denisov, V. M. Samsonov, E. McCliment, A. Morelos, S. Timm, R.A. Carrigan, Zhong Yuanyuan, D Chen, T. Dubbs, V. L. Golovtsov, I. F. Albuquerque, Li Chengze, L. N. Uvarov, M. C. Pommot Maia, N. F. Bondar, Carlos Escobar, P. S. Cooper, and C. R. Newsom

Subjects
Physics, Hyperon, General Physics and Astronomy, Sigma, High Energy Physics::Experiment, Elementary particle, Atomic physics, Nuclear Experiment, Polarization (waves), Sigma baryon
Abstract

We have measured the polarization of 375-GeV/c SIGMA+ and SIGMABAR- hyperons produced by 800-GeV/c protons incident on a Cu target. We find that the SIGMA+ polarization rises with increasing p(t) to a maximum of 16% at p(t) = 1.0 GeV/c and then decreases to 10% at p(t) = 1.8 GeV/c. We compare this SIGMA+ polarization with data at lower energies. The SIGMABAR- polarization has been measured for the first time. It has the same sign as the SIGMA+ but smaller magnitude in a similar kinematical region.

Published
1993

6. Measurement of the asymmetry parameter in the hyperon radiative decayΣ+→pγ

Author

A. V. Dobrovolsky, A. Morelos, Lang Pengfei, Tang Fukun, A. M. F. Endler, A. A. Vorobyov, H. Gottschalk, M. A. Kubantsev, Pommot Maia Mc, Lebedenko Vn, Goritchev Pa, Zhao Wenheng, Zheng Shuchen, I. F. Albuquerque, A. S. Denisov, E. McCliment, Li Yunshan, T. Dubbs, Carlos Escobar, N. K. Terentyev, R.A. Carrigan, L. N. Uvarov, M. Foucher, M. Luksys, Li Chengze, S. Timm, Tkatch, V. M. Samsonov, A. V. Khanzadeev, Kuropatkin Np, P. Gouffon, V. L. Golovtsov, J. Lach, N. F. Bondar, Zhong Yuanyuan, Mahon, V. T. Grachev, Shi Huanzhang, Vincent J Smith, D. Chen, Yan Jie, Dai Lisheng, P. S. Cooper, and C. R. Newsom

Subjects
Physics, Nuclear physics, Baryon, Particle physics, Particle decay, Hadron, Hyperon, General Physics and Astronomy, High Energy Physics::Experiment, Elementary particle, Fermion, Charged particle, Sigma baryon
Abstract

We have measured the asymmetry parameter (${\mathrm{\ensuremath{\alpha}}}_{\ensuremath{\gamma}}$) in the hyperon radiative decay ${\mathrm{\ensuremath{\Sigma}}}^{+}$\ensuremath{\rightarrow}p\ensuremath{\gamma} with a sample of 34 754\ifmmode\pm\else\textpm\fi{}212 events obtained in a polarized charged hyperon beam experiment at Fermilab. We find ${\mathrm{\ensuremath{\alpha}}}_{\ensuremath{\gamma}}$=-0.720\ifmmode\pm\else\textpm\fi{}0.086\ifmmode\pm\else\textpm\fi{}0.045, where the quoted errors are statistical and systematic, respectively.

Published
1992

7. New upper limit for the branching ratio of theΩ−→Ξ−γ radiative decay

Author

T. Dubbs, Shi Huanzhang, D Chen, N. K. Terentyev, Tkatch, I. F. Albuquerque, E. McCliment, L. N. Uvarov, Lang Pengfei, P. Gouffon, R.A. Carrigan, Alexei Khanzadeev, J. Lach, A. S. Denisov, Zhao Wenheng, Tang Fukun, A. M. F. Endler, H. Gottschalk, Mcp Maia, Zheng Shuchen, M. Luksys, V.A. Schegelsky, A. V. Dobrovolsky, An.A. Vorobyov, Carlos Escobar, A. Morelos, N. F. Bondar, Mahon, M. A. Kubantsev, Dai Lisheng, V. L. Golovtsov, V. M. Samsonov, Li Chengze, Li Yunshan, M. Foucher, Vincent J Smith, Yan Jie, P. S. Cooper, C. R. Newsom, N. P. Kuropatkin, V. T. Grachev, Zhong Yuanyuan, and S. Timm

Subjects
Physics, Particle physics, Proton, Branching fraction, Hyperon, Radiative decay, Omega, Nuclear physics, Physics::Accelerator Physics, High Energy Physics::Experiment, Limit (mathematics), Fermilab, Nuclear Experiment, Beam (structure)
Abstract

We have searched for the rare hyperon radiative decay Omega- to Xi- gamma, using the Fermilab Proton Center 375 GeV/c charged hyperon beam. Our measurement of the Omega- beam fraction at 13.6 m from production is (4.8 +_ 0.4)10**(-5). No signal was found and we determine a new upper limit of (4.6 x 10**-4) at 90% CL for the Omega- to Xi- gamma branching ratio.

Published
1994

8. Evidence for the decayKL→μ+μ−γγ

Author

S. Hidaka, S. Childress, D. A. Jensen, K. S. Nelson, G. Corti, J. Belz, S. V. Somalwar, R. Ben-David, S. A. Taegar, N. Solomey, R. L. Stone, R. Pordes, P. A. Toale, C. Qiao, R. Kessler, W. Slater, B. Cox, M. Sadamoto, E. Monnier, S. Schnetzer, V. O’Dell, T. Nakaya, P. L. McBride, L. Bellantoni, C. Bown, A. Bellavance, E. C. Swallow, J. Graham, R. Winston, B. Quinn, I. F. Albuquerque, A. Tripathi, M. Pang, G. B. Thomson, Y. W. Wah, E. Halkiadakis, S. Averitte, A. P. McManus, Douglas Bergman, P. Mikelsons, A. Ledovskoy, G. Graham, H. Nguyen, K. Senyo, R. J. Tesarek, A. R. Barker, H. G.E. Kobrak, R. Ford, J. Whitmore, K. Arisaka, V. Prasad, T. Yamanaka, B. Winstein, A. Lath, M. D. Corcoran, R. E. Ray, Elliott Cheu, G. J. Bock, M. Arenton, A. Glazov, S. Bright, R. Coleman, E. D. Zimmerman, A. Roodman, E. J. Ramberg, M. Hazumi, A. R. Erwin, P. S. Shawhan, R. Tschirhart, J. Wang, P. Shanahan, E. Blucher, A. Alavi-Harati, V. Jejer, A. Golossanov, T. Alexopoulos, J. LaDue, R. A. Swanson, H. B. White, Kazunori Hanagaki, J. Jennings, I. Suzuki, M. B. Crisler, K. Hagan, and Y. B. Hsiung

Subjects
Physics, Nuclear and High Energy Physics, Theoretical physics
Published
2000

9. Search for the decay KL --pi(0)e+e

Author

A, Alavi-Harati, I F, Albuquerque, T, Alexopoulos, M, Arenton, K, Arisaka, S, Averitte, A R, Barker, L, Bellantoni, A, Bellavance, J, Belz, R, Ben-David, D R, Bergman, E, Blucher, G J, Bock, C, Bown, S, Bright, E, Cheu, S, Childress, R, Coleman, M D, Corcoran, G, Corti, B, Cox, M B, Crisler, A R, Erwin, R, Ford, P M, Fordyce, A, Glazov, A, Golossanov, G, Graham, J, Graham, K, Hagan, E, Halkiadakis, K, Hanagaki, S, Hidaka, Y B, Hsiung, V, Jejer, J, Jennings, D A, Jensen, R, Kessler, H G, Kobrak, J, LaDue, A, Lath, A, Ledovskoy, P L, McBride, A P, McManus, P, Mikelsons, E, Monnier, T, Nakaya, K S, Nelson, H, Nguyen, V, O'Dell, M, Pang, R, Pordes, V, Prasad, C, Qiao, B, Quinn, E J, Ramberg, R E, Ray, A, Roodman, M, Sadamoto, S, Schnetzer, K, Senyo, P, Shanahan, P S, Shawhan, W, Slater, N, Solomey, S V, Somalwar, R L, Stone, I, Suzuki, E C, Swallow, R A, Swanson, S A, Taegar, R J, Tesarek, G B, Thomson, P A, Toale, A, Tripathi, R, Tschirhart, Y W, Wah, J, Wang, H B, White, J, Whitmore, B, Winstein, R, Winston, T, Yamanaka, and E D, Zimmerman

Abstract

We report on a search for the decay KL--pi(0)e+e- carried out by the KTeV/E799 experiment at Fermilab. This decay is expected to have a significant CP violating contribution and the measurement of its branching ratio could support the Cabibbo-Kobayashi-Maskawa mechanism for CP violation or could point to new physics. Two events were observed in the 1997 data with an expected background of 1.06+/-0.41 events, and we set an upper limit B(KL--pi(0)e+e-)5.1 x 10(-10) at the 90% confidence level.

Published
2000

10. Measurement of theΣ¯−lifetime and direct comparison with theΣ+lifetime

Author

Zhao Wenheng, Zheng Shuchen, J. Langland, D Chen, Alexei Khanzadeev, I. F. Albuquerque, P. S. Cooper, C. R. Newsom, L. N. Uvarov, A. V. Dobrovolsky, Li Yunshan, An.A. Vorobyov, Carlos Escobar, I. I. Tkatch, J. Lach, S. Timm, Li Chengze, Dai Lisheng, P. Gouffon, Zhong Yuanyuan, M. Luksys, R.F. Barbosa, V.A. Schegelsky, Vincent J Smith, Tang Fukun, A. M. F. Endler, A. S. Denisov, H. Gottschalk, M. Foucher, N. P. Kuropatkin, V. T. Grachev, J. R. P. Mahon, V. L. Golovtsov, T. Dubbs, Kubantsev, V. M. Samsonov, Yan Jie, E. McCliment, R.A. Carrigan, Shi Huanzhang, N. K. Terentyev, Lang Pengfei, A. Morelos, M. C. Pommot Maia, and N. F. Bondar

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Hyperon, Sigma
Published
1999

11. A Search for Light Super Symmetric Baryons

Author

M. C. Pommot Maia, N. F. Bondar, I. F. Albuquerque, L. N. Uvarov, J. R. P. Mahon, P. S. Cooper, J. Lach, A. Morelos, WH Zhao, C. R. Newsom, J. Langland, An.A. Vorobyov, I. I. Tkatch, Vincent J Smith, Dai Lisheng, M. Foucher, A. M. F. Endler, T. Dubbs, H. Gottschalk, M. Luksys, V.A. Schegelsky, A. S. Denisov, V. L. Golovtsov, Carlos Escobar, Chloe Li, SC Zheng, N. K. Terentyev, A. V. Khanzadeev, J. Yan, A. V. Dobrovolsky, E. McCliment, R.A. Carrigan, F. Tang, Yanhong Li, PF Lang, M. A. Kubantsev, S. Timm, HZ Shi, N. P. Kuropatkin, V. T. Grachev, P. Gouffon, D. Chen, YY Zhong, and V. M. Samsonov

Subjects
Physics, Nuclear reaction, Particle physics, Proton, Hadron, Hyperon, FOS: Physical sciences, General Physics and Astronomy, Elementary particle, Charged particle, High Energy Physics - Experiment, Baryon, High Energy Physics - Experiment (hep-ex), Crystallography, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Production (computer science)
Abstract

We have searched for the production and decay of light super-symmetric baryons produced in 800 GeV/c proton copper interactions in a charged hyperon beam experiment. We observe no evidence for the decays R+(uud \g^~) -> S(uds \g^~) pi+ and X-(ssd \g^~) -> S(uds \g^~) pi- in the predicted parent mass and lifetime ranges of 1700-2500 Mev/c2 and 50-500 ps. Production upper limits for R+ at xF=0.47, Pt=1.4 GeV/c2 and X- at xF=0.48, Pt=0.65 GeV/c2 of less than 10^-3 of all charged secondary particles produced are obtained for all but the highest masses and shortest lifetimes predicted., 9 pages, uuencoded postscript 4 figures uuencoded, tar-compressed file (submitted to PRL)

Published
1996

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