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Abbasi RU, Allen MG, Arimura R, Belz JW, Bergman DR, Blake SA, Shin BK, Buckland IJ, Cheon BG, Fujii T, Fujisue K, Fujita K, Fukushima M, Furlich GD, Gerber ZR, Globus N, Hibino K, Higuchi R, Honda K, Ikeda D, Ito H, Iwasaki A, Jeong S, Jeong HM, Jui CH, Kadota K, Kakimoto F, Kalashev OE, Kasahara K, Kawata K, Kharuk I, Kido E, Kim SW, Kim HB, Kim JH, Kim JH, Komae I, Kubota Y, Kuznetsov MY, Lee KH, Lubsandorzhiev BK, Lundquist JP, Matthews JN, Nagataki S, Nakamura T, Nakazawa A, Nonaka T, Ogio S, Ono M, Oshima H, Park IH, Potts M, Pshirkov S, Remington JR, Rodriguez DC, Rott C, Rubtsov GI, Ryu D, Sagawa H, Sakaki N, Sako T, Sakurai N, Shin H, Smith JD, Sokolsky P, Stokes BT, Stroman TS, Takahashi K, Takeda M, Taketa A, Tameda Y, Thomas S, Thomson GB, Tinyakov PG, Tkachev I, Tomida T, Troitsky SV, Tsunesada Y, Udo S, Urban FR, Wong T, Yamazaki K, Yuma Y, Zhezher YV, Zundel Z. An extremely energetic cosmic ray observed by a surface detector array. Science 2023; 382:903-907. [PMID: 37995237 DOI: 10.1126/science.abo5095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 10/19/2023] [Indexed: 11/25/2023]
Abstract
Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest-energy events thought to come from extragalactic sources. Their arrival is infrequent, so detection requires instruments with large collecting areas. In this work, we report the detection of an extremely energetic particle recorded by the surface detector array of the Telescope Array experiment. We calculate the particle's energy as [Formula: see text] (~40 joules). Its arrival direction points back to a void in the large-scale structure of the Universe. Possible explanations include a large deflection by the foreground magnetic field, an unidentified source in the local extragalactic neighborhood, or an incomplete knowledge of particle physics.
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Affiliation(s)
- R U Abbasi
- Physics Department, Loyola University Chicago, Chicago, IL, USA
| | - M G Allen
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - R Arimura
- Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan
| | - J W Belz
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - D R Bergman
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - S A Blake
- Stellar Science, Albuquerque, NM, USA
| | - B K Shin
- Department of Physics, Ulsan National Institute of Science and Technology, 44919, Ulsan, Korea
| | - I J Buckland
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - B G Cheon
- Department of Physics and The Research Institute of Natural Science, Hanyang University, Seongdong-gu, Seoul, Korea
| | - T Fujii
- Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan
- Hakubi Center for Advanced Research and Graduate School of Science, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
- Nambu Yoichiro Institute of Theoretical and Experimental Physics, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan
| | - K Fujisue
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - K Fujita
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - M Fukushima
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - G D Furlich
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - Z R Gerber
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - N Globus
- Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
| | - K Hibino
- Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan
| | - R Higuchi
- Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
| | - K Honda
- University of Yamanashi, Kofu, 400-8510, Japan
| | - D Ikeda
- Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan
| | - H Ito
- Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
| | - A Iwasaki
- Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan
| | - S Jeong
- Department of Physics, SungKyunKwan University, Jang-an-gu, Suwon 16419, Korea
| | - H M Jeong
- Department of Physics, SungKyunKwan University, Jang-an-gu, Suwon 16419, Korea
| | - C H Jui
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - K Kadota
- Department of Natural Sciences, Tokyo City University, Setagaya-ku, Tokyo 158-8557, Japan
| | - F Kakimoto
- Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan
| | - O E Kalashev
- Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
| | - K Kasahara
- Shibauta Institute of Technology and Sicence, Fukasaku 307, Minuma-ku, Saitama, Japan
| | - K Kawata
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - I Kharuk
- Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
| | - E Kido
- Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
| | - S W Kim
- Department of Physics, SungKyunKwan University, Jang-an-gu, Suwon 16419, Korea
| | - H B Kim
- Department of Physics and The Research Institute of Natural Science, Hanyang University, Seongdong-gu, Seoul, Korea
| | - J H Kim
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - J H Kim
- Physics Division, Argonne National Laboratory, Lemont, IL, USA
| | - I Komae
- Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan
| | - Y Kubota
- Academic Assembly School of Science and Technology Institute of Engineering, Shinshu University, Nagano, Nagano, 380-8553, Japan
| | - M Y Kuznetsov
- Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
| | - K H Lee
- Department of Physics, SungKyunKwan University, Jang-an-gu, Suwon 16419, Korea
| | - B K Lubsandorzhiev
- Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
| | - J P Lundquist
- Center for Astrophysics and Cosmology, University of Nova Gorica, Nova Gorica, Slovenia
| | - J N Matthews
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - S Nagataki
- Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
| | - T Nakamura
- Academic Assembly School of Science and Technology Institute of Engineering, Shinshu University, Nagano, Nagano, 380-8553, Japan
| | - A Nakazawa
- Academic Assembly School of Science and Technology Institute of Engineering, Shinshu University, Nagano, Nagano, 380-8553, Japan
| | - T Nonaka
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - S Ogio
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - M Ono
- Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
- Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan
| | - H Oshima
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - I H Park
- Department of Physics, SungKyunKwan University, Jang-an-gu, Suwon 16419, Korea
| | - M Potts
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - S Pshirkov
- Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
| | - J R Remington
- NASA Marshall Space Flight Center, Martin Road, Huntsville, AL, USA
| | - D C Rodriguez
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
- Integrated Support Center for Nuclear Nonproliferation and Nuclear Security, Japan Atomic Energy Agency, Tokai-mura, Ibaraki 319-1195, Japan
| | - C Rott
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
- Department of Physics, SungKyunKwan University, Jang-an-gu, Suwon 16419, Korea
| | - G I Rubtsov
- Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
| | - D Ryu
- Department of Physics, Ulsan National Institute of Science and Technology, 44919, Ulsan, Korea
| | - H Sagawa
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - N Sakaki
- Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
| | - T Sako
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - N Sakurai
- Faculty of Design Technology, 3-1-1 Nakagaito, Daito City, Osaka, Japan
| | - H Shin
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - J D Smith
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - P Sokolsky
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - B T Stokes
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - T S Stroman
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - K Takahashi
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - M Takeda
- Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8582, Japan
| | - A Taketa
- Earthquake Research Institute, University of Tokyo, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Y Tameda
- Department of Engineering Science, Faculty of Engineering, Osaka Electro-Communication University, Neyagawa-shi, Osaka 572-8530, Japan
| | - S Thomas
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - G B Thomson
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - P G Tinyakov
- Universite Libre de Bruxelles, bvd du Triomphe CP225, Brussels, Belgium
| | - I Tkachev
- Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
| | - T Tomida
- Academic Assembly School of Science and Technology Institute of Engineering, Shinshu University, Nagano, Nagano, 380-8553, Japan
| | - S V Troitsky
- Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
| | - Y Tsunesada
- Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan
- Nambu Yoichiro Institute of Theoretical and Experimental Physics, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan
| | - S Udo
- Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan
| | - F R Urban
- The Central European Institute for Cosmology and Fundamental Physics, Institute of Physics of the Czech Academy of Sciences, Na Slovance 1999/2, 182 21 Prague, Czech Republic
| | - T Wong
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
| | - K Yamazaki
- College of Engineering, Chubu University, 1200 Matsumoto, Kasugai, Aichi 487-8501, Japan
| | - Y Yuma
- Academic Assembly School of Science and Technology Institute of Engineering, Shinshu University, Nagano, Nagano, 380-8553, Japan
| | - Y V Zhezher
- Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia
| | - Z Zundel
- High Energy Astrophysics Institute and Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, USA
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Abu-Zayyad T, Aida R, Allen M, Anderson R, Azuma R, Barcikowski E, Belz JW, Bergman DR, Blake SA, Cady R, Cheon BG, Chiba J, Chikawa M, Cho EJ, Cho WR, Fujii H, Fujii T, Fukuda T, Fukushima M, Gorbunov D, Hanlon W, Hayashi K, Hayashi Y, Hayashida N, Hibino K, Hiyama K, Honda K, Iguchi T, Ikeda D, Ikuta K, Inoue N, Ishii T, Ishimori R, Ivanov D, Iwamoto S, Jui CCH, Kadota K, Kakimoto F, Kalashev O, Kanbe T, Kasahara K, Kawai H, Kawakami S, Kawana S, Kido E, Kim HB, Kim HK, Kim JH, Kim JH, Kitamoto K, Kitamura S, Kitamura Y, Kobayashi K, Kobayashi Y, Kondo Y, Kuramoto K, Kuzmin V, Kwon YJ, Lan J, Lim SI, Machida S, Martens K, Matsuda T, Matsuura T, Matsuyama T, Matthews JN, Minamino M, Miyata K, Murano Y, Myers I, Nagasawa K, Nagataki S, Nakamura T, Nam SW, Nonaka T, Ogio S, Ohnishi M, Ohoka H, Oki K, Oku D, Okuda T, Oshima A, Ozawa S, Park IH, Pshirkov MS, Rodriguez DC, Roh SY, Rubtsov GI, Ryu D, Sagawa H, Sakurai N, Sampson AL, Scott LM, Shah PD, Shibata F, Shibata T, Shimodaira H, Shin BK, Shin JI, Shirahama T, Smith JD, Sokolsky P, Stokes BT, Stratton SR, Stroman T, Suzuki S, Takahashi Y, Takeda M, Taketa A, Takita M, Tameda Y, Tanaka H, Tanaka K, Tanaka M, Thomas SB, Thomson GB, Tinyakov P, Tkachev I, Tokuno H, Tomida T, Troitsky S, Tsunesada Y, Tsutsumi K, Tsuyuguchi Y, Uchihori Y, Udo S, Ukai H, Vasiloff G, Wada Y, Wong T, Wood M, Yamakawa Y, Yamane R, Yamaoka H, Yamazaki K, Yang J, Yoneda Y, Yoshida S, Yoshii H, Zhou X, Zollinger R, Zundel Z. Upper limit on the flux of photons with energies above1019 eVusing the Telescope Array surface detector. Int J Clin Exp Med 2013. [DOI: 10.1103/physrevd.88.112005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abbasi RU, Abu-Zayyad T, Al-Seady M, Allen M, Amman JF, Anderson RJ, Archbold G, Belov K, Belz JW, Bergman DR, Blake SA, Brusova OA, Burt GW, Cannon C, Cao Z, Deng W, Fedorova Y, Finley CB, Gray RC, Hanlon WF, Hoffman CM, Holzscheiter MH, Ivanov D, Hughes G, Hüntemeyer P, Ivanov D, Jones BF, Jui CCH, Kim K, Kirn MA, Loh EC, Liu J, Lundquist JP, Maestas MM, Manago N, Marek LJ, Martens K, Matthews JAJ, Matthews JN, Moore SA, O'Neill A, Painter CA, Perera L, Reil K, Riehle R, Roberts M, Rodriguez D, Sasaki N, Schnetzer SR, Scott LM, Sinnis G, Smith JD, Sokolsky P, Song C, Springer RW, Stokes BT, Stratton S, Thomas SB, Thomas JR, Thomson GB, Tupa D, Zech A, Zhang X. Indications of proton-dominated cosmic-ray composition above 1.6 EeV. Phys Rev Lett 2010; 104:161101. [PMID: 20482038 DOI: 10.1103/physrevlett.104.161101] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 03/28/2010] [Indexed: 05/29/2023]
Abstract
We report studies of ultrahigh-energy cosmic-ray composition via analysis of depth of air shower maximum (X(max)), for air shower events collected by the High-Resolution Fly's Eye (HiRes) observatory. The HiRes data are consistent with a constant elongation rate d<X(max)>/d[log(E)] of 47.9+/-6.0(stat)+/-3.2(syst) g/cm2/decade for energies between 1.6 and 63 EeV, and are consistent with a predominantly protonic composition of cosmic rays when interpreted via the QGSJET01 and QGSJET-II high-energy hadronic interaction models. These measurements constrain models in which the galactic-to-extragalactic transition is the cause of the energy spectrum ankle at 4x10(18) eV.
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Affiliation(s)
- R U Abbasi
- Department of Physics, University of Utah, Salt Lake City, Utah, USA
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Abbasi RU, Abu-Zayyad T, Allen M, Amman JF, Archbold G, Belov K, Belz JW, Ben Zvi SY, Bergman DR, Blake SA, Brusova OA, Burt GW, Cannon C, Cao Z, Connolly BC, Deng W, Fedorova Y, Finley CB, Gray RC, Hanlon WF, Hoffman CM, Holzscheiter MH, Hughes G, Hüntemeyer P, Jones BF, Jui CCH, Kim K, Kirn MA, Loh EC, Maestas MM, Manago N, Marek LJ, Martens K, Matthews JAJ, Matthews JN, Moore SA, O'Neill A, Painter CA, Perera L, Reil K, Riehle R, Roberts M, Rodriguez D, Sasaki N, Schnetzer SR, Scott LM, Sinnis G, Smith JD, Sokolsky P, Song C, Springer RW, Stokes BT, Thomas SB, Thomas JR, Thomson GB, Tupa D, Westerhoff S, Wiencke LR, Zhang X, Zech A. First observation of the Greisen-Zatsepin-Kuzmin suppression. Phys Rev Lett 2008; 100:101101. [PMID: 18352170 DOI: 10.1103/physrevlett.100.101101] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 01/07/2008] [Indexed: 05/26/2023]
Abstract
The High Resolution Fly's Eye (HiRes) experiment has observed the Greisen-Zatsepin-Kuzmin suppression (called the GZK cutoff) with a statistical significance of five standard deviations. HiRes' measurement of the flux of ultrahigh energy cosmic rays shows a sharp suppression at an energy of 6 x 10(19) eV, consistent with the expected cutoff energy. We observe the ankle of the cosmic-ray energy spectrum as well, at an energy of 4 x 10(18) eV. We describe the experiment, data collection, and analysis and estimate the systematic uncertainties. The results are presented and the calculation of the statistical significance of our observation is described.
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Affiliation(s)
- R U Abbasi
- Department of Physics, University of Utah, Salt Lake City, Utah 84112, USA
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Abbasi RU, Abu-Zayyad T, Amann JF, Archbold G, Bellido JA, Belov K, Belz JW, Bergman DR, Cao Z, Clay RW, Cooper MD, Dai H, Dawson BR, Everett AA, Fedorova YA, Girard JHV, Gray RC, Hanlon WF, Hoffman CM, Holzscheiter MH, Hüntemeyer P, Jones BF, Jui CCH, Kieda DB, Kim K, Kirn MA, Loh EC, Manago N, Marek LJ, Martens K, Martin G, Matthews JAJ, Matthews JN, Meyer JR, Moore SA, Morrison P, Moosman AN, Mumford JR, Munro MW, Painter CA, Perera L, Reil K, Riehle R, Roberts M, Sarracino JS, Sasaki M, Schnetzer SR, Shen P, Simpson KM, Sinnis G, Smith JD, Sokolsky P, Song C, Springer RW, Stokes BT, Taylor SF, Thomas SB, Thompson TN, Thomson GB, Tupa D, Westerhoff S, Wiencke LR, VanderVeen TD, Zech A, Zhang X. Measurement of the flux of ultrahigh energy cosmic rays from monocular observations by the High Resolution Fly's Eye experiment. Phys Rev Lett 2004; 92:151101. [PMID: 15169276 DOI: 10.1103/physrevlett.92.151101] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2002] [Revised: 05/28/2003] [Indexed: 05/24/2023]
Abstract
We have measured the cosmic ray spectrum above 10(17.2) eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode. We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors. We fit the spectrum to a model consisting of galactic and extragalactic sources.
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Affiliation(s)
- R U Abbasi
- Department of Physics and High Energy Astrophysics Institute, University of Utah, Salt Lake City, Utah 84112, USA
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Sher A, Appel R, Atoyan GS, Bassalleck B, Bergman DR, Cheung N, Dhawan S, Do H, Egger J, Eilerts S, Fischer H, Herold W, Issakov VV, Kaspar H, Kraus DE, Lazarus DM, Lichard P, Lowe J, Lozano J, Ma H, Majid W, Pislak S, Poblaguev AA, Rehak P, Sher A, Thompson JA, Truöl P, Zeller ME. High statistics measurement of the K+-->pi0e+nu (K+e3) branching ratio. Phys Rev Lett 2003; 91:261802. [PMID: 14754040 DOI: 10.1103/physrevlett.91.261802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2003] [Indexed: 05/24/2023]
Abstract
E865 at the Brookhaven National Laboratory AGS collected about 70 000 K(+)(e3) events to measure the K(+)(e3) branching ratio relative to the observed K+-->pi(+)pi(0), K+-->pi(0)micro(+)nu, and K+-->pi(+)pi(0)pi(0) decays. The pi(0) in all the decays was detected using the e(+)e(-) pair from pi(0)-->e(+)e(-)gamma decay and no photons were required. Using the 2002 Particle Data Group branching ratios for the normalization decays, we obtain BR(K(+)(e3(gamma)))=(5.13+/-0.02(stat)+/-0.09(syst)+/-0.04(norm))%, where K(+)(e3(gamma)) includes the effect of virtual and real photons. This result is approximately 2.3sigma higher than the current Particle Data Group value. Implications for the V(us) element of the CKM matrix, and the matrix's unitarity are discussed.
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Affiliation(s)
- A Sher
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barbosa RF, Barker AR, Barrio M, Bellantoni L, Bellavance A, Belz J, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Halkiadakis E, Hamm J, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jensen DA, Kessler R, Kobrak HGE, LaDue J, Lath A, Ledovskoy A, McBride PL, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pordes R, Prasad V, Qi XR, Quinn B, Ramberg EJ, Ray RE, Roodman A, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Shields J, Slater W, Solomey N, Somalwar SV, Stone RL, Swallow EC, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Turner SE, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Search for the KL-->pi 0 pi 0 e+e- decay in the KTeV experiment. Phys Rev Lett 2002; 89:211801. [PMID: 12443402 DOI: 10.1103/physrevlett.89.211801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2001] [Revised: 07/12/2002] [Indexed: 05/24/2023]
Abstract
The recent discovery of a large CP violating asymmetry in KL-->pi+pi-e+e- mode has prompted us to seach for the associated KL-->pi 0 pi 0 e+e- decay mode in the KTeV-E799 experiment at Fermilab. In 2.7 x 10(11) K(L) decays, one candidate event has been observed with an expected background of 0.3 event, resulting in an upper limit for the KL-->pi 0 pi 0 e+e- branching ratio of 6.6 x 10(-9) at the 90% C.L.
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8
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barbosa RF, Barker AR, Barrio M, Bellantoni L, Bellavance A, Belz J, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Cunha A, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Halkiadakis E, Hamm J, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jensen DA, Kessler R, Kobrak HGE, LaDue J, Lath A, Ledovskoy A, McBride PL, Medvigy D, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pordes R, Prasad V, Qi XR, Quinn B, Ramberg EJ, Ray RE, Roodman A, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Shields J, Slater W, Solomey N, Somalwar SV, Stone RL, Swallow EC, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Turner SE, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Radiative decay width measurements of neutral kaon excitations using the primakoff effect. Phys Rev Lett 2002; 89:072001. [PMID: 12190514 DOI: 10.1103/physrevlett.89.072001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2001] [Indexed: 05/23/2023]
Abstract
We use K(L)'s in the 100-200 GeV energy range to produce 147 candidate events of the axial vector pair K1(1270)-K1(1400) in the nuclear Coulomb field of a Pb target and determine the radiative widths Gamma(K1(1400)-->K0+gamma)=280.8+/-23.2(stat)+/-40.4(syst) keV and Gamma(K1(1270)-->K0+gamma)=73.2+/-6.1(stat)+/-28.3(syst) keV. These first measurements appear to be lower than the quark-model predictions. We also place upper limits on the radiative widths for K(*)(1410) and K(*)(2)(1430) and find that the latter is vanishingly small in accord with SU(3) invariance in the naive quark model.
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Poblaguev AA, Appel R, Atoyan GS, Bassalleck B, Bergman DR, Cheung N, Dhawan S, Do H, Egger J, Eilerts S, Herold W, Issakov VV, Kaspar H, Kraus DE, Lazarus DM, Lichard P, Lowe J, Lozano J, Ma H, Majid W, Pislak S, Rehak P, Sher A, Thompson JA, Truöl P, Zeller ME. Experimental study of the radiative decays K+-->mu(+)nue(+)e(-) and K+-->e(+)nue(+)e(-). Phys Rev Lett 2002; 89:061803. [PMID: 12190577 DOI: 10.1103/physrevlett.89.061803] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2002] [Indexed: 05/23/2023]
Abstract
Experiment 865 at the Brookhaven Alternating Gradient Synchrotron obtained 410 K+-->e(+)nue(+)e(-) and 2679 K+-->mu(+)nue(+)e(-) events including 10% and 19% background. The branching ratios were measured to be [2.48+/-0.14(stat)+/-0.14(syst)]x10(-8) (m(ee)>150 MeV) and (7.06+/-0.16+/-0.26)x10(-8) (m(ee)>145 MeV), respectively. Results for the decay form factors are presented.
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Affiliation(s)
- A A Poblaguev
- Institute for Nuclear Research of Russian Academy of Sciences, Moscow 117 312, Russia
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10
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barbosa RF, Barker AR, Barrio M, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Hagan K, Halkiadakis E, Hamm J, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jensen DA, Kessler R, Kobrak HGE, LaDue J, Lath A, Ledovskoy A, McBride PL, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pang M, Pordes R, Prasad V, Qi XR, Quinn B, Ramberg EJ, Ray RE, Roodman A, Sadamoto M, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Shields J, Slater W, Solomey N, Somalwar SV, Stone RL, Swallow EC, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Turner SE, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Measurement of the K(L) charge asymmetry. Phys Rev Lett 2002; 88:181601. [PMID: 12005674 DOI: 10.1103/physrevlett.88.181601] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2001] [Indexed: 05/23/2023]
Abstract
We present a measurement of the charge asymmetry delta(L) in the mode K(L)-->pi(+/-)e(-/+)nu based on 298 x 10(6) analyzed decays. We measure a value of delta(L) = [3322+/-58(stat)+/-47(syst)]x10(-6), in good agreement with previous measurements and 2.4 times more precise than the current best published result. The result is used to place more stringent limits on CPT and DeltaS = DeltaQ violation in the neutral kaon system.
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Pislak S, Appel R, Atoyan GS, Bassalleck B, Bergman DR, Cheung N, Dhawan S, Do H, Egger J, Eilerts S, Herold W, Issakov VV, Kaspar H, Kraus DE, Lazarus DM, Lichard P, Lowe J, Lozano J, Ma H, Majid W, Poblaguev AA, Rehak P, Sher A, Thompson JA, Truöl P, Zeller ME. New measurement of K(+)(e4) decay and the s-pave pi pi-scattering length a(0)(0). Phys Rev Lett 2001; 87:221801. [PMID: 11736394 DOI: 10.1103/physrevlett.87.221801] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2001] [Revised: 10/01/2001] [Indexed: 05/23/2023]
Abstract
A sample of 4 x 10(5) events from the decay K(+)-->pi(+)pi(-)e(+)nu(e) (K(e4)) has been collected in experiment E865 at the Brookhaven Alternating Gradient Synchrotron. The analysis of these data yields new measurements of the K(e4) branching ratio [(4.11+/-0.01+/-0.11) x 10(-5)], the s-wave pi pi scattering length [a(0)(0) = 0.216+/-0.013(stat)+/-0.004(syst)+/-0.005(theor)], and the form factors F, G, and H of the hadronic current and their dependence on the invariant pi pi mass.
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Affiliation(s)
- S Pislak
- Physik-Institut, Universität Zürich, CH-8057 Zürich, Switzerland
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12
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barbosa RF, Barker AR, Barrio M, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Hagan K, Halkiadakis E, Hamm J, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jensen DA, Kessler R, Kobrak HG, LaDue J, Lath A, Ledovskoy A, McBride PL, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pang M, Pordes R, Prasad V, Qi XR, Quinn B, Ramberg EJ, Ray RE, Roodman A, Sadamoto M, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Shields J, Slater W, Solomey N, Somalwar SV, Stone RL, Swallow EC, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Turner SE, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. First measurement of form factors of the decay Xi(0) --> Sigma(+)e(-)nu macro(e). Phys Rev Lett 2001; 87:132001. [PMID: 11580577 DOI: 10.1103/physrevlett.87.132001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2001] [Indexed: 05/23/2023]
Abstract
We present the first measurement of the form factor ratios g(1)/f(1) (direct axial vector to vector), g(2)/f(1) (second class current), and f(2)/f(1) (weak magnetism) for the decay Xi(0)-->Sigma(+)e(-)nu macro(e) using the KTeV (E799) beam line and detector at Fermilab. From the Sigma(+) polarization measured with the decay Sigma(+)-->p pi(0) and the e(-)-nu; correlation, we measure g(1)/f(1) to be 1.32+/-(0.21)(0.17)(stat)+/-0.05(syst), assuming the SU(3)(f) (flavor) values for g(2)/f(1) and f(2)/f(1). Our results are all consistent with exact SU(3)(f) symmetry.
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barbosa RF, Barker AR, Barrio M, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Hagan K, Halkiadakis E, Hamm J, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jensen DA, Kessler R, Kobrak HG, LaDue J, Lath A, Ledovskoy A, McBride PL, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pang M, Pordes R, Prasad V, Quinn B, Qi XR, Ramberg EJ, Ray RE, Roodman A, Sadamoto M, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Shields J, Slater W, Solomey N, Somalwar SV, Stone RL, Swallow EC, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Turner SE, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Branching ratio measurement of the decay K(L) --> e(+)e(-)mu(+)mu(-). Phys Rev Lett 2001; 87:111802. [PMID: 11531512 DOI: 10.1103/physrevlett.87.111802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2001] [Indexed: 05/23/2023]
Abstract
We have collected a 43 event sample of the decay K(L)-->e(+)e(-)mu(+)mu(-) with negligible backgrounds and measured its branching ratio to be (2.62+/-0.40+/-0.17)x10(-9). We see no evidence for CP violation in this decay. In addition, we set the 90% confidence upper limit on the combined branching ratios for the lepton flavor violating decays K(L)-->e(+/-)e(+/-)mu(-/+)mu(-/+) at B(K(L)-->e(+/-)e(+/-)mu(-/+)mu(-/+))< or =1.23x10(-10), assuming a uniform phase space distribution.
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14
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barker AR, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Hagan K, Halkiadakis E, Hamm J, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jensen DA, Kessler R, Kobrak HG, LaDue J, Lath A, Ledovskoy A, McBride PL, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pang M, Pordes R, Prasad V, Quinn B, Ramberg EJ, Ray RE, Roodman A, Sadamoto M, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Shields J, Slater W, Solomey N, Somalwar SV, Stone RL, Swallow EC, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Turner SE, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Measurement of the branching ratio and form factor of K(L)-->mu(+)mu(-)gamma. Phys Rev Lett 2001; 87:071801. [PMID: 11497879 DOI: 10.1103/physrevlett.87.071801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2001] [Indexed: 05/23/2023]
Abstract
We report on the analysis of the rare decay K(L)-->mu(+)mu(-)gamma the 1997 data from the KTeV experiment at Fermilab. A total of 9327 candidate events are observed with 2.4% background, representing a factor of 40 increase in statistics over the current world sample. We find that B(K(L)-->mu(+)mu(-)gamma) = (3.62 +/- 0.04(stat) +/- 0.08(syst)) x 10(-7). The form factor parameter alpha(K*) is measured to be alpha(K*) = -0.160(+0.026)(-0.028). In addition, we make the first measurement of the parameter alpha from the D'Ambrosio-Isidori-Portolés form factor, finding alpha = -1.54 +/- 0.10. In that model, this alpha measurement limits the Cabibbo-Kobayashi-Maskawa parameter rho>-0.2.
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barker AR, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Hagan K, Halkiadakis E, Hamm J, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jensen DA, Kessler R, Kobrak HG, LaDue J, Lath A, Ledovskoy A, McBride PL, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pang M, Pordes R, Prasad V, Quinn B, Ramberg EJ, Ray RE, Roodman A, Sadamoto M, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Shields J, Slater W, Solomey N, Somalwar SV, Stone RL, Swallow EC, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Turner SE, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Measurements of the rare decay K(L) --> e(+)e(-)e(+)e(-). Phys Rev Lett 2001; 86:5425-5429. [PMID: 11415267 DOI: 10.1103/physrevlett.86.5425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2001] [Indexed: 05/23/2023]
Abstract
We observe 441 K(L)-->e(+)e(-)e(+)e(-) candidate events with a background of 4.2 events and measure B(K(L)-->e(+)e(-)e(+)e(-)) = [3.72+/-0.18(stat)+/-0.23(syst)]x10(-8) in the KTeV/E799II experiment at Fermilab. Using the distribution of the angle between the planes of the e(+)e(-) pairs, we measure the CP parameters beta(CP) = -0.23+/-0.09(stat)+/-0.02(syst) and gamma(CP) = -0.09+/-0.09(stat)+/-0.02(syst). We also present the first detailed study of the e(+)e(-) invariant mass spectrum in this decay mode.
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barker AR, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Hagan K, Halkiadakis E, Hamm J, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jensen DA, Kessler R, Kobrak HG, LaDue J, Lath A, Ledovskoy A, McBride PL, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pang M, Pordes R, Prasad V, Quinn B, Ramberg EJ, Ray RE, Roodman A, Sadamoto M, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Shields J, Slater W, Solomey N, Somalwar SV, Stone RL, Suzuki I, Swallow EC, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Turner SE, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Measurement of the branching ratio and asymmetry of the decay Xi degrees -->Sigma degrees gamma. Phys Rev Lett 2001; 86:3239-3243. [PMID: 11327940 DOI: 10.1103/physrevlett.86.3239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2000] [Indexed: 05/23/2023]
Abstract
We have studied the rare weak radiative hyperon decay Xi degrees -->Sigma degrees gamma in the KTeV experiment at Fermilab. We have identified 4045 signal events over a background of 804 events. The dominant Xi degrees -->Lambdapi degrees decay, which was used for normalization, is the only important background source. An analysis of the acceptance of both modes yields a branching ratio of B(Xi degrees -->Sigma degrees gamma)/B(Xi degrees -->Lambdapi degrees ) = (3.34+/-0.05+/-0.09)x10(-3). By analyzing the final state decay distributions, we have also determined that the Sigma degrees emission asymmetry parameter for this decay is alpha(XiSigma) = -0.63+/-0.09.
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barker AR, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Hagan K, Halkiadakis E, Hamm J, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jensen DA, Kessler R, Kobrak HG, LaDue J, Lath A, Ledovskoy A, McBride PL, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pang M, Pordes R, Prasad V, Quinn B, Ramberg EJ, Ray RE, Roodman A, Sadamoto M, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Shields J, Slater W, Solomey N, Somalwar SV, Stone RL, Suzuki I, Swallow EC, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Turner SE, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Study of the K(0)(L) --> pi(+)pi(-)gamma Direct Emission Vertex. Phys Rev Lett 2001; 86:761-764. [PMID: 11177934 DOI: 10.1103/physrevlett.86.761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2000] [Indexed: 05/23/2023]
Abstract
We have performed studies of the K(0)(L)-->pi(+)pi(-)gamma direct emission ( DE) and inner Bremsstrahlung ( IB) vertices, based on data collected by KTeV during the 1996 Fermilab fixed target run. We find a(1)/a(2) = -0.737+/-0.034 GeV2 for the DE form-factor parameter in the rho-propagator parametrization, and report on fits of the form factor to linear and quadratic functions as well. We concurrently measure gamma(K(0)(L)-->pi(+)pi(-)gamma,E(*)(gamma)>20 MeV)/gamma(K(0)(L)-->pi(+)pi(-)) = (20.8+/-0.3)x10(-3), and a K(0)(L)-->pi(+)pi(-)gamma DE/(DE+IB) branching ratio of 0.683+/-0.011.
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Alavi-Harati A, Albuquerque IF, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barker AR, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Fordyce PM, Glazov A, Golossanov A, Graham G, Graham J, Hagan K, Halkiadakis E, Hanagaki K, Hidaka S, Hsiung YB, Jejer V, Jennings J, Jensen DA, Kessler R, Kobrak HG, LaDue J, Lath A, Ledovskoy A, McBride PL, McManus AP, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O'Dell V, Pang M, Pordes R, Prasad V, Qiao C, Quinn B, Ramberg EJ, Ray RE, Roodman A, Sadamoto M, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Slater W, Solomey N, Somalwar SV, Stone RL, Suzuki I, Swallow EC, Swanson RA, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Search for the decay KL --> pi(0)e+e-. Phys Rev Lett 2001; 86:397-401. [PMID: 11177840 DOI: 10.1103/physrevlett.86.397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2000] [Indexed: 05/23/2023]
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.
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Alavi-Harati A, Albuquerque IF, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barker AR, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A, Golossanov A, Graham G, Graham J, Hagan K, Halkiadakis E, Hanagaki K, Hazumi M, Hidaka S, Hsiung YB, Jejer V, Jennings J, Jensen DA, Kessler R, Kobrak HGE, LaDue J, Lath A, Ledovskoy A, McBride PL, McManus AP, Mikelsons P, Monnier E, Nakaya T, Nelson KS, Nguyen H, O’Dell V, Pang M, Pordes R, Prasad V, Qiao C, Quinn B, Ramberg EJ, Ray RE, Roodman A, Sadamoto M, Schnetzer S, Senyo K, Shanahan P, Shawhan PS, Slater W, Solomey N, Somalwar SV, Stone RL, Suzuki I, Swallow EC, Swanson RA, Taegar SA, Tesarek RJ, Thomson GB, Toale PA, Tripathi A, Tschirhart R, Wah YW, Wang J, White HB, Whitmore J, Winstein B, Winston R, Yamanaka T, Zimmerman ED. Evidence for the decayKL→μ+μ−γγ. Int J Clin Exp Med 2000. [DOI: 10.1103/physrevd.62.112001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Appel R, Atoyan GS, Bassalleck B, Bergman DR, Cheung N, Dhawan S, Do H, Egger J, Eilerts S, Fischer H, Herold W, Issakov VV, Kaspar H, Kraus DE, Lazarus DM, Lichard P, Lowe J, Lozano J, Ma H, Majid W, Menzel W, Pislak S, Poblaguev AA, Rehak P, Sher A, Thompson JA, Truöl P, Zeller ME. Search for lepton flavor violation in K+ decays into a charged pion and two leptons. Phys Rev Lett 2000; 85:2877-2880. [PMID: 11005958 DOI: 10.1103/physrevlett.85.2877] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2000] [Indexed: 05/23/2023]
Abstract
A search for lepton flavor violating decays, K+ --> mu+ mu+ pi-, K+ --> e+ e+ pi-, K+ --> pi+ e+ mu-, K+ --> mu+ e+ pi-, and pi0 --> e+ mu-, was performed using the data collected in Experiment E865 at the Brookhaven Alternating Gradient Synchrotron. No signal was found in any of the decay modes. At the 90% confidence level, the branching ratios are less than 3.0x10(-9), 6.4x10(-10), 5. 2x10(-10), 5.0x10(-10), and 3.4x10(-9), respectively.
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Affiliation(s)
- R Appel
- Physics Department, Yale University, New Haven, Connecticut 06511, USA
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Appel R, Atoyan GS, Bassalleck B, Bergman DR, Brown DN, Cheung N, Dhawan S, Do H, Egger J, Eilerts S, Felder C, Fischer H, Gach M, Herold W, Issakov VV, Kaspar H, Kraus DE, Lazarus DM, Leipuner L, Lichard P, Lowe J, Lozano J, Ma H, Majid W, Menzel W, Pislak S. Improved limit on the rate of the decay K+ --> pi(+)&mgr;(+)e(-). Phys Rev Lett 2000; 85:2450-2453. [PMID: 10978079 DOI: 10.1103/physrevlett.85.2450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2000] [Indexed: 05/23/2023]
Abstract
We report results of a search for the lepton-family number violating decay K+-->pi(+)&mgr;(+)e(-) from data collected by experiment E865 in 1996 at the Alternating Gradient Synchroton of Brookhaven National Laboratory. We place an upper limit on the branching ratio at 3.9x10(-11) ( 90% C.L.). Together with results based on data collected in 1995 and an earlier experiment, E777, this result establishes a combined 90% confidence level upper limit on the branching ratio at 2.8x10(-11). We also report a new upper limit on the branching ratio for pi(0)-->&mgr;(+)e(-) of 3.8x10(-10) ( 90% C. L.).
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Affiliation(s)
- R Appel
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 and Physics Department, Yale University, New Haven, Connecticut 06511, USA
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Alavi-Harati A, Albuquerque IF, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barker AR, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A. Search for the decay K(L) --> pi(0)&mgr;(+)&mgr;(-). Phys Rev Lett 2000; 84:5279-5282. [PMID: 10990923 DOI: 10.1103/physrevlett.84.5279] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/1999] [Indexed: 05/23/2023]
Abstract
We report on a search for the decay K(L)-->pi(0)&mgr;(+)&mgr;(-) carried out as a part of the KTeV experiment at Fermilab. This decay is expected to have a significant CP violating contribution and a direct measurement will either support the Cabibbo-Kobayashi-Maskawa mechanism for CP violation or point to new physics. Two events were observed in the 1997 data with an expected background of 0.87+/-0.15 events, and we set an upper limit B(K(L)-->pi(0)&mgr;(+)&mgr;(-))<3. 8x10(-10) at the 90% confidence level.
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Affiliation(s)
- A Alavi-Harati
- University of Arizona, Tucson, Arizona 85721 and University of California at Los Angeles, Los Angeles, California 90095, USA
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Ma H, Appel R, Atoyan GS, Bassalleck B, Bergman DR, Cheung N, Dhawan S, Do H, Egger J, Eilerts S, Fischer H, Herold W, Issakov VV, Kaspar H, Kraus DE, Lazarus DM, Lichard P, Lowe J, Lozano J, Majid W, Menzel W, Pislak S, Poblaguev AA, Rehak P, Sher A, Thompson JA. New measurement of the rare decay K+ --> pi(+)&mgr;(+)&mgr;(-). Phys Rev Lett 2000; 84:2580-2583. [PMID: 11017274 DOI: 10.1103/physrevlett.84.2580] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/1999] [Indexed: 05/23/2023]
Abstract
More than 400 K+-->pi(+)&mgr;(+)&mgr;(-) events were observed in a rare K+ decay experiment at the Brookhaven Alternating Gradient Synchrotron. Normalized to the K+-->pi(+)pi(+)pi(-) decay, the branching ratio is determined to be [9.22+/-0.60(stat)+/-0. 49(syst)]x10(-8). This branching ratio and the &mgr;&mgr; mass spectrum is in very good agreement with the measurement of the K+-->pi(+)e(+)e(-) decay, but deviates significantly from the previous measurement.
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Affiliation(s)
- H Ma
- Brookhaven National Laboratory, Upton, New York 11973, USA
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Alavi-Harati A, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barker AR, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A, Golossanov A. Search for the weak decay of a lightly bound H0 dibaryon. Phys Rev Lett 2000; 84:2593-2597. [PMID: 11017277 DOI: 10.1103/physrevlett.84.2593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/1999] [Indexed: 05/23/2023]
Abstract
We present results of a search for a new form of hadronic matter, a six-quark, dibaryon state called the H0, a state predicted to exist in several theoretical models. Analyzing data collected by experiment E799-II at Fermilab, we searched for the decay H0-->Lambdappi(-) and found no candidate events. We place an upper limit on [B(H0-->Lambdappi(-))dsigma(H)/dOmega]/(dsigma(Xi)/dOmega) and, in the context of published models, exclude the region of lightly bound mass states just below the LambdaLambda mass threshold, 2.194<M(H)<2.231 GeV/c(2), with lifetimes from approximately 5x10(-10) sec to approximately 1x10(-3) sec.
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Alavi-Harati A, Albuquerque IF, Alexopoulos T, Arenton M, Arisaka K, Averitte S, Barker AR, Bellantoni L, Bellavance A, Belz J, Ben-David R, Bergman DR, Blucher E, Bock GJ, Bown C, Bright S, Cheu E, Childress S, Coleman R, Corcoran MD, Corti G, Cox B, Crisler MB, Erwin AR, Ford R, Glazov A. Observation of CP violation in K(L)-->pi(+)pi(-)e(+)e(-) decays. Phys Rev Lett 2000; 84:408-411. [PMID: 11015925 DOI: 10.1103/physrevlett.84.408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/1999] [Indexed: 05/23/2023]
Abstract
We report the first observation of a manifestly CP violating effect in the K(L)-->pi(+)pi(-)e(+)e(-) decay mode. A large asymmetry was observed in the distribution of these decays in the CP-odd and T-odd angle straight phi between the decay planes of the e(+)e(-) and pi(+)pi(-) pairs in the K(L) center of mass system. After acceptance corrections, the overall asymmetry is found to be [13.6+/-2. 5(stat)+/-1.2(syst)]%. This is the largest CP-violating effect yet observed when integrating over the entire phase space of a mode and the first such effect observed in an angular variable.
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