Phys. Rev. Lett.
95,
242001
(2005)
[6 pages]
Measurement of the Tensor Structure Function b1 of the Deuteron
A. Airapetian et al. HERMES Collaboration
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A. Airapetian31, N. Akopov31, Z. Akopov31, M. Amarian8,31, V. V. Ammosov23, A. Andrus16, E. C. Aschenauer8, W. Augustyniak30, R. Avakian31, A. Avetissian31, E. Avetissian12, P. Bailey16, D. Balin22, V. Baturin22, M. Beckmann7, S. Belostotski22, S. Bernreuther10, N. Bianchi12, H. P. Blok21,29, H. Böttcher8, A. Borissov18, A. Borysenko12, M. Bouwhuis16, J. Brack6, A. Brüll17, V. Bryzgalov23, G. P. Capitani12, T. Chen4, H. C. Chiang16, G. Ciullo11, M. Contalbrigo11, P. F. Dalpiaz11, R. De Leo3, M. Demey21, L. De Nardo1, E. De Sanctis12, E. Devitsin19, P. Di Nezza12, J. Dreschler21, M. Düren14, M. Ehrenfried10, A. Elalaoui-Moulay2, G. Elbakian31, F. Ellinghaus8, U. Elschenbroich13, R. Fabbri21, A. Fantoni12, A. Fechtchenko9, L. Felawka27, B. Fox6, S. Frullani25, G. Gapienko23, V. Gapienko23, F. Garibaldi25, K. Garrow1,26, E. Garutti21, D. Gaskell6, G. Gavrilov7,27, V. Gharibyan31, G. Graw20, O. Grebeniouk22, L. G. Greeniaus1,27, I. M. Gregor8, K. Hafidi2, M. Hartig27, D. Hasch12, D. Heesbeen21, M. Henoch10, R. Hertenberger20, W. H. A. Hesselink21,29, A. Hillenbrand10, M. Hoek14, Y. Holler7, B. Hommez13, G. Iarygin9, A. Ivanilov23, A. Izotov22, H. E. Jackson2, A. Jgoun22, R. Kaiser15, E. Kinney6, A. Kisselev22, M. Kopytin8, V. Korotkov23, V. Kozlov19, B. Krauss10, V. G. Krivokhijine9, L. Lagamba3, L. Lapikás21, A. Laziev21,29, P. Lenisa11, P. Liebing8, L. A. Linden-Levy16, K. Lipka8, W. Lorenzon18, H. Lu5, J. Lu27, S. Lu14, B.-Q. Ma4, B. Maiheu13, N. C. R. Makins16, Y. Mao4, B. Marianski30, H. Marukyan31, F. Masoli11, V. Mexner21, N. Meyners7, O. Mikloukho22, C. A. Miller1,27, Y. Miyachi28, V. Muccifora12, A. Nagaitsev9, E. Nappi3, Y. Naryshkin22, A. Nass10, M. Negodaev8, W.-D. Nowak8, K. Oganessyan7,12, H. Ohsuga28, N. Pickert10, S. Potashov19, D. H. Potterveld2, M. Raithel10, D. Reggiani11, P. E. Reimer2, A. Reischl21, A. R. Reolon12, C. Riedl10, K. Rith10, G. Rosner15, A. Rostomyan31, L. Rubacek14, J. Rubin16, D. Ryckbosch13, Y. Salomatin23, I. Sanjiev2,22, I. Savin9, A. Schäfer24, C. Schill12, G. Schnell8,28, K. P. Schüler7, J. Seele16, R. Seidl10, B. Seitz14, R. Shanidze10, C. Shearer15, T.-A. Shibata28, V. Shutov9, M. C. Simani21,29, K. Sinram7, M. Stancari11, M. Statera11, E. Steffens10, J. J. M. Steijger21, H. Stenzel14, J. Stewart8, F. Stinzing10, U. Stösslein6, P. Tait10, H. Tanaka28, S. Taroian31, B. Tchuiko23, A. Terkulov19, A. Tkabladze13, A. Trzcinski30, M. Tytgat13, A. Vandenbroucke13, P. B. van der Nat21,29, G. van der Steenhoven21, M. C. Vetterli26,27, V. Vikhrov22, M. G. Vincter1, C. Vogel10, M. Vogt10, J. Volmer8, C. Weiskopf10, J. Wendland26,27, J. Wilbert10, Y. Ye5, Z. Ye7, S. Yen27, B. Zihlmann21, and P. Zupranski30 (HERMES Collaboration)
1Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1, Canada
2Physics Division, Argonne National Laboratory, Argonne, Illinois 60439-4843, USA
3Istituto Nazionale di Fisica Nucleare, Sezione di Bari, 70124 Bari, Italy
4School of Physics, Peking University, Beijing 100871, China
5Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
6Nuclear Physics Laboratory, University of Colorado, Boulder, Colorado 80309-0390, USA
7DESY, 22603 Hamburg, Germany
8DESY, 15738 Zeuthen, Germany
9Joint Institute for Nuclear Research, 141980 Dubna, Russia
10Physikalisches Institut, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
11Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara and Dipartimento di Fisica, Università di Ferrara, 44100 Ferrara, Italy
12Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, 00044 Frascati, Italy
13Department of Subatomic and Radiation Physics, University of Gent, 9000 Gent, Belgium
14Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
15Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
16Department of Physics, University of Illinois, Urbana, Illinois 61801-3080, USA
17Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
18Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
19Lebedev Physical Institute, 117924 Moscow, Russia
20Sektion Physik, Universität München, 85748 Garching, Germany
21Nationaal Instituut voor Kernfysica en Hoge-Energiefysica (NIKHEF), 1009 DB Amsterdam, The Netherlands
22Petersburg Nuclear Physics Institute, St. Petersburg, Gatchina, 188350 Russia
23Institute for High Energy Physics, Protvino, Moscow region, 142281 Russia
24Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany
25Istituto Nazionale di Fisica Nucleare, Sezione Roma 1, Gruppo Sanità and Physics Laboratory, Istituto Superiore di Sanità, 00161 Roma, Italy
26Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
27TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
28Department of Physics, Tokyo Institute of Technology, Tokyo 152, Japan
29Department of Physics and Astronomy, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands
30Andrzej Soltan Institute for Nuclear Studies, 00-689 Warsaw, Poland
31Yerevan Physics Institute, 375036 Yerevan, Armenia
Received 8 June 2005; published 5 December 2005
The Hermes experiment has investigated the tensor spin structure of the deuteron using the 27.6 GeV/c positron beam of DESY HERA. The use of a tensor-polarized deuteron gas target with only a negligible residual vector polarization enabled the first measurement of the tensor asymmetry Azzd and the tensor structure function b1d for average values of the Bjorken variable 0.01<⟨x⟩<0.45 and of the negative of the squared four-momentum transfer 0.5 GeV2<⟨Q2⟩<5 GeV2. The quantities Azzd and b1d are found to be nonzero. The rise of b1d for decreasing values of x can be interpreted to originate from the same mechanism that leads to nuclear shadowing in unpolarized scattering.
© 2005 The American Physical Society
URL:
http://link.aps.org/doi/10.1103/PhysRevLett.95.242001
DOI:
10.1103/PhysRevLett.95.242001
PACS:
13.60.−r, 13.88.+e, 14.20.Dh, 14.65.−q
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