Measurement of the spin asymmetry in the photoproduction of pairs of high-pT hadrons at HERMES

被引:191
作者
Airapetian, A [1 ]
Akopov, N
Amarian, M
Aschenauer, EC
Avakian, H
Avakian, R
Avetissian, A
Bains, B
Baumgarten, C
Beckmann, M
Belostotski, S
Belz, JE
Benisch, T
Bernreuther, S
Bianchi, N
Blouw, J
Böttcher, H
Borissov, A
Brack, J
Brauksiepe, S
Braun, B
Brückner, W
Brüll, A
Bulten, HJ
Capitani, GP
Carter, P
Chumney, P
Cisbani, E
Court, GR
Dalpiaz, PF
De Sanctis, E
De Schepper, D
Devitsin, E
Huberts, PKAD
Di Nezza, P
Düren, M
Dvoredsky, A
Elbakian, G
Ely, J
Fantoni, A
Ferstl, M
Fiedler, K
Filippone, BW
Fischer, H
Fox, B
Franz, J
Frullani, S
Funk, MA
Gärber, Y
Garibaldi, F
机构
[1] Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada
[2] Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada
[3] Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA
[4] CALTECH, WK Kellogg Radiat Lab, Pasadena, CA 91125 USA
[5] Univ Colorado, Nucl Phys Lab, Boulder, CO 80309 USA
[6] DESY, Deutsch Elekt Synchrotron, D-22603 Hamburg, Germany
[7] DESY, D-15738 Zeuthen, Germany
[8] Joint Inst Nucl Res, Dubna 141980, Russia
[9] Univ Erlangen Nurnberg, Inst Phys, D-91058 Erlangen, Germany
[10] Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy
[11] Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy
[12] Florida Int Univ, Dept Phys, Miami, FL 33199 USA
[13] Univ Freiburg, Fak Phys, D-79104 Freiburg, Germany
[14] Univ Ghent, Dept Subat & Radiat Phys, B-9000 Ghent, Belgium
[15] Max Planck Inst Kernphys, D-69029 Heidelberg, Germany
[16] Univ Illinois, Dept Phys, Urbana, IL 61801 USA
[17] Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA
[18] Univ Liverpool, Dept Phys, Liverpool L69 7ZE, Merseyside, England
[19] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA
[20] Univ Marburg, Inst Phys, D-35037 Marburg, Germany
[21] MIT, Nucl Sci Lab, Cambridge, MA 02139 USA
[22] Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA
[23] PN Lebedev Phys Inst, Moscow 117924, Russia
[24] Univ Munich, Sekt Phys, D-85748 Garching, Germany
[25] New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA
[26] NIKHEF, NL-1009 DB Amsterdam, Netherlands
[27] Petersburg Nucl Phys Inst, St Petersburg 188350, Russia
[28] Univ Regensburg, Inst Theoret Phys, D-93040 Regensburg, Germany
[29] Ist Nazl Fis Nucl, Sez Sanita, I-00161 Rome, Italy
[30] Ist Super Sanita, Phys Lab, I-00161 Rome, Italy
[31] TRIUMF, Vancouver, BC V6T 2A3, Canada
[32] Tokyo Inst Technol, Tokyo 152, Japan
[33] Free Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands
[34] Yerevan Phys Inst, Yerevan 375036, Armenia
关键词
D O I
10.1103/PhysRevLett.84.2584
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
We present a measurement of the longitudinal spin asymmetry Ali in photoproduction of pairs of hadrons with high transverse momentum pi. Data were accumulated by the HERMES experiment using a 27.5 GeV polarized positron beam and a polarized hydrogen target internal to the HERA storage ring. For h(+)h(-) pairs with p(T)(h1) > 1.5 GeV/c and p(T)(h2) > 1.0 GeV/c, the measured asymmetry is A(parallel to) = -0.28 +/- 0.12(stat) +/- 0.02(syst). This negative value is in contrast to the positive asymmetries typically measured in deep inelastic scattering: from protons, and is interpreted to arise from a positive gluon polarization.
引用
收藏
页码:2584 / 2588
页数:5
相关论文
共 35 条
[1]   Next-to-leading order QCD analysis of polarized deep inelastic scattering data [J].
Abe, K ;
Akagi, T ;
Anderson, BD ;
Anthony, PL ;
Arnold, RG ;
Averett, T ;
Band, HR ;
Berisso, CM ;
Bogorad, P ;
Borel, H ;
Bosted, PE ;
Breton, V ;
Buenerd, MJ ;
Cates, GD ;
Chupp, TE ;
Churchwell, S ;
Coulter, KP ;
Daoudi, M ;
Decowski, P ;
Erickson, R ;
Fellbaum, JN ;
Fonvieille, H ;
Gearhart, R ;
Ghazikhanian, V ;
Griffioen, KA ;
Hicks, RS ;
Holmes, R ;
Hughes, EW ;
Igo, G ;
Incerti, S ;
Johnson, JR ;
Kahl, W ;
Khayat, M ;
Kolomensky, YG ;
Kuhn, SE ;
Kumar, K ;
Kuriki, M ;
LombardNelsen, R ;
Manley, DM ;
Marroncle, J ;
Maruyama, T ;
Marvin, T ;
Meyer, W ;
Meziani, ZE ;
Miller, D ;
Mitchell, G ;
Olson, M ;
Peterson, GA ;
Petratos, GG ;
Pitthan, R .
PHYSICS LETTERS B, 1997, 405 (1-2) :180-190
[2]   Flavor decomposition of the polarized quark distributions in the nucleon from inclusive and semi-inclusive deep-inelastic scattering [J].
Ackerstaff, K ;
Airapetian, A ;
Akopov, N ;
Akushevich, I ;
Amarian, M ;
Aschenauer, EC ;
Avakian, H ;
Avakian, R ;
Avetissian, A ;
Bains, B ;
Barrow, S ;
Baumgarten, C ;
Beckmann, M ;
Belostotski, S ;
Belz, JE ;
Benisch, T ;
Bernreuther, S ;
Bianchi, N ;
Blanchard, S ;
Blouw, J ;
Böttcher, H ;
Borissov, A ;
Brack, J ;
Bray, B ;
Brauksiepe, S ;
Braun, B ;
Brons, S ;
Brückner, W ;
Brüll, A ;
Bruins, EEW ;
Bulten, HJ ;
Cadman, RV ;
Capitani, GP ;
Carter, P ;
Chumney, P ;
Cisbani, E ;
Court, GR ;
Dalpiaz, PF ;
De Leo, R ;
Delheij, PPJ ;
De Sanctis, E ;
De Schepper, D ;
Devitsin, E ;
Huberts, PKAD ;
Di Nezza, P ;
Düren, M ;
Dvoredsky, A ;
Ely, J ;
Elbakian, G ;
Emerson, J .
PHYSICS LETTERS B, 1999, 464 (1-2) :123-134
[3]   The HERMES spectrometer [J].
Ackerstaff, K ;
Airapetian, A ;
Akopov, N ;
Amarian, M ;
Andreev, V ;
Aschenauer, EC ;
Avakian, R ;
Avakian, H ;
Avetissian, A ;
Bains, B ;
Barrow, S ;
Beckhusen, W ;
Beckmann, M ;
Belostotski, S ;
Belz, E ;
Benisch, T ;
Bernreuther, S ;
Bianchi, N ;
Blouw, J ;
Bottcher, H ;
Borissov, A ;
Brack, J ;
Braun, B ;
Bray, B ;
Brons, S ;
Bruckner, W ;
Brull, A ;
Bulten, HJ ;
Capitani, GP ;
Carter, P ;
Chumney, P ;
Cisbani, E ;
Clark, S ;
Colilli, S ;
Coombes, H ;
Court, GR ;
Delheij, P ;
Devitsin, E ;
de Jager, CW ;
De Sanctis, E ;
De Schepper, D ;
Huberts, PKAD ;
Di Nezza, P ;
Doets, M ;
Duren, M ;
Dvoredsky, A ;
Elbakian, G ;
Emerson, J ;
Fantoni, A ;
Fechtchenko, A .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 1998, 417 (2-3) :230-265
[4]   Polarised quark distributions in the nucleon from semi-inclusive spin asymmetries [J].
Adeva, B ;
Akdogan, T ;
Arik, E ;
Arvidson, A ;
Badelek, B ;
Bardin, G ;
Baum, G ;
Berglund, P ;
Betev, L ;
Birsa, R ;
de Botton, N ;
Bradamante, F ;
Bravar, A ;
Bressan, A ;
Bultmann, S ;
Burtin, E ;
Crabb, D ;
Cranshaw, J ;
Cuhadar, T ;
Dalla Torre, S ;
van Dantzig, R ;
Derro, B ;
Deshpande, A ;
Dhawan, S ;
Dulya, C ;
Eichblatt, S ;
Fasching, D ;
Feinstein, F ;
Fernandez, C ;
Forthmann, S ;
Frois, B ;
Gallas, A ;
Garzon, JA ;
Gilly, H ;
Giorgi, M ;
von Goeler, E ;
Goertz, S ;
Gracia, G ;
de Groot, N ;
Grosse Perdekamp, M ;
Haft, K ;
von Harrach, D ;
Hasegawa, T ;
Hautle, P ;
Hayashi, N ;
Heusch, CA ;
Horikawa, N ;
Hughes, VW ;
Igo, G ;
Ishimoto, S .
PHYSICS LETTERS B, 1998, 420 (1-2) :180-190
[5]   Next-to-leading order QCD analysis of the spin structure function g1 -: art. no. 112002 [J].
Adeva, B ;
Akdogan, T ;
Arik, E ;
Badelek, B ;
Bardin, G ;
Baum, G ;
Berglund, P ;
Betev, L ;
Birsa, R ;
de Botton, N ;
Bradamante, F ;
Bravar, A ;
Bressan, A ;
Bültmann, S ;
Burtin, E ;
Cavata, C ;
Crabb, D ;
Cranshaw, J ;
Çuhadai, T ;
Dalla Torre, S ;
van Dantzig, R ;
Derro, B ;
Deshpande, A ;
Dhawan, S ;
Dulya, C ;
Eichblatt, S ;
Fasching, D ;
Feinstein, F ;
Fernandez, C ;
Forthmann, S ;
Frois, B ;
Gallas, A ;
Garzon, JA ;
Gilly, H ;
Giorgi, M ;
von Goeler, E ;
Goertz, S ;
Gracia, G ;
de Groot, N ;
Perdekamp, MG ;
Haft, K ;
von Harrach, D ;
Hasegawa, T ;
Hautle, P ;
Hayashi, N ;
Heusch, CA ;
Horikawa, N ;
Hughes, VW ;
Igo, G ;
Ishimoto, S .
PHYSICAL REVIEW D, 1998, 58 (11) :1120021+11200215
[6]   Measuring polarized gluon and quark distributions with meson photoproduction [J].
Afanasev, A ;
Carlson, CE ;
Wahlquist, C .
PHYSICAL REVIEW D, 1998, 58 (05)
[7]   Elastic and inelastic photoproduction of J/psi mesons at HERA [J].
Aid, S ;
Andreev, V ;
Andrieu, B ;
Appuhn, RD ;
Arpagaus, M ;
Babaev, A ;
Bahr, J ;
Ban, J ;
Ban, Y ;
Baranov, P ;
Barrelet, E ;
Barschke, R ;
Bartel, W ;
Barth, M ;
Bassler, U ;
Beck, E ;
Behrend, HJ ;
Belousov, A ;
Berger, C ;
Bernardi, G ;
Bernet, R ;
BertrandCoremans, G ;
Besancon, M ;
Beyer, R ;
Biddulph, P ;
Bispham, P ;
Bizot, JC ;
Blobel, V ;
Borras, K ;
Botterweck, F ;
Boudry, V ;
Braemer, A ;
Braunschweig, W ;
Brisson, V ;
Bruncko, D ;
Brune, C ;
Buchholz, R ;
Bungener, L ;
Burger, J ;
Busser, FW ;
Buniatian, A ;
Burke, S ;
Burton, MJ ;
Buschhorn, G ;
Campbell, AJ ;
Carli, T ;
Charles, F ;
Charlet, M ;
Clarke, D ;
Clegg, AB .
NUCLEAR PHYSICS B, 1996, 472 (1-2) :3-31
[8]   A DIRECT DETERMINATION OF THE GLUON DENSITY IN THE PROTON AT LOW-X [J].
AID, S ;
ANDREEV, V ;
ANDRIEU, B ;
APPUHN, RD ;
ARPAGAUS, M ;
BABAEV, A ;
BAHR, J ;
BAN, J ;
BAN, Y ;
BARANOV, P ;
BARRELET, E ;
BARSCHKE, R ;
BARTEL, W ;
BARTH, M ;
BASSLER, U ;
BEEK, HP ;
BEHREND, HJ ;
BELOUSOV, A ;
BERGER, C ;
BERNARDI, G ;
BERNET, R ;
BERTRANDCOREMANS, G ;
BESANCON, M ;
BEYER, R ;
BIDDULPH, P ;
BISPHAM, P ;
BIZOT, JC ;
BLOBEL, V ;
BORRAS, K ;
BOTTERWECK, F ;
BOUDRY, V ;
BRAEMER, A ;
BRASSE, F ;
BRAUNSCHWEIG, W ;
BRISSON, V ;
BRUNCKO, D ;
BRUNE, C ;
BUCHHOLZ, R ;
BUNGENER, L ;
BURGER, J ;
BUSSER, FW ;
BUNIATIAN, A ;
BURKE, S ;
BURTON, MJ ;
BUSCHHORN, G ;
CAMPBELL, AJ ;
CARLI, T ;
CHARLES, F ;
CHARLET, M ;
CLARKE, D .
NUCLEAR PHYSICS B, 1995, 449 (1-2) :3-21
[9]   Photoproduction of D-*+/- mesons in electron-proton collisions at HERA [J].
Aid, S ;
Andreev, V ;
Andrieu, B ;
Appuhn, RD ;
Arpagaus, M ;
Babaev, A ;
Bahr, J ;
Ban, J ;
Ban, Y ;
Baranov, P ;
Barrelet, E ;
Barschke, R ;
Bartel, W ;
Barth, M ;
Bassler, U ;
Beck, HP ;
Behrend, HJ ;
Belousov, A ;
Berger, C ;
Bernardi, G ;
Bernet, R ;
BertrandCoremans, G ;
Besancon, M ;
Beyer, R ;
Biddulph, P ;
Bispham, P ;
Bizot, JC ;
Blobel, V ;
Borras, K ;
Botterweck, F ;
Boudry, V ;
Braemer, A ;
Braunschweig, W ;
Brisson, V ;
Bruncko, D ;
Brune, C ;
Buchholz, R ;
Bungener, L ;
Burger, J ;
Busser, FW ;
Buniatian, A ;
Burke, S ;
Burton, MJ ;
Buschhorn, G ;
Campbell, AJ ;
Carli, T ;
Charlet, M ;
Clarke, D ;
Clegg, AB ;
Clerbaux, B .
NUCLEAR PHYSICS B, 1996, 472 (1-2) :32-51
[10]   Measurement of the proton spin structure function g1p with a pure hydrogen target [J].
Airapetian, A ;
Akopov, N ;
Akushevich, I ;
Amarian, M ;
Aschenauer, EC ;
Avakian, H ;
Avakian, R ;
Avetissian, A ;
Bains, B ;
Baumgarten, C ;
Beckmann, M ;
Belostotski, S ;
Belz, E ;
Benisch, T ;
Bernreuther, S ;
Bianchi, N ;
Blouw, J ;
Böttcher, H ;
Borissov, A ;
Brack, J ;
Brauksiepe, S ;
Braun, B ;
Brons, S ;
Brückner, W ;
Brüll, A ;
Bulten, HJ ;
Capitani, GP ;
Carter, P ;
Chumney, P ;
Cisbani, E ;
Court, GR ;
Dalpiaz, PF ;
De Leo, R ;
De Sanctis, E ;
De Schepper, D ;
Devitsin, E ;
Huberts, PKAD ;
Di Nezza, P ;
Düren, M ;
Dvoredsky, A ;
Elbakian, G ;
Ely, J ;
Fantoni, A ;
Fechtchenko, A ;
Ferstl, M ;
Fick, D ;
Fiedler, K ;
Filippone, BW ;
Fischer, H ;
Fox, B .
PHYSICS LETTERS B, 1998, 442 (1-4) :484-492