Flavor asymmetry of the light quark sea from semi-inclusive deep-inelastic scattering

被引：211

作者：

Ackerstaff, K ^{[1
]}

Airapetian, A

Akopov, N

Akushevich, I

Amarian, M

Ashenauer, 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

Bray, B

Brons, S

Brückner, W

Brüll, A

Bruins, EEW

Bulten, KJ

Cadman, RV

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

Fantoni, A

Fechtchenko, A

Ferstl, M

Fiedler, K

Filippone, BW

Fischer, H

机构：

[1] Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada

[2] Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA

[3] CALTECH, WK Kellogg Radiat Lab, Pasadena, CA 91125 USA

[4] Univ Colorado, Nucl Phys Lab, Boulder, CO 80309 USA

[5] DESY, D-22603 Hamburg, Germany

[6] DESY, D-15738 Zeuthen, Germany

[7] Joint Inst Nucl Res, Dubna 141980, Russia

[8] Univ Erlangen Nurnberg, Inst Phys, D-91058 Erlangen, Germany

[9] Univ Ferrara, Dipartmento Fis, I-44100 Ferrara, Italy

[10] Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy

[11] Florida Int Univ, Dept Phys, Miami, FL 33199 USA

[12] Univ Freiburg, Fak Phys, D-79104 Freiburg, Germany

[13] State Univ Ghent, Dept Subatom & Radiat Phys, B-9000 Ghent, Belgium

[14] Max Planck Inst Kernphys, D-69029 Heidelberg, Germany

[15] Univ Illinois, Dept Phys, Urbana, IL 61801 USA

[16] Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA

[17] Univ Liverpool, Dept Phys, Liverpool L69 7ZE, Merseyside, England

[18] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA

[19] Univ Marburg, Inst Phys, D-35037 Marburg, Germany

[20] MIT, Nucl Sci Lab, Cambridge, MA 02139 USA

[21] Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA

[22] PN Lebedev Phys Inst, Moscow 117924, Russia

[23] Univ Munich, Sekt Phys, D-85748 Garching, Germany

[24] New Mexico State Univ, Dept Phys, Las Cruces, NM 88003 USA

[25] NIKHEF H, NL-1009 DB Amsterdam, Netherlands

[26] Petersburg Nucl Phys Inst, St Petersburg 188350, Russia

[27] Ist Nazl Fis Nucl, Sez Sanita, I-00161 Rome, Italy

[28] Ist Super Sanita, Phys Lab, I-00161 Rome, Italy

[29] Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada

[30] TRIUMF, Vancouver, BC V6T 2A3, Canada

[31] Tokyo Inst Technol, Tokyo 152, Japan

[32] Vrije Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands

[33] Yerevan Phys Inst, Yerevan 375036, Armenia

来源：

PHYSICAL REVIEW LETTERS | 1998年 / 81卷 / 25期

关键词：

D O I：

10.1103/PhysRevLett.81.5519

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The flavor asymmetry of the light quark sea of the nucleon is determined in the kinematic range 0.02 < x < 0.3 and 1 < Q(2) < 10 GeV2 for the first time from semi-inclusive deep-inelastic scattering. The quantity [(d) over bar(x) - (u) over bar(x)]/[u(x) - d(x)] is derived from a relationship between the yields of positive and negative pions from unpolarized hydrogen and deuterium targets. The flavor asymmetry (d) over bar - (u) over bar is found to be nonzero and x dependent, showing an excess of (d) over bar over (u) over bar quarks in the proton.

引用

页码：5519 / 5523

页数：5

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