The cos2{phi} azimuthal asymmetry of unpolarized dilepton production at the Z pole

Journal Article · Tue Nov 01 04:00:00 EDT 2011 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.84.094002· OSTI ID:21608008

Zhun, Lu ^[1]; Schmidt, Ivan ^[2]

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1. Department of Physics, Southeast University, Nanjing 211189 (China)
2. Departamento de Fisica, y Centro Cientifico-Tecnologico de Valparaiso, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile)

We calculate the Boer-Mulders effect contribution to the cos2{phi} azimuthal asymmetry of unpolarized dilepton production near the Z-pole. Based on the tree-level expression in the transverse momentum dependent factorization framework, we show that the corresponding asymmetry near the Z-pole is negative, which is opposite to the asymmetry in the low Q{sup 2} region, dominated by the production via a virtual photon. We calculate the asymmetry generated by the Boer-Mulders effect near the Z-pole at the Relativistic Heavy Ion Collider (RHIC), with {radical}(s)=500 GeV. We find that the magnitude of the asymmetry is several percent, and therefore it is measurable. The experimental confirmation of this sign change of the asymmetry from the low Q{sup 2} region to the Z-pole provides direct evidence of the chiral-odd structure of quarks inside an unpolarized nucleon.

• OSTI ID: 21608008
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 9 Vol. 84; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCELERATORS
ASYMMETRY
BARYONS
BOSONS
BROOKHAVEN RHIC
CHIRALITY
COMPUTERIZED SIMULATION
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
GEV RANGE
GEV RANGE 100-1000
HADRONS
HEAVY ION ACCELERATORS
LINEAR MOMENTUM
MASSLESS PARTICLES
NUCLEONS
PARTICLE PROPERTIES
PHOTONS
QUARKS
SIMULATION
STORAGE RINGS
TRANSVERSE MOMENTUM