The Drell-Yan Process

The Drell-Yan Process

The helicity distribution of antiquark in nucleon can be obtained by the polarized Drell-Yan Processes. The following figure shows the schematic diagram of the Drell-Yan process.

In a parton-model, the cross section for the Drell-Yan processes is given by the following equation.

The asymmetry for the longitudinal spin polarization is given by the following euqation,

, where

Therefore, the measurement of the longitudinal spin asymmetry of the Drell-Yan process will provide information about the helicity distributions of quarks and antiquarks in nucleon.


c.f. Deep Inelastic Scattering

The helicity distribution of charged partons (quarks and antiquarks as a whole) in nucleon can be obtained from the Polarized Deep Inelastic Scattering of leptons.

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11 January 1995 T.Ichihara (