Intrinsic transverse momentum and the polarized Drell-Yan process

Abstract

In this paper we study the leading-twist cross section for polarized Drell-Yan scattering at measured lepton-pair transverse momentum Q T . W e nd that for a hadron with spin 1=2 the quark content a t t wist-two is described by six distribution functions for each a v or, which depend on both the lightcone momentum fraction x, and the quark transverse momentum k 2 T . These functions have a simple partonic interpretation. The cross sections for both longitudinal and transverse polarizations are expressed in terms of convolution integrals over the distribution functions.

Studies of the transverse structure of the nucleon at JLab

“…Higher twist observables are important for understanding the long-range quark-gluon dynamics and they are accessible as leading contributions [21][22][23]. Recently, higher twist effects in SIDIS were interpreted in terms of average transverse forces acting on the active quarks in the instant after being struck by the virtual photon [24].…”

Structure functions in the polarized Drell-Yan processes with spin-1/2 and spin-1 hadrons. II. Parton model

“…Parton-model analyses of the Drell-Yan process with spin-1/2 hadrons were reported by Ralston-Soper [8], Donohue-Gottlieb [9], and Tangerman-Mulders (TM) [10]. In order to clarify the difference from the spin-1/2 case, we discuss our Drell-Yan process along the TM formalism.…”

“…[10], we explain it in order to present the definitions of kinematical variables and functions for understanding the subsequent sections. The cross section is written in terms of the lepton tensor L µν and the hadron tensor W µν as [7] dσ…”

“…Nevertheless, the perpendicular vectors are often used because they are convenient due to the orthogonal relation. The lepton tensor is expressed in terms of these quantities as [10] …”

Structure of Hadrons in Hard Processes

“…The most general way to parametrize Φ using only the constraints from hermiticity and parity invariance, is [2,3] …”