QCD analysis of polarized parton densities

Abstract

We present the results of QCD fits to global data on deep-inelastic polarised lepton-hadron scattering. We find that it is possible to fit the data with strongly broken SU (2) flavour for the polarised sea densities. This can be tested in W production at polarised RHIC. The data fails to pin down polarised singlet sea quark and gluon densities. We explore the uncertainties in detail and show that improvement in statistics, achievable at polarised HERA for measurement of A1 at moderately low values of x, have large payoffs in terms of the improvement in measurement of gluon densities.

Rapidity density fluctuations in 14.5A GeV/c 28Si-nucleus interactions

“…It may be interesting to note from the Table that values of parameter 'b' increases with decreasing GK . Similar behaviour for dependence of < U max > on < N s > has also been reported by other workers [3][4][5][6][7][8]. …”

Polarized deeply inelastic scattering (DIS) structure functions for nucleons and nuclei

“…We can then use Eqs. (26,27) to obtain the polarized nucleon structure functions g Figures 8 and 9 we present our results using the parametrization of Eqs. (28,29) which is based on the numerical results of Ref.…”

Is the polarized antiquark sea in the nucleon flavor symmetric?

“…Several comprehensive analyses of the polarized deep inelastic scattering (DIS) data, based on next-to-leading-order quantum chromodynamics (QCD), have appeared recently [1][2][3][4][5][6][7][8][9][10][11]. In these analyses the polarized parton density functions (PDFs) are either written in terms of the well-known parameterizations of the unpolarized PDFs or parameterized independently, and the unknown parameters are determined by fitting the polarized DIS data.…”