SU(4) Chiral Quark Model with Configuration Mixing
arXiv:hep-ph/0302042 · doi:10.1103/PhysRevD.67.074001
Abstract
Chiral quark model with configuration mixing and broken SU(3)\times U(1) symmetry has been extended to include the contribution from c\bar c fluctuations by considering broken SU(4) instead of SU(3). The implications of such a model have been studied for quark flavor and spin distribution functions corresponding to E866 and the NMC data. The predicted parameters regarding the charm spin distribution functions, for example, Δc, \frac{Δc}{ΔΣ}, \frac{Δc}{c} as well as the charm quark distribution functions, for example, \bar c, \frac{2\bar c}{(\bar u+\bar d)}, \frac{2 \bar c}{(u+d)} and \frac{(c+ \bar c)}{\sum (q+\bar q)} are in agreement with other similar calculations. Specifically, we find Δc=-0.009, \frac{Δc}{ΔΣ}=-0.02, \bar c=0.03 and \frac{(c+ \bar c)}{\sum (q+\bar q)}=0.02 for the \chiQM parameters a=0.1, α=0.4, β=0.7, ζ_{E866}=-1-2 β, ζ_{NMC}=-2-2 βand γ=0.3, the latter appears due to the extension of SU(3) to SU(4).
10 RevTeX pages. Accepted for publication in Phys. Rev. D