Lattice computations of small x parton distributions in a model of parton densities in very large nuclei

May, 1996
22 pages
Published in:
  • Phys.Rev.D 54 (1996) 5795-5803
e-Print:
Report number:
  • DOE-ER-40561-261,
  • INT-96-00-126,
  • TPI-MINN-96-06,
  • NUC-MINN-96-8-T

Citations per year

19962002200820142019012345
Abstract:
Using weak coupling methods McLerran and Venugopalan\cite{LV1} expressed the parton distributions in large nuclei as correlation functions of a two dimensional Euclidean field theory. The theory has the dimensionful coupling g 2μg~2 \mu , where μ 2A 1/3\mu~2\sim A~{1/3} is the valence quark color charge squared per unit area. We use a lattice regularization to investigate these correlation functions both analytically and numerically for the simplified case of SU(2)SU(2) gauge theory. In weak coupling (g 2μL<<5g~2\mu L<< 5), where LL is the transverse size of the nucleus, the numerical results agree with the {\it analytic} lattice weak coupling results. For g 2μL>>5g~2\mu L>> 5, no solutions exist at O(a 4a~4) where aa is the lattice spacing. This suggests an ill-defined infrared behavior for the two dimensional theory. A recent proposal of McLerran et al.\cite{Kovner} for an {\it analytic} solution of the classical problem is discussed briefly.
  • 12.38.Bx
  • 12.38.Mh
  • gauge field theory: SU(2)
  • lattice field theory
  • dimension: 2
  • nuclear physics
  • nucleus: heavy
  • momentum spectrum: parton
  • correlation function
  • differential equations: solution