ar X iv : h ep - l at / 0 10 60 20 v 1 2 6 Ju n 20 01 RADIAL CORRELATIONS BETWEEN TWO QUARKS

In nuclear many-body problems the short-range correlation between two nucleons is well described by the corresponding correlation in the two-body problem. Therefore , as a first step in any attempt at an analogous description of many-quark systems, it is necessary to know the two-quark correlation. With this in mind, we study the light quark distribution in a heavy-light meson with a static heavy quark. The charge and matter radial distributions of these heavy-light mesons are measured on a lattice with a light quark mass about that of the strange quark. Both distributions can be well fitted upto r ≈ 0.7 fm with the exponential form w 2 i (r), where w i (r) = A exp(−r/r i). For the charge(c) and matter(m) distributions rc ≈ 0.32(2)fm and rm ≈ 0.24(2)fm. We also discuss the normalisation of the total charge (defined to be unity in the continuum limit) and matter integrated over all space, finding 1.30(5) and 0.4(1) respectively for a lattice spacing ≈ 0.17 fm. 1 Correlations between two nucleons In nuclear many-body problems it is well known that the short-range correlations between pairs of nucleons are often well described by the corresponding correlations of the two-body problem. For example: • Few nucleon systems. The NN correlations for the deuteron, 3 He and 4 He, when normalised to each other at their maxima, are essentially indistinguishable upto about 2 fm. Only for larger internucleon distances do the binding energy differences play a role 1. • Many-nucleon systems. Often variational methods are used and a typical trial wavefunction is taken to be of the form |Ψ T >= [Π i, (1) where Ψ(Shell Model) is simply a product(antisymmetrised) of single nucleon wavefunctions – encoding the long range correlations. However,