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here i summarize the central results described in a single long parallel session talk , which was comprised of two distinct studies of lattice qcd .
the first of these is concerned with the direct lattice calculation of the landua gauge nonperturbative gluon propagator , an understanding of which is central to our understanding of the nature of confinement .
the second topic is a lattice calculation of the strangeness magnetic moment of the nucleon .
different confining quark models predict a variety of results for this quantity and so lattice calculations provide a benchmark against which we can test our understanding of hadron structure .
the infrared behaviour of the gluon propagator is important for an understanding of confinement .
previous conjectures range from a strong divergence  @xcite to a propagator that vanishes in the infrared  @xcite .
lattice qcd should in principle be able to resolve this issue by first - principles , model - independent calculations . however , lattice studies have been inconclusive up to now,@xcite since they have not been able to access sufficiently low momenta
. the lower limit of the available momenta on the lattice is given by @xmath4 , where @xmath5 is the length of the lattice . here
we will report results using a lattice with a length of 3.3  fm in the spatial directions and 6.7  fm in the time direction .
this gives us access to momenta as small as 400  mev .
the gluon field @xmath6 can be extracted from the link variables @xmath7 using @xmath8 .
inverting and fourier transforming this , we obtain a _ ( ) & & _ x e^-i(x+/2 ) a_(x+/2 ) + & = & , where @xmath9 and @xmath10 .
the available momentum values @xmath11 are given by @xmath12 , @xmath13 , where @xmath14 is the number of points in the @xmath15 direction .
the gluon propagator @xmath16 is defined as @xmath17 .
the landau gauge propagator in the continuum has the structure @xmath18d(q^2)$ ] . at tree level
, @xmath19 will have the form @xmath20 . on the lattice , this becomes d^(0 ) ( ) = 1/_()^2 .
[ eq : lat - tree ] since qcd is asymptotically free , we expect that up to logarithmic corrections , @xmath21 in the ultraviolet .
hence we define the new momentum variable @xmath22 by @xmath23 and work with this throughout .
the ( bare ) lattice gluon propagator is related to the renormalised continuum propagator @xmath24 via @xmath25 .
the renormalisation constant @xmath26 can be found by imposing a momentum subtraction renormalisation condition @xmath27 .
the asymptotic behaviour of the renormalised gluon propagator in the continuum is given to one - loop level by @xmath28^{-d_d}$ ] with @xmath29=13/44 $ ] , where both the gauge parameter @xmath30 and the number of fermion flavours @xmath31 are zero in this calculation .
we have analysed three lattices , with different values for the volume and lattice spacing .
the details are given in table  [ tab : sim - params ] . in the following , we are particularly interested in the deviation of the gluon propagator from the tree level form .
we will therefore factor out the tree level behaviour and plot @xmath32 rather than @xmath19 itself .
.simulation parameters [ cols="<,^,^,^,>,^,^",options="header " , ]      we have evaluated the gluon propagator on an asymmetric lattice with a large physical volume . by studying the anisotropies in the data , and comparing the data with those from a smaller lattice , we have been able to conclude that finite size effects are under control on the large lattice .
a clear turnover in the behaviour of @xmath32 has been observed at @xmath33gev , indicating that the gluon propagator diverges less rapidly than @xmath34 in the infrared , and may be infrared finite or vanishing .
the data are consistent with a functional form @xmath35 , where d_ir = , [ eq : ir - prop ] @xmath36 gev , and @xmath37 is the appropriate asymptotic form .
a more detailed analysis  @xcite of the asymptotic behaviour reveals that the one - loop formula remains insufficient at @xmath38 .
issues for future study include the effect of gribov copies and of dynamical fermions .
we also hope to use improved actions to perform realistic simulations at larger lattice spacings .
this would enable us to evaluate the gluon propagator on larger physical volumes , giving access to lower momentum values .
we summarize some recent results @xcite on nucleon electromagentic form factors , including the strangeness electric and magnetic form factors .
the strangeness content of the nucleon has been a topic of considerable recent interest for a variety of reasons .
the studies of nucleon spin structure functions in polarized deep inelastic scattering experiments at cern and slac @xcite , combined with neutron and hyperon @xmath39 decays , have turned up a surprisingly large and negative polarization from the strange quark .
in addition , there is a well - known long - standing discrepancy between the pion - nucleon sigma term extracted from the low energy pion - nucleon scattering  @xcite and that from the octect baryon masses  @xcite .
this discrepancy can be reconciled if a significant @xmath40 content in the nucleon  @xcite is admitted . to address some of these issues , an experiment to measure the neutral weak magnetic form factor @xmath41 via elastic parity - violating electron scattering at backward angles was recently carried out by the sample collaboration  @xcite .
the strangeness magnetic form factor is obtained by subtracting out the nucleon magnetic form factors @xmath42 and @xmath43 .
the reported value is @xmath44gev@xmath45 and does not yet provide a strong constraint on the sign .
theoretical predictions of @xmath46 vary widely .
the values from various models and analyses range from @xmath47 in a qcd equalities analysis  @xcite to @xmath48 in an @xmath49 chiral bag model  @xcite .
while a few give positive values  @xcite , most model predictions are negative with a typical range of @xmath50 to @xmath51 .
summaries of these predictions can be found in refs .
@xcite a similar situation exists for the strangeness electric mean - square radius @xmath3 .
a number of the predictions are positive while a few are negative .
elastic @xmath52 and @xmath53 parity - violation experiments are currently planned at tjnaf  @xcite to measure the asymmetry @xmath54 at forward angles to extract @xmath3 .
hopefully , they will settle the issue of its sign .
the lattice formulation of the electromagnetic and other form factors has been given in detail in the past  @xcite .
here , we shall concentrate on the di contribution , where the strangeness current contributes . in the euclidean formulation
, the sachs em form factors can be obtained by the combination of two- and three - point functions @xmath55 @xmath56 where @xmath57 is the nucleon interpolating field and @xmath58 the vector current . with large euclidean time separation , i.e. @xmath59 and @xmath60 , where @xmath61 is the lattice spacing , @xmath62 where @xmath63 and @xmath64 .
we shall use the conserved current from the wilson action which , being point - split , yields slight variations on the above forms and these are given in ref .
@xcite our 50 quenched gauge configurations were generated on a @xmath65 lattice at @xmath66 . in the time direction ,
fixed boundary conditions were imposed on the quarks to provide larger time separations than available with periodic boundary conditions .
we also averaged over the directions of equivalent lattice momenta in each configuration ; this has the desirable effect of reducing error bars .
numerical details of this procedure are given in refs .
@xcite the dimensionless nucleon masses @xmath67 for @xmath68 , 0.152 , and 0.148 are 0.738(16 ) , 0.882(12 ) , and 1.15(1 ) respectively .
the corresponding dimensionless pion masses @xmath69 are 0.376(6 ) , 0.486(5 ) , and 0.679(4 ) . extrapolating the nucleon and pion masses to the chiral limit we determine @xmath70 and @xmath71 . using the nucleon mass to set the scale to study nucleon properties  @xcite ,
the lattice spacing @xmath72 gev is determined .
the three @xmath73 then correspond to quark masses of about 120 , 200 , and 360 mev respectively .
the strangeness current @xmath74 contribution appears in the di only .
the full details of the extraction can be found in ref .
@xcite and we satisfy ouselves here by simply quoting the results .
we use a monopole form to extrapolate @xmath75 with nonzero @xmath76 to @xmath77 , giving @xmath78 .
correlations are taken into account and the error is from jackknifing the fitting procedure .
a similar analysis is done for the strange sachs electric form factor @xmath79 and we find that @xmath80 is consistent with zero as it should be .
we find for the electric mean - square radius @xmath81 .
financial support from the australian research council is gratefully acknowledged .
this contribution summarizes a presentation combining two topics in lattice qcd . 
 firstly , the gluon propagator in landau gauge is calculated in quenched qcd on a large ( @xmath0 ) lattice at @xmath1 . 
 new structure seen in the infrared region survives conservative cuts to the lattice data , and serves to exclude a number of models that have appeared in the literature . 
 secondly , i report on a recent lattice qcd calculation of the strangeness magnetic moment of the nucleon . 
 the result is @xmath2 . 
 the strangeness sachs electric mean - square radius @xmath3 was also found to be small and negative .