Alladi Ramakrishnan Hall

Moments of pion distribution amplitude using OPE on the lattice

Santanu Mondal

We will show our calculation of the moments of pion distribution amplitude
using a method proposed in Phys.Rev.D73:014501(2006) [hep-lat/0507007].
Since the method requires a fine lattice, it becomes practical only
recently. The procedure is based on calculating the suitable, bilocal
current-current products sandwiched between a pion state and vacuum on the
lattice. Then the lattice calculations of these quantities can be matched
with the formulae obtained by using Euclidean operator product expansion
(OPE), to calculate moments. Use of a fictitious, valance heavy quark
facilitates the calculation in a number of ways. Our exploratory numerical
result shows opportunities to overcome difficulties in operator mixing and
renormalisation that the traditional method suffers from. However, data at
finer lattice spacings that are currently being produced are needed in order
to control the continuum extrapolation.