出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present the status of a lattice calculation for the K ! matrix elements
of the S = 1 e
ective weak Hamiltonian which are relevant in the determination of 0=
and for the I = 1=2 rule, directly with two pion in the nal state. For I = 3=2
matrix elements, we propose a strategy to study the chiral behaviour at next to leading
order in ChPT. Some preliminary results for the matrix elements of Q+, Q7 and Q8 are
given. Finally, we briefly discuss the I = 1=2 case which, due to the requirement of
non-perturbative subtraction, is much more dicult. We show the signal observed for the
matrix elements of Q− and Q6.
