The maximally twisted lattice QCD action of an SUf(2) doublet of mass degenerate Wilson quarks gives raise to a real positive fermion determinant and it is invariant under the product of standard parity times the change of sign of the coefficient of the Wilson term. The existence of this spurionic symmetry implies that O(a) improvement is either automatic or achieved through simple linear combinations of quantities taken with opposite external three-momenta. We show that in the case of maximal twist all these nice results can be extended to the more interesting case of a mass non-degenerate quark pair.
Frezzotti, R., Rossi, G. (2004). Twisted-mass lattice QCD with mass non-degenerate quarks. In Nuclear Physics B - Proceedings Supplements (pp.193-202) [10.1016/S0920-5632(03)02477-0].
Twisted-mass lattice QCD with mass non-degenerate quarks
FREZZOTTI, ROBERTO;
2004-01-01
Abstract
The maximally twisted lattice QCD action of an SUf(2) doublet of mass degenerate Wilson quarks gives raise to a real positive fermion determinant and it is invariant under the product of standard parity times the change of sign of the coefficient of the Wilson term. The existence of this spurionic symmetry implies that O(a) improvement is either automatic or achieved through simple linear combinations of quantities taken with opposite external three-momenta. We show that in the case of maximal twist all these nice results can be extended to the more interesting case of a mass non-degenerate quark pair.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
