Scheme dependence of weak matrix elements in the 1/Nc expansion

• We show how the scheme- and scale-dependence of the short-distance operator product expansion with four-quark operators can be correctly accounted for in the framework of the 1/Nc-expansion once the hadronization of two-quark currents has been fixed. We show formulas explicitly in the case of the BK-parameter. We then use them together with our earlier estimates of the long-distance effects. We compare Chiral Perturbation Theory at Leading- and Next-to-Leading-Order with the ENJL model results in the chiral limit. Good matching between the long-and short-distance regimes is obtained and our final value for the physical scheme independent B̂K is 0.77 ± 0.05 ± 0.05.

Subject headings

NATURVETENSKAP  -- Fysik -- Subatomär fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Subatomic Physics (hsv//eng)

Keyword

1/N Expansion

CP violation

Kaon Physics

Publication and Content Type

art (subject category)

ref (subject category)