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Titolo: Dimensioneight operators in the weak OPE
Autore: Cirigliano, V; Donoghue, JF; Golowich, E;
 Indirizzi:
 Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA Univ Massachusetts Amherst MA USA 01003 s & Astron, Amherst, MA 01003 USA
 Titolo Testata:
 JOURNAL OF HIGH ENERGY PHYSICS
fascicolo: 10,
volume: 2000,
anno: 2000,
pagine: NIL_978  NIL_1001
 SICI:
 10298479(200010)2000:10<NIL_978:DOITWO>2.0.ZU;2U
 Fonte:
 ISI
 Lingua:
 ENG
 Soggetto:
 HADRONIC MATRIXELEMENTS; QCD SUMRULES; RENORMALIZATIONGROUP; DELTAI=1/2 RULE; 4FERMION OPERATORS; LEADING LOGARITHMS; NONLEPTONIC DECAYS; K>PIPI DECAYS; 1/NC EXPANSION; LIMIT;
 Keywords:
 standard model; weak decays; kaon physics;
 Tipo documento:
 Article
 Natura:
 Periodico
 Settore Disciplinare:
 Physical, Chemical & Earth Sciences
 Citazioni:
 42
 Recensione:
 Indirizzi per estratti:
 Indirizzo: Cirigliano, V Univ Massachusetts, Dept Phys & Astron, Amherst, MA 01003 USA Univ Massachusetts Amherst MA USA 01003 herst, MA 01003 USA



 Citazione:
 V. Cirigliano et al., "Dimensioneight operators in the weak OPE", J HIGH EN P, 2000(10), 2000, pp. NIL_978NIL_1001
Abstract
We argue that there is a potential aw in the standard treatment of weak decay amplitudes, including that of epsilon'/epsilon. We show that (contrary to conventional wisdom) dimensioneight operators do contribute to weak amplitudes, at order G(F)alpha (s) and without 1/MW(2) suppression. We demonstrate the existence of these operators through the use of a simple weak hamiltonian. Their contribution appears in different places depending on whichscheme is adopted in performing the OPE. If one performs a complete separation of short and long distance physics within a cutoff scheme, dimensioneight operators occur in the weak hamiltonian at order G(F)alpha (s)/mu (2),mu being the separating scale. However, in an (MS) over bar renormalization scheme for the OPE the dimensioneight operators do not appear explicitlyin the hamiltonian at order G(F)alpha (s). In this case, matrix elements must include physics above the scale mu, and it is here that dimension eighteffects enter. The use of a cutoff scheme (especially quark model methods)for the calculation of the matrix elements of dimensionsix operators is inconsistent with (MS) over bar unless there is careful matching including dimensioneight operators. The contribution of dimensioneight operators canbe minimized by working at large enough values of the scale mu. We find from sum rule methods that the contribution of dimensioneight operators to the dimensionsix operator Q(7)((6)) is at the 100% level for mu = 1.5 GeV. This suggests that presently available values of mu are too low to justify the neglect of these effects. Finally, we display the dimensioneight operators which appear within the Standard Model at one loop.
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Documento generato il 28/09/20 alle ore 18:38:15