Suppression of πNN ( 1535 ) Coupling in the QCD Sum Rule
نویسندگان
چکیده
The πN N * and ηN N * coupling constants are studied in the QCD sum rule (N * ≡ N (1535)). We investigate the two point functions between the vacuum and a one meson state in the soft meson limit, extracting the contributions from N (1535) in the way we have formulated previously. The operator product expansion is performed up to the terms of dimension eight. We find that g πN N * vanishes to this order, while g ηN N * has a finite contribution. The results of the QCD sum rule are compared with those of low energy effective models.
منابع مشابه
The πNN and πNN(1535) couplings in QCD
We study the two point correlation function of two nucleon currents sandwiched between the vacuum and the pion state. The light cone QCD sum rules are derived for the πNN coupling gπNN and the πNN(1535) coupling gπNN∗ . The contribution from the excited states and the continuum is subtracted cleanly through the double Borel transform with respect to the two external momenta, p1, p 2 2 = (p − q)...
متن کاملThe suppression of πNN(1535) coupling in QCD
The light cone QCD sum rules are employed to calculate the πNN(1535) coupling gπNN∗ . We study the two point correlation function of two nucleon currents sandwiched between the vacuum and the pion state. The contribution from the excited states and the continuum is subtracted cleanly through the double Borel transform with respect to the nucleon andN(1535) momenta, p1, p 2 2 = (p−q) . Our calcu...
متن کاملar X iv : h ep - p h / 96 10 52 0 v 2 1 7 Fe b 19 97 Suppression of πNN ( 1535 ) Coupling in the QCD Sum Rule
The πN N * and ηN N * coupling constants are studied based on the two point functions between the vacuum and a one meson state in the soft meson limit. In terms of a suitably constructed interpolating field for the nucleon and resonances, we have found that the πN N * couplings vanish, while ηN N * couplings remain finite. This result explains a relatively suppressed coupling of πN N (1535) as ...
متن کاملSuppression of πNN(1535) Coupling in the QCD Sum Rule
The πNN∗ and ηNN∗ coupling constants are studied in the QCD sum rule (N∗ ≡ N(1535)). We investigate the two point functions between the vacuum and a one meson state in the soft meson limit. The operator product expansion is explicitly performed up to terms of dimension eight. We find that gπNN∗ vanishes to this order, while gηNN∗ has a finite contribution. The vanishing of gπNN∗ is a rigorous c...
متن کاملQCD sum rule calculation of the πNN coupling - revisited
In the conventional QCD sum rule calculation for the πNN coupling beyond the soft-pion limit, there are three distinct Dirac structures, each of which can be used to construct separate sum rule. We point out subtleties in the previous sum rule results, based on one of the Dirac structure, associated with using either the PV or the PS coupling schemes in modeling the phenomenological side. We pr...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1996