$K\rightarrow \pi\pi e^+e^-$ decays and chiral low-energy constants
نویسندگان
چکیده
منابع مشابه
decays and chiral low - energy constants *
The branching ratios of the measured decay KL → ππee and of the still unmeasured decay K → ππee are calculated to next-to-leading order in Chiral Perturbation Theory (CHPT). Recent experimental results are used to determine two possible values of the combination (N r 16 −N17) of weak lowenergy couplings (LECs) from the O(p4) chiral Lagrangian. The obtained values are compared to the predictions...
متن کاملChiral Low-Energy Constants
The progress in determining the coupling constants of mesonic chiral Lagrangians is reviewed, with emphasis on the work performed in three successive European Networks (Eurodaphne I and II, Euridice). Reliable estimates of those constants are essential for making full use of next-to-next-to-leading-order calculations in chiral perturbation theory. The precision in the values of the strong coupl...
متن کاملLow-Energy Constants from Resonance Chiral Theory
I discuss the recent attempts to build an effective chiral Lagrangian incorporating massive resonance states. A useful approximation scheme to organize the resonance Lagrangian is provided by the large-NC limit of QCD. Integrating out the resonance fields, one recovers the usual chiral perturbation theory Lagrangian with explicit values for the low-energy constants, parameterized in terms of re...
متن کاملTowards a consistent estimate of the chiral low - energy constants ∗
Guided by the large-N C limit of QCD, we construct the most general chiral resonance Lagrangian that can generate chiral low-energy constants up to O(p 6). By integrating out the resonance fields, the low-energy constants are parametrized in terms of resonance masses and couplings. Information on those couplings and on the low-energy constants can be extracted by analysing QCD Green functions o...
متن کاملMesonic low-energy constants
We review the status of the coupling constants of chiral Lagrangians in the meson sector, the so-called low-energy constants (LECs). Special emphasis is put on the chiral SU(2) and SU(3) Lagrangians for the strong interactions of light mesons. The theoretical and experimental input for determining the corresponding LECs is discussed. In the two-flavour sector, we review the knowledge of the O(p...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The European Physical Journal C
سال: 2001
ISSN: 1434-6044,1434-6052
DOI: 10.1007/s100520100652