13 research outputs found
On the Origin of the Enhancementof CP-violating Charge Asymmetries in Decays Predicted from Chiral Theory
We present an analysis of the enhancement of CP-violating charge asymmetries
in decays. Calculations of decay amplitudes are performed
on the basis of bosonized strong and weak Lagrangians derived from
QCD-motivated quark Lagrangians. We show that the interplay of fourth-order
contributions of chiral Lagrangians for strong interactions and penguin
operators in weak interactions significantly enhances the charge asymmetries.Comment: DESY 92-106, 15
Calculation of Heat-Kernel Coefficients and Usage of Computer Algebra
The calculation of heat-kernel coefficients with the classical DeWitt
algorithm has been discussed. We present the explicit form of the coefficients
up to in the general case and up to for the minimal parts.
The results are compared with the expressions in other papers. A method to
optimize the usage of memory for working with large expressions on universal
computer algebra systems has been proposed.Comment: 12 pages, LaTeX, no figures. Extended version of contribution to
AIHENP'95, Pisa, April 3-8, 199
Vector and Scalar Meson Resonances in Decays
Corrections to induced by vector and scalar meson
exchange are investigated within chiral perturbation theory.Comment: 15pages, Latex-file, TUM-T31-41/9
Quadrupole polarizabilities of the pion in the Nambu--Jona-Lasinio model
The electromagnetic dipole and quadrupole polarizabilities of the neutral and
charged pions are calculated in the Nambu--Jona-Lasinio model. Our results
agree with the recent experimental analysis of these quantities based on
Dispersion Sum Rules. Comparison is made with the results from the Chiral
Perturbation Theory.Comment: 9 pages, 1 fi
Charged Kaon K \to 3 pi CP Violating Asymmetries at NLO in CHPT
We give the first full next-to-leading order analytical results in Chiral
Perturbation Theory for the charged Kaon K \to 3 pi slope g and decay rates
CP-violating asymmetries. We have included the dominant Final State
Interactions at NLO analytically and discussed the importance of the unknown
counterterms. We find that the uncertainty due to them is reasonable just for
\Delta g_C, i.e. the asymmetry in the K^+ \to pi^+ pi^+ pi^- slope g; we get
\Delta g_C = -(2.4 +- 1.2) 10^{-5}. The rest of the asymmetries are very
sensitive to the unknown counterterms. In particular, the decay rate
asymmetries can change even sign. One can use this large sentivity to get
valuable information on those counterterms and on Im(G_8) coupling --very
important for the CP-violating parameter epsilon'_K-- from the eventual
measurement of these asymmetries. We also provide the one-loop O(e^2 p^2)
electroweak octet contributions for the neutral and charged Kaon K \to 3 pi
decays.Comment: 43+2 pages, 2 figures. Version accepted in JHEP. Small changes in the
final numerics of CP asymmetries due to change in input valu
Heat-kernel calculation of the quark determinant and computer algebra
SIGLEAvailable from TIB Hannover: RA2999(92-153) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman