scholarly journals Radiative kaon decays and the penguin contribution to the rule

2005 ◽  
Vol 730 (1-2) ◽  
pp. 1-36 ◽  
Author(s):  
Jean-Marc Gérard ◽  
Christopher Smith ◽  
Stéphanie Trine
Keyword(s):  
Kaon Decays ◽  
Penguin Contribution

scholarly journals SU(3) analysis of four-quark operators: K → ππ and vacuum matrix elements

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
A. Pich ◽  
A. Rodríguez-Sánchez
Keyword(s):  
Dispersion Relations ◽  
Matrix Elements ◽  
Lattice Data ◽  
Kaon Decays ◽  
Spectral Functions ◽  
Penguin Contribution ◽  
Electroweak Penguin ◽  
Dynamical Parameters ◽  
Analytical Approaches ◽  
Dynamical Origin

Abstract Hadronic matrix elements of local four-quark operators play a central role in non-leptonic kaon decays, while vacuum matrix elements involving the same kind of operators appear in inclusive dispersion relations, such as those relevant in τ-decay analyses. Using an SU(3)L ⊗ SU(3)R decomposition of the operators, we derive generic relations between these matrix elements, extending well-known results that link observables in the two different sectors. Two relevant phenomenological applications are presented. First, we determine the electroweak-penguin contribution to the kaon CP-violating ratio ε′/ε, using the measured hadronic spectral functions in τ decay. Second, we fit our SU(3) dynamical parameters to the most recent lattice data on K → ππ matrix elements. The comparison of this numerical fit with results from previous analytical approaches provides an interesting anatomy of the ∆I = $$ \frac{1}{2} $$ 1 2 enhancement, confirming old suggestions about its underlying dynamical origin.

A POSSBLE INDICATION OF LARGE 'PENGUIN'-CONTRIBUTIONS TO THE KS→ππ DECAY

1991 ◽  
Vol 06 (29) ◽  
pp. 2693-2696 ◽  
Author(s):  
JIANG LIU
Keyword(s):  
Experiment Data ◽  
Kaon Decays ◽  
Penguin Contribution

Experiment data on the decay D0→π+π-, combined with a factorization hypothesis, may be used to estimate the size of 'penguin'-contributions to the ΔI=1/2 kaon decays. The result of such an analysis supports the expectation that the ΔI=1/2 rule in the kaon decays may arise from a large 'penguin'-contribution enhancement.

scholarly journals EXTENDED ANALYSIS OF THE “PENGUIN” PART OF THE K→ππ AMPLITUDE

1995 ◽  
Vol 10 (28) ◽  
pp. 4065-4086 ◽  
Author(s):  
A.A. PENIN ◽  
A.A. PIVOVAROV
Keyword(s):  
Theoretical Description ◽  
Effective Theory ◽  
Interaction Matrix ◽  
Matrix Elements ◽  
Kaon Decays ◽  
Penguin Contribution ◽  
The Standard Model ◽  
Penguin Operator ◽  
Extended Analysis

We make an attempt to clarify the role of the annihilation or “penguin” mode in the description of the K→ππ decay within the Standard Model. Attention is centered on new operators in the effective ΔS=1 Hamiltonian and the violation of factorization for mesonic matrix elements of the local four-quark operators. We propose a regular method to evaluate the mesonic matrix elements of K→ππ transitions based on the study of three-point correlators via QCD sum rules using the chiral effective theory as an underlying low energy model for strong interaction. Matrix elements of the QCD penguin operator are calculated within this approach. The total “penguin” contribution is found to be relatively large, which improves the theoretical description of the ΔI=1/2 rule in nonleptonic kaon decays.

Detecting hyperphotons in kaon decays

1989 ◽  
Vol 40 (5) ◽  
pp. 1716-1719 ◽  
Author(s):  
Josip Trampetić ◽  
S. H. Aronson ◽  
Hai-Yang Cheng ◽  
Ephraim Fischbach ◽  
Carrick Talmadge
Keyword(s):  
Kaon Decays

Rare kaon decays at NA31

1990 ◽  
Vol 16 ◽  
pp. 472
Author(s):  
Heinz Rohrer
Keyword(s):  
Kaon Decays

DirectCP-violating rare kaon decays with charged Higgs bosons

1992 ◽  
Vol 46 (7) ◽  
pp. 2950-2954 ◽  
Author(s):  
G. Bélanger ◽  
C. Q. Geng ◽  
P. Turcotte
Keyword(s):  
Higgs Bosons ◽  
Kaon Decays ◽  
Charged Higgs ◽  
Charged Higgs Bosons

Symmetry violating kaon decays

1980 ◽  
Vol 335 (1-2) ◽  
pp. 529-535 ◽  
Author(s):  
Ernest M. Henley
Keyword(s):  
Kaon Decays

Kaon physics at the CERN-SPS

2015 ◽  
Vol 39 ◽  
pp. 1560100
Author(s):  
Mario Vormstein
Keyword(s):  
Kaon Physics ◽  
Current Status ◽  
Photon Mass ◽  
Kaon Decay ◽  
Kaon Decays ◽  
Preliminary Results ◽  
Dark Photon ◽  
Mixing Parameter ◽  
Upper Limits ◽  
Photon Signal

The NA48/2 and NA62 collaborations report on recent results, current status, and prospects of kaon physics at the CERN-SPS. The NA62 collaborations aims to measure the decay [Formula: see text] with an uncertainty of 10% or better. The NA62 detector and preliminary results from a pilot run in 2014 are presented. In addition, recent results of the NA48/2 collaboration are reported. A search for Dark Photons has been performed in [Formula: see text] decays via the kaon decays [Formula: see text] and [Formula: see text]. No dark photon signal was observed and new upper limits on the mixing parameter [Formula: see text] and the dark photon mass were computed. We also report the first observation of the kaon decay [Formula: see text].

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