Determination of the Δ<i>S</i>= 1 weak Hamiltonian in the SU(4) chiral limit through topological zero-mode wave functions

Hernández, P.; Laine, M.; Peña, Carlos; Torro, E.; Wennekers, Jan; Wittig, Hartmut

doi:10.1088/1126-6708/2008/05/043

Cited by 11 publications

(15 citation statements)

References 45 publications

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“…The aim is to understand the role of the charm quark in the ∆I = 1/2 enhancement. Our work extends the results for the GIM limit m c = m u in [30,31]. The numerical techniques developed in [32] have been instrumental in the lattice QCD computation of amplitudes involving eye diagrams.…”

Section: Discussionsupporting

confidence: 73%

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Exploring the role of the charm quark in theΔI=1/2rule

Endress

Peña

2014

Phys. Rev. D

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Abstract:We study the dependence on the charm quark mass of the leading-order lowenergy constants of the ∆S = 1 effective Hamiltonian, with the aim of elucidating the role of the charm mass scale in the ∆I = 1/2 rule for K → ππ decay. To that purpose, finite- techniques are used to obtain a signal for penguin contractions in correlation functions involving four-fermion operators. The important role played by the subtractions required to construct renormalised amplitudes for m c = m u is discussed in detail. We find evidence that the moderate enhancement of the ∆I = 1/2 amplitude previously found in the GIM limit m c = m u increases only slightly as m c abandons the light quark regime. Hints of a stronger enhancement for even higher values of m c are also found, but their confirmation requires a better understanding of the subtraction terms.

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Section: Discussionsupporting

confidence: 73%

“…Results in the GIM limit were obtained in [30,31] from quenched QCD simulations with overlap quarks. It was found that in this case the I = 2 amplitude is already very close to its physical value, and that a significant enhancement is already present.…”

Section: Introductionmentioning

confidence: 99%

Exploring the role of the charm quark in theΔI=1/2rule

Endress

Peña

2014

Phys. Rev. D

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“…In this section the propagator techniques are applied to an ongoing project to study the role of the charm quark in the explanation of the ∆I = 1/2 rule [18,19,20]. Our physics results are presented in a companion paper [21]; preliminary results from this study have also been reported in Ref.…”

Section: Eye Diagrams For K → πmentioning

confidence: 99%

“…Our main target application for this setup lies within a long-term project to study the role of the charm quark in the ∆I = 1/2 rule for non-leptonic kaon decay [18,19,20]. More specifically, we will consider the severe signal-to-noise ratio arising in the computation of "eye diagrams" (penguin contractions), that appear as contributions to K → π transition amplitudes mediated by the ∆S = 1 weak effective Hamiltonian.…”

Section: Introductionmentioning

confidence: 99%

Variance reduction with practical all-to-all lattice propagators

Endress¹,

Peña²,

Sivalingam³

2015

Computer Physics Communications

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Abstract:We discuss all-to-all quark propagator techniques in two (related) contexts within Lattice QCD: the computation of closed quark propagators, and applications to the so-called "eye diagrams" appearing in the computation of non-leptonic kaon decay amplitudes. Combinations of low-mode averaging and diluted stochastic volume sources that yield optimal signal-to-noise ratios for the latter problem are developed. We also apply a recently proposed probing algorithm to compute directly the diagonal of the inverse Dirac operator, and compare its performance with that of stochastic methods. At fixed computational cost the two procedures yield comparable signal-to-noise ratios, but probing has practical advantages which make it a promising tool for a wide range of applications in Lattice

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“…Several attempts to study the ∆I = 1/2 rule on the lattice have been made. For example, an ongoing project based on the role of the charm quark has been developed in [43,44,45,46], see also [47].…”

Section: The ∆I = 1/2 Rulementioning

confidence: 99%

$K \to \pi\pi$ decays and the Delta I = 1/2 rule

Garrón¹

2016

Proceedings of the 8th International Workshop on Chiral Dynamics — PoS(CD15)

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In this short review, I present the recent lattice computations of kaon weak matrix elements relevant to K → ππ decays and neutral kaon mixing. These matrix elements are key to the theoretical determination of the CP violation parameters ε and ε . Impressive progress has been achieved recently, in particular the first realistic computation of ε /ε with physical kinematics has been reported in [1]. The novelty is the ∆I = 1/2 channel, whereas the ∆I = 3/2 contribution is now computed at several values of the lattice spacing and extrapolated to the continuum limit. I will also present the status of B K and discuss its error budget, with a particular emphasis on the perturbative error. Finally I will review the matrix elements of neutral kaon mixing beyond the Standard Model and will argue that the discrepancy observed by different collaborations could be explained by the renormalisation procedure of the relevant four-quark operators.

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Determination of the ΔS= 1 weak Hamiltonian in the SU(4) chiral limit through topological zero-mode wave functions

Cited by 11 publications

References 45 publications

Exploring the role of the charm quark in theΔI=1/2rule

Exploring the role of the charm quark in theΔI=1/2rule

Variance reduction with practical all-to-all lattice propagators

$K \to \pi\pi$ decays and the Delta I = 1/2 rule

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