New Dipole Penguin Contribution to K --&gt; pi pi decays

Eeg, Jan O.; Kumericki, Kresimir; Picek, Ivica

doi:10.48550/arxiv.0803.2106

Cited by 2 publications

(2 citation statements)

References 27 publications

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“…This result is also confirmed by a similar calculation within the 'rotated' picture. Before using this result for the calculation of , let us note that the additional contribution from the offshell chromomagnetic sdg vertex, shown in [39] to be of the same order as Q g in the SM, is strongly suppressed in the case of nonchiral interactions (again because the mass insertion happens inside the W loop).…”

Section: Bosonization Of Qgmentioning

confidence: 99%

New physics inϵ′from chromomagnetic contributions and limits on left-right symmetry

et al. 2012

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New physics in the chromomagnetic flavor changing transition s ! dg Ã can avoid the strong GlashowIliopoulos-Maiani suppression of the standard model and lead to large contributions to CP-violating observables, in particular to the 0 parameter, that we address here. We discuss the case of the left-right symmetric models, where this contribution implies bounds on the phases of the right-handed quark mixing matrix, or in generic models with large phases a strong bound on the left-right symmetry scale. To the leading order, a numeric formula for 0 as a function of the short-distance coefficients for a wide class of models of new physics is given.Flavor-changing processes still offer one of the best means for spotting signs of physics beyond the standard model (SM). The K decays into pions are among the best studied channels both experimentally and theoretically, and despite the hadronic uncertainties in the theoretical predictions, can serve as a great tool for probing new physics. The reason is that for a number of observables, in particular the CP violating ones, the SM contribution is extremely small, mainly due to the Glashow-Iliopoulos-Maiani (GIM) mechanism [1] and the fact that the CP violating phase in the SM is suppressed by the smallness of the quark mixing angles. In turn, in the SM the GIM mechanism is intimately related to the chiral nature of the weak interactions. As a result, probes of processes involving the GIM mechanism are well suited to test for nonchiral interactions. This is paradigmatic in one popular extension of the SM, left-right (LR) symmetry [2], which altogether gives a framework for restoration of parity in fundamental interactions, nonzero neutrino masses, as well as violation of lepton number and flavor [3] both at the reach of the coming round of experiments, fitting especially well with the scenario of TeV scale LR symmetry [4][5][6]. The related direct searches at LHC, with important signatures through the new interactions and same-sign dileptons [7], can explore this possibility up to $6 TeV [8] and are already beginning to probe this interesting region [9][10][11]. It is then important to assess the bounds on the model from existing phenomena.In the LR models, based the SUð2Þ L Â SUð2Þ R Â Uð1Þ BÀL gauge group, modifications of GIM are mainly due to the new right-handed gauge boson W R and to its mixing with the standard weak gauge boson W L . Bounds on the scale of the new right-handed gauge interaction were already addressed since the early days, a notorious example being the ÁM K box diagram [12,13] where the GIM enhancement adds to a chiral enhancement of the matrix elements, and still leads today to the strongest bound on the scale of LR symmetry, M W R * 2:5-3 TeV [4]. Similar effects hold for the CP-violation parameter [14]. The bottom line is that the interplay of nonchiral interactions with the hierarchy of quark masses and mixings can lead to dramatic effects in loop diagrams. This is especially true in the phenomenology of strange mesons, and in particular for the dir...

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Section: Bosonization Of Qgmentioning

confidence: 99%

New physics inϵ′from chromomagnetic contributions and limits on left-right symmetry

et al. 2012

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“…The SM predicts |ǫ| SM = 2.06 +0.47 −0.53 × 10 −3 [28], but for ǫ ′ the SM calculation still involves a large uncertainty [29]. Consequently, we require that…”

Section: ǫ and ǫ ′mentioning

confidence: 99%

Probing new physics in charm couplings with flavor-changing neutral currents

Tandean

Valencia

2009

Phys. Rev. D

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Low-energy experiments involving kaon, B-meson, D-meson, and hyperon flavor-changing neutral transitions have confirmed the loop-induced flavor-changing neutral current (FCNC) picture of the standard model (SM). The continuing study of these processes is essential to further refine this picture and ultimately understand the flavor dynamics. In this paper we consider deviations from the SM in the charm sector and their effect on FCNC processes. Specifically, we parametrize new physics in terms of left-and right-handed anomalous couplings of the W boson to the charm quark. We present a comprehensive study of existing constraints and point out those measurements that are most sensitive to new physics of this type.

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New Dipole Penguin Contribution to K --> pi pi decays

Cited by 2 publications

References 27 publications

New physics inϵ′from chromomagnetic contributions and limits on left-right symmetry

New physics inϵ′from chromomagnetic contributions and limits on left-right symmetry

Probing new physics in charm couplings with flavor-changing neutral currents

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