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Related papers: Consistent Prediction for Direct CP Violation and …

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The leading order contribution to the direct CP asymmetry in tau^{+/-} -> K^{+/-} pi^0 nu_{tau} decay rates is evaluated within the Standard Model. The weak phase required for CP violation is introduced through an interesting mechanism…

High Energy Physics - Phenomenology · Physics 2009-11-11 D. Delepine , G. Lopez Castro , L. T. Lopez Lozano

The K to pi pi system is analyzed in the chiral limit and at NLO in 1/N_c. The Delta I = 1/2 rule is reproduced and we obtain a large value for epsilon' / epsilon.

High Energy Physics - Phenomenology · Physics 2017-08-23 Johan Bijnens , Joaquim Prades

Since the standard model contribution is virtually absent, any observation of direct CP violation in the Cabibbo-favored charmed meson decays would be evidence of new physics. In this paper, we conduct a quantitative study on direct CP…

High Energy Physics - Phenomenology · Physics 2018-11-14 Naoyuki Haba , Hiroyuki Umeeda , Toshifumi Yamada

We discuss the theoretical and experimental status of the CP violating ratio eps'/eps. We revise our 1997 standard-model estimate-based on hadronic matrix elements computed in the chiral quark model up to O(p^4) in the chiral expansion-by…

High Energy Physics - Phenomenology · Physics 2014-11-17 Stefano Bertolini , Jan O. Eeg , Marco Fabbrichesi

We present a recent analysis of epsilon'/epsilon in the 1/N_c expansion. We show that the 1/N_c corrections to the matrix element of Q_6 are large and positive, indicating a Delta I = 1/2 enhancement similar to the one of Q_1 and Q_2 which…

High Energy Physics - Phenomenology · Physics 2009-10-31 T. Hambye , P. H. Soldan

What do we know about CPT symmetry? We conclude that the direcrt measurement of CPT violation leads to a result that CPT violation force is limited to about 30% of CP violating forces. The best test of CPT symmetry is to see if theoretical…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. I. Sanda

We use both old and new theoretical developments in QCD dispersion relation constraints on the scalar form factor in the decay K --> \pi l \nu_l to obtain constraints on the strange quark mass. The perturbative QCD side of the calculation…

High Energy Physics - Phenomenology · Physics 2014-11-17 Richard F. Lebed , Karl Schilcher

The CP parameters $\epsilon$ and $\epsilon'/\epsilon$ are calculated in the aspon model of spontaneous CP violation, a model which solves the strong CP problem. A new range for the scale of spontaneous breaking of CP is found. It is shown…

High Energy Physics - Phenomenology · Physics 2014-11-17 Paul H. Frampton , Masayasu Harada

We report on recent advances at understanding the $\Delta I= 1/2$ rule for kaons. We get reasonable matching between short-- and long--distances for scales between between 0.6 and 1.0 GeV and reproduce the $\Delta I=1/2$ rule huge…

High Energy Physics - Phenomenology · Physics 2009-10-31 Joaquim Prades

Recent work by J.Prades and myself on $K\to\pi\pi$ is described. The method we use to consistently connect long and short distances is described and numerical results for the $\Delta I=1/2$ rule and on $B_6$, the parameter relevant for the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Johan Bijnens

In the presence of large New Physics contributions to loop-induced b->s transitions, sizable direct CP violation in B-> phi K decays is expected on general grounds. We compute explicitly CP-violating effects using QCD factorization and find…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Ciuchini , L. Silvestrini

Chiral-scale perturbation theory $\chi$PT$_\sigma$ has been proposed as an alternative to chiral $SU(3)_L\times SU(3)_R$ perturbation theory which explains the $\Delta I = 1/2$ rule for kaon decays. It is based on a low-energy expansion…

High Energy Physics - Phenomenology · Physics 2016-06-08 R. J. Crewther , Lewis C. Tunstall

We propose the complex group theoretical Clebsch-Gordon coefficients as a novel origin of CP violation. This is manifest in our model based on SU(5) combined with the double tetrahedral group, T'. Due to the presence of the doublet…

High Energy Physics - Phenomenology · Physics 2015-05-14 Mu-Chun Chen , K. T. Mahanthappa

Firstly, we use the recent ALEPH/OPAL data on the V-A spectral functions for fixing the continuum threshold with which the first and second Weinberg sum rules should be satisfied in the chiral limit. Then, we predict the values of the…

High Energy Physics - Phenomenology · Physics 2009-09-25 Stephan Narison

We study spontaneous CP violation as a solution to the strong CP problem in left-right symmetric theories. The discrete CP symmetry is broken by a complex vacuum expectation value of a right-handed Higgs doublet. Heavy vectorlike down-type…

High Energy Physics - Phenomenology · Physics 2019-07-03 Sebastian Ohmer

The direct CP violation parameter Re(epsilon'/epsilon) has been measured from the decay rates of neutral kaons into two pions using the NA48 detector at the CERN SPS. The 2001 running period was devoted to collecting additional data under…

High Energy Physics - Experiment · Physics 2008-11-26 J. R. Batley , NA48 collaboration

The present theoretical status of the parameter for direct CP violation epsilon'/epsilon in the Standard Model is reviewed and compared with most recent experimental measurements of the same quantity. After collecting the basic expressions…

High Energy Physics - Phenomenology · Physics 2007-05-23 Matthias Jamin

We study direct CP violation in the hadronic decay $B^{\pm} \to \rho^{0}\pi^{\pm}$, including the effect of $\rho - \omega$ mixing. We find that the CP violating asymmetry is strongly dependent on the CKM matrix elements, especially the…

High Energy Physics - Phenomenology · Physics 2010-02-17 X. -H. Guo , O. Leitner , A. W. Thomas

We point out that the observed CP violation in Bd - bar{Bd} mixing, taking into account the measured ratio Delta Md / Delta Ms, the recently improved lattice value of the non-perturbative parameter BK and an additional effective suppression…

High Energy Physics - Phenomenology · Physics 2008-11-26 Andrzej J. Buras , Diego Guadagnoli